JP2012252932A - Battery pack, battery pack manufacturing method, power storage system, electronic apparatus, electric vehicle and power system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack, in which a molding part coating a battery has a proper physical property corresponding to a portion.SOLUTION: A molding part made of reaction hardening resin coating at least one part of an outer surface of a battery integrally has a first portion with large thickness, and a second portion with thickness of the reaction hardening resin smaller than that of the first portion. The molding part satisfies at least one of conditions 1 and 2. The condition 1 is that a maximum yield stress of the second portion is larger than a maximum yield stress of the first portion by 3% or more and 100% or less. The condition 2 is that the maximum yield stress of the second portion is larger than the maximum yield stress of the first portion by 3% or more and 100% or less.

Description

  The present disclosure relates to, for example, a battery pack for a secondary battery, a battery pack manufacturing method, a power storage system using the battery pack, an electronic device, an electric vehicle, and an electric power system.

  Battery packs including batteries such as lithium ion secondary batteries are widely used as mobile electronic devices, electric vehicles, backup power supplies, and the like. Generally, a battery pack includes one or a plurality of secondary batteries (also referred to as cells) and a protection circuit including a detection unit that detects battery voltage, current, and temperature, such as a laminate film, a synthetic resin case, and the like. It is set as the structure integrated by the exterior. The battery pack may have an authentication resistor and an authentication circuit.

  In order to reduce the size and weight of electronic devices, the battery design is light and thin, and it is required to efficiently use the storage space in the device. As a battery that satisfies such requirements, a lithium ion secondary battery having a large energy density and output density is most suitable.

  A lithium ion secondary battery includes a battery element having a positive electrode and a negative electrode that can be doped and dedoped with lithium ions. The battery element is enclosed in a metal can or a metal laminate film and electrically connected to the battery element. The protection operation during charging / discharging is controlled by the circuit board.

  Among them, lithium ion polymer secondary batteries using a gel polymer electrolyte are widely used in order to prevent leakage of the electrolytic solution, which becomes a problem when a conventional liquid electrolytic solution is used. In a lithium ion polymer secondary battery, electrode terminals are connected, a belt-like positive electrode and a negative electrode coated with a polymer electrolyte on both sides are laminated via a separator, and then wound in the longitudinal direction to produce a battery element. The battery element is packaged with a laminate film to form a battery, and the battery is housed in a resin mold case to form a battery pack.

  As described in Patent Document 1 or Patent Document 2, a battery pack that does not use an outer case has been proposed as a battery pack that can greatly simplify the assembly process. That is, a battery pack is manufactured by connecting a circuit board to a battery to form a battery component, temporarily fixing the battery component in a molding chamber of a mold for resin molding, and injecting a molten reaction curable resin into the molding chamber. The The resin molding part forms an outer case of the battery pack and can integrally fix the circuit board, the connection terminal, and the battery.

JP 2008-140757 A JP 2009-181802 A

  Reaction curable resin has better fluidity than thermoplastic resin, so there are few restrictions on the resin thickness on the maximum surface of the battery pack from the viewpoint of fluidity. Must have sufficient strength. Therefore, the resin thickness is increased, and there is a limit to increasing the energy density of the battery.

  Conventionally, the battery and the circuit board are covered with a common resin. However, different physical properties may be desirable depending on the location of the resin. For example, a resin that covers a battery and a resin that covers a circuit board have different physical properties. That is, it is desirable that the resin covering the battery has a high maximum yield stress in order to be able to absorb the volume change of the battery, and the resin covering the circuit board is excellent in impact resistance. It is desirable.

  In order to give different physical properties depending on the part of the battery pack, conventionally, it has been necessary to prepare a part molded by two-color molding or using another resin. However, such a molding method has a problem that the efficiency is low as compared with the case where molding is performed once with one kind of resin.

  An object of the present disclosure is to provide a battery pack in which physical properties are adaptively controlled by a part while increasing the energy density of the battery, a battery pack manufacturing method, a power storage system using the battery pack, an electronic device, an electric vehicle, and a power system It is to provide.

In order to solve the above-described problem, the battery pack of the present disclosure includes one or more batteries,
A molded part made of a reactive curable resin covering at least a part of the outer surface of the battery,
In the molding part, the first part where the thickness of the reactive curable resin is large and the second part where the thickness of the reactive curable resin is smaller than the first part are integrally formed, and the following condition 1 And a battery pack that satisfies at least one of the conditions 2.
Condition 1: The maximum yield stress of the second part measured according to JIS K 7127 is 3% or more and 100% or less larger than the maximum yield stress of the first part. Condition 2: According to JIS K 7110 The impact strength of the first part measured by the Izod impact test is 3% to 100% greater than the impact strength of the second part.

According to the present disclosure, when at least a part of the outer surface of one or a plurality of batteries is covered with a molded part made of a reactive curable resin, physical properties that differ depending on the site are given by using reaction heat of the reactive curable resin. ,
The ratio (t1 / t2) between the resin thickness t1 of the first part where the thickness of the reactive curable resin is large and the resin thickness t2 of the second part where the thickness of the reactive curable resin is small is 13.5 or more and 50 or less. This is a method of manufacturing a battery pack.

In the present disclosure, when at least a part of the outer surface of one or a plurality of batteries is covered with a molded part made of a reactive curable resin,
The high temperature block is brought into contact with a part or the whole of the outer surface of the mold for molding the first part having a large thickness of the reaction curable resin,
A low-temperature block is brought into contact with a part or the whole of the outer surface of the mold for molding the second part where the thickness of the reaction curable resin is smaller than that of the first part;
This is a battery pack manufacturing method in which the temperature of the reaction curable resin during molding is varied.

The present disclosure is a power storage system in which the above-described battery pack is charged by a power generation device that generates power from renewable energy.
The present disclosure is a power storage system that includes the battery pack described above and supplies power to an electronic device connected to the battery pack.
The present disclosure is an electronic device that receives power from the battery pack described above.
The present disclosure is an electric vehicle that includes a conversion device that receives power from the battery pack and converts the power into a driving force of the vehicle, and a control device that performs information processing related to vehicle control based on information related to the battery pack. .
The present disclosure has a power information transmission / reception unit that transmits and receives signals to and from other devices via a network,
It is an electric power system which performs charge / discharge control of the battery pack mentioned above based on the information which the electric power information transmission / reception part received.
The present disclosure is a power system that receives power from the above-described battery pack or supplies power to the battery pack from a power generation device or a power network.

  According to the present disclosure, it is possible to provide a battery pack that is excellent in impact resistance and has a large maximum yield stress by coating a battery and a circuit board using one kind of resin, for example, a reactive curable resin.

It is a perspective view which shows the example of the external appearance of the battery pack in this indication. It is a basic diagram used for description of an example of the coating process by the exterior film of a battery element. It is a perspective view used for description of an example of a battery element. It is an approximate line figure used for explanation at the time of resin molding of battery parts. It is a top view which shows an example of a battery component. It is a perspective view of an example of a metallic mold. It is sectional drawing used for description of an example of the shaping | molding process of a shaping | molding part. It is sectional drawing used for description of an example of the shaping | molding process of a shaping | molding part. It is sectional drawing used for description of the other example of the formation process of a formation part. It is a perspective view of the other example of a metal mold | die. It is sectional drawing used for description of the other example of the formation process of a formation part. It is sectional drawing used for description of the other example of the formation process of a formation part. It is sectional drawing used for description of the further another example of the formation process of a formation part. It is sectional drawing used for description of an example of the formation process when not using an exterior member. It is sectional drawing used for description of an example of the formation process when not using an exterior member. It is sectional drawing used for description of the other example of the formation process in the case of not using an exterior member. It is a basic diagram for demonstrating the application example of a battery pack. It is a basic diagram for demonstrating the other application example of a battery pack.

  Hereinafter, embodiments of the present disclosure will be described. Note that the embodiments described below are preferred specific examples of the present disclosure, and various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise specified, the present invention is not limited to these embodiments.

"Example of battery pack"
As shown in FIG. 1, the battery pack 1 has a flat rectangular parallelepiped appearance. A frame-shaped exterior member (also referred to as a frame) 11, a battery 12, and a battery protection circuit board 13 are integrally covered with a molding portion (exterior body) 10 made of a reaction curable resin. The battery 12 is a lithium ion secondary battery packaged by, for example, a laminate film.

  The exterior member 11 includes a top cover portion, a bottom cover portion, and side cover portions on both sides. In the top cover portion, for example, a plurality of openings are formed. In the example shown in FIG. 1, an opening 14a, an opening 14b, and an opening 14c are formed in the top cover. The terminal surfaces formed on the circuit board 13 are exposed to the outside through the respective openings. For example, the terminal surface of the positive electrode terminal is exposed through the opening 14a. The terminal surface of the negative electrode terminal is exposed through the opening 14b. The ground terminal surface is exposed through the opening 14c. Note that the number of openings is not limited to three. For example, an opening 15 may be formed through which a communication terminal for communicating with an external device to which the battery pack 1 is connected is exposed.

  As will be described later, an element formed by winding or laminating a positive electrode and a negative electrode with a separator interposed therebetween is referred to as a battery element, and a configuration in which the battery element is covered with a laminate film is referred to as a battery. The battery pack 1 is integrally molded as described above. The battery pack 1 may or may not have an exterior member.

The circuit board 13 is mounted with a circuit component 19 such as an ID resistor for identifying a battery pack, in addition to a protection circuit including a temperature protection element such as a fuse, a thermal resistance element (PTC element), and a thermistor. In addition, a plurality of contact portions (for example, two or three) are formed. The protection circuit includes a charge / discharge control FET (Field Effect Transistor)
Field effect transistor), an IC (Integrated Circuit) for monitoring the secondary battery and controlling the charge / discharge control FET is provided.

  The heat-sensitive resistance element is connected in series with the battery element, and when the temperature of the battery becomes higher than the set temperature, the electrical resistance increases rapidly and substantially interrupts the current flowing through the battery. The fuse is also connected in series with the battery element. When an overcurrent flows through the battery, the fuse is blown by its own current to cut off the current. In addition, a heater resistor is provided in the vicinity of the fuse. When an overvoltage is applied, the temperature of the heater resistor rises, so that the current is cut off.

  Furthermore, when the terminal voltage of the secondary battery exceeds 4.3 V to 4.4 V, for example, there is a possibility that a dangerous state such as heat generation or ignition may occur. For this reason, the protection circuit monitors the voltage of the secondary battery, and when the voltage exceeds 4.3V to 4.4V and becomes overcharged, the charge control FET is turned off to prohibit charging. Further, when the terminal voltage of the secondary battery is overdischarged to below the discharge prohibition voltage and the secondary battery voltage becomes 0V, the secondary battery may be in an internal short-circuit state and cannot be recharged. For this reason, when the secondary battery voltage is monitored and an overdischarge state occurs, the discharge control FET is turned off to prohibit discharge.

  An example of the battery will be described. As shown in FIGS. 2 and 3, the battery is a battery element 20 formed by winding or laminating a positive electrode 21 and a negative electrode 22 with separators 23 a and 23 b interposed therebetween, and is wrapped with a laminate film 27 that is a package. is there. As shown in FIG. 2, the battery element 20 is accommodated in a rectangular plate-shaped recess 27a formed in a laminate film 27 which is a package, and its peripheral part (three sides excluding the bent part) is thermally welded and sealed. The A portion where the laminate film 27 is joined is a terrace portion. The terraces on both sides of the recess 27a are bent toward the recess 27a.

  In addition, as the laminate film 27 which is a package, a conventionally known metal laminate film, for example, an aluminum laminate film can be used. As the aluminum laminate film, a film suitable for drawing and suitable for forming the recess 27a for accommodating the battery element 20 is preferable.

  In general, an aluminum laminate film has a laminated structure in which an adhesive layer and a surface protective layer are disposed on both sides of an aluminum layer, and a polypropylene layer (PP) as an adhesive layer in order from the inside, that is, the surface side of the battery element 20. Layer), an aluminum layer as a metal layer, and a nylon layer or a polyethylene terephthalate layer (PET layer) as a surface protective layer.

  Moreover, as the laminate film 27 which is a package, in addition to the aluminum laminate film, it may be a single-layer or double-layer film and include a polyolefin film. The thickness of the laminate film 27 is 0.2 mm or less, for example.

  As shown in FIG. 3, a strip-shaped positive electrode 21, a separator 23 a, a strip-shaped negative electrode 22 disposed opposite to the positive electrode 21, and a separator 23 b are sequentially stacked, and the stacked body is wound in the longitudinal direction. . A gel electrolyte 24 is applied to both surfaces of the positive electrode 21 and the negative electrode 22. A positive electrode lead 25 a connected to the positive electrode 21 and a negative electrode lead 25 b connected to the negative electrode 22 are led out from the battery element 20. The positive electrode lead 25a and the negative electrode lead 25b are coated with sealants 26a and 26b, which are resin pieces such as maleic anhydride-modified polypropylene (PPa), in order to improve adhesion to the laminate film 27 to be packaged later. Yes.

  The battery components will be described more specifically. However, the present disclosure can be applied to batteries other than the batteries described below. For example, the electrolyte is not limited to a gel, and a liquid or solid electrolyte may be used. Furthermore, the present disclosure can also be applied to a battery of a type in which these plate-like components are laminated, instead of a type of winding a belt-like positive electrode, a separator, and a negative electrode.

(Positive electrode)
The positive electrode 21 is formed by forming a positive electrode active material layer containing a positive electrode active material on both surfaces of a positive electrode current collector. As the positive electrode current collector, for example, a metal foil such as an aluminum (Al) foil, a nickel (Ni) foil, or a stainless steel (SUS) foil is used.

The positive electrode active material layer includes, for example, a positive electrode active material, a conductive agent, and a binder. As the positive electrode active material, mainly Li _x MO ₂ (wherein M represents one or more transition metals, x is different depending on the charge / discharge state of the battery, and is usually 0.05 or more and 1.10 or less). A composite oxide of lithium and a transition metal is used. As a transition metal constituting the lithium composite oxide, cobalt (Co), nickel (Ni), manganese (Mn), or the like is used.

Specific examples of such a lithium composite oxide include lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), and lithium manganate (LiMn ₂ O ₄ ). A solid solution in which a part of the transition metal element is substituted with another element can also be used. Examples thereof include nickel cobalt composite lithium oxide (LiNi _0.5 Co _0.5 O ₂ , LiNi _0.8 Co _0.2 O _2, etc.). These lithium composite oxides can generate a high voltage and have an excellent energy density. Furthermore, TiS _2, MoS _2, may be used NbSe _2, V ₂ O no lithium metal sulfides such as ₅ or metal oxide as a cathode active material. As the positive electrode active material, a mixture of a plurality of these materials may be used.

  As the conductive agent, for example, a carbon material such as carbon black or graphite is used. As the binder, for example, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), or the like is used. Moreover, as a solvent, N-methyl-2-pyrrolidone (NMP) etc. are used, for example.

(Negative electrode)
The negative electrode 22 is formed by forming a negative electrode active material layer containing a negative electrode active material on both surfaces of a negative electrode current collector. As the negative electrode current collector, for example, a metal foil such as a copper (Cu) foil, a nickel (Ni) foil, or a stainless steel (SUS) foil is used.

The negative electrode active material layer includes, for example, a negative electrode active material, a conductive agent, and a binder. As the negative electrode active material, lithium metal, a lithium alloy, a carbon material that can be doped / undoped with lithium, or a composite material of a metal material and a carbon material is used. Specific examples of carbon materials that can be doped / undoped with lithium include graphite, non-graphitizable carbon, graphitizable carbon, and the like. More specifically, pyrolytic carbons and cokes (pitch coke, needle coke). , Petroleum coke), graphites, glassy carbons, organic polymer compound fired bodies (phenol resins, furan resins, etc., calcined at an appropriate temperature), carbon fibers, activated carbon and other carbon materials are used. be able to. Furthermore, as a material capable of doping and dedoping lithium, polymers such as polyacetylene and polypyrrole, and oxides such as LxTiyOz such as SnO ₂ and Li ₄ Ti ₅ O ₁₂ can be used.

  Various materials can be used as materials capable of alloying lithium, such as tin (Sn), cobalt (Co), indium (In), aluminum (Al), silicon (Si), and these. Often alloys are used. When metallic lithium is used, it is not always necessary to use powder as a coating film with a binder, and a rolled lithium metal plate may be used.

  As the binder, for example, polyvinylidene fluoride (PVdF), styrene butadiene rubber (SBR) or the like is used. As the solvent, for example, N-methyl-2-pyrrolidone (NMP), methyl ethyl ketone (MEK), distilled water or the like is used.

(Electrolytes)
As the electrolyte, an electrolyte salt and a non-aqueous solvent that are generally used in lithium ion secondary batteries can be used. Specific examples of the non-aqueous solvent include ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone, dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dipropyl carbonate ( DPC), ethylpropyl carbonate (EPC), or a solvent in which hydrogen of these carbonates is substituted with halogen. One of these solvents may be used alone, or a plurality of these solvents may be mixed with a predetermined composition.

As the electrolyte salt, one that dissolves in a non-aqueous solvent is used, and a combination of a cation and an anion is used. As the cation, an alkali metal or an alkaline earth metal is used. As the anion, Cl ⁻ , Br ⁻ , I ⁻ , SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , CF ₃ SO ₃ ^{− and the} like are used. Specifically, lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (
LiBF ₄ ), bis (trifluoromethanesulfonyl) imide lithium (LiN (CF ₃ SO ₂ ) ₂ ), bis (pentafluoroethanesulfonyl) imide lithium (LiN (C ₂ F ₅ SO ₂ ) ₂ ) lithium perchlorate (LiClO) ₄ ). The electrolyte salt concentration is not particularly limited as long as it can be dissolved in a solvent, but the lithium ion concentration is preferably in the range of 0.4 mol / kg or more and 2.0 mol / kg or less with respect to the nonaqueous solvent. .

  In the case of using a polymer electrolyte, a polymer electrolyte is obtained by incorporating a gel polymer electrolyte solution obtained by mixing a nonaqueous solvent and an electrolyte salt into a matrix polymer. The matrix polymer has a property compatible with a non-aqueous solvent. As such a matrix polymer, silicon gel, acrylic gel, acrylonitrile gel, polyphosphazene modified polymer, polyethylene oxide, polypropylene oxide, and their composite polymers, cross-linked polymers, modified polymers, and the like are used. Further, as a fluorine-based polymer, polyvinylidene fluoride (PVdF), a copolymer containing vinylidene fluoride (VdF) and hexafluoropropylene (HFP) as repeating units, vinylidene fluoride (VdF) and trifluoroethylene (TFE). And a polymer such as a copolymer having a repeating unit. Such a polymer may be used individually by 1 type, and may mix and use 2 or more types.

  The polymer electrolyte preferably contains a metal oxide or composite oxide containing any of Si, Al, Ti, Zr, and W. This is because the insulation at the time of abnormality is secured, the safety and reliability are improved, and the swelling suppression effect at high temperatures can be expected.

(Separator)
The separators 23a and 23b are made of, for example, a porous film made of a polyolefin-based material such as polypropylene (PP) or polyethylene (PE), or a porous film made of an inorganic material such as a ceramic nonwoven fabric. It may have a structure in which porous films of seeds or more are laminated. Among these, polyethylene and polypropylene porous films are the most effective.

  In general, the thickness of the separator is preferably 5 μm to 50 μm, more preferably 7 μm to 30 μm. If the separator is too thick, the amount of the active material filled decreases, the battery capacity decreases, and the ionic conductivity decreases and the current characteristics deteriorate. On the other hand, if the film is too thin, the mechanical strength of the film decreases.

“Battery pack components”
FIG. 4 shows components of the battery pack in a stage before resin molding. As described above, the battery pack includes the exterior member 11, the battery 12, and the circuit board 13 as main components. The exterior member 11, the battery 12, and the circuit board 13 are integrated by the molding unit 10. The exterior member 11, the battery 12, and the circuit board 13 integrated by the molding unit 10 are referred to as a battery component 30.

  The exterior member 11 is, for example, a frame having a front surface, a rear surface, a left side surface, and a right side surface, and a storage space is formed inside the exterior member 11. The shape of the exterior member 11 is not limited to a frame body, and may be a U-shape or a box body with one surface opened. Openings 14 a, 14 b, 14 c corresponding to the terminal surfaces formed on the circuit board 13 are formed in the top cover (front surface) of the exterior member 11.

  The circuit board 13 is accommodated in the gap between the inner surface of the top cover of the exterior member 11 and the end surface of the battery 12. The accommodated circuit board 13 is fixed in close contact with the inner surface of the top cover, for example, by riveting. By fixing the circuit board 13 in close contact with the inner surface of the exterior member 11, it is possible to prevent the highly curable reactive curable resin from flowing into the terminal surface of the circuit board 13. Furthermore, the circuit board 13 can be accurately positioned in the process of filling with a reactive curable resin described later and performing the molding. When the circuit board 13 is attached to the exterior member 11, the terminal portions 17a, 17b, and 17c of the terminal surface 16 are exposed to the outside through the openings 14a, 14b, and 14c.

  Further, as shown in FIGS. 5A and 5B, the battery 12 is accommodated in the internal space of the exterior member 11. Then, the positive electrode lead 25 a and the negative electrode lead 25 b of the battery 12 are connected to predetermined locations on the circuit board 13. Thereafter, the molded portion 10 is formed by filling the reactive curable resin. The exterior member 11, the battery 12, and the circuit board 13 are integrated by the molding unit 10.

"Resin molding"
Next, the outline of formation of the molded part 10 of a battery pack is demonstrated. A battery component 30 including the exterior member 11, the battery 12, and the circuit board 13 is accommodated in a mold cavity (molding space) 43 of the molding apparatus as shown in FIG. 6. In addition, you may make it resin-mold a some battery and a circuit board. The mold includes an upper mold 41 and a lower mold 42.

  One gate, for example, the lower die 42 is provided with two gate holes (not shown). One gate hole is a passage through which a resin, for example, a reaction curable resin flows during molding, and the other gate hole is a passage through which the resin is discharged during molding. The upper mold 41 and the lower mold 42 are made of metal, plastic, or ceramic material. A cavity 43 in which the battery component 30 is stored is formed in one mold, for example, the lower mold 42. The cavity 43 is substantially equal to the outer dimension of the exterior member 11.

  As shown in FIG. 7, the battery component 30 is stored in the cavity 43 of the lower mold 42, and the upper mold 41 is overlaid on the lower mold 42. In this state, the peripheral surfaces of the upper mold 41 and the lower mold 42 are in close contact with each other. As shown in FIG. 8, a molding cavity is formed by both the upper mold 41 and the lower mold 42, and the resin flows into the cavity when the resin is filled. A spacer may be disposed between the upper surface and / or lower surface of the battery 12 and the facing surface of the cavity 43 as necessary. In FIG. 8 and other drawings, only the resin portion is hatched.

  After the resin is cured, the upper mold 41 and the lower mold 42 are released, and the battery pack 1 (see FIG. 1) in which the battery 12 and the circuit board 13 of the battery component 30 are covered with the molding unit 10 is molded. As shown in FIG. 8, the first portion 51 a having a large thickness covering the circuit board 13, the whole or a part of the main surface (upper surface and lower surface) of the battery 12 and the small thickness covering the side surface of the battery 12. The two portions 51b are integrally formed. The first portion 51 a is a molded part that exists between the end surface of the battery 12 on the top cover side and the surface of the exterior material 11 that faces the circuit board 13. The second portion 51b is a molded part that covers the upper and lower surfaces of the battery 12 and the end surface on the bottom cover side. However, it is also possible not to provide the resin at the central portion of the upper surface and the lower surface of the battery 12.

(Give different physical properties depending on molding conditions)
The present disclosure adjusts the resin temperature at the time of molding (at the time of polymerization reaction) between the first part (thick part) and the second part (thin part) of the molded part 10, and adjusts each physical property. It will be different. That is, at least one of the following condition 1 and condition 2 is satisfied.

Condition 1: The maximum yield stress of the second part measured according to JIS K 7127 is 3% or more and 100% or less larger than the maximum yield stress of the first part. Condition 2: According to JIS K 7110 The impact strength of the first part measured by the Izod impact test is 3% to 100% greater than the impact strength of the second part.

  The large maximum yield stress of the second portion 51b having a small thickness covering the whole or a part of the main surface (upper surface and lower surface) of the battery 12 and the side surface of the battery 12 is a rubbery physical property corresponding to the expansion of the battery 12. There is expected. Furthermore, since the impact strength of the first portion 51a having a large thickness covering the circuit board 13 is large, the impact strength of the top cover portion can be increased, and the circuit board 13 can be protected.

(Give different physical properties using reaction heat during molding)
In order to give such physical properties to the first part 51a and the second part 51b, the temperature of the resin at the time of molding the first part 51a is compared with the temperature of the resin at the time of molding the second part 51b. And is considered expensive. As shown in FIG. 8, since the first portion 51a is thicker than the second portion 51b, the amount of reaction heat generated during curing in the first portion 51a is the second portion 51b. More than. The resin thickness of the part 51a is t1, and the resin thickness of the part 51b is t2.

  That is, the temperature of the resin when the first portion 51a is cured is high, and the temperature of the resin when the second portion 51b is cured is low. Since the temperature at the time of curing differs depending on the resin thickness at the time of molding, the maximum yield stress of the second part 51b can be made larger than that of the first part 51a. At the same time, the impact strength of the first portion 51a having a large thickness covering the circuit board 13 can be increased as compared with the second portion 52b, and the impact strength of the top cover portion can be increased. Protection can be ensured.

  In addition, the flowability and moldability of the resin are excellent at the part where the molding temperature is low, so that it is possible to prevent defective production such as coating failure at the thinnest part on the side of the battery pack and air bubbles remaining, and increase productivity. Can do. Accordingly, it has become possible to easily add functions according to parts, which has conventionally been performed by two-color molding or by preparing parts by separate molding, and according to the present disclosure, a highly functional battery pack can be efficiently provided. When using reaction heat, in order to ensure any physical properties, the resin thickness t1 of the thick portion where the thickness of the reactive curable resin is large, and the resin thickness t2 of the thin portion where the thickness of the reactive curable resin is small, The ratio (t1 / t2) is 1.2 or more and 100 or less, preferably 13.5 or more and 50 or less. As shown in FIG. 9, the thickness of the resin covering the battery 12 can be increased and the thickness of the resin covering the circuit board 13 can be decreased depending on the configuration of the mold. In this case, the thickness of the resin covering the battery 12 is t2, and the thickness of the resin covering the circuit board 13 is t1.

  As shown in FIGS. 10 and 11, since it is not desirable that the difference in the reaction heat is averaged through the mold when the desired physical properties are given to each part using the reaction heat at the time of curing of the resin. Further, the heat insulating materials 44 and 45 may be provided near the boundary between the parts. The heat insulating material is a material having a low thermal conductivity.

  That is, the heat insulating material 44 is provided so as to divide the upper mold into the first upper mold 41a and the second upper mold 41b in the vicinity of the boundary between the first part and the second part of the upper mold. A heat insulating material 45 is provided so as to divide the lower mold into a first lower mold 42a and a second lower mold 42b in the vicinity. The heat insulation materials 44 and 45 can maintain a temperature difference due to reaction heat generated during resin curing. As a result, it becomes easy to give different desired physical properties to the first part and the second part, respectively.

  As shown in FIG. 12, the battery component 30 is stored in the cavity 43 of the lower molds 42a and 42b, and the upper molds 41a and 41b are stacked on the lower mold. The formed cavity is filled with resin. After the resin is cured, the upper mold and the lower mold are released, and the battery pack 1 (see FIG. 1) in which the battery 12 and the circuit board 13 of the battery component 30 are covered with the molding unit 10 is molded.

  The amount of reaction heat generated in the thick first portion 51a is larger than the amount of reaction heat generated in the thin second portion 51b, and at a higher temperature than that of the second portion 51b. The resin in the first portion 51a is cured. As a result, the maximum yield stress of the second part 51b can be increased as compared with the first part 51a depending on the resin thickness at the time of molding. At the same time, the impact strength of the first portion 51a having a large thickness covering the circuit board 13 is larger than that of the second portion 52b, and the impact strength of the top cover portion can be increased. Protection can be ensured.

(Give different physical properties by externally adjusting the mold temperature)
In the example described above, different physical properties are imparted to the first part 51a and the second part 51b by utilizing the reaction heat of the resin by changing the thickness of the molding part. On the other hand, you may make it provide a different physical property with respect to the 1st site | part 51a and the 2nd site | part 51b by adjusting the temperature of a metal mold | die with an external apparatus.

  As shown in FIG. 13, the upper mold and the lower mold are thermally separated from each other by the heat insulating materials 44 and 45. The heater block 46a is disposed so as to be in contact with the outer surface of the upper mold 41a for molding the first portion 51a. Similarly, heater blocks 46b and 46c are arranged so as to be in contact with the outer surfaces of the bottom surface and the side surface of lower mold 42b. The heater blocks 46a, 46b, and 46c incorporate a heater and are controlled to a desired temperature. As the heater blocks 46a, 46b, and 46c, a heat storage material may be used instead of the heating mechanism or in combination with the heating mechanism. Furthermore, the heater block may be brought into contact with a part of the surface of the mold.

  The cold block 47a is disposed so as to be in contact with the outer surface of the upper mold 41b for molding the second portion 51b. Similarly, cold blocks 47b and 47c are arranged so as to be in contact with the outer surfaces of the bottom surface and the side surface of lower die 42b. The cold blocks 47a, 47b and 47c are cooled by water cooling or air cooling. As the cold blocks 47a, 47b and 47c, a cold insulating material may be used instead of the cooling mechanism or in combination with the cooling mechanism. Further, the cold block may be brought into contact with a part of the surface of the mold.

  When the heater block 46a, 46b, 46c and the cold block 47a, 47b, 47c are used to locally control the temperature distribution of the mold, the difference between the lowest temperature of the molding part and the highest temperature is 10 ° C or more and 200 ° C. The following is preferable. More preferably, it is 15 degreeC or more and 50 degrees C or less.

"Modification of exterior member"
The exterior member 11 described above has a front surface, a rear surface, a left side surface, a right side surface, an upper surface, and a lower surface, corresponding to the shape of the battery and forming a space in which the battery can be accommodated. The upper surface and the lower surface of the exterior member 11 have a rectangular hollow shape so that a part of the upper surface and the lower surface of the battery 12 is exposed when the battery 12 is combined with the exterior member 11. However, the shape of the exterior member is not limited to such a shape. For example, when the exterior member and the battery are combined, the left side surface and a part of the right side surface of the battery may be exposed. As a further modification of the exterior member, a box-shaped exterior member having a closed bottom surface may be used.

"Example without exterior members"
Furthermore, in the present disclosure, providing the exterior member is not an essential matter, and a configuration without the exterior member is also possible. As shown in FIG. 14, the battery component 30 including the battery 12 and the circuit board 13 is stored in a cavity (molding space) of a mold (upper mold 41 and lower mold 42) of the molding apparatus. In addition, you may make it resin-mold a some battery and a circuit board. One gate, for example, the lower die 42 is provided with two gate holes (not shown). One gate hole is a passage through which a resin, for example, a reaction curable resin flows during molding, and the other gate hole is a passage through which the resin is discharged during molding. The upper mold 41 and the lower mold 42 are made of metal, plastic, or ceramic material.

  Then, as shown in FIG. 15, the cavity is filled with resin. After the resin is cured, the upper mold 41 and the lower mold 42 are released, and a battery pack in which the battery 12 and the circuit board 13 of the battery component 30 are covered with the molding unit 10 is molded. The first portion 51a having a large thickness covering the circuit board 13 and the second portion 51b having a small thickness covering the whole or a part of the main surface (upper surface and lower surface) of the battery 12 and the side surface of the battery 12 are integrated. Formed. The first portion 51 a is a molded part that exists between the end surface of the battery 12 on the top cover side and the facing surface of the circuit board 13. The second portion 51b is a molded part that covers the upper and lower surfaces of the battery 12 and the end surface on the bottom cover side. However, it is also possible not to provide the resin at the central portion of the upper surface and the lower surface of the battery 12. The resin thickness of the part 51a is t1, and the resin thickness of the part 51b is t2.

  In the present disclosure, the resin curing temperature is made different between the first part (thick part) and the second part (thin part) of the molded part 10 to make each physical property different. That is, at least one of Condition 1 and Condition 2 described above is satisfied. Specifically, the resin temperature of the first part 51a is high and the resin temperature of the second part 51b is lower than that of the first part 51a depending on the amount of reaction heat during curing. As a result, the maximum yield stress of the second part 51b can be increased as compared with the first part 51a, that is, the elongation rate can be increased, and the molded part can follow the expansion of the battery 12. it can. At the same time, the impact strength of the first portion 51a having a large thickness covering the circuit board 13 is larger than that of the second portion 52b, and the impact strength of the top cover portion can be increased. Protection can be ensured.

  Further, as shown in FIG. 16, the upper mold and the lower mold are thermally separated by the heat insulating materials 44 and 45, respectively, and the molded portion of the first portion 51a is heated by the heater blocks 46a, 46b and 46c. Further, the molded portion of the second portion 51b is cooled by the cold blocks 47a, 47b and 47c. By externally controlling the temperature at the time of resin molding, different physical properties (condition 1 and / or condition 2) can be given to each of the first portion 51a and the second portion 51b.

"Resin for molding part"
The molding unit 10 is made of a reaction curable resin such as a thermosetting resin that cures by reacting with heat and an ultraviolet curable resin that cures by reacting with ultraviolet rays. The molded part 10 is a resin molded member formed by curing a reactive curable resin.

(Reactive curable resin)
Examples of the reaction curable resin include at least one selected from urethane resin, epoxy resin, acrylic resin, silicon resin, and dicyclopentadiene resin. Among these, at least one selected from urethane resin, epoxy resin, acrylic resin, and silicon resin is preferable.

(Urethane resin)
The urethane resin is produced from a polyol and a polyisocyanate. As the urethane resin, it is preferable to use an insulating polyurethane resin defined below. The insulating polyurethane resin is a resin that can obtain a cured product having a volume eigenvalue (Ω · cm) of 10 ¹⁰ Ω · cm or more measured at 25 ± 5 ° C. and 65 ± 5% RH. The insulating polyurethane resin preferably has a dielectric constant of 6 or less (1 MHz) and an insulating breakdown voltage of 15 KV / mm or more.

The insulating polyurethane resin has a volume specific resistance value of 10 ¹⁰ Ω · cm or more, preferably by adjusting the oxygen content of the polyol, the concentration of eluted ions or the number of types of eluted ions, and the like. Can be obtained by adjusting to 10 ¹¹ Ω · cm or more. In particular, when the volume specific resistance value is 10 ¹¹ Ω · cm or more, the insulation of the cured product is well maintained and can be collectively sealed with the protection circuit board of the secondary battery. The volume resistivity value is measured according to JIS C 2105. A measurement voltage of 500 V is applied to the sample (thickness: 3 mm) at 25 ± 5 ° C. and 65 ± 5% RH, and the value after 60 seconds is measured.

  Examples of the urethane resin include a polyester system using a polyester polyol, a polyether system using a polyether polyol, and a urethane resin using another polyol. These may be used alone or in combination of two or more. The polyol may contain a powder. As this powder, inorganic particles such as calcium carbonate, aluminum hydroxide, aluminum oxide, silicon oxide, titanium oxide, silicon carbide, silicon nitride, calcium silicate, magnesium silicate, carbon, polymethyl acrylate, polyethyl acrylate Organic polymer particles such as polymethyl methacrylate, polyethyl methacrylate, polyvinyl alcohol, carboxymethyl cellulose, polyurethane, and polyphenol can be used. These can be used alone or as a mixture. The surface of the particles may be subjected to a surface treatment, and polyurethane and polyphenol may be used as foam powder. Further, the powder used in the present disclosure includes a porous material.

(Polyol)
(Polyester)
The polyester-based polyol is a reaction product of a fatty acid and a polyol. Examples of the fatty acid include hydroxy-containing long chain fatty acids such as ricinoleic acid, oxycaproic acid, oxycapric acid, oxyundecanoic acid, oxylinoleic acid, oxystearic acid, and oxyhexanedecenoic acid.

  Polyols that react with fatty acids include glycols such as ethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol and diethylene glycol, trifunctional polyols such as glycerin, trimethylolpropane and triethanolamine, and tetrafunctionals such as diglycerin and pentaerythritol. Polyols, hexafunctional polyols such as sorbitol, octafunctional polyols such as sugar, alkylene oxides corresponding to these polyols and addition polymerization products of aliphatic, alicyclic, and aromatic amines, and the alkylene oxides and polyamide polyamines. Examples include addition polymerization products. Of these, glyceride ricinoleate, polyester polyol of ricinoleic acid and 1,1,1-trimethylolpropane, and the like are preferable.

(Polyether type)
Polyether-based polyols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 4,4′-dihydroxyphenylpropane, and 4,4′-dihydroxyphenyl. Dihydric alcohol such as methane or glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexanetriol, trihydric or higher polyhydric alcohol such as pentaerythritol, ethylene oxide, propylene oxide, butylene oxide, Examples include addition polymerization products with alkylene oxides such as α-olefin oxides.

(Other polyols)
Examples of other polyols include carbon-carbon polyols such as acrylic polyols, polybutadiene polyols, polyisoprene polyols, hydrogenated polybutadiene polyols, AN (acrylonitrile) and SM (styrene monomers). Examples include graft-polymerized polyol, polycarbonate polyol, and PTMG (polytetramethylene glycol). In order to directly mold the battery pack, it is preferable to use a polyether-based polyol having high elastic recovery, excellent chemical resistance, and cost performance better than carbonate-based.

(Polyisocyanate)
As the polyisocyanate, aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate and the like can be used. Examples of the aromatic polyisocyanate include diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate (crude MDI), tolylene diisocyanate (TDI), polytolylene polyisocyanate (crude TDI), xylene diisocyanate (XDI), and naphthalene diisocyanate. (NDI). Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI). Examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI). In addition, polyisocyanate modified with carbodiimide (carbodiimide-modified polyisocyanate), isocyanurate-modified polyisocyanate, ethylene oxide-modified polyisocyanate, urethane prepolymer (for example, reaction product of polyol and excess polyisocyanate). And those having an isocyanate group at the molecular end) can also be used. These may be used alone or as a mixture. Among these, diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, carbodiimide-modified polyisocyanate, and ethylene oxide-modified polyisocyanate are preferable.

  Depending on the properties of the reaction curable resin, the battery pack can be improved in properties such as heat resistance, flame retardancy, impact resistance, and moisture barrier properties. For example, when a urethane resin is used, diphenylmethazine isocyanate (MDI), which has a rigid benzene ring structure and has the lowest molecular weight, is used as a hard segment structure. It is preferable that the weight mixing ratio (main agent / curing agent) is 1 or less, preferably 0.7 or less. As a result, a structure having a high crosslink density, a rigid and symmetric molecular chain is obtained, and heat resistance and good structural strength, improved flame retardancy due to urethane bonding, and high resin injection viscosity are obtained. .

  However, the more the diphenylmethazine isocyanate (MDI) component, the better the strength and moisture barrier properties. However, if it exceeds 80 wt%, there are too many hard segment structures due to MDI, resulting in poor impact resistance. . When weather resistance is particularly required, it is preferable to use a mixture of XDI, IPDI, and HDI, which are non-yellowing polyisocyanates, in MDI. In order to increase the crosslinking density, it is preferable to add a low-molecular trimethylolpropane as a crosslinking agent to the main agent.

Reactive curable resin is obtained by JIS K-7110 Izod V notch, it is preferable that the impact strength of 6 kJ / m ² or more, more preferably 10 kJ / m ² or more. This is because when the impact strength is 6 kJ / m ² or more, it has excellent characteristics in a 1.9 m drop test and a 1 m drop test. This is because when the impact strength is 10 kJ / m ² or more, very excellent characteristics can be obtained in a drop test that is assumed to have the highest probability of occurrence in the market. Here, the higher the molecular weight distribution (number average molecular weight / weight average molecular weight), the better the fluidity and moldability of the resin, but the impact resistance tends to deteriorate, so the fluidity is at least a viscosity of 80 mPa · s. Preferably, the viscosity is adjusted in the range of 200 mPa · s or more and 600 mPa · s or less.

It is preferable that the reactive curable resin has a flame retardance with a fire spread area of 25 cm ² or less according to the standard of UL746C3 / 4 inch flame combustion test at a thickness of 0.05 mm or more and less than 0.4 mm.

  When a urethane resin is used as the reaction curable resin, the flame retardant polyol preferably includes a structure represented by the formula (1). This is because by adding a flame retardant component to the inside of the structure of the urethane resin, the flame retardancy is particularly improved when the resin thickness is thin, and the structural strength can be secured.

PO (XR) ₃ ... Formula (1)
(R = H, alkyl group, phenyl group, X = S, O, N, (CH ₂ ) n: n is an integer of 1 or more)

  Even when the above urethane resin is not used, if the thickness of the reactive curable resin is small, the impact resistance is improved by reducing the glass transition point (glass transition temperature), and the resin shrinks due to the flame of the burner. However, the substantial thickness of the resin increases, making it difficult to spread the fire and improving flame retardancy. On the other hand, if the glass transition point is too low or the glass transition point is too high, the strength and safety tend to decrease.

  Therefore, the glass transition point of the reaction curable resin is preferably 60 ° C. or higher and 150 ° C. or lower, and the melting (decomposition) temperature is preferably 200 ° C. or higher and 400 ° C. or lower. Further, the glass transition point is more preferably 85 ° C. or higher and 120 ° C. or lower. The melting (decomposition) temperature is more preferably 240 ° C or higher and 300 ° C or lower. When the glass transition point is less than 60 ° C., it is difficult to ensure the strength as an exterior at an environmental temperature of 45 ° C. If the glass transition point exceeds 150 ° C., it may cause a serious accident due to a delay in releasing the energy stored in the battery during misuse.

  Even if the glass transition temperature is 60 ° C. or higher and 150 ° C. or lower, if the melting temperature (decomposition temperature) is 200 ° C. or higher and 400 ° C. or lower, the flame retardancy is improved due to the contribution of the endothermic reaction by melt decomposition. If the melting (decomposition) temperature is less than 200 ° C., carbonization is promoted and heat is absorbed at the initial stage of formation of the heat insulating layer, so that it cannot contribute to flame retardancy. Even if the melting (decomposition) temperature exceeds 400 ° C., the endothermic timing is too late to contribute to flame retardancy.

  The reaction curable resin preferably has a viscosity of 80 mPa · s or more and less than 1000 mPa · s. By adjusting the viscosity within this range, it is possible to suppress the coating failure of the maximum surface of the battery, thereby suppressing the deterioration of the characteristics of the battery pack. Furthermore, since the reaction curable resin takes a longer time to cure than the thermoplastic resin, the fluidity is excellent. However, when the viscosity is high, the holding power of the mold is increased, the production apparatus is expensive and the productivity is low, and the improvement of the volume energy density and the low cost due to the thinning of the molded member of the pack cannot be achieved. On the other hand, if the viscosity is too low, the fluidity will be too high in the future, so that the production rate may decrease due to burrs from the molding die and the seepage of the resin to the substrate portion, which may increase the defect rate.

  Reaction curable resins (for example, urethane resins) have strong adhesiveness to metals because they are adhesive, and it is possible to adhere to thermoplastic resins with polar groups to obtain a tough integral structure. Although the thermoplastic polyamide resin also has adhesiveness, its adhesive strength is weak, so that physical adhesion reinforcement and high filling pressure are required, but reactive curable resins do not have such restrictions. The relationship between the adhesiveness of the urethane resin and the agglomerated structure is not clear, but it has been found that the adhesiveness tends to decrease as the crosslink density is increased. Therefore, it is preferable to use a member having a large amount of active hydrogen on the surface or a member having a large number of polar groups that easily form hydrogen bonds with the urethane resin as the adhesive member.

  Similarly, it is preferable to prevent the separation from the member by providing an undercut portion in the fitting portion with the member, or to increase the substantial adhesion area by roughening the member surface or making a notch. Furthermore, the aggregation structure of the urethane resin is controlled by the temperature conditions at the time of curing, and the adhesiveness is improved by increasing the polar groups on the surface by lowering the temperature, and the adhesiveness is lowered by raising the temperature, It is preferable to control the releasability of.

(Additive)
Additives such as fillers, flame retardants, antifoaming agents, antibacterial agents, stabilizers, plasticizers, thickeners, antifungal agents, and other resins may be included in the reaction curable resin.

  As the flame retardant, triethyl phosphate, tris (2,3 dibromopropyl) phosphate, or the like can be used. As other additives, fillers such as antimony trioxide and zeolite, and colorants such as pigments and dyes can be used. As other additives, fillers such as antimony trioxide and zeolite, and colorants such as pigments and dyes can be used.

(catalyst)
It is preferable to add a catalyst to the reaction curable resin. From metal-based isocyanuration catalysts such as tertiary amines and fatty acid metal salts, known catalysts such as organotin compounds, and main agents having nitrogen functional groups that do not contain hydrogen that have been modified with carbodiimide or ethylene oxide in the main chain of the resin It is preferable to use a mixture of two or more catalysts having different catalytic activities even at the same selected temperature. This is because if two or more kinds of catalysts are used, the resin skeleton can be easily controlled when adjusting the resin physical properties using reaction heat.

  The catalyst is added for the purpose of advancing the reaction between the isocyanate and the polyol compound and dimerization and trimerization of the isocyanate, and a known catalyst can be used. Specifically, triethylenediamine, 2-methyltriethylenediamine, tetramethylhexanediamine, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, pentamethylhexanediamine, dimethylaminoethyl ether, trimethylaminopropylethanolamine, tridimethylaminopropylhexahydro Tertiary amines such as triazine and tertiary ammonium salts can be used.

  The metal-based isocyanurate-forming catalyst is preferably used in the range of 0.5 to 20 parts by weight with respect to 100 parts by weight of the polyol. If the amount of the metal-based isocyanurate catalyst is less than 0.5 parts by weight, it is not preferable because sufficient isocyanurate formation does not occur. Moreover, even if the amount of the metal-based isocyanurate-forming catalyst is more than 20 parts by weight with respect to 100 parts by weight of the polyol, the effect corresponding to the amount added cannot be obtained.

  Examples of the metal-based isocyanurate catalyst include fatty acid metal salts, specifically, dibutyltin dilaurate, lead octylate, potassium ricinoleate, sodium ricinoleate, potassium stearate, sodium stearate, olein. There may be mentioned potassium acid, sodium oleate, potassium acetate, sodium acetate, potassium naphthenate, sodium naphthenate, potassium octylate, sodium octylate, and mixtures thereof.

  In addition, an organic tin compound is used as the catalyst, and examples thereof include tri-n-butyltin acetate, n-butyltin trichloride, dimethyltin dichloride, dibutyltin dichloride, and trimethyltin hydroxide. These catalysts may be used as they are, or dissolved in a solvent such as ethyl acetate so that the concentration is 0.1 to 20%, and 0.01 to 1 mass as a solid content with respect to 100 parts by mass of isocyanate. You may add so that it may become a part. Thus, the compounding amount of the catalyst is added as it is or in a state dissolved in a solvent so that the solid content is 0.01 to 1 part by mass with respect to 100 parts by mass of isocyanate. Is preferable, and 0.05 to 0.5 parts by mass is particularly preferable. That is, if the blending amount of the catalyst is too small, such as less than 0.01 part, the formation of the polyurethane resin molded product is slow, and the resin is not cured and the molding becomes difficult. On the other hand, if the amount exceeds 1 part by mass, the formation of the resin becomes extremely fast and it is difficult to mold as a shape maintaining polymer layer.

When two or more kinds of catalysts are used, the reaction curable resin is urethane, and as the at least one catalyst, a main agent prepolymer represented by the following chemical formula is preferably used.

  Thus, by having N group in the prepolymer molecular chain of the main agent, not only quick curability can be exhibited but also flame retardancy can be improved. In addition, although this molecular structure has a catalytic action, it is preferable to use it simultaneously with an organotin compound or a metal-based isocyanurate-catalyst because a difference in reaction rate is easily produced.

(Metal oxide oxide filler)
The molded part 10 may include a metal oxide filler. Metal oxide fillers include silicon (Si), aluminum (Al), titanium (Ti), zirconium (Zr), zinc (Zn), magnesium (Mg) oxides, or any mixture of these oxides. be able to. Such a metal oxide filler fulfills the function of improving the hardness of the molding part 10 and is disposed in contact with a layer containing a reactive curable resin. For example, the metal oxide filler is placed in a reactive curable resin. In this case, it is preferable that the layer is uniformly dispersed throughout the layer containing the reaction curable resin.

  The mixing amount of the metal oxide filler can be appropriately changed according to the polymer type of the layer containing the reaction curable resin. However, when the mixing amount with respect to the mass of the layer containing the reaction curable resin is less than 3%, the hardness of the exterior material may not be sufficiently increased. On the other hand, when the mixing amount exceeds 60%, there may be a problem due to formability during production and brittleness of the ceramic. Therefore, the mixing amount of the metal oxide filler with respect to the mass of the layer containing the reaction curable resin is preferably about 2 to 50%.

  Further, if the average particle size of the metal oxide filler is reduced, although the hardness is increased, there is a possibility that the filling property at the time of molding is affected and the productivity is deteriorated. On the other hand, if the average particle size of the metal oxide filler is increased, it may be difficult to obtain the desired strength, and sufficient dimensional accuracy as a battery pack may not be obtained. Therefore, the average particle size of the metal oxide filler is preferably 0.1 to 40 μm, and more preferably 0.2 to 20 μm.

  Furthermore, various shapes such as a spherical shape, a scale shape, a plate shape, and a needle shape can be adopted as the shape of the metal oxide filler. Although not particularly limited, a spherical shape is preferable because it is easy to produce and can be obtained at a low cost with a uniform average particle diameter, and a needle-like shape having a high aspect ratio is preferable because it can easily increase the strength as a filler. . Furthermore, a scale-like thing is preferable since the filling property can be improved when the filler content is increased. In addition, it is possible to mix and use fillers having different average particle diameters or to mix and use fillers having different shapes depending on applications and materials.

  The molding part 10 can contain various additives in addition to the metal oxide. For example, an ultraviolet absorber, a light stabilizer, a curing agent, or any mixture thereof can be added to a layer containing a reaction curable resin and coexist with a metal oxide filler.

<Internal release agent>
Although the reaction curable resin is excellent in adhesiveness, if the adhesiveness is too strong, for example, there is a possibility of causing deformation of the product and poor appearance when releasing. Therefore, natural waxes such as carnauba wax, polyolefin waxes such as polyethylene wax, amide waxes such as montanic acid amide, ester waxes such as montanic acid ester, silicone compounds such as silicone oil, higher fatty acids such as stearic acid, etc. It is preferable to add a metal salt of a higher fatty acid such as zinc stearate or an internal mold release agent such as polytetrafluoroethylene (PTFE).
In particular, when a fibrous fluoropolymer such as Daikin Polyflon MPA FA500H is used as an internal mold release agent, even if a smoke generating material or dripping material is generated during combustion, dripping is suppressed and fire spread is prevented. It is preferable because the flame retardancy can be improved.

(Epoxy resin)
Here, an epoxy resin that can be used in the present disclosure will be described. The epoxy resin is produced from an epoxy prepolymer and a curing agent. The prepolymer may contain a powder. As this powder, inorganic particles such as calcium carbonate, aluminum hydroxide, aluminum oxide, silicon oxide, titanium oxide, silicon carbide, silicon nitride, calcium silicate, magnesium silicate, carbon, polymethyl acrylate, polyethyl acrylate Organic polymer particles such as polymethyl methacrylate, polyethyl methacrylate, polyvinyl alcohol, carboxymethyl cellulose, polyurethane, and polyphenol can be used. These can be used alone or as a mixture. The surface of the particles may be subjected to a surface treatment, and polyurethane and polyphenol may be used as foam powder. Further, powders that can be used in the present disclosure include porous materials.

(Prepolymer)
Known epoxy prepolymers such as bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, hydrogenated bisphenol A epoxy resin, cycloaliphatic epoxy resin, glycidyl ether of organic carboxylic acids can be used. . Furthermore, in the present disclosure, one or more of these can be used. A glycidyl ether type or a glycidyl ester type is more preferable in terms of curing speed than an internal epoxy type such as cyclohexene oxide or epoxidized polybutadiene. Examples of the glycidyl ether type include an epoxychlorohydrin condensate of bisphenol A. Moreover, it is preferable on the viscosity to use a bisphenol F type epoxy resin.

(Curing agent)
Examples of the curing agent include amines and modified amines such as ketimine, polyamide resins, imidazoles, polymercaptan, acid anhydrides, and light / ultraviolet curing agents. These may be used alone or in combination of two or more.

(Amines)
Examples include chain aliphatic amines, cycloaliphatic amines, and aromatic amines.
The chain aliphatic amine is preferably diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenediamine, diethylaminopropylamine, hexamethylenediamine such as AMINE248, and derivatives thereof. Cycloaliphatic amines include N-aminoethylpiperazine, mensendiamine, isophoronediamine, Ramiron C-260, Araldit HY-964, S Cure211 to 212, Wandamine HM, 1,3-bisaminomethylcyclohexane, and derivatives thereof. preferable.

The aliphatic aromatic amine is preferably m-xylenediamine, Showamin X, amine black, Showamin black, Showamin N, Showamin 1001, Showaamine 1010, and derivatives thereof.

  The aromatic amine is preferably metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and derivatives thereof. The polymercaptan is preferably used by mixing liquid polymercaptan and polysulfide resin with amines.

  Examples of acid anhydrides include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitate, glycerol tris trimellitate, maleic anhydride, tetrahydrophthalic anhydride, endomethylenetetrahydro Preferred are phthalic anhydride, hexahydrophthalic anhydride, succinic anhydride, methylcyclohexene dicarboxylic acid anhydride, alkylstyrene-maleic anhydride copolymer, chlorendic anhydride, polyzelaic anhydride, and derivatives thereof. More preferred are methyltetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, methylhexahydrophthalic anhydride, and derivatives thereof.

As the light / ultraviolet curing agent, diphenyliodonium hexafluorophosphate, triphenylsulfonium hexafluorophosphate, and derivatives thereof are preferable. In order to directly mold the battery pack, it is preferable to use an amine-based curing agent that is excellent in chemical resistance and fast-curing, or acid anhydrides that are less likely to corrode the substrate than the amine-based curing agent.
Depending on the properties of the reaction curable resin, the battery pack can be improved in properties such as heat resistance, flame retardancy, impact resistance and moisture barrier properties.

"Exterior materials"
The exterior member 11 will be described. As a material constituting the exterior member 11, it is preferable to use a thermoplastic resin such as polycarbonate, polypropylene, or polyamide. This is because it is possible to respond quickly and inexpensively by using a thermoplastic resin having a molding cycle shorter than that of the thermosetting resin, for the shape change of the top, bottom, etc., which is frequently switched as a battery pack.

  The exterior member 11 has a front surface, a rear surface, a left side surface, a right side surface, an upper surface, and a lower surface, corresponding to the shape of the battery and forming a space in which the battery 12 can be accommodated. The upper surface and the lower surface of the exterior member 11 have a rectangular hollow shape so that a part of the upper surface and the lower surface of the battery is exposed when the battery 12 is combined with the exterior member 11.

"Example"
In order to facilitate understanding of the present disclosure, examples and comparative examples will be described. The contents of the present disclosure are not limited to the contents of the following examples and comparative examples.

  Examples 1 to 8 and Comparative Examples 1 to 3 will be described with reference to Table 1, Table 2, and Table 3.

Tables 1, 2 and 3 are originally one table, but are divided into three in the horizontal direction due to the description space. Each item shown in Table 1 is as follows in order.
Material of reaction curable resin: Resins r1 to r4 forming the molding part 10
r1: Polyester polyurethane r2: Polyether polyurethane r3: Thermoplastic polycarbonate r4: Thermoplastic polypropylene

  Molding technique: A technique for giving different physical properties to the first part and the second part. Method 1 is a method using the reaction heat of the resin, and Method 2 is a method of adjusting the temperature of the mold externally.

Catalyst in molded part 1: Catalysts c1 to c7 for resin in molded part 10
Molded part catalyst 2: Catalysts c8 to c14 for resin in molded part 10
c1: triethylenediamine c2: tetramethylhexanediamine c3: n-butyltin trichloride c4: dimethyltin dichloride c5: trimethyltin hydroxide c6: dibutyltin dichloride c7: tri-n-butyltin acetate c8: sodium oleate c9: (OH) ₂ — (P═O) CH ₂ N (OH) _{2
c10: (CH 3 O) 2} - (P = O) CH 2 N (CH 2 OH) 2
_{c11: (C 2 H 5 O} ) 2 - (P = O) CH 2 N (C 2 H 4 OH) 2
_{c12: (C 3 H 7 O} ) 2 - (P = O) CH 2 N (C 3 H 6 OH) 2
_{c13: (C 3 H 7 O} ) 2 - (P = O) CH 2 N (C 4 H 8 OH) 3
_{c14: (C 2 H 5 O} ) 2 - (P = O) CH 2 N (C 2 H 4 OH) (CH 2 OH)

Internal mold release agent: Internal mold release agent p1 for resin of molding part 10: Carnauba wax p2: Zinc stearate p3: Silicone oil p4: PTFE

The maximum yield stress (N / mm ² ) of the thick part (first part) and the thin part (second part) of the reaction curable resin and the difference between them were measured.
(Measurement of tensile strength)
Based on the JIS K7127 plastic tensile test, the tensile strength at room temperature was estimated. The apparatus used was a tensile tester AG-20 manufactured by Shimadzu Corporation, and five test pieces were produced for each part of the battery pack at 1/4 scale of the 1B test piece, and the average value of the maximum yield stress was obtained.

The impact strength (kJ / mm ² ) of each of the thick part (first part) and the thin part (second part) of the reaction curable resin and the difference between them were measured.
(Measurement of impact resistance)
The impact resistance at room temperature was estimated based on the JIS K7110 Izod impact test. The apparatus obtained the average value of five test pieces using the digital impact tester DG-UB of Toyo Seiki Seisakusho.

Each item shown in Table 2 is as follows in order.
Mold design value (mm) (thickness t1 of thin part and thickness t2 of thick part)
Thickness ratio (t2 / t1)

  As manufacturing conditions, a curing method and a curing time were defined. As a curing method, heating, standing at room temperature, h1 (200 ° C. melt extrusion molding), and h2 (220 ° C. melt extrusion molding) were used. In Examples 1 to 8, heating at 60 ° C. to 80 ° C. was performed, and the curing time was about 3 to 10 minutes. Comparative Example 1 was left at room temperature and the curing time was 1 day. Comparative Example 2 was a curing method h1, and the curing time was 20 seconds. Comparative Example 3 was a curing method h2, and the curing time was 30 seconds.

(Glass transition point)
Glass transition point of reaction curable resin (Tg) (° C)
Among the stress-temperature curves obtained by measuring TMA / SS7100 manufactured by SII Nanotechnology as thermomechanical analyzer TMA (ThermoMechanical Analyzer) in constant load stress measurement mode at a heating rate of 10 ° C / min. The glass transition temperature (Tg) was determined using the tangent line at which the stress was softened.

Battery packaging w1 to w4
w1: Aluminum laminate w2: Polyethylene film + PET film 2 layers w3: Vacuum-deposited polyethylene film + PET film 2 layers w4: Vacuum-deposited polypropylene film single layer

Each item shown in Table 3 is as follows in order. Table 3 describes items related to effects.
The following six items were measured as effects.
Rated energy density (Wh / l), number of filled bubbles (number per 100 pieces), 0 ° C cycle expansion (mm), expansion after storage for 1 month at 60 ° C and 90% RH (mm), 0 ° C 1m drop test Number of defects (number per 10 pieces), flame retardancy (fire spread area (cm ² ))

(Rated energy density)
At a temperature of 23 ° C., a constant current and constant voltage charge of 1 C for 15 hours at an upper limit of 4.2 V and a constant current discharge of 1 C up to a final voltage of 2.5 V are repeated, and the rated energy density is set to the discharge capacity of the first cycle. I asked for it.
Rated energy density (Wh / l) = (average discharge voltage (V) × rated capacity (Ah) / volume of battery pack (l)
In addition, 1C shows the electric current value which can discharge | release the capacity | capacitance of a battery in 1 hour.

(Battery pack swelling (mm))
The secondary battery pack that was fabricated and charged and discharged for the first time was charged again at 0 ° C. to 4.2 V for 3 hours, and the thickness of the battery pack was measured as the thickness before the cycle. For a design capacity of 1500 mAh, charging is performed at a constant current and constant voltage of 1500 mA for up to 4.2 V for 3 hours, and discharging is performed at a constant current of 150 mA up to a final voltage of 2.5 V for one cycle. This was repeated 300 times in a constant temperature bath at 60 ° C. After 300 cycles, the battery pack was charged again at 0 ° C. to 4.2 V for 3 hours, and the thickness of the battery pack was measured to determine the thickness after the cycle. A value obtained by subtracting the thickness of the battery pack before the cycle from the thickness of the battery pack after the cycle was determined as the swelling after storage.

  For each secondary battery pack that was separately charged and discharged for the first time, after measuring the thickness of the battery pack, the battery pack was charged again to 4.2 V for 3 hours and then stored in a constant temperature and humidity chamber at 60 ° C. and 90% RH. Stored for months and measured the thickness of the battery pack after storage. A value obtained by subtracting the battery pack thickness before storage from the battery pack thickness after storage was determined as the swelling after storage.

(Measurement of 0 ° C 1m drop test)
The battery pack was stored at 0 ° C. for 3 hours and dropped three times immediately after removal. NG was obtained when an external damage such as a crack or a hole was exposed. Ten battery packs were tested, and the number of defective products was counted.

(Measurement of flame retardancy)
Based on the standard of UL746C3 / 4 inch flame combustion test, three 300 mm × 300 mm flat test pieces uniformly formed to the same thickness as the thinnest part of the battery pack were used. A burner flame adjusted to / 4 inch flame was applied and held for 30 seconds, after which the burner flame was released from the test piece. The burner flame was applied to the same place at intervals of 1 minute for another 30 seconds, and then the burner flame was released. Confirm that the flammable combustion duration is less than 1 minute after the first and second flame contact, and that the combustion area of the test piece is 25 cm ² or less, which is the area below the footprint of the battery pack. The piece thickness was judged to meet the UL746C3 / 4 inch flame burn test.

Example 1
R1 (polyester polyurethane) was used as the reaction curable resin for forming the molded part 10. Molding method 2 (method of adjusting the temperature of the mold externally) was used. C1 (triethylenediamine) and c8 (sodium oleate) were used as two types of catalysts for the reaction curable resin in the molded part. The difference in maximum yield stress between the first site and the second site was 3.2%. The difference in impact strength was 10%. The thickness ratio t2 / t1 between the two parts was 33.3.

The effect of Example 1 is as follows.
Rated energy density: 500 (Wh / l)
Number of defective foams (number per 100): 8
0 ° C cycle swelling: 0.7 (mm)
Swelling after 1 month storage at 60 ° C 90% RH: 0.7 (mm)
0 ° C 1m drop test failure number (number per 10 pieces): 3
Flame retardancy (fire spread area: 24 (cm ² )

(Example 2)
The reaction curable resin and the molding technique are the same as those in Example 1. C2 (tetramethylhexanediamine) and c7 (tri-n-butyltin acetate) were used as two types of catalysts for the reaction curable resin in the molded part. The difference in maximum yield stress between the first part and the second part was 50%. The difference in impact strength was 6%. The thickness ratio t2 / t1 between the two parts was set to 25.0.

The effect of Example 2 is as follows.
Rated energy density: 500 (Wh / l)
Number of defective foams (number per 100): 6
0 ° C cycle swelling: 0.6 (mm)
Swelling after storage for 1 month at 60 ° C 90% RH: 0.5 (mm)
0 ° C 1m drop test defect number (number per 10 pieces): 2
Flame resistance (fire spread area: 22 (cm ² )

(Example 3)
R2 (polyether polyurethane) was used as a reaction curable resin for forming the molded part 10. Molding method 2 (method of adjusting the temperature of the mold externally) was used. C3 (n-butyltin trichloride) and c9 ((OH) ₂ — (P═O) CH ₂ N (OH) ₂ ) were used as two types of catalysts for the reaction curable resin in the molded part. The maximum yield stress difference between the first and second sites was 6.4%. The difference in impact strength was 14.3%. The thickness ratio t2 / t1 between the two parts was set to 16.7.

The effect of Example 3 is as follows.
Rated energy density: 520 (Wh / l)
Number of defective foams (number per 100): 3
0 ° C cycle swelling: 0.5 (mm)
Swelling after storage for 1 month at 60 ° C 90% RH: 0.5 (mm)
0 ° C 1m drop test defect number (number per 10 pieces): 1
Flame retardancy (fire spread area: 19 (cm ² )

Example 4
The reaction curable resin and the molding technique for forming the molding part 10 are the same as those in Example 3. C4 (Dimethyltin dichloride) and c10 ((CH ₃ O) ₂ — (P═O) CH ₂ N (CH ₂ OH) ₂ ) were used as two types of catalysts for the reaction curable resin in the molded part. The difference in maximum yield stress between the first part and the second part was 33%. The difference in impact strength was 22.2%. The thickness ratio t2 / t1 between the two parts was 13.8.

The effect of Example 4 is as follows.
Rated energy density: 520 (Wh / l)
Number of defective foams (number per 100): 2
0 ° C cycle swelling: 0.5 (mm)
Swelling after storage for 1 month at 60 ° C and 90% RH: 0.4 (mm)
0 ° C 1m drop test defect number (number per 10 pieces): 1
Flame resistance (fire spread area: 15 (cm ² )

(Example 5)
The reactive curable resin that forms the molded part 10 is the same as that of the fourth embodiment. Molding method 1 (method using reaction heat of resin) was used. C5 (Trimethyltin hydroxide) and c11 ((C ₂ H ₅ O) ₂ — (P═O) CH ₂ N (C ₂ H ₄ OH) ₂ ) are used as two types of catalysts for the reaction curable resin in the molded part. used. The difference in maximum yield stress between the first part and the second part was 33%. The difference in impact strength was 25%. The thickness ratio t2 / t1 between the two parts was set to 36.7.

The effect of Example 5 is as follows.
Rated energy density: 540 (Wh / l)
Number of defective foams (number per 100): 1
0 ° C cycle swelling: 0.4 (mm)
Swelling after 1 month storage at 60 ° C 90% RH: 0.3 (mm)
0 ° C 1m drop test defect number (number per 10 pieces): 0
Flame resistance (fire spread area: 11 (cm ² )

(Example 6)
The reactive curable resin and the molding technique for forming the molding part 10 are the same as those in Example 5. C6 (dibutyltin dichloride) and c12 ((C ₃ H ₇ O) ₂ — (P═O) CH ₂ N (C ₃ H ₆ OH) ₂ ) are used as two types of catalysts for the reaction curable resin in the molding part. did. The maximum yield stress difference between the first and second sites was 15%. The difference in impact strength was 37.5%. The thickness ratio t2 / t1 between the two parts was set to 27.5.

The effect of Example 6 is as follows.
Rated energy density: 550 (Wh / l)
Number of defective foams (number per 100): 1
0 ° C cycle swelling: 0.3 (mm)
Swelling after storage for 1 month at 60 ° C and 90% RH: 0.2 (mm)
0 ° C 1m drop test defect number (number per 10 pieces): 0
Flame resistance (fire spread area: 9 (cm ² )

(Example 7)
The reactive curable resin and the molding technique for forming the molding part 10 are the same as those in Example 6. C5 (Trimethyltin hydroxide) and c13 ((C ₃ H ₇ O) ₂ — (P═O) CH ₂ N (C ₄ H ₈ OH) ₃ ) are used as two types of catalysts for the reaction curable resin in the molded part. used. The difference in maximum yield stress between the first part and the second part was 14%. The difference in impact strength was 37.5%. The thickness ratio t2 / t1 between the two parts was set to 18.3.

The effects of Example 7 are as follows.
Rated energy density: 560 (Wh / l)
Number of defective foams (number per 100): 0
0 ° C cycle swelling: 0.2 (mm)
Swelling after storage for 1 month at 60 ° C and 90% RH: 0.2 (mm)
0 ° C 1m drop test defect number (number per 10 pieces): 0
Flame resistance (fire spread area: 6 (cm ² )

(Example 8)
The reactive curable resin and the molding technique for forming the molding part 10 are the same as those in Example 7. C5 (Trimethyltin hydroxide) and c14 ((C ₂ H ₅ O) ₂ — (P═O) CH ₂ N (C ₂ H ₄ OH) (CH ₂ ) OH)) was used. The difference in maximum yield stress between the first part and the second part was 14%. The difference in impact strength was 37.5%. The thickness ratio t2 / t1 between the two parts was set to 18.3.

The effect of Example 8 is as follows.
Rated energy density: 560 (Wh / l)
Number of defective foams (number per 100): 0
0 ° C cycle swelling: 0.2 (mm)
Swelling after storage for 1 month at 60 ° C and 90% RH: 0.2 (mm)
0 ° C 1m drop test defect number (number per 10 pieces): 0
Flame retardancy (fire spread area: 5 (cm ² )

(Comparative Example 1)
R1 (polyester polyurethane) was used as the reaction curable resin for forming the molded part 10. The molding method is a normal molding method, and does not vary the resin temperature during formation depending on the part. Only c7 (tri-n-butyltin acetate) was used as the catalyst. The difference in maximum yield stress between the first part and the second part was 2%. The difference in impact strength was 0%. The thickness ratio t2 / t1 between the two parts was 13.8.

The measurement results of Comparative Example 1 are as follows.
Rated energy density: 350 (Wh / l)
Number of defective foams (number per 100): 93
0 ° C cycle swelling: 2.2 (mm)
Swelling after 1 month storage at 60 ° C 90% RH: 1.5 (mm)
0 ° C 1 m drop test failure number (number per 10 pieces): 10
Flame retardant (fire spread area: 35 cm ² )

(Comparative Example 2)
R3 (thermoplastic polycarbonate) was used as a resin for forming the molded part 10. The molding method is a normal molding method. No catalyst is used. The difference in maximum yield stress between the first part and the second part was 0%. The difference in impact strength was 0%. The thickness ratio t2 / t1 between the two parts was 13.8.

The measurement results of Comparative Example 2 are as follows.
Rated energy density: 380 (Wh / l)
Number of defective foams (number per 100): 95
0 ° C cycle swelling: 1.7 (mm)
Swelling after storage for 1 month at 60 ° C and 90% RH: 2.1 (mm)
0 ° C 1 m drop test failure number (number per 10 pieces): 10
Flame resistance (fire spread area: 78 (cm ² )

(Comparative Example 3)
R4 (thermoplastic polypropylene) was used as the resin for forming the molded part 10. The molding method is a normal molding method. No catalyst is used. The difference in maximum yield stress between the first part and the second part was 2%. The difference in impact strength was 0%. The thickness ratio t2 / t1 between the two parts was 13.8.

The measurement results of Comparative Example 3 are as follows.
Rated energy density: 420 (Wh / l)
Number of defective foams (number per 100): 98
0 ° C cycle swelling: 2 (mm)
Swelling after storage for 1 month at 60 ° C and 90% RH: 2.3 (mm)
0 ° C 1 m drop test failure number (number per 10 pieces): 10
Flame retardancy (fire spread area: 81 (cm ² )

(Evaluation for effect)
The evaluation obtained from Table 1, Table 2, and Table 3 will be described. The battery pack according to the present disclosure has the following effects.

-Compared to battery packs with uniform resin physical properties, the number of times until the 1.9m drop test was greatly improved, and deformation was also suppressed (high temperature part).
-Compared to battery packs with uniform resin properties, the amount of deformation in the torsion test was improved (high temperature part).
-Compared to battery packs with uniform resin properties, the amount of moisture permeation to the substrate was improved (high temperature part).
-Cycle characteristics were improved compared to battery packs with uniform resin properties (low temperature part).
-Compared to battery packs with uniform resin properties, the amount of deformation in the high-temperature storage test was improved (low-temperature part).
-Compared to battery packs that use two-color molding or parts that were prepared separately, the raw material costs were lower and the costs were lower.
-Compared to battery packs that use two-color molding or separate molding, the productivity tact is improved and the cost is reduced.
-Compared to battery packs that use two-color molding or separate molding, the yield has improved and the cost has been reduced.

Application example
An application example of the battery pack 1 described above will be described. The use of the battery pack 1 is not limited to the application examples shown below.

"Storage system in a house as an application example"
An example in which the present disclosure is applied to a residential power storage system will be described with reference to FIG. For example, in the power storage system 100 for the house 101, electric power is stored from the centralized power system 102 such as the thermal power generation 102a, the nuclear power generation 102b, and the hydroelectric power generation 102c through the power network 109, the information network 112, the smart meter 107, the power hub 108, and the like. Supplied to the device 103. At the same time, power is supplied to the power storage device 103 from an independent power source such as the home power generation device 104. The electric power supplied to the power storage device 103 is stored. Electric power used in the house 101 is fed using the power storage device 103. The same power storage system can be used not only for the house 101 but also for buildings.

  The house 101 is provided with a power generation device 104, a power consumption device 105, a power storage device 103, a control device 110 that controls each device, a smart meter 107, and a sensor 111 that acquires various types of information. Each device is connected by a power network 109 and an information network 112. As the power generation device 104, a solar cell, a fuel cell, a windmill, or the like is used, and the generated power is supplied to the power consumption device 105 and / or the power storage device 103. The power consuming device 105 is a refrigerator 105a, an air conditioner 105b, a television receiver 105c, a bath 105d, and the like. Furthermore, the electric power consumption device 105 includes an electric vehicle 106. The electric vehicle 106 is an electric vehicle 106a, a hybrid car 106b, and an electric motorcycle 106c. The electric vehicle 106 may be an electric assist bicycle.

  The power storage device 103 includes a secondary battery or a capacitor. For example, a lithium ion battery is used. The lithium ion battery may be a stationary type or used in the electric vehicle 106. The battery pack of the present disclosure described above can be applied to the power storage device 103. The smart meter 107 has a function of measuring the usage amount of commercial power and transmitting the measured usage amount to an electric power company. The power network 109 may be any one or a combination of DC power supply, AC power supply, and non-contact power supply.

  The various sensors 111 are, for example, human sensors, illuminance sensors, object detection sensors, power consumption sensors, vibration sensors, contact sensors, temperature sensors, infrared sensors, and the like. Information acquired by the various sensors 111 is transmitted to the control device 110. Based on the information from the sensor 111, the weather condition, the human condition, etc. can be grasped, and the power consumption device 105 can be automatically controlled to minimize the energy consumption. Furthermore, the control device 110 can transmit information regarding the house 101 to an external power company or the like via the Internet.

  The power hub 108 performs processing such as branching of power lines and DC / AC conversion. Communication methods of the information network 112 connected to the control device 110 include a method using a communication interface such as UART (Universal Asynchronous Receiver-Transmitter), wireless communication such as Bluetooth, ZigBee, and Wi-Fi. There is a method of using a sensor network according to the standard. The Bluetooth method is applied to multimedia communication and can perform one-to-many connection communication. ZigBee uses the physical layer of IEEE (Institute of Electrical and Electronics Engineers) 802.15.4. IEEE 802.15.4 is the name of a short-range wireless network standard called PAN (Personal Area Network) or W (Wireless) PAN.

  The control device 110 is connected to an external server 113. The server 113 may be managed by any one of the house 101, the power company, and the service provider. The information transmitted and received by the server 113 is, for example, information related to power consumption information, life pattern information, power charges, weather information, natural disaster information, and power transactions. These pieces of information may be transmitted / received from a power consuming device (for example, a television receiver) in the home, or may be transmitted / received from a device outside the home (for example, a mobile phone). Such information may be displayed on a device having a display function, such as a television receiver, a mobile phone, or a PDA (Personal Digital Assistants).

  A control device 110 that controls each unit includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like, and is stored in the power storage device 103 in this example. The control device 110 is connected to the power storage device 103, the home power generation device 104, the power consumption device 105, the various sensors 111, the server 113 and the information network 112, and adjusts, for example, the amount of commercial power used and the amount of power generation. have. In addition, you may provide the function etc. which carry out an electric power transaction in an electric power market.

  As described above, the electric power can be stored not only in the centralized power system 102 such as the thermal power 102a, the nuclear power 102b, and the hydraulic power 102c but also in the power generation device 104 (solar power generation, wind power generation). it can. Therefore, even if the generated power of the home power generation device 104 fluctuates, it is possible to perform control such that the amount of power to be sent to the outside is constant or discharge is performed as necessary. For example, the electric power obtained by solar power generation is stored in the power storage device 103, and midnight power with a low charge is stored in the power storage device 103 at night, and the power stored by the power storage device 103 is discharged during a high daytime charge. You can also use it.

  In this example, the control device 110 is stored in the power storage device 103. However, the control device 110 may be stored in the smart meter 107, or may be configured independently. Furthermore, the power storage system 100 may be used for a plurality of homes in an apartment house, or may be used for a plurality of detached houses.

"Vehicle power storage system as an application example"
An example in which the present disclosure is applied to a power storage system for a vehicle will be described with reference to FIG. FIG. 18 schematically illustrates an example of a configuration of a hybrid vehicle that employs a series hybrid system to which the present disclosure is applied. A series hybrid system is a car that runs on an electric power driving force conversion device using electric power generated by a generator driven by an engine or electric power once stored in a battery.

  The hybrid vehicle 200 includes an engine 201, a generator 202, a power driving force conversion device 203, driving wheels 204a, driving wheels 204b, wheels 205a, wheels 205b, a battery 208, a vehicle control device 209, various sensors 210, and a charging port 211. Is installed. The battery pack 1 of the present disclosure described above is applied to the battery 208.

  The hybrid vehicle 200 runs using the power driving force conversion device 203 as a power source. An example of the power driving force conversion device 203 is a motor. The electric power / driving force converter 203 is operated by the electric power of the battery 208, and the rotational force of the electric power / driving force converter 203 is transmitted to the driving wheels 204a and 204b. In addition, by using a direct current-alternating current (DC-AC) or reverse conversion (AC-DC conversion) where necessary, the power driving force conversion device 203 can be applied to either an alternating current motor or a direct current motor. The various sensors 210 control the engine speed via the vehicle control device 209 and control the opening (throttle opening) of a throttle valve (not shown). The various sensors 210 include a speed sensor, an acceleration sensor, an engine speed sensor, and the like.

  The rotational force of the engine 201 is transmitted to the generator 202, and the electric power generated by the generator 202 by the rotational force can be stored in the battery 208.

  When the hybrid vehicle decelerates by a braking mechanism (not shown), the resistance force at the time of deceleration is applied as a rotational force to the power driving force conversion device 203, and the regenerative power generated by the power driving force conversion device 203 by this rotational force is applied to the battery 208. Accumulated.

  The battery 208 is connected to a power source outside the hybrid vehicle, so that it can receive power from the external power source using the charging port 211 as an input port and store the received power.

  Although not shown, an information processing apparatus that performs information processing related to vehicle control based on information related to the secondary battery may be provided. As such an information processing apparatus, for example, there is an information processing apparatus that displays a remaining battery level based on information on the remaining battery level.

  In addition, the above demonstrated as an example the series hybrid vehicle which drive | works with a motor using the electric power generated with the generator driven by an engine, or the electric power once stored in the battery. However, the present disclosure is also effective for a parallel hybrid vehicle that uses both engine and motor outputs as drive sources, and switches between the three modes of running with the engine alone, running with the motor alone, and engine and motor running as appropriate. Applicable. Furthermore, the present disclosure can be effectively applied to a so-called electric vehicle that travels only by a drive motor without using an engine.

"Modification"
Although a plurality of embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made. For example, the present disclosure can be applied to a secondary battery other than a lithium ion secondary battery.

  Note that the configurations and the like in the respective embodiments and modifications can be appropriately combined within a range where no technical contradiction occurs.

This indication can also take the following composition, for example.
(1)
One or more batteries;
A molded part made of a reaction curable resin covering at least a part of the outer surface of the battery,
In the molding part, a first portion where the thickness of the reactive curable resin is large and a second portion where the thickness of the reactive curable resin is smaller than the first portion are integrally formed, and A battery pack that satisfies at least one of the following conditions 1 and 2.
Condition 1: The maximum yield stress of the second part measured according to JIS K 7127 is 3% or more and 100% or less larger than the maximum yield stress of the first part. Condition 2: According to JIS K 7110 The impact strength of the first part measured by an equivalent Izod impact test is 3% or more and 100% or less greater than the impact strength of the second part (2)
The battery pack according to (1), wherein the one or more batteries are formed by wrapping a battery element with a film package, and the second part is included in the molded part that covers the battery.
(3)
A protection circuit for the battery;
The battery pack according to any one of (1) and (2), wherein the first portion is included in the molded portion that covers the protection circuit.
(4)
The reaction curable resin is at least one selected from the group consisting of silicon, epoxy, acrylic and urethane;
The battery pack according to any one of (1) to (3), wherein the glass transition temperature of the reactive curable resin after molding is 60 ° C. or higher and 140 ° C. or lower.
(5)
The reactive curable resin contains two or more reactive curable catalysts;
The battery pack according to any one of (1) to (4), wherein the reaction activity of the reaction curable catalyst differs by 15% or more at 60 ° C.
(6)
The reaction curable resin is urethane;
The battery pack according to any one of (1) to (5), wherein the at least one reaction curable catalyst is a main agent prepolymer represented by the above chemical formula.
(7)
When at least a part of the outer surface of one or more batteries is covered with a molded part made of a reactive curable resin, different physical properties are given depending on the site using the reaction heat of the reactive curable resin,
The ratio (t1 / t2) between the resin thickness t1 of the first part where the thickness of the reactive curable resin is large and the resin thickness t2 of the second part where the thickness of the reactive curable resin is small is 13.5 or more 50 The manufacturing method of the battery pack which is the following.
(8)
When covering at least a part of the outer surface of one or more batteries with a molded part made of a reaction curable resin,
A high temperature block is brought into contact with a part or the whole of the outer surface of a mold for molding the first portion having a large thickness of the reaction curable resin,
A low-temperature block is brought into contact with a part or the whole of the outer surface of a mold for molding a second part having a thickness smaller than that of the first part as compared with the first part;
A method for producing a battery pack, wherein the temperature of the reaction curable resin during molding is varied.
(9)
The method for manufacturing a battery pack according to claim 8, wherein a member having low thermal conductivity is used for a part of the mold.
(10)
A power storage system in which the battery pack according to any one of (1) to (6) is charged by a power generation device that generates power from renewable energy.
(11)
A power storage system that includes the battery pack according to any one of (1) to (6) and supplies electric power to an electronic device connected to the battery pack.
(12)
An electronic device that receives power from the battery pack according to any one of (1) to (6).
(13)
(1)-(6) The control which performs the information processing regarding vehicle control based on the conversion apparatus which receives supply of electric power from the battery pack in any one, and converts it into the driving force of a vehicle, and the information regarding the said battery pack An electric vehicle having the apparatus.
(14)
It has a power information transmission / reception unit that transmits / receives signals to / from other devices via the network,
The electric power system which performs charge / discharge control of the battery pack in any one of (1)-(6) based on the information which the said electric power information transmission / reception part received.
(15)
An electric power system that receives electric power from the battery pack according to any one of (1) to (6) or supplies electric power to the battery pack from a power generation device or an electric power network.

DESCRIPTION OF SYMBOLS 1 ... Battery pack 10 ... Molding part 11, 11a ... Exterior member 12 ... Battery 13 ... Circuit board 14a, 14b, 14c ... Opening 30 ... Battery component 41 ... Upper mold 42 ... Lower mold 44, 45 ... Insulating materials 46a-46c ... Heater blocks 47a-47c ... Cold block 51a ... First part 51b ... Second part

Claims (15)

One or more batteries;
A molded part made of a reaction curable resin covering at least a part of the outer surface of the battery,
In the molding part, a first portion where the thickness of the reactive curable resin is large and a second portion where the thickness of the reactive curable resin is smaller than the first portion are integrally formed, and A battery pack that satisfies at least one of the following conditions 1 and 2.
Condition 1: The maximum yield stress of the second part measured according to JIS K 7127 is 3% or more and 100% or less larger than the maximum yield stress of the first part. Condition 2: According to JIS K 7110 The impact strength of the first part measured by the conforming Izod impact test is 3% or more and 100% or less greater than the impact strength of the second part.   2. The battery pack according to claim 1, wherein the one or more batteries are formed by wrapping a battery element with a film package, and the second part is included in the molded part that covers the battery. A protection circuit for the battery;
The battery pack according to claim 1, wherein the first part is included in the molded part that covers the protection circuit. The reaction curable resin is at least one selected from the group consisting of silicon, epoxy, acrylic and urethane;
The battery pack according to claim 1, wherein the glass transition temperature of the reactive curable resin after molding is 60 ° C. or higher and 140 ° C. or lower. The reaction curable resin contains two or more catalysts;
The battery pack according to claim 1, wherein the reaction activity of the catalyst differs by 15% or more at 60 ° C. The reaction curable resin is urethane;
The battery pack according to claim 1, wherein when two or more kinds of catalysts are used, at least one of the catalysts is a main agent prepolymer represented by the following chemical formula.

When at least a part of the outer surface of one or more batteries is covered with a molded part made of a reactive curable resin, different physical properties are given depending on the site using the reaction heat of the reactive curable resin,
The ratio (t1 / t2) between the resin thickness t1 of the first part where the thickness of the reactive curable resin is large and the resin thickness t2 of the second part where the thickness of the reactive curable resin is small is 13.5 or more 50 The manufacturing method of the battery pack which is the following. When covering at least a part of the outer surface of one or more batteries with a molded part made of a reaction curable resin,
A high temperature block is brought into contact with a part or the whole of the outer surface of a mold for molding the first portion having a large thickness of the reaction curable resin,
A low-temperature block is brought into contact with a part or the whole of the outer surface of a mold for molding a second part having a thickness smaller than that of the first part as compared with the first part;
A method for producing a battery pack, wherein the temperature of the reaction curable resin during molding is varied.   The method for manufacturing a battery pack according to claim 8, wherein a member having low thermal conductivity is used for a part of the mold.   A power storage system in which the battery pack according to any one of claims 1 to 6 is charged by a power generation device that generates power from renewable energy.   A power storage system comprising the battery pack according to claim 1 and supplying electric power to an electronic device connected to the battery pack.   The electronic device which receives supply of electric power from the battery pack of any one of Claims 1-6.   A converter that receives supply of electric power from the battery pack according to any one of claims 1 to 6 and converts the power into a driving force of the vehicle, and a control that performs information processing related to vehicle control based on information related to the battery pack. An electric vehicle having the apparatus. It has a power information transmission / reception unit that transmits / receives signals to / from other devices via the network,
The electric power system which performs charging / discharging control of the battery pack of any one of Claims 1-6 based on the information which the said electric power information transmission / reception part received.   The electric power system which receives supply of electric power from the battery pack of any one of Claims 1-6, or supplies electric power to the said battery pack from an electric power generating apparatus or an electric power network.

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