Cross Citation with Related Applications
[2]
This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0017331 dated February 14, 2019, and all contents disclosed in the documents of the Korean patent application are incorporated as a part of this specification.
[3]
technical field
[4]
The present invention relates to a secondary battery and a battery module, and more particularly, to a secondary battery and a battery module that can prevent explosion and secure stability by rapidly discharging gas generated inside the battery case to the outside during abnormal operation it's about
background
[5]
In general, types of secondary batteries include a nickel cadmium battery, a nickel hydrogen battery, a lithium ion battery, and a lithium ion polymer battery. These secondary batteries are not only used in small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, Portable Game Devices, Power Tools and E-bikes, but also in large products requiring high output such as electric and hybrid vehicles and surplus power generation. It is also applied and used in power storage devices that store power or renewable energy and power storage devices for backup.
[6]
In order to manufacture the electrode assembly, a cathode, a separator, and a cathode are manufactured, and these are laminated. Specifically, a positive electrode active material slurry is applied to a positive electrode current collector, and a negative electrode active material slurry is applied to a negative electrode current collector to prepare a positive electrode and a negative electrode. And when a separator is interposed between the manufactured positive electrode and the negative electrode and stacked, unit cells are formed, and the unit cells are stacked on each other, thereby forming an electrode assembly. And when the electrode assembly is accommodated in a specific case and an electrolyte is injected, a secondary battery is manufactured.
[7]
Conventionally, when a secondary battery operates abnormally, such as exposed to high temperature, overcharged or overdischarged, the separator contracts due to heat generation, and the positive electrode and the negative electrode directly contact each other, thereby increasing the possibility of a short circuit. Due to such a short circuit, rapid electron movement occurs inside the battery, and as a result, when heat and side reactions occur, the secondary battery may explode, resulting in a safety problem. In particular, when an electrical malfunction such as overcharge, overdischarge, or external short circuit occurs, a high current flows and the heat conductivity of the current collector is low, so that the temperature of the current collector is higher than that of the active material layer. After that, heat was diffused and thermal, chemical, and electrochemical reactions of components such as active materials and electrolytes were added, leading to thermal runaway.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[8]
An object of the present invention is to provide a secondary battery and a battery module capable of preventing explosion and securing stability by rapidly discharging gas generated inside a battery case to the outside during abnormal operation.
[9]
The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.
means of solving the problem
[10]
A secondary battery according to an embodiment of the present invention for solving the above problems includes an electrode assembly formed by alternately stacking an electrode and a separator; a battery case accommodating the electrode assembly therein; a piezoelectric element disposed outside the cup portion for accommodating the electrode assembly in the battery case, the piezoelectric element supplying power to the outside by applying pressure when the volume of the battery case expands; And one end is sharply formed, when power is applied from the piezoelectric element, the one end is extended toward the battery case includes a perforated portion for perforating the battery case.
[11]
In addition, the perforated part may be made of an electroactive polymer (EAP).
[12]
In addition, the piezoelectric element may be attached to the outer surface of the cup part.
[13]
In addition, the piezoelectric element may be attached to the center of the cup part.
[14]
In addition, the piezoelectric element may have a shape corresponding to the cup portion.
[15]
In addition, the conducting wire connected to the piezoelectric element may be connected to the other end of the perforated part.
[16]
In addition, the perforated part may perforate the cup part in the battery case.
[17]
In addition, the perforated portion may be formed in close contact with the sealing portion of the battery case.
[18]
In addition, the other end of the perforated portion may be located at a vertex of the battery case.
[19]
In addition, the perforated portion may be formed in close contact with a portion of the sealing portion formed along the peripheral edge of the battery case.
[20]
The battery module according to an embodiment of the present invention for solving the above problems is an electrode assembly formed by alternately stacking electrodes and separators, a battery case accommodating the electrode assembly therein, and accommodating the electrode assembly in the battery case A piezoelectric element disposed on the outside of the cup part to supply power to the outside by receiving pressure when the volume of the battery case expands, and one end is sharply formed, and when power is applied from the piezoelectric element, the one end is the battery a secondary battery extending toward the case and including a perforated portion for perforating the battery case; and a housing accommodating the secondary battery therein.
[21]
In addition, the perforated part may be made of an electroactive polymer (EAP).
[22]
In addition, the piezoelectric element may be attached to the inner surface of the housing.
[23]
In addition, the perforated portion may be formed in close contact with the inner edge of the housing.
[24]
In addition, the perforated part may perforate the cup part in the battery case.
[25]
The present invention also provides a battery pack including the battery module, and provides a device including the battery pack.
[26]
The device includes a computer, a notebook computer, a smart phone, a mobile phone, a tablet PC, a wearable electronic device, a power tool, an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid an electric vehicle (Plug-in Hybrid Electric Vehicle, PHEV) or an electric power storage device, but is not limited thereto.
[27]
Since the structure of the battery pack and device and their manufacturing method are known in the art, detailed description thereof will be omitted herein.
[28]
Other specific details of the invention are included in the detailed description and drawings.
Effects of the Invention
[29]
According to the embodiments of the present invention, there are at least the following effects.
[30]
During abnormal operation, when the volume of the battery case expands and power is generated from the piezoelectric element, the perforated part perforates the battery case to quickly discharge the gas generated inside the battery case to the outside to prevent explosion and secure stability. have.
[31]
The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present specification.
Brief description of the drawing
[32]
1 is an assembly view of a secondary battery according to an embodiment of the present invention.
[33]
2 is a perspective view of a secondary battery according to an embodiment of the present invention.
[34]
3 is a plan view of a secondary battery according to an embodiment of the present invention.
[35]
4 is an enlarged cross-sectional view of a secondary battery according to an embodiment of the present invention.
[36]
5 is a plan view of a secondary battery when one end of a perforated portion of the secondary battery is extended according to an embodiment of the present invention.
[37]
6 is an enlarged cross-sectional view of the secondary battery when one end of the perforated portion of the secondary battery is extended according to an embodiment of the present invention.
[38]
7 is an assembly view of a battery module according to another embodiment of the present invention.
[39]
8 is an assembly view of the battery module when one end of the perforated part of the battery module is extended according to another embodiment of the present invention.
Modes for carrying out the invention
[40]
Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.
[41]
Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly specifically defined.
[42]
The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural, unless specifically stated otherwise in the phrase. As used herein, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other components in addition to the stated components.
[43]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[44]
1 is an assembly view of a secondary battery 1 according to an embodiment of the present invention, and FIG. 2 is a perspective view of the secondary battery 1 according to an embodiment of the present invention.
[45]
According to an embodiment of the present invention, when the battery case 13 expands and power is generated from the piezoelectric element 135 during abnormal operation, the perforated part 136 perforates the battery case 13 to thereby perforate the battery case 13 . (13) It is possible to prevent explosion and secure stability by quickly discharging the gas generated in the inside to the outside.
[46]
To this end, the secondary battery 1 according to an embodiment of the present invention includes an electrode assembly 10 formed by alternately stacking electrodes and separators; a battery case 13 accommodating the electrode assembly 10 therein; A piezoelectric element ( 135); and one end 1361 is sharply formed, and when power is applied from the piezoelectric element 135 , the one end 1361 is extended toward the battery case 13 and a perforated portion for perforating the battery case 13 . (136).
[47]
The electrode assembly 10 is formed by alternately stacking electrodes and separators. First, a slurry in which an electrode active material, a binder, and a plasticizer are mixed is applied to a positive electrode current collector and a negative electrode current collector to prepare a positive electrode and a negative electrode, and the electrode assembly 10 having a predetermined shape is formed by laminating them on both sides of a separator Then, the electrode assembly 10 is inserted into the battery case 13, and the electrolyte is injected and then sealed.
[48]
Specifically, the electrode assembly 10 includes two types of electrodes, such as an anode and a cathode, and a separator interposed between the electrodes to insulate the electrodes from each other. The electrode assembly 10 may be of a stack type, a jelly roll type, a stack-and-fold type, or the like. Two types of electrodes, that is, a positive electrode and a negative electrode, have a structure in which an active material slurry is applied to an electrode current collector in the form of a metal foil or metal mesh including aluminum and copper, respectively. In general, the slurry may be formed by stirring a granular active material, an auxiliary conductor, a binder, a plasticizer, and the like in a state in which a solvent is added. The solvent is removed in a subsequent process.
[49]
As shown in FIG. 1 , the electrode assembly 10 includes an electrode tab 11 . The electrode tab 11 is respectively connected to the positive electrode and the negative electrode of the electrode assembly 10 , and protrudes from one side of the electrode assembly 10 to the outside, so that there is a path through which electrons can move between the inside and the outside of the electrode assembly 10 . do. The current collector of the electrode assembly 10 includes a portion to which the electrode active material is applied and a distal portion to which the electrode active material is not applied, that is, an uncoated portion. In addition, the electrode tab 11 may be formed by cutting the uncoated area or may be formed by connecting a separate conductive member to the uncoated area by ultrasonic welding or the like. As shown in FIG. 1 , the electrode tabs 11 may protrude side by side from one side of the electrode assembly 10 in the same direction, but are not limited thereto and may protrude in different directions.
[50]
An electrode lead 12 is connected to the electrode tab 11 of the electrode assembly 10 by spot welding or the like. A part of the electrode lead 12 is surrounded by the insulating portion 14 . The insulating part 14 is located limitedly in the sealing part 134 to which the upper case 131 and the lower case 132 of the battery case 13 are heat-sealed, and the electrode lead 12 is attached to the battery case 13 . glue it together In addition, electricity generated from the electrode assembly 10 is prevented from flowing to the battery case 13 through the electrode lead 12 , and the sealing of the battery case 13 is maintained. Accordingly, the insulating portion 14 is made of a non-conductive material that does not conduct electricity well. In general, as the insulating part 14, an insulating tape that is easy to attach to the electrode lead 12 and has a relatively thin thickness is often used. have.
[51]
One end of the electrode lead 12 is connected to the electrode tab 11 , and the other end protrudes to the outside of the battery case 13 , respectively. That is, the electrode lead 12 has one end connected to the positive electrode tab 111 , and one end connected to the positive electrode lead 121 and the negative electrode tab 112 extending in the protruding direction of the positive electrode tab 111 , and the negative electrode tab 112 includes a negative lead 122 extending in the protruding direction. On the other hand, as shown in FIG. 1 , the positive lead 121 and the negative lead 122 both have the other end protruding to the outside of the battery case 13 . Accordingly, electricity generated inside the electrode assembly 10 may be supplied to the outside. In addition, since the positive electrode tab 111 and the negative electrode tab 112 are formed to protrude in various directions, respectively, the positive electrode lead 121 and the negative electrode lead 122 may also extend in various directions.
[52]
The material of the positive lead 121 and the negative lead 122 may be different from each other. That is, the positive electrode lead 121 may be made of the same aluminum (Al) material as the positive electrode current collector, and the negative electrode lead 122 may be made of the same copper (Cu) material as the negative electrode current collector or nickel (Ni) coated copper. And a portion of the electrode lead 12 protruding to the outside of the battery case 13 becomes a terminal portion, and is electrically connected to the external terminal.
[53]
The battery case 13 is a pouch made of a soft material. Hereinafter, the battery case 13 will be described as a pouch. The battery case 13 accommodates and seals the electrode assembly 10 so that a portion of the electrode lead 12, that is, the terminal portion is exposed. As shown in FIG. 1 , the battery case 13 includes an upper case 131 and a lower case 132 . A cup portion 133 is formed in the lower case 132 to provide an accommodating space 1331 accommodating the electrode assembly 10 , and the upper case 131 has the electrode assembly 10 in the battery case 13 . The accommodation space 1331 is covered from the top so as not to be separated to the outside of the . At this time, as shown in FIG. 1 , the cup part 133 provided with the accommodation space 1331 is also formed in the upper case 131 , so that the electrode assembly 10 may be accommodated therein. The upper case 131 and the lower case 132 may be manufactured with one side connected to each other as shown in FIG.
[54]
A piezoelectric element (Piezoelectric Element, 135) is disposed on the outside of the cup portion 133, when the volume of the battery case 13 is expanded, the pressure is applied to supply power to the outside. In addition, one end 1361 of the perforated portion 136 is sharply formed, and when power is applied from the piezoelectric element 135 , the one end 1361 is extended toward the battery case 13 to hold the battery case 13 . perforate A detailed description of the piezoelectric element 135 and the perforated portion 136 will be described later.
[55]
When the electrode lead 12 is connected to the electrode tab 11 of the electrode assembly 10 and the insulating part 14 is formed on a portion of the electrode lead 12 , the cup part 133 of the lower case 132 is provided. The electrode assembly 10 is accommodated in the accommodation space 1331 , and the upper case 131 covers the space from the top. Then, the electrolyte is injected therein and the sealing part 134 formed on the edges of the upper case 131 and the lower case 132 is sealed. The electrolyte is to move lithium ions generated by the electrochemical reaction of the electrode during charging and discharging of the secondary battery 1, and a polymer using a non-aqueous organic electrolyte or a polymer electrolyte, which is a mixture of lithium salt and high-purity organic solvents. may include. Through this method, as shown in FIG. 2 , the pouch-type secondary battery 1 may be manufactured.
[56]
3 is a plan view of the secondary battery 1 according to an embodiment of the present invention, and FIG. 4 is an enlarged cross-sectional view of the secondary battery 1 according to an embodiment of the present invention.
[57]
As shown in FIG. 3 , the secondary battery 1 according to an embodiment of the present invention includes a piezoelectric element 135 and a perforated portion 136 . The piezoelectric element 135 is an element whose shape is deformed when applied with a physical external force such as pressure or stress, and a voltage is generated accordingly. Representative piezoelectric elements 135 include barium titanate, Rochelle salt, and the like.
[58]
The piezoelectric element 135 is disposed outside the cup portion 133 of the battery case 13 . Accordingly, when gas is generated inside the battery case 13 and the volume of the battery case 13 expands, pressure is applied. Accordingly, a voltage may be generated in the piezoelectric element 135 to supply power to the outside. In particular, according to an embodiment of the present invention, the piezoelectric element 135 may be directly attached to the outer surface of the cup portion 133 . Thereby, it is possible to respond sensitively to the expansion of the volume of the battery case 13 . That is, even if the volume of the battery case 13 is slightly expanded, it is possible to directly generate a voltage and supply power to the outside.
[59]
As shown in FIG. 3 , the piezoelectric element 135 may have a shape corresponding to the cup portion 133 . For example, if the cup part 133 has a rectangular shape, the piezoelectric element 135 also has a rectangular shape, and if the cup part 133 has a circular shape, the piezoelectric element 135 also has a circular shape. can Accordingly, in proportion to the degree of deformation when the cup portion 133 is deformed, the pressure may be applied to the piezoelectric element 135 .
[60]
In addition, the piezoelectric element 135 is preferably attached to the approximately central portion of the cup portion (133). If gas is generated inside the battery case 13 , the cup portion 133 having the greatest flexibility is deformed the most. At this time, since the piezoelectric element 135 is attached to the center of the cup part 133 , when the cup part 133 is deformed, the piezoelectric element 135 may receive pressure uniformly as a whole.
[61]
The perforated portion 136 may have a long and thin wire shape, and when power is applied from the piezoelectric element 135 , the shape is deformed to perforate the battery case 13 . Such a perforated portion 136 may be made of an electroactive polymer (ElectroActive Polymers, EAP). The electroactive polymer is a polymer that can be deformed such as expansion, contraction and bending by electrical stimulation. Representative electroactive polymers include ferroelectric polymers and dielectric elastomers. In particular, as ferroelectric polymers, polyvinylidene fluoride (PVDF)-based polymers with relatively large piezoelectric properties are widely used.
[62]
The perforated part 136 may be formed in close contact with the sealing part 134 of the battery case 13 as shown in FIG. 4 . Thereby, it is possible to prevent the perforated portion 136 from being damaged by external friction without significantly changing the size and shape of the secondary battery 1 . If the length of the perforated portion 136 is formed to a certain extent, as shown in FIG. 3 , the perforated portion 136 is a part of the sealing portion 134 formed along the peripheral edge of the battery case 13 . It can be formed in close contact. However, the present invention is not limited thereto, and the perforated portion 136 may be formed in the battery case 13 in various ways, such as being formed along the outer surface of the cup portion 133 accommodating the electrode assembly 10 in the battery case 13 . .
[63]
5 is a plan view of the secondary battery 1 when one end 1361 of the perforated portion 136 of the secondary battery 1 is extended according to an embodiment of the present invention, and FIG. 6 is an embodiment of the present invention. It is an enlarged cross-sectional view of the secondary battery 1 when one end 1361 of the perforated part 136 of the secondary battery 1 according to FIG.
[64]
When a pressure is applied to the piezoelectric element 135, a voltage is generated to supply power to the outside. That is, when gas is generated inside the battery case 13 and the volume of the battery case 13 expands, the piezoelectric element 135 receives pressure to supply power to the outside. In addition, the shape of the perforated portion 136 is changed when the one end 1361 is sharply formed and power is applied from the piezoelectric element 135 . In particular, as shown in FIG. 5 , one end 1361 of the perforated part 136 extends toward the battery case 13 , and the battery case 13 is perforated.
[65]
The perforated portion 136 is preferably a perforated cup portion 133 in the battery case 13 . As a result, the inside and outside of the battery case 13 are connected, and the gas generated inside the battery case 13 is rapidly discharged to the outside to prevent explosion and ensure stability.
[66]
One end 1361 of the perforated portion 136 is not located near the vertex of the cup portion 133 , but is located in the center of the corner of the cup portion 133 as shown in FIG. 5 . As a result, as shown in FIG. 6 when one end 1361 of the perforated portion 136 is extended, the cup portion 133 is easily perforated because the central portion of the corner has weaker rigidity than near the vertex of the cup portion 133 . can be
[67]
On the other hand, the other end 1362 of the perforated part 136 is not located in the center of the corner of the cup part 133 , but is located near the vertex of the cup part 133 as shown in FIG. 5 . In addition, the conductive wire 1351 connected to the piezoelectric element 135 is connected to the other end 1362 of the perforated portion 136 . Accordingly, it is possible to minimize the disconnection or damage of the conductive wire 1351 connected to the piezoelectric element 135 by an external obstacle.
[68]
7 is an assembly view of the battery module 2 according to another embodiment of the present invention.
[69]
According to an embodiment of the present invention, the piezoelectric element 135 is directly attached to the outer surface of the cup part 133 of the battery case 13 , and the perforated part 136 is attached to the sealing part 134 of the battery case 13 . is formed closely. Thereby, the piezoelectric element 135 can react sensitively to the expansion of the volume of the battery case 13 , and without significantly changing the size and shape of the secondary battery 1 , the perforated portion 136 is subjected to external friction. damage can be prevented.
[70]
However, according to another embodiment of the present invention, when the secondary battery 1a is assembled into the battery module 2, the piezoelectric element 135a and the perforated portion 136a are formed in the battery case 13 of the secondary battery 1a. Instead, it may be formed in the housing 20 of the battery module 2 . Accordingly, it is easier to fix the piezoelectric element 135a and the perforated portion 136a to the housing 20 having rigidity than the pouch-type battery case 13 having flexibility.
[71]
The battery module 2 according to another embodiment of the present invention includes an electrode assembly 10 formed by alternately stacking electrodes and a separator, a battery case 13 accommodating the electrode assembly 10 therein, and the battery case In (13), a piezoelectric element 135a disposed outside the cup portion 133 for accommodating the electrode assembly 10 and supplied with power to the outside by receiving a pressure when the volume of the battery case 13 expands; and , one end 1361a is sharply formed, and when power is applied from the piezoelectric element 135a, the one end 1361a is extended toward the battery case 13 and a perforated part for perforating the battery case 13 a secondary battery (1) including (136a); and a housing 20 accommodating the secondary battery 1 therein.
[72]
The housing 20 accommodates the secondary battery 1 therein, and as shown in FIG. 7 , the upper and lower housings 20 are coupled to each other at both sides of the secondary battery 1 to accommodate the secondary battery 1 . can be accepted The housing 20 may accommodate only one secondary battery 1 therein, but is not limited thereto and may accommodate a plurality of secondary batteries 1 .
[73]
The piezoelectric element 135a and the perforated part 136a according to another embodiment of the present invention are formed in the housing 20 of the battery module 2 . In particular, the piezoelectric element 135a is disposed on the outside of the cup portion 133 of the battery case 13 , but is attached to the inner surface of the housing 20 instead of being directly attached to the outer surface of the cup portion 133 . However, since the inner surface of the housing 20 and the cup part 133 of the battery case 13 are located very close to each other, when gas is generated inside the battery case 13 and the volume of the battery case 13 expands, the piezoelectric The element 135a directly supplies power to the outside.
[74]
The perforated portion 136a is formed in close contact with the inner edge of the housing 20 . In addition, the perforated portion 136a may have a long and thin wire shape, and when power is applied from the piezoelectric element 135a, the shape is deformed to perforate the battery case 13 . The perforated portion 136a may be made of an electroactive polymer (EAP).
[75]
8 is an assembly view of the battery module 2 when one end 1361a of the perforated portion 136a of the battery module 2 is extended according to another embodiment of the present invention.
[76]
When gas is generated inside the battery case 13 and the volume of the battery case 13 expands, the piezoelectric element 135a receives pressure to supply power to the outside. And, one end 1361a of the perforated portion 136a is sharply formed, and when power is applied from the piezoelectric element 135a, as shown in FIG. 8 , one end 1361a of the perforated portion 136a is the battery case. Extends toward (13), the battery case (13) is perforated.
[77]
The perforated portion 136a is preferably a perforated cup portion 133 in the battery case 13 . And one end 1361a of the perforated part 136a is located in the center of the corner of the cup part 133 . Accordingly, when the one end 1361a of the perforated portion 136a is extended, the cup portion 133 can be easily perforated.
[78]
Those of ordinary skill in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and various embodiments derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.
Claims
[Claim 1]
an electrode assembly formed by alternately stacking electrodes and separators; a battery case accommodating the electrode assembly therein; a piezoelectric element disposed outside the cup portion for accommodating the electrode assembly in the battery case, the piezoelectric element supplying power to the outside by applying pressure when the volume of the battery case expands; and a perforated part having one end formed sharply, and when power is applied from the piezoelectric element, the one end extending toward the battery case and perforating the battery case.
[Claim 2]
The secondary battery of claim 1 , wherein the perforated portion is made of an electroactive polymer (EAP).
[Claim 3]
The secondary battery of claim 1 , wherein the piezoelectric element is attached to an outer surface of the cup part.
[Claim 4]
The secondary battery of claim 1 , wherein the piezoelectric element is attached to the center of the cup part.
[Claim 5]
The secondary battery of claim 1 , wherein the piezoelectric element has a shape corresponding to the cup portion.
[Claim 6]
The secondary battery according to claim 1, wherein the conductive wire connected to the piezoelectric element is connected to the other end of the perforated part.
[Claim 7]
The secondary battery of claim 1 , wherein the perforated portion perforates the cup portion in the battery case.
[Claim 8]
The secondary battery of claim 1, wherein the perforated portion is formed in close contact with the sealing portion of the battery case.
[Claim 9]
The secondary battery according to claim 8, wherein the other end of the perforated part is located at a vertex of the battery case.
[Claim 10]
The rechargeable battery of claim 8 , wherein the perforated portion is formed in close contact with a portion of a sealing portion formed along a peripheral edge of the battery case.
[Claim 11]
An electrode assembly formed by alternately stacking electrodes and separators, a battery case for accommodating the electrode assembly therein, and a cup portion for accommodating the electrode assembly in the battery case, when the volume of the battery case expands, the pressure A piezoelectric element for supplying power to the outside by receiving a , and one end is sharply formed, and when power is applied from the piezoelectric element, the one end extends toward the battery case and includes a perforated part for perforating the battery case secondary battery; and a housing accommodating the secondary battery therein.
[Claim 12]
The battery module according to claim 11, wherein the perforated portion is made of an electroactive polymer (EAP).
[Claim 13]
The battery module according to claim 11, wherein the piezoelectric element is attached to an inner surface of the housing.
[Claim 14]
The battery module according to claim 11, wherein the perforated portion is formed in close contact with the inner edge of the housing.
[Claim 15]
The battery module of claim 11 , wherein the perforated portion perforates the cup portion in the battery case.
[Claim 16]
A battery pack comprising the battery module according to claim 11 .
[Claim 17]
A device comprising the battery pack according to claim 16 .