CN-122000607-A - Electrochemical device and electric equipment

Abstract

The application provides an electrochemical device and electric equipment, wherein the electrochemical device comprises a packaging bag, an electrode assembly, a first electrode lug, a second electrode lug and a deformation piece, the packaging bag is provided with a sealing part, the electrode assembly is accommodated in the packaging bag, one ends of the first electrode lug and the second electrode lug are respectively connected with the electrode assembly, the other ends of the first electrode lug and the second electrode lug extend out of the packaging bag from the sealing part respectively, at least part of the deformation piece is made of memory alloy, the deformation piece is in heat conduction connection with the electrode assembly, at least part of the deformation piece is arranged on the sealing part, the electrode assembly comprises a first pole piece, a second pole piece and a separation film arranged between the first pole piece and the second pole piece, and the deformation piece is connected with the first pole piece. The deformation piece can rapidly induce abnormal temperature change in the electrochemical device and deform, so that the packaging bag is broken, heat and pressure of the electrochemical device are released, the probability of safety accidents caused by overhigh temperature of the electrochemical device can be reduced, and the safety of the electrochemical device can be improved.

Inventors

• Jin Zhesheng

Assignees

• 宁德新能源科技有限公司

Dates

Publication Date

20260508

Application Date

20230327

Claims (15)

1. 1. An electrochemical device, comprising: a packaging bag having a sealing portion; an electrode assembly contained in the package bag; a first tab and a second tab, one end of each of which is connected to the electrode assembly, and the other end of which extends out of the packing bag from the sealing part; The deformation piece is at least partially made of memory alloy, is in heat conduction connection with the electrode assembly, and is at least partially arranged on the sealing part; The electrode assembly comprises a first pole piece, a second pole piece and an isolating film, wherein the isolating film is arranged between the first pole piece and the second pole piece, and the deformation piece is connected with the first pole piece.
2. 2. The electrochemical device of claim 1, wherein the deformation member comprises a first segment and a second segment connected to each other, the first segment being made of the memory alloy, at least a portion of the first segment being provided at the sealing portion, the second segment being further connected to the electrode assembly for conducting heat of the electrode assembly to the first segment.
3. 3. The electrochemical device of claim 2 wherein the material thermal conductivity of the second section is greater than the material thermal conductivity of the first section.
4. 4. The electrochemical device of claim 2, wherein the length of the first segment is a1 and the length of the deformable member is a2 along the extension direction of the deformable member, satisfying 1:10≤a1:a2 <1:1.
5. 5. The electrochemical device of claim 1, wherein the deformation member is integrally made of the memory alloy.
6. 6. The electrochemical device of claim 1, wherein the deformable member has a polygonal or elliptical cross-section.
7. 7. The electrochemical device of claim 1, wherein the memory alloy has a recovery stress of F, satisfying 100 mpa≤f≤500 MPa.
8. 8. The electrochemical device of claim 1, wherein the thickness of the deformation member is less than the thickness of the first tab and the thickness of the second tab, respectively.
9. 9. The electrochemical device according to claim 1, wherein the first tab, the second tab, and the deformation member are located at the same end in a length direction of the electrochemical device.
10. 10. The electrochemical device according to claim 9, wherein the first tab and the second tab are disposed at intervals in a width direction of the electrochemical device, and the deformation member is located between the first tab and the second tab.
11. 11. The electrochemical device according to claim 10, wherein a distance between the first tab and the second tab in a width direction of the electrochemical device is b1, and a dimension of the deformation member in the width direction of the electrochemical device is b2, such that b2 is equal to or less than b1-2mm.
12. 12. The electrochemical device according to claim 9, wherein the first tab and the deformation member are disposed at an interval in a width direction of the electrochemical device, and the second tab is located between the first tab and the deformation member.
13. 13. The electrochemical device according to claim 1, wherein the first electrode sheet comprises a coating region provided with an active material layer on both sides and an empty current collector region provided with an active material layer on one side and an active material layer on the other side, the deformation member is connected to the side of the empty current collector region where the active material layer is not provided, and the deformation member passes through the sealing portion and is connected with the sealing portion by a gel.
14. 14. The electrochemical device of claim 1, wherein the portion of the deformation member located within the package is coated with a thermally conductive and insulating layer.
15. 15. An electrical consumer comprising an electrochemical device according to any one of claims 1-14.

Description

Electrochemical device and electric equipment The application relates to a divisional application of China patent application 202310303045.5 which is filed on 27 days of 2023 and 03 and is named as an electrochemical device and electric equipment. Technical Field The application relates to the technical field of batteries, in particular to an electrochemical device and electric equipment. Background With the high-speed development of mobile terminals, electric automobiles and the like, the requirements on the charging speed and capacity of the battery are higher, and accordingly, the safety requirements on the battery are also higher, and the requirements on the hot box test of the battery are also more and more strict. Therefore, how to improve the safety of the battery is a problem to be solved in the battery field. At present, when carrying out quick charge or hot box test to the battery, the inside short time of battery can make electrolyte decompose into gas simultaneously in a large number of heats, causes the inside pressure of battery to increase fast, and current pressure release structure can not in time make the reaction to the inside high temperature of battery and in time the pressure release, will cause situations such as explosion, has the potential safety hazard. Disclosure of Invention The application aims to provide an electrochemical device and electric equipment so as to improve the safety of a battery. In a first aspect, the present application provides an electrochemical device comprising: an electrode assembly contained in the package bag; one ends of the first electrode lug and the second electrode lug are respectively connected with the electrode assembly, and the other ends of the first electrode lug and the second electrode lug extend out of the packaging bag from the sealing part respectively; The deformation piece is at least partially made of memory alloy, is in heat conduction connection with the electrode assembly, and is at least partially arranged on the sealing part. In the above technical scheme, set up the deformation spare of at least partly being made by memory alloy, and make deformation spare and electrode assembly heat conduction be connected, the sealing portion of wrapping bag is located to at least part of deformation spare, when electrode assembly's temperature is higher, make deformation spare can quick induction electric chemistry device in the temperature anomaly change and produce deformation, thereby help break open the wrapping bag, with release electrochemical device's heat and pressure, and then can reduce the probability of causing the incident because of electrochemical device's high temperature, can improve electrochemical device's security. In some embodiments, the deformation member includes a first segment and a second segment connected to each other, the first segment being made of a memory alloy, at least a portion of the first segment being disposed in the seal, the second segment being further connected to the electrode assembly for conducting heat from the electrode assembly to the first segment. In the above technical scheme, divide into first section and second section with deformation spare, first section is made by memory alloy, and at least part locates in the sealing, can deform in order to break the wrapping bag, realizes electrochemical device's heat and release of pressure, and the second section still is connected with electrode assembly for with electrode assembly's heat conduction to first section for first section can be heated deformation. In some embodiments, the material thermal conductivity of the second section is greater than the material thermal conductivity of the first section. In the above technical scheme, the material coefficient of heat conductivity of the second section is greater than the material coefficient of heat conductivity of the first section, so that the second section can transfer heat to the first section more quickly, the first section can be deformed by heating more quickly to break the packaging bag, and the heat and pressure release of the electrochemical device is realized. In some embodiments, the length of the first segment is a1 and the length of the deformable member is a2 along the extension direction of the deformable member, satisfying 1:10≤a1:a2 <1:1. In the above technical scheme, along the extending direction of the deformation piece, the length of the first section is a1, the length of the deformation piece is a2, and the requirements are met that 1:10 is less than or equal to a1:a2 is less than or equal to 1:1, on one hand, the deformation piece can generate enough deformation quantity to break the packaging bag so as to release heat and pressure of the electrochemical device, and on the other hand, the second section can accelerate the heat conduction speed of the deformation piece so as to generate deformation faster to break the packaging bag, and further improve the safety of the elec