KR100571233B1 - Secondary Battery - Google Patents

Abstract

A safety device is coupled to at least one side of a bare cell comprising a container-type can, an electrode assembly embedded in the can through an opening of the can, and a cap assembly closing the opening of the can, wherein the safety device is coupled to the bare cell. In the secondary battery is provided with a resin mold in contact with the side surface and at least part of the surface of the safety device, wherein the resin mold is composed of at least two layers when the resin mold is in contact with the bare cell based on the contact surface. A secondary battery characterized by the above is disclosed. In the resin mold, the direct adhesive layer directly contacting the bare cell is made of a relatively high adhesive material layer, and the indirect adhesive layer is preferably made of a relatively low adhesive material layer.

According to the present invention, the molding resin mold can be stably attached to the secondary battery, thereby strongly bonding the bare cell and the safety device, and the molding resin mold or the safety devices are formed in the bare cell by bending or twisting by external force. Departure can be prevented.

Description

Secondary Battery

1 is a schematic exploded perspective view of an example of a conventional lithium ion resin pack battery in a stage before being bonded by a molding resin;

2 is a perspective view showing a conventional lithium ion resin pack secondary battery in a state bonded by a molding resin;

3 to 5 are partial cross-sectional views showing important processes for implementing the present invention in a resin pack battery having a bare cell and a safety device of the same type as in FIG.

6 is an exploded perspective view of the assembly of the bare cell components and the safety device for forming the present invention;

7 is a perspective view showing a state immediately before forming an assembly of a battery and a safety device in a bare cell state for formation of the present invention;

Fig. 8 is a sectional view showing a state in which an assembly of a bare cell and a safety device is fixed to a molded resin mold.

* Explanation of symbols for the main parts of the drawings

100: bare cell 111: positive terminal

113: through hole for the terminal 112: electrolyte injection hole

130: negative electrode terminal 110: cap plate

120: gasket 150: terminal plate

160: plug 190: insulation case

191: lead through hole 192: electrolyte through hole

20,200: molded resin portion 210: high adhesive material layer

220: low adhesive material layer 217: negative electrode lead

211 can 212 electrode assembly

213: anode 214: separate

215: cathode 216: anode lead

30,300: protection circuit board 35: circuit part

36,37,360,370: connection terminals 31,32,310,320: external terminals

311: external terminal surface

41, 42: connection lead 410, 420: lead plate

43,140,430: Insulation plate 500: Molded resin frame

The present invention relates to a secondary battery, and more particularly, to a bare cell including an electrode assembly, a can, and a cap assembly, and a secondary battery formed by electrically connecting a protective circuit board to the bare cell.

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.

By the way, a battery has the possibility of emitting much energy as an energy source. In the case of a secondary battery, energy is stored in itself in a state where it is charged, and in the process of charging, energy is accumulated from other energy sources. When an abnormality of a secondary battery such as an internal short circuit occurs in such a process or state, energy stored in the battery is released in a short time, which may cause safety problems such as ignition and explosion.

Accordingly, the secondary battery is equipped with various safety devices to prevent fire or explosion due to an abnormality of the battery itself in the charged state or during the charging process. Safety devices are connected to the positive and negative terminals of the bare cell by a conductor structure, commonly referred to as a lead plate. These safety devices cut off the current when the battery voltage rises rapidly due to a high temperature rise of the battery, excessive charge or discharge, or the like, thereby preventing the battery from rupturing or igniting. The safety devices connected to the bare cell include a protection circuit that senses an abnormal current or voltage and prevents current flow, a positive temperature coefficient (PTC) element operating by overheating due to the abnormal current, and a bimetal.

The secondary battery in a state in which the bare cell and the safety device are combined is stored in a separate case to form a secondary battery having a completed appearance. Thereafter, without using a separate case, the safety device terminals such as the bare cell and the protection circuit board are first connected by welding, and the bare cell and the protection circuit are physically filled by filling a molding resin in the space or surrounding space therebetween. In many cases, the resin pack secondary batteries are bonded to each other.

In the case of the resin pack secondary battery, the appearance can be smoothed by molding or the thickness corresponding to the case can be reduced compared to the case where a core pack having safety devices attached to a bare cell is completed in a case. There is no advantage.

1 is a schematic exploded perspective view of an example of a conventional lithium ion resin pack battery that is in a step prior to being bonded by molding resin, and FIG. 2 is a view of a conventional lithium ion resin pack secondary battery bonded by molding resin. It is a perspective view showing.

1 and 2, a protective circuit board 30 is disposed side by side on a surface where electrode terminals 130 and 111 of a bare cell are formed in a resin pack battery. As shown in FIG. 2, the gap between the bare cell 100 and the protection circuit board 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 terminals 31 and 32 of the battery are exposed to the outside.

The bare cell 100 is provided with a positive terminal 111 and a negative terminal 130 on side surfaces facing the protective circuit board 30. The positive terminal 111 may be a cap plate made of aluminum or an aluminum alloy or a nickel-containing metal plate bonded on the cap plate. The negative electrode terminal 130 is a terminal protruding in the shape of a protrusion on the cap plate, and is electrically isolated from the cap plate 110 by an insulator gasket interposed therebetween.

The protective circuit board 30 is formed by a circuit formed on a panel made of resin, and external terminals 31 and 32 and the like are formed on an outer surface thereof. This substrate 30 has substantially the same size and shape as the opposing surface (cap plate surface) of the bare cell 100.

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 terminals 31 and 32 are formed, that is, the inner surface. The circuit part 35 is provided with the protection circuit etc. for protecting a battery from overcharge and overdischarge at the time of charge / discharge. The circuit portion 35 and each of the external terminals 31 and 32 are electrically connected by a conductive structure passing through the protective circuit board 30.

Connection leads 41 and 42, an insulating plate 43, and the like are disposed between the bare cell 100 and the protection circuit board 30. The connection leads 41 and 42 are usually made of nickel and are formed for electrical connection with the connection terminals 36 and 37 of the cap plate 110 and the protection circuit board 30, and have a 'L' shape or a planar structure. . Resistance spot welding may be used for the connection of the connection leads 41 and 42 to the respective terminals 36 and 37. In this example, a breaker or the like is separately formed in the connection lead 42 between the protective circuit board and the negative electrode terminal. 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 connection lead 42 connected to the negative electrode terminal 130 and the cap plate serving as the positive electrode.

However, when the bare cell 100, the protection circuit board 30, and other battery parts are formed into a pack battery using molding resin, as shown above, the battery parts such as the protection circuit board 30 may be removed in the pack battery state. The molded resin part 20 fixedly coupled to the bare cell 100 has a material different from that of the bare cell 100 made of metal such as the cap plate 110 or the can, and the adhesion area is weak because the contact area is not large. there is a problem.

In order to strengthen the adhesive strength, the connection structure such as the lead plate (connection lead) is enlarged and used as a reinforcement structure, or a reinforcement structure separate from the connection lead and the like is welded to the cap plate, and a space is partially provided between the reinforcement structure and the bare cell. It is conceivable how to form the molded resin to cover the reinforcing structure while filling the space. If the lead plate or the reinforcing structure is large, it is located deep in the molding resin mold to increase the adhesive force between the mold including the safety device and the bare cell.

But. Since the molded resin mold must cover the reinforcing structure, this type of reinforcing structure has a limitation in expanding because the size of the battery must be limited. In addition, when the protrusion of the reinforcing structure is large, the mold end is far from the cap plate contact surface of the mold and the bare cell, so that when the lateral force acts on the mold end, the bending external force acting on the contact surface is likely to be large.

In addition, the heterogeneity of the molding resin and the material of the metal reinforcing structure also makes it difficult to increase the adhesive strength. For example, in the case of forming a protruding structure with a simple form of a metal reinforcing structure, and the protruding structure extends into the molding resin, it may include a safety device when the molded resin portion and the bare cell portion of the battery are pulled up and down due to the heterogeneity of the material. The molded resin portion is likely to be separated from the bare cell.

In order to reduce the reinforcing structure while increasing the bonding strength of the molded resin part and the bare cell, as described above, the reinforcing structure may be complicated and the resin may be formed while surrounding the reinforcing structure. For example, a gap may be formed between the bare cell and the reinforcing structure coupled to the bare cell, and the gap may be filled with the molding resin to surround the reinforcing structure. Japanese Patent Publication No. 2003-7282 shows that this type of structure is disclosed.

However, even in this case, only the reinforcing structure may prevent the molded resin mold from having sufficient bonding force, and the resin may not be evenly filled between the protective circuit board and the bare cell when the resin is poured. If the resin is not filled, the bonding structure may be further weakened.

The present invention is to solve the above problems of the conventional resin pack secondary battery, to provide a secondary battery having a configuration capable of strengthening the bonding of the molded resin mold surrounding the safety device, such as a protective circuit board attached to the bare cell. The purpose.

An object of the present invention is to provide a secondary battery that can be bonded to the bare cell and the reinforcing structure, the molding resin mold bonded to the bare cell while wrapping it even if the reinforcing structure is small and simple in the conventional resin pack secondary battery.

The present invention for achieving the above object is a safety device is coupled to at least one side of a bare cell comprising a container-type can, an electrode assembly embedded in the can through the opening of the can, a cap assembly closing the opening of the can, In the secondary battery, a resin mold is provided to contact the side of the bare cell to which the safety device is coupled and at least a part of the surface of the safety device,

The resin mold is characterized in that the resin mold is composed of at least two layers based on the contact surface in contact with the bare cell.

In the present invention, the direct adhesive layer, which is a resin mold layer directly contacting the bare cell, is composed of a relatively high adhesive material layer, and the indirect adhesive layer, which is a layer of a resin mold located on the opposite side of the bare cell and the safety device, is relatively relative to the high adhesive material layer. It is preferred to consist of a low adhesive material layer. At this time, the high adhesive material layer may be made of a bare cell or a metal part constituting the safety device and an epoxy resin and other adhesive components capable of maintaining high adhesive strength, and the low adhesive material layer may be a polyolefin-based resin layer that may be used as an exterior material. , Polyester resin layers, polyamides, polyurethanes and the like can be used. The two layers will usually differ in components, but may be two layers in which the bonding structure differs depending on the formation conditions even if the components are identical.

As the polyolefin resin, polypropylene, chlorinated polypropylene, polyethylene, ethylene propylene copolymer, polyethylene and acrylic acid copolymer, polypropylene and acrylic acid copolymer, etc. may be used. As polyester resin, polyethylene terephthalate and polybutyl Lenterephthalates, polyethylene naphthalates, polyester copolymers, polycarbonates, and the like can be used.

In the present invention, when the direct adhesive layer directly contacting the side of the bare cell is a high adhesive material layer, the high adhesive material layer may be formed by a molding resin molding method.

In order to form the secondary battery of the present invention, a method of attaching a safety device to the bare cell after forming a high adhesive material layer in advance on a corresponding adhesive surface of the bare cell may be used. In this case, the resin mold consists of at least two layers only at the contact surface where the resin mold contacts the bare cell. Since the adhesion between the protective circuit board and the resin mold, which is a safety device, is generally not a big problem, even if only the contact surface of the bare cell and the resin mold is formed of a double layer of a high adhesive material and a general resin, the adhesion of the bare cell and the safety device in the secondary battery is achieved. There is no big problem.

Meanwhile, in order to form the secondary battery of the present invention, a method of dipping a corresponding portion of a cell with a safety device in a liquid high adhesive material or spraying a high adhesive material on the corresponding portion with a spray may be used. Can be used. In this case, the resin mold will be composed of at least two layers based on the contact surface where the resin mold contacts the bare cell and the safety device.

In the present invention, since the direct adhesive layer may be a heat-adhesive material when forming the direct adhesive layer directly contacting one side of the bare cell, the bare cell and the safety device may be heated to room temperature or higher to improve the adhesive strength, and may be above a predetermined temperature. The material forming the direct adhesive layer may be provided on the bare cell and safety device surfaces at a certain temperature or may be heated after the adhesive layer has been applied and dried.

In the present invention, the direct adhesive layer is sufficient to only serve to mediate the surface of the bare cell and the indirect adhesive layer, and may have a thickness of about 0.05 mm to about 3 mm.

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

3 to 5 are partial cross-sectional views showing important processes for implementing the present invention to a resin pack battery having a bare cell and a safety device similar to that of FIG.

Referring to FIG. 3, the separated secondary battery parts as shown in FIG. 1 are combined. Since the protruding portions of the connection terminal 360 and the lead plate 410 are joined by welding, the protective circuit board 300 and the bare cell 100 are integrated. The empty space 10 between the cap plate 110 of the bare cell 100 to which the lead plate 410 is welded and the protection circuit board 300 except for the welded connection terminal 360 and the lead plate 410 portion. Is formed.

Referring to FIG. 4, in the secondary battery assembly of FIG. 3, the surface of the lead plate 410 and the front surface of the protective circuit board 300 which form a structure protruding from the surface of the cap plate 110 and the cap plate surface are raised. An adhesive material layer 210 is formed. The thickness of this material layer can be determined by adjusting the viscosity by adjusting the solvent, temperature, etc. of the liquid high adhesive material. In general, the thickness of the highly adhesive material layer 210 is preferably kept thin as 0.1 mm or less.

In this case, a portion of the protective circuit board to be used as the external terminal 310 of the completed battery is problematic when an insulating layer is formed on the surface 311. The high adhesive material layer 210 of the portion of the surface 311 is removed with a solvent after a process of dipping in a liquid high adhesive material, or capping or taping on the external terminal surface before the process of dipping in a liquid high adhesive material. Do not form through.

Referring to FIG. 5, as shown in FIG. 4, the cap plate 110 of the bare cell 100 in the secondary battery assembly having the high adhesive material layer 210 formed on the surface of the cap plate 110 and the protection circuit board 300 is formed. ) And the protective circuit board 300 are filled with a conventional molding resin material, and the molded resin part 200 of the resin pack secondary battery as shown in FIG.

In the resin pack secondary battery in this state, a secondary battery safety device such as the protection circuit board 300 is attached to the bare cell 100 via the molded resin part 200. In addition, the molding resin part 200 may be formed of a plurality of layers, and the normal molding resin layer or the low adhesive material layer 220 may be formed on the cap plate 110 and the lead plate through the high adhesive material layer 210. 410 is attached to a contact surface with a metal such as the surface of the protective circuit board 300.

Conventionally, the adhesion between these heterogeneous components at the surface of these metal parts and the contact lead between the surface of the connecting lead projecting into the resin mold and the resin mold is added to the mechanical support force of the welded lead portion projecting on the resin mold, thereby adding to the external force. It acts as a resistance to bending or twisting. And the adhesion between the heterogeneous components was not large. However, in the present invention, this adhesive force is determined by the smaller of the adhesive force between the surface of the metal component and the high adhesive material, and the adhesive force between the high adhesive material and the low adhesive resin layer, and the adhesive force between them is all the metal component surface. It can be made to achieve the state outstanding compared with the adhesive force between and a normal resin material. Therefore, the resistance by bending or twisting by external force becomes large, and even if the support strength of the connection lead portion is small, the adhesive force alone has a strong resistance to deformation by external force.

Hereinafter, the present invention will be described further through the process of forming an embodiment of the present invention.

6 is an exploded perspective view of a lithium pack battery in a bare cell component and a safety device assembly for forming the present invention, and FIG. 7 is a perspective view showing a state immediately before assembly of the bare cell and the safety device.

6 and 7, the lithium pack battery is combined with a can 211, an electrode assembly 212 accommodated in the can 211, and an open top of the can 211 to form a top of the can. It has a bare cell comprising a cap assembly for sealing.

The electrode assembly 212 is formed by winding a laminate of an anode 213, a separator 214, a cathode 215, and a separator formed in a thin plate or film form in a spiral shape.

The positive electrode 213 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 mainly composed of lithium-based oxides coated on both surfaces thereof. The positive electrode lead 216 is electrically connected to the positive electrode 213 in a region of the positive electrode current collector in which the positive electrode active material layer is not formed.

The negative electrode 215 includes a negative electrode current collector made of a conductive metal sheet, 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 lead 217 is also connected to a region of the negative electrode current collector in which the negative electrode active material layer is not formed.

The positive electrode 213 and the negative electrode 215 and the positive and negative lead 216 and 217 may be arranged with different polarities, and the two electrodes 213 and 215 may be arranged at the boundary where the positive and negative lead 216 and 217 are drawn out from the electrode assembly 212. Insulation tapes 218 are wound around each other to prevent short circuits between them.

The separator 214 is made of polyethylene, polypropylene, or a copolymer of polyethylene and polypropylene. Separator 214 is formed to be wider than the positive electrode and the negative electrode 213, 215 is advantageous to prevent short circuit between the electrode plates.

The square can 211 as in the present embodiment is formed of aluminum or an aluminum alloy having a substantially rectangular parallelepiped shape. The electrode assembly 212 is received through the open top of the can 211 so that the can 211 serves as a container for the electrode assembly 212 and the electrolyte. The can 211 may itself serve as a terminal, but in this embodiment, the cap plate 110 of the cap assembly serves as a positive electrode terminal.

The cap assembly is provided with a flat cap plate 110 having a size and shape corresponding to the open top of the can 211. In the central portion of the cap plate 110, a through hole 113 for the terminal is formed to allow the negative electrode to pass therethrough. A tubular gasket 120 is installed outside the cathode terminal 130 penetrating the center of the cap plate 110 to electrically insulate the cathode terminal 130 from the cap plate 110. The insulation plate 140 is disposed on the lower surface of the cap plate 110 near the center of the cap plate 110 and the through hole 113 for the terminal. The terminal plate 150 is provided on the bottom surface of the insulating plate 140.

The negative electrode terminal 130 is inserted through the through hole 113 for the terminal while the gasket 120 surrounds the outer circumferential surface thereof. The bottom portion of the negative electrode terminal 130 is electrically connected to the terminal plate 150 with the insulating plate 140 interposed therebetween.

The positive lead 216 drawn from the positive electrode 213 is welded to the lower surface of the cap plate 110, and the negative lead 217 drawn from the negative electrode 215 is folded to the lower end of the negative electrode terminal 130 in a meandering state. Welded

On the other hand, an insulating case 190 is provided on the upper surface of the electrode assembly 212 to electrically cover the electrode assembly 212 and the cap assembly and at the same time cover the upper end of the electrode assembly 212. . A lead through hole 191 is formed to allow the center portion of the electrode assembly 212 and the cathode lead 217 to pass therethrough, and an electrolyte passage hole 192 is formed at the other side thereof.

An electrolyte injection hole 112 is formed at one side of the cap plate 110. After the electrolyte is injected into the electrolyte injection hole 112, a stopper 160 is installed to seal the electrolyte injection hole. Welding of the periphery of the cap plate 110 and the side wall of the can 211 is performed by coupling the cap assembly with the can 211.

The lead plate 410 having a parallel sidewall on the cap plate 110 and connecting to the bottom of the sidewall and having a bottom surface having a hole in the stopper 160 is welded around the stopper 160. The lead plate (connection lead) is for electrical connection, but later, as the side wall protrudes toward the molding resin portion at the interface with the molding resin portion, it is embedded in the molding resin portion to serve to fix the molding resin portion and the bare cell. have. The lead plate 410 may have a 'c'-shaped sidewall or a' b'-shaped sidewall.

The lead plate 410 is preferably made of nickel, nickel alloy or nickel plated stainless steel, and the thickness of the lead plate is generally 0.05 to 0.5 mm in a general range. The thickness of the lead plate 410 is related to the thickness of the can and the welding convenience. When the thickness of the lead plate 410 is thick, a pack is formed by filling the space between the battery can 211 sealed with the cap assembly and the protective circuit board 300 with resin. The battery has an advantageous side because it can increase the resistance strength against external force when twisting or bending the battery.

In addition, when the lead plate protrudes for a long time, the contact surface with the resin mold increases, and thus the adhesive force is increased. However, the size of the secondary battery is limited because there is a problem that the size of the secondary battery increases. Since the welding of the cap plate 110 is usually made of aluminum or an aluminum alloy, the thermal conductivity is high, and the resistance is insignificant. Therefore, the resistance welding is not suitable, and the welding may be performed by laser welding.

Subsequently, welding is performed between the lead plates 410 and 420 and the connection terminals 360 and 370 of the protection circuit board 300. As a result, the secondary battery assembly in the state as shown in FIG.

The secondary battery assembly of FIG. 3 is held in a can portion, and the cap plate 110 and the protection circuit board 300 are immersed in a liquid high adhesive material, and then taken out to dry or cure. Therefore, as shown in FIG. 4, a highly adhesive material layer 210 is formed on the surface of the cap lead 110 and the connection leads 410 and 420 forming the structure protruding from the cap plate surface and the front surface of the protective circuit board 300. . The thickness of this material layer can be determined by adjusting the viscosity by adjusting the solvent, temperature, etc. of the liquid high adhesive material. In the aspect of reducing the size and weight of the secondary battery and easily removing a portion formed on an unnecessary portion, the thickness of the highly adhesive material layer 210 may be kept thin at 0.1 mm or less. When the entire secondary battery is coated with a resin to form an exterior, the entire secondary battery assembly of FIG. 3 may be immersed in a liquid high adhesive material.

As shown in FIG. 4, the secondary battery assembly having the high adhesive material layer 210 formed on the cap plate and the protective circuit board surface is inserted into the molding resin mold 500 and fixed as shown in FIG. 8. By filling the empty space of the mold by pouring the liquid molding resin, the molding resin is filled between the bare cell cap plate and the protection circuit board, and the resin is as shown in Fig. 2 in cross-section with the protection circuit board. The molded resin part 200 of the pack secondary battery is formed.

On the other hand, in the resin pack secondary battery in the state as shown in FIG. 5, the external terminal surface is covered by the high adhesive material layer 210 in the state as shown in FIG. 4 by dip processing. Therefore, the high adhesive material layer may be removed by wiping the outer terminal surface 311 of the protective circuit board with the solvent for the high adhesive material layer 210 in a state where the molded resin mold 500 is removed. In this process, the highly adhesive material layer on the surface of the can, which is the side of the bare cell, can also be removed. At this time, the solvent is a material that does not act as a solvent for the low adhesive material layer, the high adhesive material layer in the resin pack secondary battery, both the low adhesive material layer and the part of the metal surface of the battery parts are low. Since it is covered with the adhesive material layer, the entire secondary battery layer may be removed by wiping the entire secondary battery with a solvent.

According to the present invention, the molded resin mold can be stably attached to the secondary battery, thereby strongly bonding the bare cell and the safety device. That is, it is possible to prevent the molded resin mold or the safety devices from leaving the bare cell by bending or twisting by external force.

According to the present invention, since the reinforcing structure or size of the bare cell can be made smaller and simpler when the same mechanical bond strength is required, the resin in the resin molding can be more easily and evenly filled.

Claims (7)

A safety device coupled to at least one side of a bare cell comprising a container-shaped can, an electrode assembly embedded in the can through an opening of the can, and a cap assembly closing the opening, wherein the bare safety device is coupled In a secondary battery provided with a resin mold in contact with the side surface of the cell and at least part of the surface of the safety device, The resin mold may include a direct adhesive layer directly contacting the bare cell and an indirect adhesive layer bonded to the bare cell with the direct adhesive layer interposed therebetween when the resin mold is in contact with the bare cell. Secondary battery made with. The method of claim 1, The direct adhesive layer, which is a resin mold layer that directly contacts the bare cell, is made of a relatively high adhesive material layer for metal, The indirect adhesive layer is a secondary battery, characterized in that consisting of a relatively low adhesion material layer to the metal. The method of claim 2, The high adhesive material layer is made of an epoxy resin, The low adhesive material layer is a secondary battery, characterized in that made of one of a polyolefin-based resin layer, a polyester-based resin layer, polyamide, polyurethane. The method of claim 2, And the direct adhesive layer is formed by dipping or spraying at least a portion of the secondary battery assembly in which the safety device is coupled to a liquid high adhesive material layer material. The method of claim 2, The direct adhesive layer is a heat adhesive material, The material forming the direct adhesive layer is formed on the bare cell and the safety device surface at a predetermined temperature or more, and is formed by applying heat after it is once laminated. The method of claim 2, The direct adhesive layer is a secondary battery, characterized in that having a thickness of 0.05mm to 3mm. The method of claim 1, The resin mold is composed of at least two layers based on the contact surface of the resin mold with the safety device and the bare cell, The direct adhesive layer, which is a resin mold layer that directly contacts the bare cell and the safety device, is made of a relatively high adhesive material layer, The secondary battery, characterized in that the indirect adhesive layer, which is a resin mold layer positioned on the opposite side of the bare cell, based on the high adhesive material layer, is formed of a relatively low adhesive material layer.

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