KR101340020B1 - Rechargeable battery - Google Patents

Abstract

The present invention relates to a secondary battery, and more particularly, to a secondary battery including a bare cell having a cap plate and a protective circuit module having a protective circuit board, wherein the protective circuit board is electrically connected to one side of the cap plate. The present invention relates to a secondary battery comprising a protection circuit connection member connected thereto. According to the present invention, a bare circuit and a protection circuit are formed by forming a protection circuit connection member on a cap plate in place of a conventional positive electrode lead plate. The fixing force between the boards is strengthened to prevent a poor mechanical strength or a poor electrical connection.

Protective circuit connection member, connection member coupling part, molding resin fixing member, fixing member coupling groove

Description

Secondary Battery {RECHARGEABLE BATTERY}

1 is a perspective view of a bare cell and a protection circuit board of a secondary battery according to an embodiment of the present invention are combined;

2 is a front view of a bare cell and a protection circuit board of a secondary battery according to an embodiment of the present invention are combined;

3A is a partial cross-sectional view in which the protective circuit connection member and the connection member coupling portion are coupled according to an embodiment of the present invention.

Figure 3b is another partial cross-sectional view of the protection circuit connection member and the connection member coupling portion according to an embodiment of the present invention.

4 is a perspective view in which a bare cell and a molding resin portion in which a protection circuit board of a secondary battery is coupled according to an embodiment of the present invention;

Figure 5a is a partial cross-sectional view of the cap plate formed integrally with the molded resin fixing member according to an embodiment of the present invention.

Figure 5b is a cross-sectional view of another portion of the cap plate is inserted into the fixing member fixing groove is coupled to the molded resin fixing member according to an embodiment of the present invention.

6 is a longitudinal cross-sectional view of a bare cell of a rechargeable battery according to an exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: bare cell 110: electrode assembly

111: anode plate 112: cathode plate

113: separator 114: anode tab

115: negative electrode tab 120: can

130: cap assembly 140: cap plate

141: terminal through hole 142: electrolyte inlet

143: stopper 144: safety band

145: protection circuit connecting member 146: molding resin fixing member

147: fixing member coupling groove 150: electrode terminal

160: gasket 170: insulation plate

180: terminal plate 190: insulation case

191: electrolyte passage 200: protective circuit module

210: protective circuit board 211: coupling member coupling portion

220: connection terminal, negative electrode terminal 230: lead plate, negative electrode lead plate

240: Safety element, PTC 250: Insulation plate

300: molding resin

The present invention relates to a secondary battery, and to a secondary battery having a fixing force between a bare cell and a protection circuit board.

In general, secondary batteries have been recently developed and used because they are rechargeable and have a possibility of miniaturization and large capacity. Representative secondary batteries that have been recently developed and used include nickel-hydrogen (Ni-MH) batteries, lithium-ion (Li-ion) batteries, and lithium (Li) polymer batteries.

Most of the bare cells of these secondary batteries contain an electrode assembly consisting of a positive electrode, a negative electrode, and a separator in a can made of aluminum or an aluminum alloy, the can is closed with a cap assembly, and an electrolyte is injected into the can to seal the cap assembly. Is formed. When the can is formed of aluminum or an aluminum alloy, the light weight of the aluminum can make the battery lighter, and it does not corrode even when used for a long time under high voltage.

In particular, the lithium ion battery has a much higher energy density per weight than a disposable battery, and thus, it is possible to implement an ultralight battery, and the average voltage per cell is 3.6V, which is three times higher than the average voltage of 1.2V of other rechargeable batteries such as a nickel-cell battery or a nickel-metal hydride battery. It has a compact effect. In addition, the lithium ion battery has a self-discharge rate of less than 5% per month at 20 ° C, which is about one third of that of a nickel-cadmium battery or nickel-metal hydride battery, and is environmentally friendly by not using heavy metals such as cadmium (Cd) or mercury (Hg). In addition, there is an advantage that can be charged and discharged 1000 times or more in a normal state. Therefore, based on these advantages, the development of information communication technology has been rapidly progressed.

The bare cell is connected to safety devices such as Positive Temperature Coefficient (PTC), Thermal Fuse and Protective Circuit Module (PCM) and other battery components in a separate hard pack. It is stored, or by using a hot melt resin to form a finished appearance through the mold.

On the other hand, the connection terminal connected to the protective circuit board is electrically connected to the bare cell through a separate lead plate. That is, the cap plate provided in the bare cell and the positive terminal of the protective circuit board are connected by the positive lead plate.

The cap plate and the anode lead plate are generally joined by welding, and since the anode lead plate aligned on the cap plate before welding is easily distracted in spite of a small external force, the manufacturer has a great deal of reordering the anode lead plate. There is a problem that labor and cost are consumed.

In addition, the welding is made by laser welding, there is a problem that the charging phenomenon and the electric shock is generated by the laser beam irradiation, the external force is transmitted to the welding portion, the distortion of the anode lead plate occurs. Therefore, if the welding of the cap plate and the positive lead plate is not properly made, the positive lead plate may not function properly, resulting in poor mechanical strength or poor electrical connection to the finished secondary battery.

In addition, when the part formed of the hot melt resin is warped or impacted from the outside after welding, the force is transmitted to the anode lead plate, but one surface of the anode lead plate is attached to the cap plate by welding. It can be easily removed from the cap plate by an external impact. Therefore, when the welding site is separated, the anode lead plate and the cap plate may be electrically connected only by contact. In this case, the contact resistance between the positive lead plate and the cap plate may increase, causing a lot of heat. Also, when the positive lead plate is completely separated from the cap plate, the electric circuit may be disconnected and it may not be used as a secondary battery anymore. There is this.

Accordingly, an object of the present invention is to provide a secondary battery which is devised to solve the above-mentioned problems and to prevent a failure of mechanical strength or a poor electrical connection by reinforcing the fixing force of the bare cell and the protection circuit board.

Another object of the present invention is to provide a secondary battery in which the production process of the secondary battery is simplified, thereby improving productivity and reducing costs and maximizing profit.

Still another object of the present invention is to provide a secondary battery that increases the shear stress of the molded resin part and prevents deformation that may be bent or bent by an external force.

In order to achieve the above object, a secondary battery according to the present invention includes a bare cell provided with a cap plate and a protection circuit module provided with a protection circuit board having a protection circuit. A protective circuit connection member for electrically connecting the bare cell and the protective circuit board is included.

In addition, the protective circuit connection member may be integrally formed on the cap plate.

In addition, the protective circuit connection member may be formed of a rod-shaped pin.

In addition, the protective circuit board may be formed with a connection member coupling portion is coupled to the protective circuit connection member in a position corresponding to the protective circuit connection member.

In addition, the connection member coupling portion may be made of a through hole is inserted into the protective circuit connection member.

In addition, the connection member coupling portion may be formed of a groove into which the protective circuit connection member is inserted.

In addition, the protective circuit connection member and the connection member coupling portion may be connected by soldering coupling.

In addition, the protective circuit connection member and the connection member coupling portion may be connected by welding.

In addition, the soldering coupling may be made in at least some of the upper and lower portions of the protective circuit board.

In addition, the welding coupling may be made of a contact welding coupling.

In addition, a molding resin may be formed in a space between the upper end of the bare cell and the protection circuit module.

In addition, the other side of the cap plate may be configured to further include a molding resin fixing member for preventing the molding resin from being separated by an external force.

In addition, the molded resin fixing member may be integrally formed on the cap plate with a rod-shaped pin.

In addition, the molded resin fixing member is inserted into the fixing member coupling groove formed in the cap plate may be detachably connected.

In addition, the molded resin fixing member and the fixing member coupling groove may be coupled and separated by a corresponding screw thread.

Hereinafter, with reference to the accompanying drawings illustrating a preferred embodiment of a secondary battery according to an embodiment of the present invention in detail.

According to an exemplary embodiment of the present invention, as shown in FIGS. 1 and 4, an inner pack battery is a bare cell 100 and an electrical connection with the bare cell 100. The protection circuit module 200 is connected, and the molding resin unit 300 is coupled to the bare cell 100 to which the protection circuit module 200 is connected.

As shown in FIG. 6, the bare cell 100 includes an electrode assembly 110, a can 120 in which the electrode assembly 110 is accommodated, and a cap assembly sealing an upper opening of the can 120. 130 is included and configured.

The electrode assembly 110 is laminated and wound with a positive electrode plate 111 coated with a positive electrode active material, a negative electrode plate 112 coated with a negative electrode active material, and a separator 113 interposed between the positive electrode plate 111 and the negative electrode plate 112. It is formed.

The positive electrode tab 114 is electrically connected to a region of the positive electrode current collector on which the positive electrode active material layer is not formed, and the negative electrode tab on the negative electrode current collector on which the negative electrode active material layer is not formed on the negative electrode plate 112. 115 is electrically connected. In this case, an insulating tape may be wound around the boundary portion from which the electrode tabs are drawn from the electrode assembly 110 to prevent a short circuit between the electrode tab and the two electrode plates. In addition, the separator 113 is formed to be wider than the positive electrode plate 111 and the negative electrode plate 112 is advantageous to prevent a short circuit between the electrode plates.

Meanwhile, an insulating case 190 may be installed on the upper surface of the electrode assembly 110 to cover the electrical insulation of the electrode assembly 110 and the cap assembly 130 and to cover the upper end of the electrode assembly 110. , Insulation case 190 is made of a polymer resin having an insulating property. In addition, a through hole is formed in the center portion of the insulating case 190 to allow the negative electrode tab 115 to pass therethrough, and an electrolyte through hole 191 is formed at the side portion thereof.

The can 120 is formed of an aluminum or aluminum alloy having a substantially rectangular parallelepiped shape, and the electrode assembly 110 is accommodated through an open top to serve as a container for the electrode assembly 110 and the electrolyte. In addition, the can 120 may itself serve as a terminal.

The cap assembly 130 has a flat cap plate 140 having a size and shape corresponding to the open top of the can 120. In this case, a terminal through hole 141 is formed in the central portion of the cap plate 140, and a tube-shaped gasket 160 for electrical insulation between the electrode terminal 150 and the cap plate 140 penetrating through the terminal through hole 141. ) Is installed. In addition, an insulating plate 170 is disposed on a lower surface of the cap plate 140, and a terminal plate 180 is provided on a lower surface of the insulating plate 170. In addition, the bottom portion of the electrode terminal 150 is electrically connected to the terminal plate 180. The positive electrode tab 114 drawn from the positive electrode plate 111 is welded to the lower surface of the cap plate 140, and the negative electrode tab 115 drawn from the negative electrode plate 112 is bent in a zigzag shape at the lower end of the electrode terminal 150. Welded with wealth.

The cap plate 140 has an electrolyte injection hole 142 formed therein, and a cap 143 is installed to seal the electrolyte injection hole 142 after the electrolyte is injected. The stopper 143 is a ball-shaped base material formed of aluminum or an aluminum-containing metal, and is placed on the electrolyte injection hole 142 and mechanically press-fitted into the electrolyte injection hole 142. In addition, the plug 143 is welded to the cap plate 140 around the electrolyte inlet 142 for sealing. On the other hand, the cap plate 140 is a safety band 144 is formed. The safety vent 144 is damaged when the pressure inside the battery rises above a predetermined pressure to prevent the battery from igniting and exploding.

In addition, the cap plate 140 is configured to include a protective circuit connection member 145 electrically connected to the protective circuit board 210 to be described later of the protective circuit module 200 on one side. The protective circuit connection member 145 is formed integrally with the cap plate 140 in the present embodiment, it is made of a rod-shaped pin and may be formed of a nickel-containing metal material.

On the other hand, the protective circuit connecting member 145 may be detachably connected to the cap plate 140 in another embodiment. That is, a groove in which the protective circuit connection member 145 is inserted is formed on the cap plate 140, and may be coupled and separated by a detachable means formed on a coupling surface of the protective circuit connection member 145 and the groove. Can be. In this case, the detachable means may be made of a screw thread.

In addition, the cap plate 140 is configured to further include a molding resin fixing member 146 on the other side to prevent the molding resin 300 from being separated from the bare cell 100 by an external force. That is, the molding resin fixing member 146 increases the shear strength of the molding resin part 300 against an external force such as a bending test or a twisting test of the secondary battery, thereby forming the molding resin part 300. It prevents the departure from the bare cell (100).

As shown in FIG. 5A, the molded resin fixing member 146 may be formed integrally with the cap plate 140 by being made of a rod-shaped pin in the same manner as the protective circuit connecting member 145. have.

On the other hand, the molding resin fixing member 146 may be detachably connected to the cap plate 140, as shown in Figure 5b in another embodiment. That is, a fixing member coupling groove 147 into which the molding resin fixing member 146 is inserted is formed in the cap plate 140, and the outer circumferential surface of the molding resin fixing member 146 and the fixing member coupling groove 147 are formed. Corresponding screw threads are formed on the inner circumferential surface so that they can be combined and separated. On the other hand, the molded resin fixing member 146 may be made of a screw shape of course.

As shown in FIGS. 1 and 2, the protection circuit module 200 includes a protection circuit board 210, a connection terminal 220 electrically connected to the protection circuit board 210, and the bare cell. 100 and the lead plate 230 for easily connecting the connection terminal 220, and a safety element 240 to prevent overcurrent, overcharge, overdischarge of the secondary battery is included.

The protective circuit board 210 is disposed parallel to the cap plate 140 at the top of the bare cell 100, and is almost the same as the cap plate 140 opposite to the bare cell 100. It is made of a plate shape having a size and shape, a protection circuit is formed to block the overcharge or over-discharge of the battery to promote the stability of the battery.

The protection circuit board 210 has a connection member coupling portion 211 to which the protection circuit connection member 145 is coupled at a position corresponding to the protection circuit connection member 145 included in the cap plate 140.

As shown in FIG. 3A, the connection member coupling part 211 includes a through hole through which the protection circuit connection member 145 is inserted. After the protective circuit connection member 145 is coupled with the connection member coupling part 211, an upper surface of the protective circuit connection member 145 is exposed on the protective circuit board. Meanwhile, the protection circuit connection member 145 inserted into the connection member coupling portion 211 formed through the hole may be connected to the protection circuit board 210 by soldering coupling in one coupling method, wherein the soldering coupling has a land portion. Since both of the protection circuit board 210 is possible up and down, it is made in the upper and lower parts of the protective circuit board 210, that is, the upper and lower parts of the connection member coupling portion 211. Of course, the soldering coupling may be made at a portion of the upper and lower portions of the connection member coupling portion 211. In addition, the protective circuit connection member 145 may be connected to the protective circuit board 210 by a welding coupling in another coupling method, the welding coupling is made of a contact welding coupling.

As shown in FIG. 3B, the connection member coupling part 211 may be formed as a groove into which the protection circuit connection member 145 is inserted and inserted. The protection circuit connection member 145 fitted into the connection member coupling portion 211 formed as the groove is protected by soldering coupling or welding coupling in the same manner as the protection circuit connection member 145 inserted into the connection member coupling portion 211 formed through the hole. It may be connected to the circuit board 210. At this time, the soldering coupling is made in the lower portion of the protective circuit board 210, that is, the lower portion of the connection member coupling portion 211, the welding coupling is made by contact welding coupling.

On the other hand, the protective circuit board 210 is electrically connected to the connection terminal 220 on one side, the protective circuit and the protective circuit connecting member 145 is a conductive structure that passes through the protective circuit board 210 Electrical connection.

The connection terminal (hereinafter referred to as a 'cathode terminal') 220 functions as the cathode terminal 220 in the present embodiment, and the lead plate (hereinafter referred to as a 'cathode lead plate') 230 It is electrically connected to the safety device 240. In this case, the negative electrode lead plate 230 is usually made of nickel to easily connect the bare cell 100 and the protection circuit module 200. That is, the negative electrode lead plate 230 has the negative electrode terminal 220 connected to one side, and the safety device 240 is connected to the other side. At this time, the negative lead plate 230 is made of an 'L' shaped structure or a planar structure.

On the other hand, the insulating plate 250 is installed on the cap plate 140 to insulate between the negative lead plate 230 and the cap plate 140 to be the positive electrode. The insulating plate 250 is made of an adhesive tape material to attach and fix the negative lead plate 230 to the bare cell 100.

The safety device 240 is installed to safely protect the battery from overcurrent, overcharge, and overdischarge of the secondary battery. One side is connected to the electrode terminal 150 of the bare cell 100 by the self-connecting terminal. The side is connected to the negative lead plate 230. A fuse, a bimetal, a positive temperature device (PTC) 240, etc. may be installed as the safety device 240. In the present embodiment, when the safety device 240 exceeds a predetermined temperature range, current flows quickly. Blocking and coming back to the temperature range is composed of a positive temperature element (PTC) 240 to quickly resume the flow of current.

The molding resin part 300 is formed by filling a molten resin in a space between the bare cell 100 and the protection circuit module 200 electrically connected thereto.

Hereinafter, the operation of the secondary battery according to an embodiment of the present invention.

According to the secondary battery according to the exemplary embodiment of the present invention, the protection circuit connection member 145 is formed on the bare cell 100 of the secondary battery. As shown in FIG. 3A, the protection circuit connection member 145 is formed integrally with one side of the cap plate 140 formed on the top of the bare cell 100. Therefore, in the process of electrically connecting the bare cell 100 and the protection circuit module 200, a process of coupling the anode lead plate and the cap plate 140 by laser welding using a conventional anode lead plate This avoids the occurrence of the first problem associated with the welding. In addition, the fixing force of the bare cell 100 and the protection circuit module 200 is strengthened due to the integrity of the protection circuit connection member 145 and the cap plate 140. In addition, the protective circuit connection member 145 is coupled to the connection member coupling portion 211 of the protective circuit board 210, the connection member coupling portion 211 is through-hole so that the protective circuit connection member 145 is inserted and fitted. Is formed. That is, the protection circuit connection member 145 is inserted into the connection member coupling portion 211, and then, the coupling portion is connected by soldering coupling or welding coupling, so that the bare cell 100 and the protection circuit module ( 200 is electrically connected.

On the other hand, the cap plate 140, the molding resin fixing member 146 is further formed on the other side. As shown in FIG. 5A, the molded resin fixing member 146 is formed of a rod-like pin in the same manner as the protective circuit connecting member 145 and is integrally formed with the cap plate 140. On the other hand, as shown in FIG. 5B, the molded resin fixing member 146 has a screw thread formed on an outer circumferential surface thereof, and a fixing thread formed with a corresponding screw thread on an inner circumferential surface thereof so that the molded resin fixing member 146 is inserted and coupled and separated. The recombination groove 147 may be formed on the cap plate 140. A space is formed between the molding resin fixing member 146 and the protective circuit board 210, and the molding resin part 300 formed by filling the space is supported and fixed by the molding resin fixing member 146. do. Accordingly, the molding resin fixing member 146 increases the shear stress of the molding resin part 300 against external force, such as a bending test or a twisting test of a secondary battery, thereby forming the molding resin part 300. It prevents the departure from the bare cell (100).

It is to be understood that the invention is not limited to the specific embodiments thereof with reference to the embodiment described or illustrated in the drawings and that various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims. It will be understood that various modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

As described above, the secondary battery according to the present invention includes a protective circuit board connecting member electrically connecting the bare cell and the protective circuit board to one side of the cap plate, replacing the conventional positive lead plate, thereby forming the bare cell and the protective circuit board. The fixing force of the liver is strengthened, thereby preventing the failure of the mechanical strength or the failure of the electrical connection.

Another effect of the present invention is that the manufacturing process of the secondary battery is simplified to increase productivity and reduce costs, thereby maximizing profit.

Another effect of the present invention is to include a fixing member on the other side of the cap plate to increase the shear stress of the molding resin to prevent the deformation of the molding resin can be bent or bent by the external force.

Claims (15)

In the secondary battery comprising a bare cell having a cap plate and a protective circuit module provided with a protective circuit board having a protective circuit, A protection circuit connection member for electrically connecting the bare cell and the protection circuit board to one side of the cap plate; And And a molding resin formed in a space between the upper end of the bare cell and the protection circuit module. The method according to claim 1, The protective circuit connection member is a secondary battery, characterized in that formed integrally with the cap plate. 3. The method of claim 2, The protective circuit connection member is a secondary battery, characterized in that consisting of a rod-shaped pin. The method of claim 3, The protective circuit board is a secondary battery, characterized in that the connection member coupling portion for coupling the protective circuit connection member is formed in a position corresponding to the protective circuit connection member. 5. The method of claim 4, The connection member coupling part is a secondary battery, characterized in that the protective circuit connection member is made of a through hole is inserted. 5. The method of claim 4, The connection member coupling part is a secondary battery, characterized in that the protective circuit connection member is made of a groove inserted. The method according to claim 5 or 6, The secondary battery, characterized in that the protective circuit connection member and the connection member coupling portion is connected by soldering coupling. The method according to claim 5 or 6, The protective circuit connection member and the connection member coupling portion is a secondary battery, characterized in that connected by welding. 8. The method of claim 7, The soldering coupling is a secondary battery, characterized in that at least part of the upper and lower portions of the protective circuit board. 9. The method of claim 8, The weld bond is a secondary battery, characterized in that made of a contact weld bond. delete The method according to claim 1, And a molding resin fixing member on the other side of the cap plate to prevent the molding resin from being separated by an external force. 13. The method of claim 12, The molded resin fixing member is a secondary battery, characterized in that integrally formed on the cap plate with a rod-shaped pin. 13. The method of claim 12, The molded resin fixing member is inserted into a fixing member coupling groove formed in the cap plate, the secondary battery, characterized in that detachably connected. 15. The method of claim 14, And the molded resin fixing member and the fixing member coupling groove are coupled and separated by a corresponding screw thread.

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