KR20080013212A - Rechargeable battery - Google Patents

Abstract

A secondary battery is provided to increase the bonding force between a bare cell and a lead plate by fixing the lead plate to a cap plate with a screw, and to improve the shear stress of a molding resin portion against external force. A secondary battery comprises: a bare cell including an electrode assembly having a cathode plate, an anode plate and a separator, a casing for receiving the electrode assembly and an electrolyte, and a cap assembly including a cap assembly having a cap plate(920) for sealing the opening of the casing; a protection circuit module connected electrically to the cap plate through a lead plate(1060,1070); and a fixing member for fixing one surface of the lead plate to the cap plate.

Description

Rechargeable Battery

1 is a schematic partially exploded perspective view of an example of a conventional secondary battery in a stage before being bonded by a molding resin.

2 is a perspective view showing a conventional secondary battery bonded to a molding resin.

3 is an exploded perspective view showing a state before the secondary battery according to the first embodiment of the present invention is bonded by a molding resin.

4 is a perspective view illustrating a state before a bare cell and a protection circuit module are connected in a secondary battery according to a first exemplary embodiment of the present invention.

5 is a cross-sectional view taken along a line A-A of a cap assembly portion of a bare cell to which a protection circuit module is not connected in the secondary battery of FIG. 4.

6 is a cross-sectional view taken along line B-B of FIG. 4 of a battery in which a bare cell and a protection circuit module of FIG. 4 are connected to each other and a molding resin is bonded therebetween.

7 is a perspective view illustrating a state before a bare cell and a protection circuit module are connected in a secondary battery according to a second exemplary embodiment of the present invention.

FIG. 8 is a cross-sectional view taken along a line C-C of a cap assembly of a bare cell to which a protection circuit module is not connected in the secondary battery of FIG. 7.

9 is a cross-sectional view of a cap assembly of a bare cell to which a protection circuit module is not connected in a secondary battery according to a third exemplary embodiment of the present invention.

10 is a cross-sectional view of a cap assembly part of a bare cell to which a protection circuit module is not connected in a secondary battery according to a fourth exemplary embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

100, 500: bare cell 120, 520, 720, 920: cap plate

130, 530, 730, 930: Gasket 140, 540, 730, 940: Electrode terminal

150, 550, 750, 750: Insulation plate 160, 560, 760, 760: Insulation plate

170, 570, 770, 970: stopper 192, 592, 792, 992: groove for fixing member

210: protrusion 220: holder

260, 660, 860, 1060: anode lead plate

262, 662: bottom

262a, 662a, 862a, 1062a: hole for fixing member

264, 664, 864, 1064: sidewalls

270, 670, 870, 1070: cathode lead plate

280, 680, 880, 1080: fixing member

282, 682, 882, 1082: head of the fixing member

284, 684, 884, 1084: body part of the fixing member

300: protection circuit module 360: positive connection terminal

370: negative electrode connecting terminal 400: molded resin portion

594, 794, 994: grooves for support members 620, 820, 1020: support members

622, 822, 1022: head of support member 624, 824, 1024: body of support member

625, 825, 1025: stepped surfaces 883, 1063: support groove of the fixing member

1023: support groove of the support member

The present invention relates to a secondary battery, and more particularly, to a secondary battery capable of increasing the bonding force between the bare cell and the lead plate using a screw and increasing the shear stress of the molded resin part against external force.

Secondary batteries have been researched and developed in recent years due to the possibility of recharging and miniaturization and large capacity. Representative examples of the recent development and use include nickel-hydrogen (Ni-MH) batteries, lithium (Li) batteries and lithium-ion (Li-ion) batteries.

Most of the bare cells in these secondary batteries contain an electrode assembly consisting of a positive electrode, a negative electrode, and a separator in a can, which is usually made of aluminum or an aluminum alloy, the can is closed with a cap assembly, and an electrolyte is injected into the can. And by sealing. When the can is formed of aluminum or an aluminum alloy, the light property of aluminum can be used to reduce the weight of the battery, and there is an advantage such that it does not corrode even when used for a long time under high voltage.

The bare cell is typically provided with an electrode terminal insulated from the peripheral portion at the top thereof, and the electrode terminal is connected to one electrode of the electrode assembly in the bare cell to form a positive terminal or a negative terminal of the battery. The can itself has a polarity opposite to that of the electrode terminal.

The electrode terminals of the sealed secondary battery bare cell are electrically connected to terminals of safety devices such as a positive temperature coefficient (PTC) element, a thermal fuse, and a protective circuit module. Safety devices are connected to the positive and negative electrodes of the bare cell to prevent the risk of battery rupture by cutting off the current when problems such as battery overheating or excessive voltage surge due to excessive charge and discharge occur.

Usually, it is not easy in the form of a bare cell, and material to directly connect and electrically connect the electrode of a bare cell, and electrical terminals, such as a protective circuit module. Thus, a conductor structure called a lead plate serves to connect the positive and negative electrodes of the battery and the electrical terminals of safety devices such as protective circuit modules. As a material of the lead plate, nickel or a nickel alloy is usually used, but stainless steel plated with nickel is used. In this way, the bare cell and the protection circuit module are electrically connected by welding with the lead plate.

The safety device and the bare cell may be stored in a separate pack in an electrically connected state, or may be covered with a molten resin to fill a space to form a battery pack.

1 is a schematic partially exploded perspective view of an example of a conventional secondary battery in a step before being bonded by a molding resin, and FIG. 2 is a perspective view showing a conventional secondary battery in a state bonded by the molding resin.

1 and 2, in a conventional secondary battery, a protection circuit board 30 is disposed side by side on a surface on which electrode terminals 11 and 12 of a bare cell 10 are formed. As shown in FIG. 2, the gap between the bare cell 10 and the protective circuit board 30 is filled with a molding resin. When filled with the molding resin, the molding resin may cover the outer surface of the protective circuit board, but the external input / output terminals 31 and 32 of the battery are exposed to the outside.

The bare cell 10 is provided with a positive terminal 11 and a negative terminal 12 on the side facing the protective circuit board 30. The positive terminal 11 may be a cap plate itself made of aluminum or an aluminum alloy or a nickel-containing metal plate bonded on the cap plate. The negative electrode terminal 12 is a terminal projecting in the shape of a protrusion on the cap plate, and is electrically isolated from the cap plate 13 by an insulator gasket interposed therebetween.

The protective circuit board 30 has a circuit formed on a panel made of resin, and external input / output terminals 31 and 32 are formed on the outer surface thereof. The substrate 30 has substantially the same size and shape as the opposing surface (cap plate surface) of the bare cell 10.

The circuit part 35 and the connection terminals 36 and 37 are provided on the rear surface of the protective circuit board 30 on which the external input / output terminals 31 and 32 are formed, that is, the inner surface. The circuit section 35 is provided with a protection circuit for protecting the battery from overcharge and overdischarge during charge and discharge. The circuit section 35 and the respective external input / output terminals 31 and 32 are electrically connected by a conductive structure passing through the protective circuit board 30.

Lead plates 41 and 42, an insulating plate 43, and the like are disposed between the bare cell 10 and the protection circuit board 30. The lead plates 41 and 42 are usually made of nickel and are formed for electrical connection between the cap plate 13 and the connection terminals 36 and 37 of the protective circuit board 30 and have a 'L' shape or a planar structure. . The lead plates 41 and 42 and the connection terminals 36 and 37 are generally joined by spot welding. Here, the lead plates 41 and 42 are divided into an anode lead plate 41 serving as an anode and a cathode lead plate 42 serving as a cathode. In addition, the connection terminals 36 and 37 are also divided into a positive connection terminal 36 serving as a positive electrode and a negative connection terminal 37 serving as a negative electrode. In this example, a breaker or the like is separately formed in the negative lead plate 42 between the protective circuit board 30 and the negative electrode terminal 12. In this case, the breaker is excluded from the circuit portion 35 of the protective circuit board. The insulating plate 43 is provided to insulate between the negative electrode lead plate 42 connected to the negative electrode terminal 12 and the cap plate 13 serving as the positive electrode. The insulating plate 43 is made of an adhesive tape material so that the negative lead plate 42 is attached to and fixed to the bare cell 10.

The protective circuit board 30 and other battery accessories are fixedly coupled to the bare cell 10 by the molding resin part 20, as shown in FIG. Here, the external input / output terminals 31 and 32 are formed to be exposed on the upper surface of the molded resin portion 20.

In the conventional secondary battery having the above configuration, each of the lead plates 41 and 42, which is a medium for electrically connecting the bare cell 10 and the protection circuit board 30, has a positive terminal of the bare cell 10. When connected to each of the cap plate 13 and the negative electrode terminal 12 serving as (11), the negative lead plate 42 is connected to the negative electrode terminal 12 while being attached to the insulating plate 43 made of adhesive tape material The anode lead plate 41 is coupled to the cap plate 13 by laser welding and electrically connected thereto. In this way, the positive lead plate 41 and the negative lead plate 42 are electrically connected to the bare cell 10.

However, laser welding, which is performed to couple the anode lead plate 42 to the cap plate 13 of the bare cell 10, is performed in the form of spot welding, in which the output of the laser beam for welding is strictly controlled. If not, problems are likely to occur. For example, if the output of the laser beam is weak, only the bottom surface of the anode lead plate 41 in contact with the cap plate 13 is partially melted, and the cap plate 13 positioned below the bottom surface is not sufficiently melted, resulting in poor welding strength. Easy to lose In this case, it is easy to see a case where the anode lead plate 41 falls from the bare cell 10 during a bending test or a twisting test in a subsequent process or a battery pack. Since the welding strength draws a statistical distribution to some extent, in order to sufficiently melt the cap plate 13 below the bottom of the anode lead plate 41, the laser beam output must be large and the laser beam output loss is excessive. In addition, even when the laser beam output is excessive, problems such as damage to the welded portion of the cap plate 13 may occur. When the problem of the breakage of the welded portion of the cap plate 13 is increased and a hole is formed in the cap plate 13, a problem may occur in that the electrolyte inside the bare cell 10 may leak out.

In addition, in the conventional secondary battery, when the bare cell 10, the protective circuit board 30, and other battery parts are formed into an inner pack battery using a molding resin, the protective circuit board 30 is formed in the inner pack battery state. The molded resin part 20 which fixedly couples the battery parts to the bare cell 10 is different in material from the bare cell 10 made of metal such as the cap plate 13 or the can, and the contact area thereof is not large. There is a problem that it is vulnerable to torsion or bending caused by external force. Therefore, there is a problem that the molding resin portion 20 may be separated from the cap plate 13.

The present invention is to solve the above-mentioned problems, to provide a secondary battery that can be fixed to the cap plate by a screw to the lead plate to increase the bonding force between the bare cell and the lead plate and to increase the shear stress of the molded resin portion against external force For the purpose of

The secondary battery of the present invention for achieving the above object comprises a electrode assembly comprising a positive electrode plate, a negative electrode plate and a separator, a case for receiving the electrode assembly and the electrolyte, a cap plate and a cap assembly for closing the opening of the case A bare cell provided; A protection circuit module electrically connected to the cap plate through a lead plate; And a fixing member for fixing one surface of the lead plate to the cap plate.

The molding resin unit may further include a cap plate region including the protection circuit module.

The other surface of the lead plate may extend in the direction of the protection circuit module at a portion of the peripheral portion of the one surface and may be coupled to the connection terminal of the protection circuit module by welding.

A fixing member hole may be formed in a part of one surface of the lead plate.

The fixing member may be coupled to the cap plate through a hole for the fixing member of the lead plate.

The fixing member may be a screw having a head portion extending over one surface of the lead plate and a body portion connected to the head portion with a screw thread on an outer edge thereof and fitted to the cap plate.

The head of the fixing member may have a support groove formed on the outer surface.

The cap plate may have a fixing member groove so that the body portion of the fixing member may be coupled.

The inner circumference of the groove for the fixing member may be formed in a shape corresponding to the thread of the body portion of the fixing member.

A support member may be further installed on the cap plate of the cap assembly.

The support member may include a protrusion and a holder fitted to the protrusion.

The support member may be a screw having a head portion spaced upward from the upper surface of the cap plate, and a body portion connected to the head portion with a screw thread on an outer circumference thereof and partly fitted to the cap plate.

The head of the support member may have a support groove formed on the outer surface.

The cap plate may have a groove for the support member so that the body portion of the support member may be coupled.

The inner circumference of the groove for the support member may be formed in a shape corresponding to the screw thread of the body portion.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 is an exploded perspective view illustrating a state before the secondary battery according to the first embodiment of the present invention is bonded by a molding resin, and FIG. 4 is a bare cell and a protection circuit module in the secondary battery according to the first embodiment of the present invention. This is a perspective view showing a state before the connection, Figure 5 is a cross-sectional view taken along the line AA of the cap assembly portion of the bare cell is not connected to the protective circuit module of Figure 4, Figure 6 is the bare cell of Figure 4 4 is a cross-sectional view taken along a line BB of FIG. 4, with the protection circuit module connected and a molding resin bonded therebetween.

Referring to FIG. 3, the rechargeable battery according to the first exemplary embodiment of the present invention is coupled to a case 111, an electrode assembly 112 accommodated in the case 111, and an open upper end of the case 111. It comprises a bare cell 100 and a protection circuit module 300 having a cap assembly for sealing the top of the case.

The electrode assembly 112 is formed by winding a laminate of a positive electrode plate 113, a separator 114, a negative electrode plate 115, and a separator formed in a thin plate or film shape in a spiral shape.

The positive electrode plate 113 includes a positive electrode current collector made of a thin metal plate having excellent conductivity, such as aluminum foil, and a positive electrode active material layer composed mainly of lithium-based oxides coated on both surfaces thereof. The positive electrode tab 113 is electrically connected to a region of the positive electrode current collector in which the positive electrode active material layer is not formed.

The negative electrode plate 115 includes a negative electrode current collector made of a conductive metal plate, such as a copper foil, and a negative electrode active material layer mainly composed of a carbon material coated on both surfaces thereof. The negative electrode tab 117 is also connected to the negative electrode plate 115 in the region of the negative electrode current collector in which the negative electrode active material layer is not formed.

The positive electrode plate 113 and the negative electrode plate 115, the positive electrode tab 116, and the negative electrode tab 117 may be arranged with different polarities, and the positive electrode tab 116 and the negative electrode tab 117 may be disposed from the electrode assembly 112. Insulating tapes 118 are wound around the lead portions to prevent short circuits between the two electrode plates 113 and 115.

The separator 114 is made of polyethylene, polypropylene, or a copolymer of polyethylene and polypropylene. Separator 114 is formed to be wider than the positive electrode plate 113 and the negative electrode plate 115 is advantageous to prevent short circuit between the electrode plates.

The case 111 is formed of aluminum or an aluminum alloy having a substantially rectangular parallelepiped shape. The electrode assembly 112 is accommodated through the open top of the case 111 so that the case 111 serves as a container of the electrode assembly 112 and an electrolyte (not shown). The case 111 can itself perform a terminal role. In the first embodiment of the present invention, the case 111 serves as a positive electrode terminal, the cap plate 120 of the cap assembly coupled to the case 111 also serves as a positive electrode terminal. Of course, according to the embodiment, the case and the cap plate may serve as the negative terminal.

The cap assembly is provided with a flat cap plate 120 having a size and shape corresponding to the open upper end of the case 111. The through hole 121 for the terminal is formed in the center portion of the cap plate 120 to allow the electrode terminal 140 to pass therethrough. A tube-shaped gasket 130 is installed outside the electrode terminal 140 penetrating the center portion of the cap plate 120 to electrically insulate the electrode terminal 140 from the cap plate 120. The insulation plate 150 is disposed on the lower surface of the cap plate 120 near the center of the cap plate 120 and the through hole 121 for the terminal. The terminal plate 160 is installed on the bottom surface of the insulating plate 150.

The electrode terminal 140 is inserted through the terminal through hole 121 in a state in which the gasket 130 surrounds the outer circumferential surface. Here, the electrode terminal 140 serves as a negative terminal having a polarity opposite to that of the positive terminal of the case 111 and the cap assembly. The bottom portion of the electrode terminal 140 is electrically connected to the terminal plate 160 with the insulating plate 150 interposed therebetween.

The positive electrode tab 116 drawn from the positive electrode 113 is welded to the lower surface of the cap plate 120, and the negative electrode tab 117 drawn from the negative electrode 115 is folded in a meandering state to the lower end of the electrode terminal 140. do.

On the other hand, an insulating case 180 is provided on the upper surface of the electrode assembly 112 to electrically cover the electrode assembly 112 and the cap assembly and at the same time to cover the upper end of the electrode assembly 112. . The insulating case 180 is an insulating polymer resin, preferably made of polypropylene. The negative electrode tab hole 181 is formed in the center portion of the insulating case 180 to allow the negative electrode tab 117 to pass therethrough, and the positive electrode tab hole 182 is formed at one side thereof to allow the positive electrode tab 116 to pass therethrough. In addition, the electrolyte passing hole 183 is formed at the other side of the insulating case 180. The electrolyte passage hole may not be formed separately.

An electrolyte injection hole 122 is formed at one side of the cap plate 120. After the electrolyte is injected into the electrolyte injection hole 122, a stopper 170 is installed to seal the electrolyte injection hole. The stopper 170 is formed by placing a ball-shaped base material made of aluminum or an aluminum-containing metal on the electrolyte injection hole 122 and mechanically indenting the electrolyte injection hole 212. The plug 170 is welded to the cap plate 120 around the electrolyte injection hole 122 for sealing. For ease of welding, the stopper 170 is preferably formed of the same material as the cap plate 120.

In addition, a support member having a protrusion coupled to the protrusion 210 and the protrusion 210 is formed at the other side of the cap plate 120.

The protrusion 210 is in the form of a column forming a rectangular quadrangle when viewed from above. The bond strength between the protrusion 210 and the cap plate 120 should be high in order for the protrusion 210 to serve as a support that resists external force. Therefore, the protrusion 210 is preferably made of the same material as the cap plate 120 and integrally molded at the time of molding, and when separately formed, the protrusion 210 should have a material that can be welded with sufficient strength to the cap plate 120.

The holder 220 is coupled to the protrusion 210. The holder 220 has a groove formed in the center when viewed from above, so that the protrusion 210 can be inserted without extra when inserted. Therefore, even if a force is applied to the holder 220 in a state where the holder 220 is fitted to the protrusion 210, the holder 220 is not easily separated from the protrusion 210. The holder 220 may be coupled in such a way as to simply cover the protrusion 210 to simplify the process, but is preferably welded to bond with more certain strength. When combined with the protrusion 210 by welding, the holder 220 is also preferably made of the same material as or similar to the protrusion 210. The support member including the protrusion 210 and the holder 220 is particularly provided between the bare cell 100 and the protective circuit module 300 to fix the protective circuit module 300 to the bare cell 100 in a fixed manner. In the secondary battery including a resin molded part (not shown) formed by filling the resin serves to increase the shear stress of the resin molded part against an external force such as a bending test or a twisting test.

With the above structure, the bare cell battery 100 is completed by welding the periphery of the cap plate 120 and the sidewall of the can 111.

The completed bare cell 100 is electrically connected to the protection circuit module 300 through the lead plates 260 and 270.

The lead plates 260 and 270 are divided into an anode lead plate 260 serving as an anode and a cathode lead plate 270 serving as a cathode. The positive lead plate 260 is fixed to and electrically connected to the cap plate 120 serving as the positive terminal of the bare cell 100 by the fixing member 280 to be described below, and the negative lead plate 260 is negative terminal It is electrically connected to the electrode terminal 140 that serves. In this case, the negative lead plate 260 is electrically connected between the negative lead plate 270 and the cap plate 120 serving as the positive electrode terminal when connected to the electrode terminal 140. Insulation plate 230 formed of an adhesive tape material is formed between. Accordingly, the negative lead plate 270 is attached to the insulating plate 230 and is electrically connected to the electrode terminal 140 of the bare cell 100.

As such, the positive lead plate 260 and the negative lead plate 270 electrically connected to the bare cell 100 are connected to the protection circuit module 300 by welding or the like.

The protection circuit module 300 is formed of an upper surface on which the external input / output terminal 310 is formed, and a lower surface on which a circuit part (not shown) and connection terminals 360 and 370 are provided. The connection terminals 360 and 370 may include a positive connection terminal 360 and a negative connection terminal 370, and may include a positive lead plate 260 and a negative lead plate 270 formed to be connected to the bare cell 100. It is formed into an approximately 'L' shaped structure for electrical connection. The lead plates 260 and 270 and the connection terminals 360 and 370 are generally joined by spot welding.

The bare cell 100 and the protection circuit module 300 having the structure as described above are stored in a separate pack while being electrically connected through the lead plates 260 and 270, or the interspace is filled with molten resin and coated. It forms a rechargeable secondary battery.

Next, among the lead plates 380 and 390 electrically connecting the bare cell 100 and the protection circuit module 300, the structure of the anode lead plate 260 and the anode lead plate 260 are connected to the bare cell 100. The structure of the fixing member 280 to be coupled will be described.

3 to 6, the anode lead plate 260 is fixed to the cap plate 120 of the bare cell 100 by the fixing member 280.

The anode lead plate 260 has a substantially rectangular shape in plan view, and includes a bottom surface 262 that forms one surface and a side wall 264 that forms another surface that extends upward from a portion of a peripheral portion of the bottom surface 262. Is formed.

The bottom surface 262 of the anode lead plate 260 is in contact with the cap plate 120, and a fixing member hole 262a into which the fixing member 280 to be described below is inserted is formed at one side. Here, although the fixing member hole 262a is formed at one side of the bottom 262 of the anode lead plate 260, it may be formed at the other side.

The fixing member 280 is fixed to the bare cell 100 by being coupled to the cap plate 120 through the fixing member hole 262a formed in the bottom surface 262 of the positive lead plate 260 and is electrically connected thereto. In this case, the cap plate 120 is formed at a position perpendicular to the fixing member hole 262a of the positive lead plate 260 so that the fixing member 120 can be coupled to the cap plate 120. It has a groove 190.

The fixing member 280 is connected to the head plate 282 across the bottom surface 262 of the anode lead plate 260 and has a screw thread on the outer circumference and is connected to the head plate 282 perpendicularly to the cap plate 120. The paper consists of a screw having a body portion 284.

The head portion 282 of the fixing member 280 is formed in a cylindrical shape having a circular planar shape and has a diameter larger than the diameter of the body portion 284 so as to span the bottom surface 262 of the anode lead plate 260. The head 282 may be formed in a polygonal shape, such as a quadrangular, pentagonal, hexagonal, or the like. Thus, the shape of the head 282 is not limited.

The body portion 284 of the fixing member 280 is fixed to the fixing member hole 262a of the positive lead plate 260 and the fixing member hole 262 of the cap plate 120 to be fitted into the fixing member hole 262a. And the fixing member groove 192 is formed to have the same diameter. In addition, the inner circumference of the fixing member groove 192 of the cap plate 120 into which the body portion 284 of the fixing member 280 having a screw thread is formed is formed in a shape corresponding to the nasan acid formed in the body portion 284. do. This is to allow the body portion 284 of the fixing member 280 having nasan acid to be inserted into the fixing member groove 190 of the cap plate 120 of the positive lead plate 260 while being rotated in one direction.

 The sidewall 264 of the anode lead plate 260 is formed to protrude vertically in a portion of the periphery of the bottom surface 262 in the upper direction, that is, in the direction of the protection circuit module 300 shown in FIG. 3. It exists for welding with the positive connection terminal 360. Accordingly, the anode connection terminal 360 of the protection circuit module 300 is welded to the anode lead plate sidewall 264 to form a bare cell 100 and a protection circuit module 300 electrically connected to the anode lead plate 260. ) Is electrically connected.

A process in which the positive lead plate 260 is coupled to the bare cell 100 will be described with reference to FIG. 5.

Referring to FIG. 5, the positive lead plate 260 is positioned on the cap plate 120 such that the fixing member hole 262a formed at one side of the bottom surface coincides with the fixing member groove 192 of the cap plate 120.

Then, the fixing member 280 passes through the fixing member hole 262a of the positive lead plate 260 and is fitted into the fixing member groove 192 of the cap plate 120. Then, the head portion 282 of the fixing member 280 extends over the bottom surface 282 of the anode lead plate 260, the body portion 284 having a nasan acid is the groove 192 of the cap plate 120 Is coupled to.

 As shown in FIG. 6, the anode lead plate 260 electrically connected to the bare cell 100 is connected to the anode connection terminal 360 of the protection circuit module 300 by a welding method, or the like, as described above. The bare cell 100 and the protection circuit module 300 are miraculously connected. In addition, the resin is filled in between the protective circuit module 300 and the bare cell 100, that is, the cap plate to form a molding resin 400, whereby the protective circuit module 300 is fixedly coupled to the bare cell 100. .

As described above, the secondary battery according to the first embodiment of the present invention is physically coupled to the positive lead plate 260 and the cap plate 120 by a fixing member 280 made of screws, the positive lead in the conventional secondary battery Cohesion between the positive lead plate 260 and the bare cell 100 may be increased with respect to external force than when the plate and the cap plate are joined by laser welding. In addition, in the secondary battery according to the first embodiment of the present invention, a support member including a protrusion 210 and a holder 220 is installed on the cap plate 120 to perform a bending test or twisting of the battery. By increasing the shear strength of the molded resin portion 400 against the external force, such as a) test can prevent the molding resin portion 400 is separated from the bare cell.

FIG. 7 is a perspective view illustrating a state before a bare cell and a protection circuit module are connected in a secondary battery according to a second embodiment of the present invention, and FIG. 8 is a cap assembly of a bare cell in which the module is not connected in the secondary battery of FIG. 7. It is sectional drawing which cut | disconnected the part along the line CC.

The secondary battery according to the second embodiment of the present invention is different from the secondary battery according to the first embodiment of the present invention shown in FIG. 4 except that the support member including the protrusion and the holder is provided except for installing a screw member. And have the same components. Therefore, in the secondary battery according to the second embodiment of the present invention, the description of the same components as the secondary battery according to the first embodiment of the present invention will be omitted.

7 and 8, a rechargeable battery according to a second exemplary embodiment of the present invention includes a bare lead 500 and an anode lead plate on the bare cell 500, that is, on an upper portion of the cap plate 520. 660 and a protective circuit module 300 electrically connected through the negative lead plate 670.

As described above, the bare cell 500 and the protection circuit module 300 may be accommodated in a separate pack while being electrically connected through the lead plates 660 and 670, or may be covered with a molten resin and filled with a space therebetween. It forms a secondary battery.

Next, the supporting member 620 of the secondary battery according to the second embodiment of the present invention will be described with a difference from the supporting member of the secondary battery according to the first embodiment of the present invention.

The secondary battery according to the second embodiment of the present invention includes a support member having a protrusion fitted to the protrusion and the protrusion in the secondary battery according to the first embodiment of the present invention on the cap plate 520 of the bare cell 500; Otherwise provided with a support member 620 made of screws.

Referring to FIG. 8, the support member 620 is opposite to the stopper 570 formed to block the electrolyte injection hole at one side of the cap plate 520 around the electrode terminal 540, that is, the cap plate 520. It is installed on the other side of.

The support member 620 is vertically connected to the head 622 having a screw thread on the outer circumference and a head 622 spaced upward from the upper surface of the cap plate 520 when the cap plate 520 is coupled to the cap plate 520. A portion consists of a screw having a body portion 624 fitted to the cap plate 624. Here, the support plate groove 594 is formed in the cap plate 520 so that the support member 624 may be fitted thereto.

Since the head 622 of the support member 620 has a larger diameter than the body 624 to be described below, the head 622 has a step with the body 624. The support member 620 is coupled to the cap plate 520 such that the head 622 is spaced apart from the upper surface of the cap plate 520. This forms a separation space between the step surface 625 in which the head portion 622 and the body portion 624 are stepped, and the top surface of the cap plate 520, so that the cap plate 520 and the protection circuit module 300. The molding resin part (not shown) formed by filling the resin therebetween is supported over the separation space.

Body portion 624 of the support member 620 is coupled to the groove 594 for the cap plate 520 support member. To this end, the groove 594 for the support member of the cap plate 520 has the same diameter as the body portion 624. Here, the body portion 624 of the support member 620 is coupled to the cap plate 520, the support portion for the groove 594, not part of the whole. This is because the head 622 of the support member 620 is spaced apart from the top surface of the cap plate 520, so that the molding resin part (not shown) can be spread over the support member 620, that is, the support member 620. In order to form a space between the step surface 625 and the upper surface of the cap plate 520. Here, the inner circumference of the support member groove 594 of the cap plate 520 into which the body 624 of the support member 620 is inserted is formed at the outer circumference of the body 624 of the support member 620. It is formed in a shape corresponding to the thread. This is to allow the body portion 624 of the support member 620 having nasan acid to be inserted into the support member groove 594 of the cap plate 520 while being rotated in one direction.

As described above, the secondary battery according to the second embodiment of the present invention is physically coupled to the positive lead plate 660 and the cap plate 520 by a fixing member 680 made of screws as in the first embodiment of the present invention. In this case, the bonding force between the cathode lead plate and the cap plate may be increased with respect to the external force than when the anode lead plate and the cap plate are joined by laser welding in a conventional secondary battery.

In addition, the secondary battery according to the second exemplary embodiment of the present invention may include a molded resin part (not shown) formed between the cap plate 520 and the protection circuit module by installing a support member 620 made of screws on the cap plate 520. ) So that the molded resin portion is supported by the support member 620 against an external force such as a bending test or a twisting test of the battery, thereby forming the molded resin portion (not shown). The departure from the bare cell 500 may be prevented.

9 is a cross-sectional view of a cap assembly of a bare cell to which a protection circuit module is not connected in a secondary battery according to a third exemplary embodiment of the present invention.

The secondary battery according to the third embodiment of the present invention has the same components except that the supporting groove is further formed in the fixing member as compared with the secondary battery according to the second embodiment of the present invention. Thus, the description of the same components will be omitted.

9, a rechargeable battery according to a third exemplary embodiment of the present invention includes a bare cell (not shown) and a positive lead plate 860 and a negative electrode lead on top of the bare cell, that is, on the cap plate 720. Protection circuit module 300 of FIG. 3 electrically connected through plate 870.

As described above, the bare cell (not shown) according to the third exemplary embodiment of the present invention and the protection circuit module 300 of FIG. 3 may be accommodated in a separate pack while being electrically connected through the lead plates 860 and 870. The interspace is filled with the melted resin to form a pack secondary battery.

Next, in the support groove 883 formed in the fixing member 880 of the secondary battery according to the third embodiment of the present invention having a difference from the fixing member 680 of the secondary battery according to the second embodiment of the present invention. This will be explained in detail.

The fixing member 880 formed in accordance with the third embodiment of the present invention includes a head 882 extending through the fixing member hole 862a formed on the bottom of the anode lead plate 860 and covering the bottom thereof, and an outer circumferential edge thereof. It consists of a screw having a body portion 884 which is connected to the head portion 882 perpendicularly to the head portion 882 to have a nasan acid. In addition, the fixing member 880 further includes a supporting groove 883 formed around the outer surface of the head 882.

The support groove 883 of the fixing member 880 formed according to the third embodiment of the present invention may be connected to the cap plate 720 to fix the protective circuit module 300 of FIG. 3 to the upper portion of the cap plate 720. When the molding resin is filled between the protection circuit modules 300 to form the molding resin part (not shown), the molding resin part serves to be supported over the support groove 883. The support groove 883 is formed in a third embodiment of the present invention while continuously surrounding the outer surface of the head portion 882 of the fixing member 880 in the vertical cross-sectional shape, but the vertical cross-section is a triangular or vial shape As can be formed in various forms. In addition, the support groove 883 may be in the form of one groove formed to continuously surround the outer surface of the head portion 882 of the fixing member 880, the outer surface of the head portion 882 of the fixing member 880 It may be in the form of a plurality of grooves formed at predetermined distances. Thus, the shape of the support groove 883 is not limited.

As described above, the secondary battery according to the third embodiment of the present invention physically couples the positive electrode lead plate 860 and the cap plate 720 to each other by a fixing member 880 made of screws, thereby providing a positive electrode in a conventional secondary battery. Coupling force between the positive lead plate and the cap plate may be increased with respect to external force than when the lead plate and the cap plate are joined by laser welding. In addition, the secondary battery according to the third embodiment of the present invention further forms a support groove 883 in the fixing member 880 to support the molded resin portion formed by filling the resin between the cap plate 720 and the protection circuit module. By being supported over the grooves 883, the molding resin portion can be prevented from being separated from the bare cell with respect to the external force.

In addition, the secondary battery according to the third embodiment of the present invention forms a support member 820 made of screws on the cap plate 720, like the secondary battery according to the second embodiment of the present invention, to the fixing member 880. Together with the formed support grooves 883 serves to hold the molded resin portion formed between the cap plate 520 and the protective circuit module. That is, the secondary battery according to the third embodiment of the present invention includes a support member 820 corresponding to the support member 620 serving to hold the molded resin part in the secondary battery battery according to the second embodiment of the present invention. In addition, it further comprises a support groove 883 formed in the fixing member (880). Accordingly, the secondary battery according to the third exemplary embodiment of the present invention has a molding resin portion against an external force such as a bending test or a twisting test than the secondary battery according to the second exemplary embodiment of the present invention. By increasing the shear strength, the molded resin portion can be prevented from being separated from the bare cell.

10 is a cross-sectional view of a cap assembly part of a bare cell to which a protection circuit module is not connected in a secondary battery according to a fourth exemplary embodiment of the present invention.

The secondary battery according to the fourth embodiment of the present invention illustrated in FIG. 10 has the same components except that the supporting groove is further formed in the support member, compared to the secondary battery according to the third embodiment illustrated in FIG. 9. . Thus, the description of the same components will be omitted.

Referring to FIG. 10, a rechargeable battery according to a fourth exemplary embodiment of the present invention includes a bare cell (not shown) and a cathode lead plate 1060 and an anode lead on an upper portion of the bare cell, that is, an upper portion of the cap plate 920. It comprises the protective circuit module 300 of FIG. 3 electrically connected through the plate 1070.

As described above, the bare cell (not shown) according to the fourth exemplary embodiment of the present invention and the protection circuit module 300 of FIG. 3 may be accommodated in a separate pack while being electrically connected through the lead plates 1060 and 1070. The interspace is filled with the melted resin to form a pack secondary battery.

Next, in the support groove 1023 formed in the support member 1020 of the secondary battery according to the fourth embodiment of the present invention having a difference from the support member 820 of the secondary battery according to the third embodiment of the present invention This will be explained in detail.

The supporting member 1020 of the secondary battery according to the fourth exemplary embodiment of the present invention is opposite to the stopper 970 formed to block the electrolyte injection hole on one side of the cap plate 920 around the electrode terminal 940. The other side of the cap plate 920 is installed.

The support member 1020 is vertically connected to the head 1022 with the head 1022 spaced apart from the upper surface of the cap plate 920 and the outer periphery when coupled to the cap plate 920 A part consists of a screw having a body portion 1024 fitted to the cap plate 920. The support member 1020 further includes a support groove 1023 formed around the outer surface of the head 1022.

The support groove 1023 of the support member 1020 formed according to the fourth embodiment of the present invention has a cap plate 920 to securely couple the protection circuit module 300 of FIG. 3 to the top of the cap plate 820. When the molding resin is filled between the protection circuit modules 300 to form the molding resin part (not shown), the molding resin part serves to be supported over the support groove 883. The support groove 1023 is formed while continuously surrounding the outer surface of the head 1022 of the support member 1020 in the fourth embodiment of the present invention, the vertical cross-sectional shape is rectangular, but the vertical cross-section is a triangular or bottle shape It may be formed in a variety of forms, such as. In addition, the support groove 1023 may be in the form of a groove formed by continuously surrounding the outer surface of the head 1022 of the support member 1020, or on the outer surface of the head 1022 of the support member 1020 It may be in the form of a plurality of grooves formed at predetermined distances. Thus, the shape of the support groove 1023 is not limited.

As described above, the secondary battery according to the fourth exemplary embodiment of the present invention has the positive electrode lead plate 1060 and the cap plate 920 attached to the fixing member 880 made of screws like the secondary battery according to the third exemplary embodiment of the present invention. By physically bonding to each other, the bonding force of the positive electrode lead plate and the cap plate with respect to the external force can be increased compared to the case where the positive electrode lead plate and the cap plate in the conventional secondary battery by laser welding. In addition, the secondary battery according to the fourth embodiment of the present invention further forms a support groove 1083 in the fixing member 1020 to support the molding resin portion formed by filling the resin between the cap plate 920 and the protection circuit module. By being supported over the grooves 1083, it is possible to prevent the molding resin portion from leaving the bare cell with respect to the external force.

In addition, the secondary battery according to the fourth embodiment of the present invention forms a support member 1020 made of screws on the cap plate 920 and the cap plate 920 together with the support groove 1083 formed in the fixing member 1080. ) And a molded resin part formed between the protective circuit module. In addition, the secondary battery according to the fourth embodiment of the present invention includes a support member 1020 corresponding to the support member 820 serving to hold the molded resin part in the secondary battery battery according to the third embodiment of the present invention. The support groove 1023 is further formed to increase the shear strength of the molded resin part against external force, such as a bending test or a twisting test, than in the case of the secondary battery according to the third embodiment of the present invention. The resin portion can be prevented from being separated from the bare cell.

As described above, in the secondary battery according to the present invention, the positive electrode lead plate and the cap plate are physically coupled to each other by a fixing member made of screws, and when the positive electrode lead plate and the cap plate are joined by laser welding in a conventional secondary battery. It is possible to increase the bonding force between the anode lead plate and the cap plate against external force. Accordingly, in the secondary battery according to the present invention, the laser process performed to fix the positive lead plate and the cap plate may be omitted to prevent defects caused by the laser process, thereby reducing the manufacturing failure of the battery, and reducing the manufacturing process of the battery. Can be simplified.

In addition, the secondary battery according to the present invention is further provided with a support member made of a screw on the cap plate, the molded resin portion formed by filling the resin between the cap plate and the protective circuit module to be supported over the support member, thereby molding against external force The resin portion can be prevented from being separated from the bare cell.

As described above, the present invention is not limited to the specific preferred embodiments described above, and any person having ordinary skill in the art to which the present invention pertains without departing from the gist of the present invention claimed in the claims. Various modifications are possible, of course, and such changes are within the scope of the claims.

Claims (15)

A bare cell comprising a positive electrode plate, a negative electrode plate, and a separator including a separator, a case accommodating the electrode assembly and an electrolyte, and a cap assembly including a cap plate and closing an opening of the case; A protection circuit module electrically connected to the cap plate through a lead plate; And And a fixing member for fixing one surface of the lead plate to the cap plate. The method of claim 1, And a molding resin part in a cap plate region including the protection circuit module. The method according to claim 1 or 2, The other surface of the lead plate extends in the direction of the protection circuit module at a portion of the peripheral portion of the one side, the secondary battery, characterized in that coupled to the connection terminal of the protection circuit module by welding. The method of claim 3, wherein Secondary battery, characterized in that the fixing member hole is formed in a portion of one side of the lead plate. The method of claim 4, wherein The fixing member is a secondary battery, characterized in that coupled to the cap plate through the fixing member hole of the lead plate. The method of claim 5, The fixing member is a secondary battery, characterized in that the screw having a head portion that extends over one surface of the lead plate, and a body portion that is connected to the head portion having a screw thread on the outer edge and fitted to the cap plate. The method of claim 6, Secondary battery, characterized in that the head of the fixing member has a support groove formed on the outer surface. The method according to claim 6 or 7, The cap plate has a secondary battery, characterized in that it has a groove for the fixing member so that the body portion of the fixing member can be coupled. The method of claim 8, The inner circumference of the groove for the fixing member is a secondary battery, characterized in that formed in a shape corresponding to the screw thread of the body portion of the fixing member. The method of claim 2, Secondary battery, characterized in that the support member is further installed on the cap plate of the cap assembly. The method of claim 10, The support member is a secondary battery comprising a protrusion and a holder fitted to the protrusion. The method of claim 10, The support member is a secondary screw characterized in that it has a head portion spaced apart from the upper surface of the cap plate, and a body portion having a screw thread on the outer circumference and connected to the head portion, a part of which is fitted to the cap plate. battery. The method of claim 11, Secondary battery, characterized in that the head of the support member has a support groove formed on the outer surface. The method according to claim 12 or 13, The cap plate has a secondary battery characterized in that it has a groove for the support member to be coupled to the body portion of the support member. The method of claim 14, The inner circumferential edge of the groove for the support member is formed in a shape corresponding to the screw thread of the body portion.

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