KR20180107900A - Secondary Battery Cell with Less Modification of External Form of Battery Case - Google Patents

Abstract

The present invention provides a secondary battery cell. The secondary battery cell includes a main body where an electrode assembly includes electrode plates having mutually opposite polarities and a separator, and an electrode terminal projecting from the end part of the main body. The electrode terminal includes a tab-lid coupling part located inside a battery case together with the electrode assembly, and a terminal connection part protruding outside the battery case. The tab-lid coupling part has a double-curved shape in a direction opposite to each other in an inner space between the end part of the main body and the inner surface of the battery case facing the end part and supports the shape of the inner space.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a secondary battery cell,

The present invention relates to a battery cell having less external deformation of a battery case.

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.

Specifically, it is an object of the present invention to provide a battery case in which the tab-to-lead engaging portion located in the inner space of the battery case has a double-curved shape in the mutually opposing direction so that the space between the end of the electrode assembly and the electrode assembly receiving portion of the battery case And the secondary battery cell is supported by the bending portion of the tab-to-lead coupling portion so that external deformation of the battery case can be suppressed.

In order to accomplish the above object, the present invention provides a secondary battery cell,

A secondary battery cell in which an electrode assembly is built in a battery case together with an electrolyte,

The electrode assembly includes a main body including electrode plates and a separator having mutually opposite polarities, and an electrode terminal protruding from an end of the main body;

The electrode terminal includes a tab-lid coupling portion located inside the battery case together with the electrode assembly, and a terminal connection portion protruding outside the battery case;

The tab-and-lid coupling portion supports the shape of the inner space in a double-folded shape in a direction opposite to each other in an inner space between an end portion of the main body and the inner surface of the battery case facing the end portion.

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 cell according to the present invention, the tab-and-lid coupling portion supports the shape of the inner space in a double-folded shape in the mutually opposing directions in the inner space between the end portion of the main body and the inner surface of the battery case facing the end portion The movement of the electrode assembly on the battery case is restricted even if the secondary battery cell is moved down due to a shock or the like, so that the above-described problem can be solved.

Moreover, even if a vacuum process is performed in the process of sealing the battery case, the tab-and-lid coupling portion can be prevented from shrinking the portion of the battery case, thereby preventing occurrence of defects such as wrinkles.

In one specific example, the battery case may be a pouch-shaped battery case of a laminate sheet including a metal layer and a resin layer.

The battery case further includes a first cover having a first housing part for inserting a part of the body, and a second cover having a second housing part for inserting the remaining part of the body,

Wherein the first space and the second cover have a first space defined between an end portion of the main body and the inner surface of the first cover facing the end portion and a second space facing the end portion of the main body, And a second space between the inner surfaces of the first and second covers. In the battery case having such a structure, the tab-and-lid coupling portion may be located over the first space and the second space.

In the present invention, the tab-and-lid coupling portion includes the electrode tabs and the electrode leads defining the electrode terminals of the secondary battery cell, and means a portion of the electrode terminals located only in the first space and the second space. That is, since the electrode tabs are located in the battery case, they are included in the tab-lead coupling portion, and a part of the electrode leads protrude outward from the battery case as a terminal connection portion. Some of the electrode leads are incorporated into the tab-and-lead joint in the concept of the present invention.

In view of the above, the specific structure of the tab-and-lead coupling portion will be described in detail below.

The tab-and-

Electrode tabs of the same polarity protruding outward from the electrode plates; And

And an electrode lead positioned in the first space and the second space, wherein electrode leads are coupled to the electrode tabs;

A first bending part coupled to an end of the folded electrode tabs such that the electrode leads are oriented from the lower end of the main body toward the upper end and the electrode tabs are bent in the upper direction from the lower end of the main body; And

And a second bent portion in which the electrode lead located in the second space is bent in the lower end direction from the upper end of the main body.

In the present invention, the electrode assembly may have a structure in which electrode plates having mutually opposite polarities are stacked with a separator interposed therebetween, or a plurality of unit cells having a structure in which electrode plates of mutually opposite polarities are stacked with a separator interposed therebetween, A separation film may be wound on the structure.

The lower end of the main body of the electrode assembly means a portion located at the lowermost one of the faces having the widest area in the electrode assembly when the respective faces of the electrode assembly are positioned parallel to the ground.

The term " top of the body " means a portion located at the uppermost one of the faces having the widest area in the electrode assembly when the respective faces of the electrode assembly are positioned parallel to the ground.

In order to facilitate understanding of this structure, when the electrode assembly assumes a structure in which a plurality of electrode plates are stacked, the electrode plate positioned at the lowest position is the lower end of the body, and the electrode plate located at the uppermost position forms the upper end of the body If the separator is formed on the electrode plates and positioned at the outermost portion of the electrode plate, the separator forms the upper and lower ends of the body.

Likewise, after the unit cells are arranged on the separation film, even in the electrode assembly having the wound structure, in the unit cell located at the outermost position, a single electrode positioned at the outermost position and a separation film surrounding the unit cell form the upper and lower ends of the body .

In this structure, the first bent portion is adjacent to the inner surface of the first cover parallel to the lower end of the body to support the shape of the first space, and the second bent portion is adjacent to the inner surface of the second cover, 2 It can support the form of space.

The first bent portion has a structure in which electrode tabs of the same polarity protruding outward from the electrode plates are gathered at a portion adjacent to the lower end of the main body and the assembled electrode tabs are bent at a first angle so as to face the upper end of the main body ;

And may include electrode tabs located in the first space and a portion of the electrode leads.

The first angle may be an angle of 0 to 20 degrees with respect to the plane of the paper, and may be directed toward the end of the main body when the angle of inclination is greater than zero degrees. This is to minimize the space occupied by the tab-lead coupling portion in the first space. However, if the electrode tabs are folded more than the angle of 20 degrees, there is a high possibility of coming into contact with the ends of the main body, and the electrode tabs are bent at a very large angle at the same time, .

When bent at the first angle, the bent portions of the electrode taps are adjacent to the inner surface of the battery case in the first space, so that they are preferably bent to have a rounded shape than the angled shape.

The electrode lead may be bent at a second angle of 150 to 180 degrees with respect to the first angle in a state of extending to the upper end of the main body along the bending direction of the electrode tabs to form the second bent portion of the tab- .

If the second angle is less than 150 degrees, the space occupied by the electrode leads in the second space is increased. If the second angle is more than 180 degrees, the leads are excessively bent and the structural stability is low.

When bent at the second angle, since the bent portion of the electrode lead is adjacent to the inner surface of the battery case in the second space, it is preferable that the electrode lead is bent so as to have a rounder shape than the angled shape.

The electrode lead is integrally connected to the terminal connection portion in a state of extending along the bending direction of the second bent portion,

The second bent portion may include a portion of the electrode lead positioned in the second space and a portion connected to the terminal connection portion and a portion where bending of the electrode lead starts.

In one specific example, a first insulating member is added from the lower end of the main body to the first bent portion so as to insulate the inner surface of the first cover;

The first insulative member may be in close contact with the inner surface of the first cover, which is parallel to the lower end of the main body, while being folded together with the first bent portion.

Further, the second insulating member is attached from the upper end of the main body to the second bent portion so as to ensure the insulating property with respect to the inner surface of the second cover,

The second insulating member may be in close contact with the inner surface of the second cover parallel to the upper end of the main body in a state of being folded together with the second bent portion.

The second insulating member may be added to the electrode lead located between the first bent portion and the second bent portion.

The first insulating member and the second insulating member may be an insulating tape or a separating film.

The insulating tape may be a polymeric insulating tape, a rubber tape, a black tape, or the like, but is not limited thereto.

The separation film may be an olefin-based polymer such as polypropylene, which is chemically resistant and hydrophobic; A sheet made of glass fiber or polyethylene, or a nonwoven fabric.

Further, the separation film may be a safety-reinforcing separator (SRS) separation membrane of organic / inorganic complex porous.

The SRS separation membrane may have a uniform pore structure formed by the interstitial volume between the inorganic particles, which is an active layer component, in addition to the pore structure contained in the separation membrane substrate itself, and the pores may cause external impact applied to the electrode assembly The lithium ion can be smoothly moved through the pores, a large amount of electrolyte can be filled, and a high impregnation rate can be exhibited, so that the performance of the battery can be improved at the same time.

Meanwhile, the battery cell of the present invention is not particularly limited in its kind, but specific examples thereof include a lithium ion (Li-ion) secondary battery having advantages of high energy density, discharge voltage and output stability, lithium polymer Li a lithium secondary battery, or a lithium-ion polymer secondary battery.

Generally, a lithium secondary battery is composed of a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte containing a lithium salt.

The positive electrode is prepared, for example, by coating a mixture of a positive electrode active material, a conductive material and a binder on a positive electrode current collector and / or an extended current collector, and then drying the resultant. Optionally, do.

The cathode current collector and / or the elongated current collector are generally made to have a thickness of 3 to 500 micrometers. The positive electrode current collector and the elongate current collector are not particularly limited as long as they have high conductivity without causing a chemical change in the battery, and examples thereof include stainless steel, aluminum, nickel, titanium, A surface treated with carbon, nickel, titanium, or silver on the surface of stainless steel may be used. The anode current collector and the elongate current collector may have various shapes such as a film, a sheet, a foil, a net, a porous body, a foam, a nonwoven fabric, or the like by forming fine irregularities on the surface thereof to increase the adhesive force of the cathode active material.

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 conductive material is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture including the cathode active material. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite such as natural graphite or 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 which assists in bonding of the active material and the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 30% 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 and drying a negative electrode active material on the negative electrode current collector and / or the extended current collector, and may optionally further include the components as described above.

The cathode current collector and / or the extension current collector are generally made to a thickness of 3 to 500 micrometers. The negative electrode current collector and / or the elongated current collector are not particularly limited as long as they have electrical conductivity without causing chemical changes in the battery, and examples thereof include copper, stainless steel, aluminum, nickel, titanium, Surface treated with carbon, nickel, titanium, silver or the like on the surface of copper or stainless steel, 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.

Examples of the negative electrode active material include carbon such as non-graphitized carbon and 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 &lt; 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 separation membrane is interposed between the anode and the cathode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the membrane is generally 0.01 to 10 micrometers, and the thickness is generally 5 to 300 micrometers. Such separation membranes include, for example, olefinic polymers such as polypropylene, which are chemically resistant and hydrophobic; A sheet or nonwoven fabric made of glass fiber, polyethylene or the like is used. When a solid electrolyte such as a polymer is used as an electrolyte, the solid electrolyte may also serve as a separation membrane.

The electrolytic solution may be a non-aqueous electrolytic solution containing a lithium salt, and is composed of a non-aqueous electrolytic solution and a lithium salt. As the non-aqueous electrolyte, non-aqueous organic solvents, organic solid electrolytes, inorganic solid electrolytes, and the like are used, but the present invention is not limited thereto.

Examples of the non-aqueous organic solvent include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma -Butyrolactone, 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 Nonionic organic solvents such as tetrahydrofuran derivatives, ethers, methyl pyrophosphate, ethyl propionate and the like can 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.

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.

For the purpose of improving the charge-discharge characteristics and the flame retardancy, the nonaqueous electrolytic solution is preferably a solution prepared by dissolving or dispersing in a solvent such as pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, hexaphosphoric triamide, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride and the like may be added have. 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), and the like.

In one specific _{example, LiPF 6, LiClO 4, LiBF} 4, LiN (SO 2 CF 3) 2 , such as a lithium salt, a highly dielectric solvent of DEC, DMC or EMC Fig solvent cyclic carbonate and a low viscosity of the EC or PC of And then adding it to a mixed solvent of linear carbonate to prepare a lithium salt-containing non-aqueous electrolyte.

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 present invention also provides a battery pack including at least one battery cell and a device including the battery pack.

As described above, in the secondary battery cell according to the present invention, the tab-and-lid coupling portion is formed in a double-folded shape in the direction opposite to each other in the internal space between the end portion of the main body and the inner surface of the battery case facing the end portion, And the movement of the electrode assembly on the battery case is limited even if the secondary battery cell moves down due to impact or impact.

1 is a schematic view of a battery cell according to the prior art;
2 is a side schematic view of a battery cell according to one embodiment of the present invention;
FIG. 3 is a schematic view of an enlarged vertical section of the region A in FIG. 2; FIG.

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

FIG. 2 is a schematic side view of a battery cell according to an embodiment of the present invention, and FIG. 3 is a schematic enlarged view of a vertical section of the battery cell of FIG.

Referring to FIGS. 2 and 3, the secondary battery cell 100 has a structure in which the electrode assembly 110 is embedded in the battery case 200 together with the electrolyte solution.

The electrode assembly 110 includes a main body 112 including electrode plates and a separator having mutually opposite polarities and an electrode terminal 130 protruding from the end side of the main body 112.

The electrode terminal 130 includes a tab-lead coupling portion 114 located inside the battery case 200 together with the electrode assembly 110 and a terminal connection portion 119 protruding outside the battery case 200.

The protrusion of the terminal connection portion 119 to the outside of the battery case 200 protrudes from the internal space of the battery case 200 in which the electrode assembly 110 is housed. A first space 212 into which the main body 112 is inserted and a portion of the electrode terminal 130 located outside the second space 222.

The tab-and-lid coupling portion 114 is formed in a double-curved shape in mutually opposite directions in an internal space between the end portion c of the main body 112 and the inner surface of the battery case 200 facing the end portion c. It supports the shape of the inner space.

The battery case 200 is a pouch-shaped battery case 200 of a laminated sheet including a metal layer and a resin layer. The battery case 200 includes a first cover 210 having a first accommodating portion for inserting a part of the main body 112, And a second cover 220 having a second accommodating portion for inserting the remaining portion of the main body 112 therein.

The first cover 210 and the second cover 220 are engaged with each other in a state where the first cover 210 and the second cover 220 are engaged with each other A first space 212 between the inner surfaces of the cover 210 and a second space 222 between the end portion c of the main body 112 and the inner surface of the second cover 220 facing the end portion c, .

In the battery case 200 having such a structure, the tab-and-lid coupling portion 114 is positioned over the first space 212 and the second space 222.

The tab-and-lid coupling portion 114 includes the electrode tabs 117 defining the electrode terminals 130 of the secondary battery cell 100 and the electrode leads 118. The tab- And a portion of the electrode terminal 130 located only in the second space 222.

That is, the electrode tabs 117 are located in the battery case 200, and thus are included in the tab-and-lid coupling portion 114. The electrode leads 118 are partially connected to the battery case 200 as terminal connection portions 119, A portion of the electrode leads 118 located in the first space 212 and the second space 222 except the first space 212 are incorporated into the tab-and-lead coupling portion 114 in the concept of the present invention.

The tab-and-lid coupling portion 114 includes electrode tabs 117 of the same polarity protruding outward from the electrode plates and an electrode lead 118 located in the first space 212 and the second space 222 . The tab-and-lid coupling portion 114 is structured such that the electrode leads 118 are coupled to the electrode tabs 117. Such bonding may be, for example, welding, soldering, or the like.

The electrode lead 118 is electrically connected to the end portion of the main body 112 at the end of the bent electrode tabs 117 in a state where the electrode tabs 117 are bent in the upper direction from the lower end of the main body 112 And a first bent portion 101 which is coupled to the upper end in the lower end and is located in the first space 212.

The tab-and-lid coupling portion 114 also includes a second bend portion 102 in which the electrode lead 118 located in the second space 222 is bent downward at the top of the main body 112.

The first bent portion 101 is formed such that the electrode taps 117 of the same polarity protruding outward from the electrode plates are gathered at a portion adjacent to the lower end of the main body 112, And includes a portion of the electrode tabs 117 and the electrode leads 118 that are located in the first space 212. The electrode tabs 117 and the electrode tabs 118 are formed in the first space 212, Although not separately shown in the drawings, the first angle is approximately 15 degrees in Fig.

Here, since the bent portion of the first bent portion 101 is adjacent to the inner surface of the battery case 200 in the first space 212, the bent portion is bent so as to have a rounded shape.

The electrode lead 118 extends from the electrode tabs 117 to the upper end of the main body 112 along the bending direction of the electrode tabs 117 and is bent at a second angle of about 180 degrees with respect to the first angle, Thereby forming the second bent portion 102 of the portion 114.

The electrode lead 118 is also integrally connected to the terminal connection portion 119 in a state of extending along the bending direction of the second bent portion 102.

Therefore, the second bent portion 102 can be understood as a portion of the electrode lead 118 located in the second space 222, and the portion where the electrode lead 118 begins to be bent and the terminal connecting portion 119 ) To the point immediately before being connected to the concept.

The above structure is such that the first bent portion 101 is adjacent to the inner surface of the first cover 210 parallel to the lower end of the main body 112 to support the shape of the first space 212 and the second bent portion 102 Is adjacent to the inner surface of the second cover 220 parallel to the upper end of the main body 112 to support the shape of the second space 222.

Therefore, in the secondary battery cell 100 according to the present invention, the tab-and-lid coupling portion 114 is formed in the inner space between the end portion of the main body 112 and the inner surface of the battery case 200 facing the end portion, The shape of the inner space is doubly bent so that the movement of the electrode assembly 110 on the battery case 200 is restricted even if the secondary battery cell 100 moves down due to impact or impact, Can be eliminated.

The first insulating member 310 is attached to the first bent portion 101 from the lower end of the body 112 so that the insulating property of the inner surface of the first cover 210 is ensured.

The first insulating member 310 is in close contact with the inner surface of the first cover 210 parallel to the lower end of the main body 112 in a bent state together with the first bent portion 101.

A second insulating member 320 is attached from the upper end of the main body 112 to the second bent portion 102 so as to ensure insulation from the inner surface of the second cover 220.

The second insulating member 320 is in close contact with the inner surface of the second cover 220 parallel to the upper end of the main body 112 in a state bent together with the second bent portion 102.

The second insulating member 320 is further added to the electrode lead 118 located between the first bent portion 101 and the second bent portion 102. The second insulating member 320 is electrically connected to the electrode lead 118 located between the first bent portion 101 and the second bent portion 102, The electrode lead 117 is further provided on the electrode tab 117 facing the electrode lead 118 in order to secure insulation of the portion where the lead 118 and the electrode tab 117 are opposed to each other.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (15)

A secondary battery cell in which an electrode assembly is built in a battery case together with an electrolyte,
The electrode assembly includes a main body including electrode plates and a separator having mutually opposite polarities, and an electrode terminal protruding from an end of the main body;
The electrode terminal includes a tab-lid coupling portion located inside the battery case together with the electrode assembly, and a terminal connection portion protruding outside the battery case;
Wherein the tab-and-lid coupling portion supports the shape of the internal space in a double-curved shape in a direction opposite to each other in an internal space between an end portion of the main body and the inner surface of the battery case facing the end portion. . The method according to claim 1,
The battery case includes a first cover having a first housing part for inserting a part of the body and a second cover having a second housing part for inserting the remaining part of the body,
Wherein the first space and the second cover have a first space defined between an end portion of the main body and the inner surface of the first cover facing the end portion and a second space facing the end portion of the main body, 2 a second space between the inner surfaces of the cover;
Wherein the tab-and-lid coupling portion is located over the first space and the second space. The connector according to claim 2, wherein the tab-
Electrode tabs of the same polarity protruding outward from the electrode plates; And
And an electrode lead positioned in the first space and the second space, wherein electrode leads are coupled to the electrode tabs;
A first bending part coupled to an end of the folded electrode tabs such that the electrode leads are oriented from the lower end of the main body toward the upper end and the electrode tabs are bent in the upper direction from the lower end of the main body; And
A second bent portion in which an electrode lead located in the second space is bent in a bottom direction from an upper end of the main body;
And the second battery cell. 4. The device according to claim 3, wherein the first bending portion is adjacent to the inner surface of the first cover parallel to the lower end of the main body and supports the shape of the first space, and the second bending portion is formed on the inner surface of the second cover The second space being adjacent to the second space. [5] The apparatus of claim 3, wherein the first bent portion has a first angle such that electrode tabs of the same polarity protruding outward from the electrode plates are gathered at a position adjacent to the lower end of the main body, Lt; / RTI &gt;
Wherein the electrode tabs and the electrode tabs are located in the first space. [6] The method of claim 5, wherein the electrode lead is bent at a second angle of 150 to 180 degrees with respect to the first angle, extending along the bending direction of the electrode taps to the upper end of the main body, And the bent portion is formed in the bent portion. [7] The apparatus of claim 6, wherein the electrode lead is integrally connected to the terminal connection portion in a state of extending along the bending direction of the second bent portion,
Wherein the second bent portion includes a portion of the electrode lead positioned in the second space and a portion connected to the terminal connection portion and a portion where the electrode lead starts bending. The secondary battery cell according to claim 5, wherein the first angle is an angle of 0 to 20 degrees with respect to a perpendicular to the ground. 5. The connector according to claim 4, wherein a first insulative member is added from the lower end of the main body to the first bent portion so as to insulate the inner surface of the first cover;
Wherein the first insulative member is in close contact with the inner surface of the first cover parallel to the lower end of the main body in a bent state together with the first bent portion. The connector according to claim 4, wherein a second insulative member is added from the upper end of the main body to the second bent portion so as to insulate the inner surface of the second cover,
Wherein the second insulative member is in close contact with an inner surface of a second cover parallel to an upper end of the main body in a bent state together with the second bent portion. The secondary battery cell according to claim 10, wherein the second insulating member is further added to an electrode lead disposed between the first bent portion and the second bent portion. The secondary battery cell according to any one of claims 9 to 11, wherein the first insulating member and the second insulating member are an insulating tape or a separating film. [5] The apparatus of claim 3, wherein the lower end of the body is positioned at the lowermost one of the faces having the widest area in the electrode assembly when each side of the electrode assembly is positioned parallel to the ground;
Wherein the upper end of the main body is a portion located at the uppermost one of the faces having the widest area in the electrode assembly when the respective faces of the electrode assembly are positioned parallel to the ground. 2. The electrode assembly according to claim 1, wherein the electrode assembly has a structure in which electrode plates having mutually opposite polarities are stacked with a separator interposed therebetween, or a plurality of unit cells having a structure in which electrode plates having mutually opposite polarities are stacked with a separator interposed therebetween are separated Wherein the separator is a structure in which the separator is wound on a film while being arranged on a film. The secondary battery cell according to claim 1, wherein the battery case is a pouch-shaped battery case of a laminate sheet including a metal layer and a resin layer.

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