JP2019067608A - Lithium ion battery - Google Patents

Abstract

To provide a lithium ion battery capable of suppressing deposition of lithium when a bent portion is generated in an electrode.SOLUTION: The lithium ion battery includes: a first conductor having a bent portion which is drawn out of a package, electrically connected to a positive electrode active material layer, and bent in a mountain fold toward an inside of the lithium ion battery; and a second conductor having a bent portion which is drawn out of the package, electrically connected to a negative electrode active material layer, and bent in a mountain fold toward the inside of the lithium ion battery. At least one of the first conductor and the second conductor is a lithium ion battery in which a bending portion is covered with an insulating covering layer.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lithium ion battery in which a positive electrode current collector, a positive electrode active material layer, a separator, a negative electrode active material layer, and a negative electrode current collector are laminated.

  Lithium ion batteries with excellent characteristics such as charge and discharge capacity are used as power supplies for portable devices, power supplies for electric vehicles, stationary batteries, etc., and various proposals have been made to further improve performance. . Among them, as a lithium ion battery having high output density and energy density, a bipolar lithium ion battery is known in which unit cells in which the positive electrode active material and the negative electrode active material are stacked with a separator interposed therebetween are stacked in series.

  In a lithium ion battery, lithium metal may be precipitated in a dendritic manner, and the precipitate may be conducted to the counter electrode to generate heat, which may cause the performance deterioration of the battery. And the method (refer patent document 1) using the porous film which has a specific pore is known as a method of controlling precipitation of lithium suitable for a bipolar | dipolar type lithium ion battery.

JP, 2013-211191, A

  In the lithium ion battery, in addition to the current collector, a member (also referred to as a tab) is connected to the current collector in order to take out the current from the current collector to the outside. According to the technology, it has not been possible to sufficiently prevent the deposition of lithium generated in the member for extracting the current to the outside.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a lithium ion battery capable of suppressing the deposition of lithium in a member for extracting current from the current collector to the outside.

  The present invention for solving the problems of the conventional example is a lithium ion battery, comprising a positive electrode current collector body, a first conductor electrically connected to the positive electrode current collector body, and the positive electrode current collector. A positive electrode active material layer formed on the negative electrode current collector body, a second conductor electrically connected to the negative electrode current collector body, a negative electrode active material layer formed on the negative electrode current collector, It is a lithium ion battery which accommodates the plate-shaped unit cell containing the separator arrange | positioned between the said positive electrode active material layer and a negative electrode active material layer in an exterior body, Comprising: Said 1st conductor The second conductor is drawn out of the outer package, and the inner surface of the outer package has a bent portion in which the surface on the side in contact with the inner surface of the outer package is bent in a valley fold. And at least one of the first conductor and the second conductor, the bending portion is covered with an insulating coating layer It is one in which it was decided to composed.

  The positive electrode current collector main body and the first electrical conductor, and the negative electrode current collector main body and the second electrical conductor may be respectively electrically connected, and may be constituted by one member, separately The members of the above may be adhered by a conductive adhesive and a metal material (such as solder).

  Here, the exterior body has a pair of exterior members, and a sealing portion disposed at the periphery of the exterior member and sealing the unit cell between the pair of exterior members, and the sealing portion A part of the sealing material to be configured may be extended to the bent portion of the first conductor or the second conductor, and the sealing portion and the insulating covering portion may be integrally formed. .

  Furthermore, the first conductor and the second conductor are fixed to the inner surface of the package, and the first conductor and the second conductor are disposed along the inner surface of the package. It may be done.

  According to the present invention, the deposition of lithium in the member for extracting the current to the outside is suppressed. Although the reason for this is not clear, if there is a conductor having a bent portion bent in a direction projecting toward the active material layer, current tends to be concentrated at the top of the bent portion inside the battery, resulting in dendrite In the present invention, it is considered that the effect of suppressing the concentration of current by insulating coating the bent portion is considered.

1 is a perspective view of an example of a lithium ion battery according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which concerns on an example of the lithium ion battery which concerns on embodiment of this invention. It is explanatory drawing showing an example of the manufacturing process of the lithium ion battery of this Embodiment. It is explanatory drawing showing the example of the coating | coated state in the bending part of the electrode body in the lithium ion battery of this Embodiment.

  Embodiments of the present invention will be described with reference to the drawings. In the following description, unless otherwise specified, the shape, size, ratio of size, etc. of each part is an example and may be different from the example here.

  The battery 10 which concerns on embodiment of this invention is the positive electrode collector 11, the positive electrode active material 12, the separator 13, the negative electrode collector so that the perspective view may be illustrated in FIG. 1, and the cross section may be illustrated in FIG. And a flat plate-shaped unit cell formed of a laminate 20 in which the negative electrode active material 15 is stacked. Further, an insulating covering layer 17 is laminated on a part of the positive electrode current collector 11 and the negative electrode current collector 14. Furthermore, the laminate 20 is housed in an outer package formed by the pair of outer packaging materials 16a and 16b. In the battery 10 shown in FIGS. 1 to 4, the positive electrode current collector 11 is a member in which the positive electrode current collector body 11 a and the first conductor 11 b are integrally formed, and the negative electrode current collector 14 is a negative electrode collector. It is a member in which the current collector body 14a and the second conductor 14b are integrally formed. The positive electrode active material 12 or the negative electrode active material 15 is laminated on the positive electrode current collector body 11 a or the negative electrode current collector body 14 a disposed in parallel with the separator 13. And the part pulled out to the outward direction of the exterior material 16 from each collector body corresponds to the 1st, 2nd conductors 11b and 14b, and these function as a charging / discharging terminal of a single battery cell.

  The positive electrode current collector body 11a and the negative electrode current collector body 14a can be configured using a metal current collector or a resin current collector.

  As the metal current collector, metal current collectors generally used in lithium ion batteries can be used, and copper, aluminum, titanium, nickel, tantalum, niobium, hafnium, zirconium, zinc, tungsten, bismuth, antimony, and these A known current collector made of one or more metals selected from the group consisting of an alloy containing one or more metals and a stainless steel alloy can be used.

  The shape of the metal current collector may be any of thin plate, metal foil and mesh, and another metal layer is further formed on the surface of the metal current collector by a method such as sputtering, electrodeposition, or coating. It may be

  As the resin current collector, a sheet-like conductive polymer and a sheet-like polymer obtained by imparting conductivity to a non-conductive polymer material can be used. Examples of the conductive polymer material include polyaniline, polypyrrole, polythiophene, polyacetylene, polyparaphenylene, polyphenylene vinylene, polyacrylonitrile and polyoxadiazole. In addition, for the purpose of improving the conductivity of the resin current collector containing a conductive polymer material, it is preferable to further include a conductive filler described later.

  As non-conductive polymer materials, polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polycycloolefin (PCO), polyethylene terephthalate (PET), polyether nitrile (PEN), polytetrafluoroethylene (PTFE), styrene butadiene rubber (SBR), polyacrylonitrile (PAN), polymethyl acrylate (PMA), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVdF), epoxy resin, silicone resin, and mixtures thereof Be

  The nonconductive polymer material is preferably polyethylene (PE), polypropylene (PP), polymethylpentene (PMP) and polycycloolefin (PCO) from the viewpoint of electrical stability, more preferably polyethylene (PE) , Polypropylene (PP) and polymethylpentene (PMP).

  A polymer obtained by imparting conductivity to a nonconductive polymer material can be obtained by mixing a nonconductive polymer material and a conductive filler, and the conductive filler is obtained from a material having conductivity. It is selected from the filler. Preferably, from the viewpoint of suppressing ion permeation in the current collector, it is preferable to use a filler obtained from a material having no conductivity with respect to ions used as a charge transfer medium. Specifically, fillers obtained from conductive carbon, aluminum, gold, silver, copper, iron, platinum, chromium, tin, indium, antimony, titanium, nickel and alloys such as stainless steel (SUS) may be mentioned. Not limited to these. Among them, from the viewpoint of corrosion resistance, it is preferably a filler obtained from aluminum, stainless steel, conductive carbon or nickel, more preferably a filler obtained from a carbon material. These conductive fillers may be used alone or in combination of two or more. In addition, as a conductive filler, what coated the metal shown above by plating etc. around a particle-type ceramic material or resin material can also be used.

  The shape of the conductive filler may be any of particulate, fibrous and aggregates thereof.

  The resin current collector can be obtained by a known method described in, for example, Japanese Patent Publication No. 2012-150905 and International Publication No. WO 2015/005116, and as a specific example, polypropylene is acetylene black as a conductive filler. After dispersing 5 to 20 parts of and then rolling with a heat press machine. Further, the thickness is also not particularly limited, and can be applied similarly to known ones or appropriately changed.

  The positive electrode current collector main body 11a and the negative electrode current collector main body 14b may use a metal current collector or a resin current collector as it is, or may use a conductive layer to be described later on the surface thereof. It is preferable that it is a metal electrical power collector or resin electrical power collector which formed the conductive layer from a viewpoint of these.

  The first conductor 11b and the conductor 14b may be formed using a metal foil made of the same material as the metal current collector forming the positive electrode current collector main body 11a and the negative electrode current collector main body 14b, respectively. The positive electrode current collector main body 11a and the first conductor 11b may be electrically connected to each other, and may be configured as one member, and separate members may be formed of a conductive adhesive, a solder, or the like. It may be electrically bonded by a known conductive bonding method. Similarly, the negative electrode current collector main body 14a and the second conductor 14b may be electrically connected to each other, and may be configured as one member, and separate members may be formed of a conductive adhesive, a solder, etc. It may be configured to be electrically bonded by the known conductive bonding method of

The composition of the positive electrode active material 12 is a slurry-like composition obtained by mixing positive electrode active material particles and an electrolytic solution. Here, as positive electrode active material particles, complex oxides of lithium and transition metal (for example, LiCoO ₂ , LiNiO ₂ , LiMnO ₂ and LiMn ₂ O ₄ ), transition metal oxides (for example, MnO ₂ and V ₂ O ₅ ), Transition metal sulfides (for example, MoS ₂ and TiS ₂ ) and conductive polymers (for example, polyaniline, polyvinylidene fluoride, polypyrrole, polythiophene, polyacetylene, poly-p-phenylene and polycarbazole) and the like can be used.

Further, the composition of the negative electrode active material 15 is a slurry-like composition obtained by mixing the negative electrode active material particles with an electrolytic solution. Here, as the negative electrode active material particles, graphite, non-graphitizable carbon, amorphous carbon, calcined high molecular compound (for example, one obtained by firing and carbonizing a phenol resin and furan resin etc.), cokes (for example, pitch coke, Needle coke and petroleum coke etc.), carbon fibers, conductive polymers (eg polyacetylene and polypyrrole etc.), tin, silicon and metal alloys (eg lithium-tin alloy, lithium-silicon alloy, lithium-aluminum alloy and lithium-aluminum) -Manganese alloys, etc., complex oxides of lithium and transition metals (e.g., Li ₄ Ti ₅ O ₁₂ etc.), etc.

  In the present embodiment, at least a portion of the surface of the positive electrode active material particles and the negative electrode active material particles contained in the respective compositions of positive electrode active material 12 and negative electrode active material 15 are the resin for coating and the conductive support agent. It is preferable that it is a coated active material particle covered with the coating agent containing these.

  When the periphery of the active material particles is covered with the covering agent, the volume change of the electrode occurring at the time of charge and discharge can be alleviated, and the deterioration of the electrode due to repeated charge and discharge can be suppressed. Examples of the coating resin include vinyl resin, urethane resin, polyester resin, polyamide resin, epoxy resin, polyimide resin, silicone resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate and the like. Among these, vinyl resins, urethane resins, polyester resins or polyamide resins are preferable.

  As a conductive support agent contained in a coating agent, it can be selected and used from the material which has electroconductivity.

  Materials having conductivity include metals [aluminum, stainless steel (SUS), silver, gold, copper and titanium, etc.], conductive carbon [carbon nanofibers, graphite, carbon black, acetylene black, Vulcan (registered trademark), ketene, etc. Cheng Black (registered trademark), Black Pearl (registered trademark), furnace black, channel black, thermal lamp black, carbon nanotubes (single-walled carbon nanotubes and multi-walled carbon nanotubes, etc.), carbon nanohorns, carbon nanoballoons, hard carbons, fullerenes, etc. And mixtures thereof, but is not limited thereto.

  These conductive aids may be used alone or in combination of two or more. Also, these alloys or metal oxides may be used. From the viewpoint of electrical stability, it is preferably aluminum, stainless steel, carbon, silver, gold, copper, titanium and a mixture thereof, more preferably silver, gold, aluminum, stainless steel and conductive carbon, still more preferably It is conductive carbon.

  Moreover, as a conductive support agent, a conductive material (a metal among the materials of the above-mentioned conductive aids) is coated around the nonconductive material such as a particle-based ceramic material, a resin material, etc. It is also possible to use a mixture of a conductive material and a conductive material (the metal of the materials of the above-mentioned conductive assistants).

  In addition, it is also possible to use, as a conductive additive, conductive fibers obtained by uniformly dispersing metal or graphite having good conductivity in synthetic fibers, conductive fibers obtained by coating the surface of organic fibers such as synthetic fibers with metal, etc. it can.

  In addition, when the positive electrode active material particles or the negative electrode active material particles are mixed with the electrolytic solution and used as the positive electrode active material 12 or the negative electrode active material 15, as the electrolytic solution, known electrolytes used for manufacturing lithium ion batteries and An electrolyte containing a non-aqueous solvent can be used.

As the electrolyte, those used for ordinary electrolytes for lithium ion batteries can be used, and lithium salts of inorganic acids such as LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ and LiClO ₄ , LiN (CF ₃ SO 4 _{2) 2, LiN (C 2} F 5 SO 2) 2 and LiC (CF ₃ SO ₂₎ is a lithium salt of an organic acid of ₃ or the like. Among these, LiPF ₆ is preferable from the viewpoint of battery output and charge-discharge cycle characteristics.

  Further, as the non-aqueous solvent, those used in general electrolytes for lithium ion batteries can be used, and examples thereof include lactone compounds, cyclic or chain carbonates, chain carboxylic esters, cyclic or chain ethers, Phosphoric acid esters, nitrile compounds, amide compounds, sulfones, sulfolanes and the like and mixtures thereof can be used. These non-aqueous solvents may be used alone or in combination of two or more non-aqueous solvents.

  Among the examples of the above non-aqueous solvents, lactone compounds, cyclic carbonates, chain carbonates and phosphates are preferable from the viewpoint of battery power and charge-discharge cycle characteristics, and lactone compounds, cyclic are more preferable. Carbonates and linear carbonates, more preferably a mixture of cyclic carbonates and linear carbonates. Particularly preferred are propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC) and a mixture of two selected from these.

  0.1-3 mol / L is preferable based on the capacity | capacitance of electrolyte solution, and, as for the density | concentration of the electrolyte contained in electrolyte solution, 0.5-2 mol / L is more preferable.

  In the present invention, it is preferable that the positive electrode active material 12 and the negative electrode active material 15 each contain a fibrous conductive filler together with the above-mentioned coated active material particles from the viewpoint of being able to reduce the ion resistance. Examples of fibrous conductive fillers include carbon fibers such as PAN-based carbon fibers and pitch-based carbon fibers, conductive fibers obtained by uniformly dispersing metal and graphite having good conductivity in synthetic fibers, and stainless steel. Examples thereof include metal fibers in which metal is fiberized, conductive fibers in which the surface of organic fibers is coated with metal, conductive fibers in which the surface of organic fibers is coated with conductive resin, and the like. Among these conductive fibers, carbon fibers are preferred.

  When the positive electrode active material 12 and the negative electrode active material 15 contain a fibrous conductive filler, the ratio of the fibrous conductive filler is preferably 0.5 to 5% by weight based on the weight of the coated active material particles.

  In the positive electrode active material 12 and the negative electrode active material 15, it is preferable that the active material particles and the conductive aid be contained at a concentration of 10 to 60% by weight based on the weight of the electrolytic solution.

  Furthermore, in the present embodiment, the separator 13 cut into a desired shape is prepared. As the separator 13, a porous film made of hydrocarbon resin such as polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP) and polyolefin (polyethylene and polypropylene etc), multilayer film of porous film (for example, PP / PE) / PP non-woven fabric made of synthetic fibers (polyester fibers, aramid fibers, etc.) and glass fibers etc., those having ceramic fine particles of silica, alumina, titania, etc. adhered to these surfaces, etc. The known separators for lithium ion batteries can be used. The shape of the separator 13 will be described later.

  The pair of exterior members 16a and 16b is formed of a base such as a laminate film that does not transmit air and an electrolytic solution. It is preferable that the exterior members 16a and 16b have a storage portion 161 having a flange portion 162 formed on the outer periphery, and the storage portion 161 has a depth corresponding to the thickness of the layer of the positive electrode active material 12 or the negative electrode active material 15. It is preferable that it is a recessed part of Note that the height from the bottom of the storage portion 161 to the flange portion 162 is inclined so as to differ by the thickness of the electrode body drawn out and the insulation coating layer laminated on one side and the other side. It may be formed.

  An example of the manufacturing process of the lithium ion battery of the present embodiment is shown in FIG. In this example, first, the positive electrode current collector 11 in which the positive electrode current collector main body 11a and the first conductor 11b are integrated is disposed and fixed in one of the package members 16a. At this time, as illustrated in FIG. 3, the first conductor 11 b extends from the positive electrode current collector main body 11 a disposed on the bottom portion 161 b of the housing portion 161 to the inner side surface 161 s and the flange portion 162. It is bent along the shape and extends to the outside of the sheathing 16 through the flange portion 162 (S1 in FIG. 3).

  At this time, as illustrated in FIG. 4, the positive electrode current collector 11 includes at least the bent portion 112 (located between the inner side surface 161 s of the storage portion 161 and the flange portion 162, and the first conductive of the positive electrode current collector 11 A state in which the heat fusible tape 171 is adhered to the positive electrode current collector 11 as the insulating covering layer 17 along the side of the body 11a that is in contact with the exterior material 16 and bent inwards) I will leave.

  In the example of FIG. 4, the heat fusible tape 171 is attached to the entire surface of the positive electrode current collector 11 on the side of the positive electrode current collector main body 11 a in contact with the exterior material 16 a. Further, the heat fusible tape 171 is attached to a portion of the bent portion 112 of the conductor 11b which is later in contact with the positive electrode active material 12 and covers the bent portion 112, and the positive electrode current collector body 11a The surface in contact with the active material 12 is not coated with the heat fusion tape 171.

  Next, the positive electrode active material 12 is filled in the housing portion 161 of the packaging material 16a (S2 in FIG. 3), and the positive electrode active material 12 is stacked on the positive electrode current collector main body 11a. A separator 13 of such a size that the outer peripheral edge reaches up to 162 is disposed on the positive electrode active material 12 (S3 in FIG. 3).

  On the other hand, as in the example of the positive electrode current collector 11 described above, the second conductor 14b is disposed in the bottom portion 161b of the storage portion 161 of the exterior member 16b in the other exterior member 16b as well. It is arranged to bend along the shape from the body 14 to the inner side surface 161s and the flange portion 162, and extends to the outside of the exterior body 16 through the flange portion 162.

  Similarly to the example of the positive electrode current collector 11 illustrated in FIG. 4, the negative electrode current collector 14 has at least the bent portion 112 (located between the inner side surface 161s of the storage portion 161 and the flange portion 162, The heat fusible tape 171 is used as an insulation coating layer 17 along the surface of the second conductor 14b of the body 14 in contact with the exterior material 16 and the inward facing surface). It is in a state of being adhered to the body 14.

  Here, as in the example of FIG. 4, the heat fusible tape 171 is attached to the entire surface of the negative electrode current collector 14 on the side of the negative electrode current collector main body 14 a in contact with the exterior material 16 b. Further, the heat fusible tape 171 is attached to a portion of the bent portion 112 of the conductor 14 which is later in contact with the negative electrode active material and covers the bent portion 112, and the negative electrode active of the negative electrode current collector body 14a. The surface in contact with the substance 15 is not coated with the heat fusion tape 171.

  Next, the negative electrode active material 15 is filled in the housing portion 161 of the packaging material 16b, and the negative electrode active material 15 is stacked on the negative electrode current collector main body 14a.

  Then, the package members 16 a and 16 b are disposed to face each other so that the positive electrode active material 12 and the negative electrode active material 15 are stacked via the separator 13. Then, the thermal adhesive tape 171 constituting the sealing portion is disposed on the flange portion 162 of the exterior members 16a and 16b, and the flange portion 162 is thermocompression-bonded (S4). At this time, the heat fusible tape 171 is fused to the package members 16a and 16b and the separator 13 to seal the unit cell inside the package.

  The lithium ion battery of the present embodiment is manufactured, for example, as described above, and has a structure whose cross section is shown in FIG. In the example of FIG. 2, the positive electrode current collector 11, the positive electrode active material layer 12 disposed on the positive electrode current collector 11, the separator 13, the negative electrode active material layer 15, and the negative electrode current collector 14 in this order A flat plate-like single battery cell is shown which is formed by stacking at

  In the present embodiment, the positive electrode current collector main body 11 b electrically connected to the positive electrode active material 12 and the first conductor 11 a partially pulled out of the exterior member 16 are integrated. The positive electrode current collector 11 has a bent portion 112 which is bent in a valley manner with the surface of the first conductor 11a in contact with the outer package facing inward.

  Then, a heat sealing tape 171 as an insulating covering layer 17 covering the bent portion 112 is attached to the bent portion 112 so as to be isolated from the positive electrode active material 12.

  Further, in the present embodiment, the negative electrode current collector main body 14 b electrically connected to the negative electrode active material 15 and the second conductor 14 b partially pulled out of the exterior material 16 are integrated. The negative electrode current collector 14 also has a bent portion 112 bent in a valley manner with the surface of the second conductor 14b in contact with the exterior material 16 facing inward.

  Further, the heat fusible tape 171 as the insulating covering layer 17 covering the entire bent portion is attached to the bent portion 112 of the negative electrode current collector 14 so as to separate the bent portion 112 from the negative electrode active material 15. .

  In the example described so far, the heat sealing tape 171 constituting the insulating covering layer 17 is extended to the flange portion 162. That is, the heat fusible tape 171 disposed on the flange portion 162 also functions as a sealing portion, and the heat fusible tape 171 functioning as the sealing portion is valley-folded with the surface in contact with the exterior material of the conductor facing inward. It is extended | stretched to the bending part bent to (The bending part which will contact | connect an active material when not coat | covering), and the precipitation part of lithium is suppressed by coat | covering a bending part as the insulation coating layer 17. FIG. Here, by integrally forming the members constituting each of the sealing portion and the covering insulating layer 17, it is possible to achieve both prevention of lithium deposition and sealing by a simple operation.

  However, although an example is described in which the member functioning as the sealing portion (the heat fusion tape 171) and the member which is the insulating covering layer 17 are integrally disposed, the present embodiment is not limited thereto. The insulating covering layer 17 may be configured by a member separate from the member to be configured to cover the bent portion 112.

  In the examples so far, the insulating covering layer 17 is laminated on the bent portions 112 of the positive electrode and the negative electrode conductors 11b and 14b to separate them from the active material layer, but the present embodiment is not limited thereto. The insulating covering layer 17 may be stacked on at least one of the positive electrode and negative electrode conductors 11 b and 14 b, preferably on both the bent portions 112.

  Furthermore, in the description so far using FIGS. 1 to 4, the positive electrode current collector 11 and the negative electrode current collector 14 are drawn to the outside of the exterior material 16 as the first and second conductors, thereby becoming electrodes. Although the configuration also serving as a conductor (electrode conductor) is illustrated, the positive electrode current collector 11 and the electrode conductor of the positive electrode are separately formed, and the negative electrode current collector 14 and the electrode conductor of the negative electrode are separately formed. It may be formed as a body, and each current collector and the electrode conductor may be electrically connected to each other to realize the first and second conductors. In this case, when the bent portion in the inside of the battery is formed not on the current collector but on the electrode conductor, and the bent portion does not cover, the bent portion serves as the insulating covering layer 17. It may be coated with

DESCRIPTION OF SYMBOLS 10 battery, 11 positive electrode collector, 12 positive electrode active material, 13 separator, 14 negative electrode collector, 15 negative electrode active material, 16 outer package, 16a, 16b outer package, 17 insulating coating layer, 20 laminate, 111, 112 Bending part, 161 storage part, 162 flange part, 171 heat fusion tape.

Claims (3)

Positive current collector body,
A first conductor electrically connected to the positive electrode current collector body,
A positive electrode active material layer formed on the positive electrode current collector;
Negative electrode current collector body,
A second conductor electrically connected to the negative electrode current collector body,
A negative electrode active material layer formed on the negative electrode current collector;
It is a lithium ion battery formed by housing a flat battery cell unit including a separator disposed between the positive electrode active material layer and the negative electrode active material layer in an outer package,
The first conductor and the second conductor are drawn out of the outer package, and the inner surface of the outer package is in contact with the inner surface of the outer package in a valley fold direction. With a bent bend,
A lithium ion battery, wherein at least one of the first conductor and the second conductor has the bent portion covered with an insulating coating layer. It is a lithium ion battery according to claim 1,
The exterior body has a pair of exterior materials, and a sealing portion disposed at each peripheral edge of the exterior materials to seal the single battery cell between the pair of exterior materials.
A part of the sealing material constituting the sealing portion is extended to the bent portion of the first conductor or the second conductor, and the sealing portion and the insulating covering portion are integrally formed. Lithium ion battery. 3. The lithium ion battery according to claim 2, wherein the first conductor and the second conductor are fixed to the inner surface of the outer package,
The lithium ion battery in which the said 1st conductor and the 2nd conductor are arrange | positioned along the inner surface of the said packaging material.

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