KR20160076735A - Secondary Battery with Improved Stability of Electrode Tab-Lead Coupling Portions - Google Patents

Abstract

The present invention relates to a secondary battery where an electrode assembly is embedded in a receiving unit of a battery case with an electrolyte. Electrode tabs of the electrode assembly are coupled to an electrode lead to form a tab-lead coupling unit. An insulating material is filled between an end unit of the electrode assembly having the tab-lead coupling unit and the receiving unit of the battery case.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a secondary battery with improved stability of an electrode tab-

The present invention relates to a secondary battery having improved stability of an electrode tab-to-lead coupling portion.

BACKGROUND ART [0002] In recent years, rechargeable secondary batteries have been widely used as energy sources for wireless mobile devices. In addition, the secondary battery is an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (HEV), and the like, which are proposed as solutions for air pollution of existing gasoline vehicles and diesel vehicles using fossil fuels (Plug-In HEV) and the like.

In a small mobile device, one or two or more battery cells are used per device, while a middle- or large-sized battery module such as an automobile is used as a middle- or large-sized battery module in which a plurality of battery cells are electrically connected due to the necessity of a large-

As the mobile devices become thinner, the battery cells used therefor are also required to have a lighter and thinner structure. In addition, since the middle- or large-sized battery module is preferably manufactured with a small size and weight, it is required to have a battery cell which can be filled with a high degree of integration and has a small weight-to-capacity.

In this respect, the use amount of prismatic batteries, pouch-shaped batteries, and the like is increasing recently. In particular, a pouch-shaped battery using an aluminum laminate sheet or the like as an exterior member has recently attracted a lot of attention due to its advantages such as small weight, low manufacturing cost, and easy shape deformation.

1 is a schematic exploded perspective view showing a general structure of a conventional pouch type secondary battery.

1, a pouch type secondary battery 10 is welded to an electrode assembly 30, a plurality of electrode taps 32, 34 extending from the electrode assembly 30, and electrode taps 32, 34 And electrode assemblies 40 and 41, and a battery case 20 that accommodates the electrode assembly.

The electrode assembly 30 is a structure in which a separator is interposed between an anode and a cathode. The electrode tabs 32 and 34 extend from the respective electrode plates of the electrode assembly 30 and the electrode leads 40 and 41 are connected to a plurality of electrode tabs 32 and 34 extending from each electrode plate, Respectively, and a part of the battery case 20 is exposed to the outside. The battery case 20 provides a space for accommodating the electrode assembly 30 and has a pouch shape. 1, a plurality of positive electrode taps 32 and a plurality of negative electrode tabs 34 may be coupled to the electrode leads 40 and 41. In the stacked electrode assembly 30, The upper end is spaced from the electrode assembly 30.

The electrode assembly 30 is housed in the battery case 20 together with the electrolyte solution and the battery case 20 is sealed through a vacuum process for removing the air in the battery compartment in which the electrode assembly 30 is embedded.

The plurality of electrode tabs 31 and 32 extending from the electrode plate of the electrode assembly 30 protrude from the electrode leads 40 and 41 in the form of a fused portion integrally joined by, Respectively. The electrode leads 40 and 41 are exposed to the outside of the battery case 20 at the opposite end to which the electrode tab fused portion is connected.

Since the electrode tabs 31 and 32 are integrally joined to form a fused portion, the inner upper end of the battery case 20 is spaced apart from the upper end surface of the electrode assembly 30 by a predetermined distance.

The electrode assembly 300 is moved to the upper end of the inner surface of the battery case 20 when the battery is dropped to the upper end thereof, that is, toward the electrode leads 40 and 41 or a physical external force is applied to the upper end surface of the secondary battery. Or the upper end thereof is crushed and the fused portion is broken or the electrode tabs 31 and 32 or the electrode leads 40 and 41 of the fused portion are pushed toward the electrode assembly 30 and come into contact with each other to cause an internal short circuit .

In addition, when the battery case 20 is subjected to a process of removing internal air by a vacuum process, the battery case is shrunk to the upper internal space of the battery case 20 in which the fused portion is located, Lt; / RTI >

The wrinkles of the battery case are shrunk and elongated together with shrinkage and expansion of the electrode assembly 30 due to charging and discharging of the secondary battery. When this process is repeated, the wrinkles are easily worn and cracked or torn Which may lead to a serious safety problem in which electrolyte leaks or foreign matter is introduced.

Therefore, there is a high need for a technique capable of fundamentally solving such problems.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

The inventors of the present application have conducted intensive research and various experiments and found that when filling an electrically insulating insulating material in a space between the end of the electrode assembly having the tab-and-lead coupling portion and the battery case receiving portion, It is possible to effectively prevent short-circuiting of the tab-lead coupling portion that may occur due to movement to the upper end of the inner surface of the case or the crushing of the upper end of the battery case, suppressing the generation of wrinkles in the battery case, thereby improving the overall safety of the secondary battery And the present invention has been accomplished.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a rechargeable battery including a rechargeable battery including an electrode assembly, And a space between the end of the electrode assembly having the tab-lead coupling portion and the battery case receiving portion is filled with an electrically insulating insulating material.

In general, an internal short circuit caused by dropping of a secondary battery, application of an external impact, or the like can act as a main cause of explosion or ignition of the battery. This is because when the drop or impact is applied, This is because of the high resistance heat caused by the current flowing in the contact resistance portion. If the internal temperature of the battery rises above a critical value due to the resistance heat, the oxide structure of the cathode active material is collapsed to cause thermal runaway, thereby causing ignition or explosion of the battery.

On the other hand, in the secondary battery according to the present invention, the space between the end portion of the electrode assembly having the tab-lead coupling portion and the battery case receiving portion is filled with an insulating material. Even if the secondary battery is dropped or an external impact is applied, The assembly can be fixed on the battery case and the movement of the electrode assembly can be suppressed.

Further, even when an external force is applied to the upper end of the battery case, the filled insulative material supports the tab-and-lid coupling portion to prevent the tab-lid coupling portion from being crushed together with the upper end of the battery case, It is possible to prevent the safety problem that the lead coupling portion is damaged or the electrode tab is brought into contact with the opposite electrode plate.

Further, in the secondary battery having the structure in which the space between the end portion of the electrode assembly having the tab-and-lead coupling portion and the battery case housing portion is filled with the insulating material, even if a vacuum process is performed during the sealing process of the battery case, It is possible to prevent the end portion of the battery case where the lead coupling portion is located from being shrunk, thereby preventing defects such as wrinkles from being issued.

In one specific example, the electrode tabs in the tab-and-lead joint portion include a welded portion integrally welded with a plurality of electrode tabs projecting from the electrode of the electrode assembly, and an electrode lead is coupled to an end portion of the welded portion . ≪ / RTI >

The tab-and-lid coupling portion may include a bent portion where the welding portion is bent upward at an angle of 30 to 70 degrees with respect to the ground;

A flat portion extending from an end of the electrode lead coupled to an end of the fused portion to an upper surface of the electrode assembly, And

A lead portion extending from the flat portion of the electrode lead and bent in parallel to an upper surface of the electrode assembly at a height corresponding to the upper surface of the electrode assembly,

. ≪ / RTI >

The welded portion including the bent portion bent at a predetermined angle has elasticity even when the electrode assembly moves to the upper end of the inner surface of the case, as compared with the welded portion that is not bent, so that the bent portion of the welded portion has elasticity, There is an advantage that the deformation of the electrode tab can be partially alleviated.

If the bending angle of the bent portion is less than 30 degrees, the above effect can not be expected. If the bending angle exceeds 70 degrees, if the electrode assembly moves to the inner surface upper end of the battery case and an external force is applied to the bent portion, So that the electrode tabs may be detached from the bent portion or may come into contact with the electrode assembly end and short-circuited.

The flat portion is inclined at a bending angle of the bending portion and extends flat to the height of the top surface of the electrode assembly. Accordingly, the tab-to-lead coupling portion has a structure in which the electrode tab protruding from the end of the electrode assembly and the flat portion are perpendicular And may have a substantially triangular shape in cross section.

In one specific example, the secondary battery has a structure in which an insulating material is filled in a space between the electrode tab projecting from the end of the electrode assembly and the flat portion, and between the end portion of the electrode assembly having the tab- The insulating material may be filled in the space in a shape such that the end surfaces of the electrode assemblies and the flat portions are formed on the vertical cross section such that the end surfaces of the secondary batteries where the tab-lead coupling portions are located correspond to the inclination of the flat portions.

That is, in the secondary battery according to the present invention, in the battery case housing portion, a space that is inevitably generated by the tab-and-lid coupling portion, that is, a space between the end portion of the electrode assembly having the tab- And an unnecessary space between the electrode tab and the flat portion is filled with an insulating material so that the secondary battery is dropped in the direction of the tap-lead coupling portion or a physical external force is applied, It is possible to prevent an external force from being applied to the tab-and-lid coupling portion.

The space between the end portion of the electrode assembly and the battery case housing portion is filled with insulating material in a vertical cross section corresponding to the inclination of the flat portion so that the end portion and flat portion of the electrode assembly are filled with insulating material, It may have a flat surface which is inclined at the same angle as the inclination.

The insulating material filled in this manner can protect the tab-lead coupling portion from both sides of the tab-lead coupling portion to protect it from external force and does not form a recess or a stepped structure in the end portion of the secondary battery, It is possible to prevent wrinkles from being generated.

In addition, the insulating material may be filled up to the height of the upper surface of the electrode assembly, parallel to the upper surface of the electrode assembly in a space between the end of the electrode assembly and the battery case receiving portion, Unnecessary wrinkles can be prevented from being generated in the battery case, and even when the battery case is subjected to a vacuum process, wrinkles do not occur in the battery case.

The tab-and-lid coupling portion includes a positive electrode tab-and-lead coupling portion and a negative electrode tab-and-lid coupling portion, and the positive electrode tab-and-lead coupling portion and the negative electrode tab-and-lead coupling portion may be formed side by side on one side of the electrode assembly.

In one specific example, the insulating material is excellent in mechanical rigidity, is not deformed, and is not particularly limited as long as it is an electrically insulating material. However, the insulating material is not limited to polyethylene, polyurethane, polypropylene, polybutylene, polyethylene terephthalate, , Polyimide, and polyimide.

On the other hand, in one specific example, the insulating material may include an insulating fluid cured by heat or air, and an insulating frame for reinforcing the form of the insulating fluid. The insulating frame may be made of the same component or different components as the insulating fluid, and may be a frame that is cured in a specific form in the form of a fluid.

Specifically, the insulating frame may have a structure in which a plurality of protrusions are formed on a straight bar.

This insulating frame can be inserted into a space between the end of the electrode assembly having the tab-and-lead coupling portion and the battery case receiving portion. In this state, when the insulating fluid is filled, the insulating frame is formed on the surface of the insulating frame, And the insulating fluid having fluidity can be partially fixed to the space between the end of the electrode assembly having the tab-and-lead coupling portion and the battery case receiving portion.

Therefore, the insulating material of the present invention is more effectively filled in the space between the end portion of the electrode assembly having the tab-lead coupling portion and the battery case receiving portion, and has an advantage of being easily cured in a specific shape.

In one specific example, the battery case is made of a laminate sheet including a metal layer and a resin layer, and can be sealed by heat-sealing after attaching the electrode assembly to the housing part.

An insulating film is attached to a contact portion between the lead portion and the battery case, and the insulating film can be thermally fused together with the battery case.

For example, the electrode assembly of the present invention may have a stacked structure in which a plurality of electrode plates are laminated with a separator formed thereon, or a plurality of unit cells such as a plurality of pull cells or bi- A stacked / folded structure of an ordered wound structure, and the like, but is not limited thereto.

The secondary battery according to the present invention is not particularly limited as long as the electrode assembly is mounted on the battery case of the laminate sheet, but it is preferably a lithium ion battery or a lithium ion polymer battery.

Such a lithium ion battery or a lithium polymer battery is composed of an anode, a cathode, an electrolyte and the like as is well known in the art, and will be described in detail below.

The anode is prepared, for example, by coating a mixture of a cathode active material, a conductive agent and a binder on a cathode current collector, and then drying the cathode active material. Optionally, a filler may be further added to the mixture.

The cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Lithium manganese oxides such as Li _{1 + x} Mn _{2 -x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ and Cu ₂ V ₂ O ₇ ; A Ni-site type lithium nickel oxide expressed by the formula LiNi _1-x M _x O ₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3); Formula _{LiMn 2-x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with an alkaline earth metal ion; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , and the like. However, the present invention is not limited to these.

The cathode current collector generally has a thickness of 3 to 500 mu m. Such a positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery, and may be formed of a material such as stainless steel, aluminum, nickel, titanium, sintered carbon, or a surface of aluminum or stainless steel Treated with carbon, nickel, titanium, silver or the like may be used. The current collector may have fine irregularities on the surface thereof to increase the adhesive force of the cathode active material, and various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric are possible.

The conductive agent is usually added in an amount of 1 to 50% by weight based on the total weight of the mixture including the cathode active material. Such a conductive agent is not particularly limited as long as it has electrical conductivity without causing a chemical change in the battery, and examples thereof include graphite such as natural graphite and artificial graphite; Carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

The binder is a component that assists in bonding of the active material and the conductive agent to the binder and in binding to the current collector, and is usually added in an amount of 1 to 50% by weight based on the total weight of the mixture containing the cathode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

The filler is optionally used as a component for suppressing the expansion of the anode, and is not particularly limited as long as it is a fibrous material without causing a chemical change in the battery. Examples of the filler include olefin polymers such as polyethylene and polypropylene; Fibrous materials such as glass fibers and carbon fibers are used.

The negative electrode is manufactured by applying a negative electrode material on the negative electrode collector and drying the same, and if necessary, the above-described components may further be included.

The negative electrode collector is generally made to have a thickness of 3 to 500 mu m. Such an anode current collector is not particularly limited as long as it has conductivity without causing chemical change in the battery, and may be formed of a material such as copper, stainless steel, aluminum, nickel, titanium, fired carbon, surface of copper or stainless steel A surface treated with carbon, nickel, titanium, silver or the like, an aluminum-cadmium alloy, or the like can be used. In addition, like the positive electrode collector, fine unevenness can be formed on the surface to enhance the bonding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams and nonwoven fabrics.

The negative electrode material may be, for example, carbon such as non-graphitized carbon or graphite carbon; _{Li x Fe 2 O 3 (0≤x≤1} ), Li x WO 2 (0≤x≤1), Sn x Me 1-x Me 'y O z (Me: Mn, Fe, Pb, Ge; Me' : Metal complex oxides such as Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, Halogen, 0 < x < Lithium metal; Lithium alloy; Silicon-based alloys; Tin alloy; _{SnO, SnO 2, PbO, PbO} 2, Pb 2 O 3, Pb 3 O 4, Sb 2 O 3, Sb 2 O 4, Sb 2 O 5, GeO, GeO 2, Bi 2 O 3, Bi 2 O 4, and Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials and the like can be used.

The non-aqueous electrolyte containing a lithium salt is composed of a solvent for a nonaqueous electrolyte and a lithium salt. Examples of the solvent include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, But are not limited to, lactone, 1,2-dimethoxyethane, tetrahydroxyfuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane, acetonitrile , Nitromethane, methyl formate, methyl acetate, triester phosphate, trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives, Tetrahydrofuran derivatives, ether, methyl pyrophosphate, ethyl propionate and the like can be used.

The lithium salt is a material that is readily soluble in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO 4, LiBF 4, LiB 10 Cl 10, LiPF 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide have.

In some cases, organic solid electrolytes, inorganic solid electrolytes, etc. may be used.

Examples of the organic solid electrolyte include a polymer electrolyte such as a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, Polymers containing ionic dissociation groups, and the like can be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides and sulfates of Li such as Li ₄ SiO ₄ -LiI-LiOH and Li ₃ PO ₄ -Li ₂ S-SiS ₂ can be used.

For the purpose of improving charge / discharge characteristics, flame retardancy, etc., non-aqueous electrolytes may be used in the form of, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride and the like are added It is possible. In some cases, halogen-containing solvents such as carbon tetrachloride and ethylene trifluoride may be further added to impart nonflammability. In order to improve the high-temperature storage characteristics, carbon dioxide gas may be further added. FEC (Fluoro-Ethylene carbonate, PRS (propene sultone), FPC (fluoro-propylene carbonate), and the like.

The present invention also provides a method of manufacturing the secondary battery,

Storing the electrode assembly in the battery case;

Fixing the mold corresponding to the external shape of the electrode assembly to the outer surface of the battery case receiving portion in the end direction of the electrode assembly;

Filling an insulating material between an end portion of the electrode assembly having the tab-and-lead engaging portion and the battery case receiving portion, drying and curing the electrode assembly;

A process in which an electrolyte is injected into the battery case housing portion, and then the battery case is vacuumed and shrunk; And

And sealing the battery case.

That is, the method according to the present invention uses a mold corresponding to the outer shape of the tab-and-lid coupling portion, so that the end front face of the secondary battery is inserted into the space between the end portion of the electrode assembly and the battery case receiving portion, It is possible to fill the insulating material so that it has a flat surface with the same slope as the slope.

The present invention also provides a battery module including at least two secondary batteries, and a device using the battery module as a power source.

As described above, in the secondary battery according to the present invention, the insulating material is filled in the space between the end portion of the electrode assembly having the tab-and-lid coupling portion and the battery case receiving portion, so that even if the secondary battery is dropped or an external impact is applied It is possible to fix the electrode assembly on the battery case and to suppress the movement. Further, the filled insulating material supports the tab-and-lid coupling portion to prevent the tap-lead coupling portion from being crushed together with the battery case top, even when an external force is applied to the upper end of the battery case, It is possible to prevent the safety problem that the lead coupling portion is damaged or the electrode tab is brought into contact with the opposite electrode plate. Further, in the secondary battery having the structure in which the space between the end portion of the electrode assembly having the tab-and-lead coupling portion and the battery case housing portion is filled with the insulating material, even if a vacuum process is performed during the sealing process of the battery case, It is possible to prevent the end portion of the battery case where the lead coupling portion is located from being shrunk, thereby preventing defects such as wrinkles from being issued.

1 is a perspective view illustrating a process of assembling a battery case and an electrode assembly in a conventional secondary battery using a pouch-shaped battery case;
2 is a perspective view of a secondary battery according to an embodiment of the present invention;
3 is a vertical cross-sectional schematic view of the tab-and-lid engagement portion of FIG. 2;
4 is a schematic view of the insulation frame of Fig.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the scope of the present invention is not limited thereto.

FIG. 2 is a perspective view of a secondary battery according to an embodiment of the present invention. FIG. 3 is a vertical sectional view of an enlarged view of the tab lead coupling portion in FIG. 2. FIG. .

Referring to these drawings, the secondary battery includes an electrode assembly 110, an electrolytic solution (not shown), and a battery case 130.

The electrode assembly 110 has a structure in which the positive electrode plate 102 and the negative electrode plate 104 are sequentially stacked with the separator 103 open. A plurality of positive electrode tabs 102 and a plurality of positive electrode tabs 112 protruding from the negative electrode plate 102 and negative electrode tabs are formed at one end 111 of the electrode assembly 110, The tabs are respectively engaged with the electrode leads to form the positive electrode tab-to-lead engaging portions 120 and 120 'and the negative electrode tab-to-lead engaging portion 120'.

The structure of the positive electrode tab-to-lead coupling portion and the negative electrode tab lead coupling portion is the same, and for convenience of explanation, the description will be made with reference to the positive electrode tab-and-lead coupling portion.

The positive electrode tab-lead coupling portion 120 includes a weld portion 122 integrally welded by the positive electrode tabs 112, a flat portion 124 of the electrode lead coupled to an end portion of the weld portion 122, And a lead portion 126 extending from the flat portion 124 and projecting outside the battery case 130.

The lead portion 126 extends from the flat portion 124 and is bent parallel to the upper surface of the electrode assembly 110 at a height corresponding to the upper surface of the electrode assembly 110.

The welded portion 122 forms a bent portion 123 that is bent at an angle of about 45 degrees with respect to the sheet surface and the flat portion 124 of the electrode lead has an angle with an angle of the bent portion 123 Extending from the end of the bonded portion 122 to the height of the upper surface of the electrode assembly 110. Therefore, the positive electrode tab 112 and the flat portion 124 form a triangular shape in a vertical section.

An insulating material 140 is filled in the space 150 between the end 111 of the electrode assembly 110 and the battery case 130. The insulating material 140 is composed of an insulating frame 142 and an insulating fluid 141 in which a plurality of protrusions 146 are formed in a straight line bar 144. The insulating frame 142 is disposed to extend across the positive electrode tab-and-lead engaging portion 120 and the negative electrode tab lead engaging portion 120 'in a space between the end portion 150 of the electrode assembly 110 and the battery case 130 And the insulating fluid 141 is filled in the space 150 between the end portion 111 of the electrode assembly 110 and the battery case receiving portion with the insulating frame 142 as a center.

The space 150 between the electrode assembly end 111 and the battery case 130 is filled with the positive electrode tab 112 and the negative electrode tab and the flat portion 124 And a space formed by the electrode assembly end 111 and the flat portion 124. In addition, Therefore, the insulating material 140 is filled in spaces between the positive and negative electrode tabs and the flat portion 124, and the electrode assembly end portion 111 excluding the positive electrode and negative electrode tab-and-lead coupling portions 120 and 120 ' Insulation material 140 is also filled in space 150 between compartments.

A space 150 between the end 111 of the electrode assembly 110 and the battery case 130 is formed in a vertical section so as to correspond to the inclination of the flat portion 124. The end portion 111 of the electrode assembly 110, The end surface 132 of the rechargeable battery 100 is covered with the insulating material 140 such that the end surface 132 of the rechargeable battery 100 is flush with the flat surface 124 ).

The insulating material 140 filled in this way is also used to protect both the positive and negative tab-and-lead coupling portions 120 and 120 'from external forces on both sides of the positive and negative tab-and-lead coupling portions 120 and 120' And it is possible to prevent unnecessary wrinkles from being generated in the battery case 120 because the secondary battery 150 does not have an indentation or a stepped structure.

The insulating material 140 is filled up to the height of the upper surface of the electrode assembly 110 and is inserted into the space 150 between the end portion 111 of the electrode assembly 110 and the battery case 130, It is possible to prevent unnecessary wrinkles from being generated in the battery case 130 because the upper surface of the secondary battery 100 is not formed with a recess or a stepped structure, Even when the battery case 130 is subjected to a vacuum process, wrinkles are prevented from being generated in the battery case 130.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (19)

A secondary battery in which an electrode assembly is embedded in a housing part of a battery case together with an electrolyte, wherein electrode tabs of the electrode assembly are coupled to an electrode lead to form a tab-lead connection part, And a space between the end portion and the battery case receiving portion is filled with an electrically insulating insulating material. The secondary battery according to claim 1, wherein the electrode assembly is a structure in which a plurality of electrode plates are stacked or a plurality of unit cells in which two or more electrode plates are stacked are wound on a separation film. The electrode assembly according to claim 1, wherein the electrode tabs in the tab-and-lid coupling portion include a plurality of electrode tabs protruding from the electrode assembly, the electrode tabs being integrally joined by welding, And the secondary battery. The connector according to claim 3, wherein the tab-
Wherein the welding portion is bent upward at an angle of 30 to 70 degrees with respect to the ground;
A flat portion extending from an end of the electrode lead coupled to an end of the fused portion to an upper surface of the electrode assembly, And
A lead portion extending from the flat portion of the electrode lead and bent in parallel to an upper surface of the electrode assembly at a height corresponding to the upper surface of the electrode assembly,
And a secondary battery. The secondary battery according to claim 4, wherein the tab-and-lid coupling portion has a triangular shape in vertical cross section between the electrode tab projecting from the end of the electrode assembly and the flat portion. The secondary battery according to any one of claims 1 to 5, wherein the secondary battery has an electrode assembly in which an insulating material is filled in a space between an electrode tab protruding from an end of the electrode assembly and a flat portion, and a tab- A space between the end portion and the battery case receiving portion is filled with an insulating material in a shape of an end portion and a flat portion of the electrode assembly on a vertical section so that the end surface of the secondary battery where the tab- Characterized in that the secondary battery. The secondary battery according to claim 6, wherein the insulating material is filled up to the height of the upper surface of the electrode assembly and parallel to the upper surface of the electrode assembly in a space between the end of the electrode assembly and the battery case receiving part. The battery module of claim 1, wherein the tab-and-lid coupling portion includes a positive electrode tab-and-lead coupling portion and a negative electrode tab-and-lid coupling portion, and the positive electrode tab-lead coupling portion and the negative electrode tab- Wherein the secondary battery comprises a secondary battery. The secondary battery according to claim 1, wherein the insulating material is at least one selected from the group consisting of polyethylene, polyurethane, polypropylene, polybutylene, polyethylene terephthalate, polyethylene butyrate, and polyimide. The secondary battery according to claim 4, wherein an insulating film is attached to a contact portion between the lead portion and the battery case. The secondary battery according to claim 1, wherein the insulating material includes an insulating fluid cured by heat or air, and an insulating frame for reinforcing the shape of the insulating fluid. 12. The secondary battery according to claim 11, wherein the insulating frame has a plurality of projections formed on a straight bar. 12. The battery pack according to claim 11, wherein the insulating frame is filled in the space between the end portion of the electrode assembly having the tab-and-lead connecting portion and the battery case receiving portion, . The secondary battery according to claim 1, wherein the battery case comprises a laminate sheet including a metal layer and a resin layer, and the electrode assembly is sealed to the housing part by thermal fusion after mounting the electrode assembly. The secondary battery according to claim 14, wherein the laminate sheet is an aluminum laminate sheet. The secondary battery according to claim 1, wherein the secondary battery is a lithium ion battery or a lithium ion polymer battery. A method of manufacturing a secondary battery according to claim 1,
Storing the electrode assembly in the battery case;
Fixing the mold corresponding to the external shape of the electrode assembly to the outer surface of the battery case receiving portion in the end direction of the electrode assembly;
Filling an insulating material between an end portion of the electrode assembly having the tab-and-lead engaging portion and the battery case receiving portion, drying and curing the electrode assembly;
A process in which an electrolyte is injected into the battery case housing portion, and then the battery case is vacuumed and shrunk; And
Sealing the battery case;
≪ / RTI > A battery module comprising at least two secondary batteries according to claim 1. A device comprising the battery module according to claim 18 as a power source.

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