Battery cells, batteries, and power consumption devices

Abstract

The present invention provides a battery cell, a battery, and a power consumption device that can satisfy the requirements for releasing internal gases from the battery cell while guaranteeing the safety performance of the battery cell. [Solution] The battery cell comprises an electrode assembly, a case 22 housing the electrode assembly, and a cover assembly closing the opening of the case. The case comprises a first wall 221 and two opposing second walls 222. The first wall connects the two second walls, and the thickness of the first wall is greater than the thickness of the second walls. The first wall is provided with a pressure release mechanism that operates to release pressure when the gas pressure inside the case reaches a threshold.

Description

Technical Field

[0001] This application relates to the field of energy storage technologies, and particularly to battery cells, batteries, and power-consuming devices.

Background Art

[0002] Batteries are widely used in electronic devices such as mobile phones, laptop computers, electric scooters, electric vehicles, electric airplanes, electric boats, electric vehicle toys, electric boat toys, electric airplane toys, and electric tools.

[0003] In the development of battery technologies, in addition to improving the performance of battery cells, safety issues are also problems that should be considered. Therefore, how to improve the safety of battery cells is an issue to be solved in battery technologies.

Summary of the Invention

[0004] Embodiments of this application provide a battery cell, a battery, and a power-consuming device that can meet the requirements for discharging internal gas of the battery cell and ensure the safety performance of the battery cell.

[0005] According to one aspect, embodiments of this application include an electrode assembly, a case for housing the electrode assembly, and a cover assembly for closing the opening of the case. The case includes a first wall and two second walls provided opposite to each other. The first wall connects the two second walls, and the thickness of the first wall is greater than the thickness of the second wall. A pressure relief mechanism is provided on the first wall, which operates to release pressure when the internal gas pressure of the case reaches a threshold value, providing a battery cell.

[0006] According to one aspect of the embodiments of this application, the thickness of the first wall is D1, the thickness of the second wall is D2, and D1 and D2 satisfy 0.05mm ≤ D1 - D2 ≤ 3mm.

[0007] According to one aspect of the embodiments of this application, the thickness of the first wall is 0.5mm or more.

[0008] According to one embodiment of the present invention, in the width direction of the first wall, the minimum distance d between the edge of the first wall and the pressure release mechanism is greater than 2 mm.

[0009] According to one embodiment of the present invention, the pressure release mechanism has a length dimension L and a width dimension D, where L and D satisfy L / D ≤ ​​8.

[0010] According to one embodiment of the present invention, the dimensions of the pressure release mechanism in the longitudinal direction of the first wall are length L, and the dimensions of the pressure release mechanism in the width direction of the first wall are D, such that L > D.

[0011] According to one embodiment of the present invention, the area of ​​the first wall is smaller than the area of ​​the second wall.

[0012] According to one embodiment of the present invention, openings are formed at both ends of the case, and each opening is closed by a cover assembly, and the case further comprises a third wall for connecting two second walls, the third wall being provided opposite the first wall, the thickness of the first wall being greater than or equal to the thickness of the third wall, and the thickness of the third wall being greater than the thickness of the second wall.

[0013] According to one embodiment of the present invention, the first wall has a through hole extending along the thickness direction of the first wall, the pressure release mechanism is provided inside the through hole, and in the thickness direction, at least one of the surface of the first wall facing the electrode assembly and the surface away from the electrode assembly is provided at a distance from the pressure release mechanism.

[0014] According to one embodiment of the present invention, the through hole is a stepped hole comprising a first hole segment, a second hole segment, and a first stepped surface connected between the first hole segment and the second hole segment, wherein the hole diameter of the first hole segment is smaller than the hole diameter of the second hole segment, the second hole segment is located on the side of the first hole segment away from the electrode assembly, a pressure release mechanism is provided in the second hole segment, and the first stepped surface is used to support the pressure release mechanism.

[0015] According to one embodiment of the present invention, the through hole further comprises a third hole segment and a second stepped surface, wherein the third hole segment is provided on the side of the second hole segment away from the first hole segment, and the second stepped surface is connected to the second hole segment and the third hole segment.

[0016] According to one embodiment of the present invention, the battery cell further comprises a protective film, the protective film being provided on the side away from the electrode assembly of the pressure release mechanism and spaced apart from the pressure release mechanism, and a chamber being formed between the protective film, the hole wall of the through hole, and the pressure release mechanism.

[0017] According to one embodiment of the present invention, the protective film is attached to a surface of the first wall away from the electrode assembly, and a communication mechanism is provided on the surface of the first wall away from the electrode assembly, with one end communicating with the chamber and the other end communicating with the external space.

[0018] According to one embodiment of the present invention, the through hole further comprises a fourth hole segment and a third stepped surface, the fourth hole segment being provided on the side of the third hole segment away from the second hole segment, the third stepped surface being connected to the third hole segment and the fourth hole segment, and the third stepped surface being provided with a communication mechanism having one end in communication with a chamber and the other end in communication with the external space.

[0019] In another embodiment, an embodiment of the present application provides a battery comprising the above-mentioned battery cell and a cooling member that covers at least a portion of the case and cools the battery cell.

[0020] In another embodiment of the present invention, in the thickness direction of the first wall, the cooling member is provided facing the first wall at least partially with a gap between them, and the cover assembly is located between the cooling member and the first wall.

[0021] According to another embodiment of the present invention, the cooling member comprises a first cooling plate and a second cooling plate spaced apart in the thickness direction, the first cooling plate having relief holes, the first cooling plate covering a first wall where the pressure release mechanism is located and the relief holes releasing pressure from the pressure release mechanism, and the second cooling plate covering the side of the case away from the pressure release mechanism.

[0022] In yet another embodiment, the present invention provides a power consumption device comprising the above-mentioned battery for supplying electrical energy.

[0023] According to the embodiment of the present invention, the battery cell, battery, and power consumption device comprises an electrode assembly, a case, and a cover assembly. The electrode assembly is housed in the case, and the opening of the case is closed by the cover assembly. The case comprises a first wall and two opposing second walls. The first wall connects the two second walls, and a pressure release mechanism is provided in the first wall. When the gas pressure inside the case reaches a threshold, the pressure release mechanism operates to release the pressure, thereby ensuring the safety performance of the battery cell. Furthermore, by making the thickness of the first wall greater than the thickness of the second walls, the thickness of the first wall is increased, strengthening the support of the explosion-proof valve by the first wall, improving the service life of the explosion-proof valve, and further ensuring the safety performance of the battery cell.

[0024] The above description is merely an outline of the proposed technology, and to better understand the technical means of this application, it can be implemented according to the specifications. To make the above and other objectives, features, and advantages of this application easier to understand, specific embodiments of this application are listed below. [Brief explanation of the drawing]

[0025] The features, advantages, and technical effects of exemplary embodiments of the present application will be described below with reference to the drawings.

[0026] [Figure 1] It is a schematic structural diagram of a vehicle according to some embodiments of the present application.

[0027] [Figure 2] It is an exploded view of a battery according to some embodiments of the present application.

[0028] [Figure 3] It is a schematic exploded structural diagram of a battery cell according to some embodiments of the present application.

[0029] [Figure 4] It is a schematic structural diagram of a case of one embodiment of the present application.

[0030] [Figure 5] It is a bottom view of a battery of one embodiment of the present application.

[0031] [Figure 6] It is an exploded view of a case of one embodiment of the present application.

[0032] [Figure 7] It is a partial cross-sectional view of a case of one embodiment of the present application.

[0033] [Figure 8] It is a schematic combination diagram of a case, a pressure relief mechanism, and a protective film of one embodiment of the present application.

[0034] [Figure 9] It is a partially enlarged view at location A in FIG. 8.

[0035] [Figure 10] It is an exploded view of a battery of another embodiment of the present application.

[0036] 1000 vehicles

[0037] 100 batteries 200 controllers 300 motor

[0038] 10 cabinets 11 Part 1 12. Part 2 13 Containment Space

[0039] 20 battery cells

[0040] 21 Cover Assembly 21a Electrode terminal 21b Lid plate

[0041] 22 cases 22a opening 221 The First Wall 222 The second wall 223 The Third Wall 224 Through hole 2241 First hole segment 2242 Second hole segment 2243 First stepped surface 2244 Third hole segment 2245 Second stepped surface 2246 Fourth hole segment 2247 Third stepped surface

[0042] 23 Electrode assembly

[0043] 24 Pressure release mechanism

[0044] 25 Protective film

[0045] 26 Communication mechanism

[0046] 27 Chambers

[0047] 30 Cooling components 31 First cooling plate 32. Second cooling plate 321 Escape hole

[0048] In the drawings, identical components are given the same reference numeral. The drawings are not drawn to actual scale. [Modes for carrying out the invention]

[0049] To further clarify the purpose, technical concept, and advantages of the embodiments of this application, the technical concept of the embodiments of this application will be clearly described below with reference to the drawings of the embodiments. Clearly, the embodiments described are only some, not all, embodiments of this application. All other embodiments obtained by a person skilled in the art without creative work based on the embodiments of this application are within the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Terms used herein are solely for the purpose of describing specific embodiments and are not intended to limit the application. The terms “equipped with” and “possessing,” and any variations thereof, in the description of the specification and claims of this application, as well as the accompanying drawings, are intended to cover the exclusive exclusions. Terms such as “first,” “second,” etc., in the specification and claims of this application or in the drawings, are for the purpose of distinguishing different subjects and are not intended to describe any particular order or subordination.

[0051] The “Examples” as used herein means that certain features, structures, or properties described with reference to the Examples may be included in at least one Example of this Application. The phrase “Examples” appearing in each location herein does not necessarily refer to the same Example, nor are they mutually exclusive, independent, or alternative Examples.

[0052] In this description, unless otherwise specifically defined and limited, the terms “attachment,” “connection,” “linking,” and “mounting” should be understood in a broad sense, for example, that a connection may be fixed, detachably connected, integrally connected, directly connected, indirectly connected via an intermediate medium, or internally connected to two elements. A person skilled in the art will be able to understand the specific meaning of these terms in this application depending on the specific circumstances.

[0053] In this application, the term "and / or" merely describes a relationship of relation that explains the related objects, and indicates that there may be three such relationships. For example, A and / or B may indicate three situations: A existing alone, A and B existing simultaneously, and B existing alone. In addition, the character " / " in this application generally indicates that the related objects before and after it are in an "or" relationship.

[0054] In the embodiments of this application, the same reference numerals indicate the same component, and for the sake of brevity, detailed descriptions of the same component are omitted in different embodiments. The dimensions such as thickness, length, and width of various components in the embodiments of this application shown in the drawings, as well as the overall thickness, length, and width of the accumulating device, are for illustrative purposes only and do not limit this application in any way.

[0055] The term "multiple" as used in this application refers to two or more (having two or more).

[0056] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, but the embodiments of this application are not limited to these. The battery cell may be flattened, rectangular, or have other shapes, but the embodiments of this application are not limited to these.

[0057] The battery described in the embodiments of this application refers to a single physical module comprising one or more battery cells that provides higher voltage and capacity. For example, the battery described in this application may include a battery module or a battery pack. The battery generally comprises a housing for packaging one or more battery cells. The housing can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0058] A battery cell comprises an electrode assembly consisting of a positive electrode sheet, a negative electrode sheet, and a separator, and a case for housing the electrode assembly. The battery cell operates primarily by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. A positive electrode current collector without the positive electrode active material layer protrudes from a positive electrode current collector with the positive electrode active material layer, and a positive electrode current collector without the positive electrode active material layer forms a positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. Negative electrode current collectors without the negative electrode active material layer protrude from negative electrode current collectors with the negative electrode active material layer, and negative electrode current collectors without the negative electrode active material layer form negative electrode tabs. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc. To ensure that it does not melt under high current, the positive electrode tabs are stacked in multiple layers, and the negative electrode tabs are stacked in multiple layers. The material of the separator may be PP (polypropylene) or PE (polyethylene), etc. Furthermore, the electrode assembly may have a wound structure or a laminated structure, but the embodiments of this application are not limited to these.

[0059] The development of battery technology requires the simultaneous consideration of a wide range of design factors, such as energy density, cycle life, discharge capacity, and charge / discharge ratio, as well as battery safety.

[0060] In battery cells, after multiple charge-discharge cycles, side reactions occur, and gas is continuously generated. This creates a constant pressure inside the battery cell, and as the pressure rises, the gas between the sheets is not removed in a timely manner, affecting the insertion and removal of lithium ions and further increasing the risk of lithium deposition. To ensure the safety of battery cells, a pressure release mechanism is generally provided in the battery cell case. This mechanism releases the gas generated inside the battery cell, thereby ensuring the safety of the battery cell.

[0061] The inventors discovered that during the use of a battery cell, the wall portion of the case, which corresponds to the pressure release mechanism, lacked sufficient support for the mechanism, affecting the lifespan of the pressure release mechanism and potentially posing a safety risk to the battery cell.

[0062] Through further extensive research, the inventors discovered that existing battery cell cases typically employ a design where each side wall is of equal thickness, and that the side walls are usually designed to be thin in order to secure usable space for the battery cell and improve its energy density. Consequently, the connection area between the pressure release mechanism and the corresponding side wall of the case is small, which is unfavorable for the connection between the pressure release mechanism and the side wall of the case, resulting in weak support for the pressure release mechanism by the side wall and further affecting the service life of the pressure release mechanism.

[0063] In view of this, an embodiment of the present invention provides a battery cell comprising an electrode assembly, a case housing the electrode assembly, and a cover assembly closing the opening of the case, wherein the case comprises a first wall and two opposing second walls, the first wall being for connecting the two second walls, the thickness of the first wall being greater than the thickness of the second walls, and the first wall being provided with a pressure release mechanism that operates to release pressure when the gas pressure inside the case reaches a threshold.

[0064] Compared to existing battery cells, the thickness of the first wall where the pressure release mechanism is located is increased, strengthening the support of the explosion-proof valve by the first wall, improving the service life of the explosion-proof valve, and further guaranteeing the safety performance of the battery cell.

[0065] The battery cell described in the embodiment of this application is applicable to batteries, power consumption devices and equipment that use batteries.

[0066] Power-consuming devices and equipment may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and power tools. Vehicles may be engine-driven vehicles, natural gas vehicles, or new energy vehicles, and new energy vehicles may be pure electric vehicles, hybrid vehicles, or range-extender vehicles. Spacecraft may include airplanes, rockets, spaceplanes, and spacecraft. Electric toys may include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric boat toys, and electric airplane toys. Power tools may include metal cutting power tools, polishing power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. The embodiments of this application are not particularly limited to the above-mentioned power-consuming devices.

[0067] For the sake of explanation, the following embodiments will be described using the example that the power consumption device is a vehicle.

[0068] Referring to Figure 1, Figure 1 is a schematic diagram of the structure of a vehicle 1000 according to some embodiments of the present application. The vehicle 1000 may be an engine-driven vehicle, a natural gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be located at the bottom, head, or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as the operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, to meet the operating power requirements for starting, navigating, and driving the vehicle 1000.

[0069] In some embodiments of the present invention, the battery 100 can be used not only as an operating power source for the vehicle 1000, but also as a drive power source for the vehicle 1000, providing driving force to the vehicle 1000 by replacing or partially replacing fuel or natural gas.

[0070] Referring to Figure 2, which is an exploded view of a battery 100 according to several embodiments of the present invention, the battery 100 comprises a housing 10 and battery cells 20 housed within the housing 10. The housing 10 is used to provide a housing space for the battery cells 20, and the housing 10 can employ various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 covering and joining together, and the first portion 11 and the second portion 12 together define a housing space 13 for housing the battery cells 20. The second portion 12 may be a hollow structure with one end open, and the first portion 11 may be a plate-like structure, with the first portion 11 covering the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a housing space 13. Both the first part 11 and the second part 12 are hollow structures with one side open, and the open side of the first part 11 may be fitted over the open side of the second part 12. Of course, the housing 10 formed by the first part 11 and the second part 12 may be of various shapes, such as a cylinder or a rectangular parallelepiped.

[0071] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that some of the multiple battery cells 20 are connected in series, while others are connected in parallel. The multiple battery cells 20 are directly connected in series, parallel, or series-parallel, and the entire assembly of the multiple battery cells 20 is housed in the housing 10. Of course, the battery 100 may also be configured as a battery module by first connecting multiple battery cells 20 in series, parallel, or series-parallel, and then the multiple battery modules may be further connected in series, parallel, or series-parallel to form an integrated unit, which is then housed in the housing 10. The battery 100 may further include other structures; for example, the battery 100 may further include bus members for realizing electrical connections between the multiple battery cells 20.

[0072] Each battery cell 20 may be a secondary battery or a primary battery, and may be, but is not limited to, a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery. The battery cell 20 may be flattened, rectangular, or have other shapes.

[0073] As shown in Figures 3 and 4, the battery cell 20 refers to the smallest unit that constitutes a battery. The battery cell 20 comprises a case 22, an electrode assembly 23, and a cover assembly 21. The case 22 is configured to house the electrode assembly 23, and the cover assembly 21 is configured to close the opening 22a of the case 22. The case 22 comprises a first wall 221 and two opposing second walls 222. The first wall 221 is configured to connect the two second walls 222, and the thickness of the first wall 221 is greater than the thickness of the second walls 222. The first wall 221 is provided with a pressure release mechanism 24, which operates to release pressure when the gas pressure inside the case 22 reaches a threshold.

[0074] Optionally, the case 22 has a housing space, and the first wall 221 and the second wall 222 contained in the case 22 may be arranged intersectingly or perpendicular to each other. The distance between the two second walls 222 may be set according to the size of the electrode assembly 23, which is located between the first wall 221 and the second wall 222.

[0075] The thickness of the first wall 221 can be understood as the thickness of each portion of the first wall 221 in a direction perpendicular to the surface of the first wall 221 facing the internal storage space of the case 22.

[0076] The thickness of the second wall 222 can be understood as the thickness of each portion of the second wall 222 in a direction perpendicular to the surface of the second wall 222 that faces the internal storage space of the case 22.

[0077] The thicknesses of the two second walls 222 may be equal, or one may be thicker than the other.

[0078] The number of openings 22a included in case 22 may be one or two, and in the case of two, the two openings 22a may be spaced apart and facing each other.

[0079] Optionally, the cover assembly 21 is a component that covers the opening 22a of the case 22 so as to isolate the internal environment of the battery cell 20 from the external environment. The shape of the cover assembly 21 may be such that it engages with the case 22 to match the shape of the case 22.

[0080] The cover assembly 21 may be optionally manufactured from a material having a certain hardness and strength (e.g., an aluminum alloy), so that the cover assembly 21 is less likely to deform when pressed and impacted, and the battery cell 20 has higher structural strength, thereby improving safety performance. The cover assembly 21 may include functional components such as electrode terminals 21a. The electrode terminals 21a may be electrically connected to the electrode assembly 23 to output or input electrical energy from the battery cell 20. The material of the cover assembly 21 may be any of several types, such as copper, iron, aluminum, stainless steel, aluminum alloy, or plastic, but the embodiments of this application are not particularly limited to these.

[0081] As shown in Figures 3 and 4, the case 22 is a component that works in cooperation with the cover assembly 21 to form the internal environment of the battery cell 20, and the formed internal environment is used to house the electrode assembly 23, electrolyte, and other components. The case 22 and the cover assembly 21 may be separate components, and the internal environment of the battery cell 20 may be formed by providing an opening 22a in the case 22 and placing the cover assembly 21 over the opening 22a.

[0082] Although not limited thereto, the cover assembly 21 and the case 22 may be integrated. Specifically, the cover assembly 21 and the case 22 may form a common connecting surface before other components enter the case, and the cover assembly 21 may be placed over the case 22 when it is necessary to seal the inside of the case 22. The case 22 may have various shapes and sizes, such as a rectangular parallelepiped or a hexagonal prism. Specifically, the shape of the case 22 may be determined according to the specific shape and size of the electrode assembly 23. The material of the case 22 may be one of several types, such as copper, iron, aluminum, stainless steel, aluminum alloy, or plastic, but the embodiments of this application are not particularly limited thereto.

[0083] The electrode assembly 23 is a component that generates an electrochemical reaction in the battery cell 20. The case 22 may contain one or more electrode assemblies 23. The electrode assembly 23 is mainly formed by winding or laminating a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The portions of the positive electrode sheet and the negative electrode sheet that have active material constitute the main body of the electrode assembly 23, and the portions of the positive electrode sheet and the negative electrode sheet that do not have active material each constitute a tab. The positive electrode tab and the negative electrode tab may both be located at one end of the main body, or they may each be located at both ends of the main body. During the charging and discharging process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs are connected to the electrode terminals 21a to form an electrical circuit.

[0084] The pressure release mechanism 24 is provided on the first wall 221 of the case 22 and releases the gas to the outside of the case 22 when the gas pressure inside the case 22 reaches a threshold. The pressure release mechanism 24 may be an explosion-proof valve that ruptures or opens to release the gas to the outside of the case 22 when the pressure reaches a threshold.

[0085] The pressure release mechanism 24 and the first wall 221 of the case 22 may be an integrated structure, or they may be manufactured as separate parts and connected as a single unit. For example, if they are provided as separate parts, they may be connected to each other by welding or other methods.

[0086] The battery cell 20 according to the embodiment of the present invention is provided such that an electrode assembly 23 is housed in a case 22 and an opening 22a of the case 22 is closed by a cover assembly 21. The case 22 comprises a first wall 221 and two opposing second walls 222, the first wall 221 being used to connect the two second walls 222, and a pressure release mechanism 24 is provided in the first wall 221 so that when the gas pressure inside the case 22 reaches a threshold, the pressure release mechanism 24 is activated to release the pressure, thereby ensuring the safety performance of the battery cell 20. Furthermore, by making the thickness of the first wall 221 greater than that of the second wall 222, the thickness of the first wall 221 is increased, strengthening the support of the explosion-proof valve by the first wall 221, increasing the connection area between the pressure release mechanism 24 and the first wall 221, thereby avoiding damage to the pressure release mechanism 24 due to insufficient connection strength between the first wall 221 and the pressure release mechanism 24 when the pressure release mechanism 24 is activated, improving the service life of the pressure release mechanism 24, and further guaranteeing the safety performance of the battery cell 20.

[0087] In some preferred embodiments, the thickness of the first wall 221 is D1, and the thickness of the second wall 222 is D2, such that D1 and D2 satisfy 0.05 mm ≤ D1 - D2 ≤ 3 mm.

[0088] The difference between the thickness D1 of the first wall 221 and the thickness D2 of the second wall 222 may be any value between 0.05 mm and 3 mm, and includes two values: 0.05 mm and 3 mm.

[0089] According to the above configuration, it is possible to control the thickness of the first wall 221 and the second wall 222 within an appropriate range, ensuring the connection and support requirements of the first wall 221 to the pressure release mechanism 24, while avoiding the problem of the thickness difference between the first wall 221 and the second wall 222 being too large, which would increase the difficulty of manufacturing the case 22. Furthermore, it is possible to ensure the required housing space of the case 22 and improve the energy density of the battery cells 20.

[0090] In some selectable embodiments, D1 and D2 may satisfy 0.1 mm ≤ D1-D2 ≤ 0.7 mm. This is advantageous for the processing of case 22 and ensures the energy density of the battery cell 20.

[0091] In some selectable embodiments, the thickness of the first wall 221 is 0.5 mm or more, and the thickness of the first wall 221 may be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc.

[0092] By adopting the above structural form for the first wall 221, the first wall 221 has sufficient thickness, which is advantageous for connection to and support of the pressure release mechanism 24, and improves the service life of the pressure release mechanism 24.

[0093] As shown in Figures 3 to 5, in some selectable embodiments, the minimum distance d between the edge of the first wall 221 and the pressure release mechanism 24 in the width direction of the first wall 221 is greater than 2 mm.

[0094] The width direction of the first wall 221 is perpendicular to the thickness direction of the first wall 221, and the edges of the first wall 221 may be understood as the outermost outline shape of the first wall 221. If the shape of the first wall 221 is rectangular, the edges of the first wall 221 are the outermost rectangular contour of the first wall 221.

[0095] By making the minimum distance d between the edge of the first wall 221 and the pressure release mechanism 24 greater than 2 mm, the connection requirements between the first wall 221 and the pressure release mechanism 24 can be ensured during the process of connecting them after the pressure release mechanism 24 is integrally molded with or separately provided with the first wall 221, thereby avoiding difficulties in molding or connecting them in their molded or connected form due to the minimum distance d between them being too small.

[0096] In some selectable embodiments, the length dimension of the pressure release mechanism 24 is L, the width dimension is D, and L and D satisfy L / D ≤ ​​8.

[0097] The longitudinal and width directions of the pressure release mechanism 24 and the thickness direction of the first wall 221 are perpendicular to each other.

[0098] According to the above configuration, the pressure release mechanism 24 is less prone to deformation during the process of being molded integrally with the first wall 221 or connected to each other after being installed separately. When the internal pressure of the battery cell 20 exceeds a preset threshold, the pressure release mechanism 24 can be activated to reduce pressure fluctuations and improve the safety performance of the battery cell 20.

[0099] In one possible configuration, the dimensions of the pressure release mechanism 24 in the longitudinal direction of the first wall 221 are length L, and the dimensions of the pressure release mechanism 24 in the width direction of the first wall 221 are D, such that L > D.

[0100] The longitudinal direction of the first wall 221 may coincide with the longitudinal direction of the pressure relief mechanism 24, and the width direction of the first wall 221 may coincide with the width direction of the pressure relief mechanism 24. With the above arrangement, the shape of the pressure relief mechanism 24 conforms to the shape of the first wall 221, ensuring the connection requirements between the pressure relief mechanism 24 and the first wall 221, and when the gas pressure inside the case 22 reaches a threshold, the pressure relief mechanism 24 is activated to help release the pressure.

[0101] In some selectable embodiments, the area of ​​the first wall 221 is smaller than the area of ​​the second wall 222.

[0102] The area of ​​the first wall 221 refers to the area of ​​the outer shape of the orthographic projection of the first wall 221 in its own thickness direction. For example, if the orthographic projection of the first wall 221 in its own thickness direction is a rectangle, then its area is the area of ​​the outer ring of that rectangle.

[0103] The area of ​​the second wall 222 refers to the area of ​​the outer shape of the orthographic projection of the second wall 222 in its own thickness direction. For example, if the orthographic projection of the second wall 222 in its own thickness direction is a rectangle, then its area is the area of ​​the outer ring of that rectangle.

[0104] By making the area of ​​the first wall 221 smaller than the area of ​​the second wall 222, when subjected to the same pressure, the pressure exerted on the first wall 221 becomes greater because the area of ​​the first wall 221 is smaller than the area of ​​the second wall 222. This is advantageous for the pressure release mechanism 24 located on the first wall 221 to activate and release the pressure.

[0105] As shown in Figures 3 to 6, in several selectable embodiments, openings 22a are formed at both ends of the case 22, and each opening 22a is closed by a cover assembly 21. The case 22 further comprises a third wall 223 for connecting two second walls 222, the third wall 223 being provided opposite the first wall 221, the thickness of the first wall 221 being greater than or equal to the thickness of the third wall 223, and the thickness of the third wall 223 being greater than the thickness of the second wall 222.

[0106] The shape of the openings 22a formed at both ends of the case 22 may be the same, preferably rectangular.

[0107] The third wall 223 is optionally provided symmetrically with a gap between it and the first wall 221, the first wall 221 may be located at the same end of the two second walls 222, and the third wall 223 may be located at the other end of the two second walls 222.

[0108] Selectively, the thickness of the third wall 223 may be understood as the thickness of each portion of the third wall 223 in a direction perpendicular to the surface of the third wall 223 facing the accommodation space inside the case 22.

[0109] Selectively, the thickness direction of the third wall 223 coincides with the thickness direction of the first wall 221.

[0110] The adoption of the above structural configuration in case 22 is advantageous for extending the electrode terminals 21a to both sides. Furthermore, the thickness of the first wall 221 is greater than or equal to the thickness of the third wall 223, and the thickness of the third wall 223 is greater than the thickness of the second wall 222. By appropriately thickening the third wall 223, it is advantageous to reinforce the strength of case 22 and improve the safety performance of case 22. At the same time, the asymmetry between the top and bottom of case 22 can be improved, and the problem of cracks caused by mismatches in material flow rates during the mold extrusion process can be solved.

[0111] In some selectable embodiments, the first wall 221 has a through hole 224 extending in the thickness direction of the first wall 221, and the pressure relief mechanism 24 is provided inside the through hole 224, and at least one of the surfaces of the first wall 221 facing the electrode assembly 23 and the surfaces away from the electrode assembly 23 is spaced apart from the pressure relief mechanism 24 in the thickness direction.

[0112] In the thickness direction of the first wall 221, the surface of the first wall 221 facing the electrode assembly 23 may be spaced apart from the pressure release mechanism 24. The surface of the first wall 221 away from the electrode assembly 23 may also be spaced apart from the pressure release mechanism 24. Naturally, in some embodiments, both the surface of the first wall 221 facing the electrode assembly 23 and the surface away from the electrode assembly 23 may be spaced apart from the pressure release mechanism 24.

[0113] This effectively prevents damage to the pressure release mechanism 24 by foreign matter inside and / or outside the battery cell 20, thereby improving the safety performance of the battery cell 20.

[0114] As shown in Figures 7 to 9, in a preferred embodiment, the through hole 224 is a stepped hole, and the through hole 224 comprises a first hole segment 2241, a second hole segment 2242, and a first stepped surface 2243 connected between the first hole segment 2241 and the second hole segment 2242, wherein the hole diameter of the first hole segment 2241 is smaller than the hole diameter of the second hole segment 2242, the second hole segment 2242 is located on the side of the first hole segment 2241 away from the electrode assembly 23, the pressure release mechanism 24 is provided in the second hole segment 2242, and the first stepped surface 2243 is used to support the pressure release mechanism 24.

[0115] The cross-sections of the first hole segment 2241 and the second hole segment 2242 may be polygonal, and if the first hole segment 2241 and the second hole segment 2242 are polygonal, the hole diameters of the first hole segment 2241 and the hole diameters of the second hole segment 2242 may be the hole diameters of the circumscribed or inscribed circles of both.

[0116] With the above installation, the pressure release mechanism 24 can be restricted in position by the first stepped surface 2243. At the same time, it is possible to install the pressure release mechanism 24 at a distance from the surface of the first wall 221 that faces the electrode assembly 23, thereby preventing damage to the pressure release mechanism 24 from components such as the electrode assembly 23 inside the battery cell 20.

[0117] In some embodiments, the through-hole 224 further comprises a third hole segment 2244 and a second stepped surface 2245, wherein the third hole segment 2244 is located on the side of the second hole segment 2242 away from the first hole segment 2241, and the second stepped surface 2245 is connected to the second hole segment 2242 and the third hole segment 2244.

[0118] With the above installation, the surface of the first wall 221 away from the electrode assembly 23 and the pressure release mechanism 24 are installed with a gap between them, further preventing damage to the pressure release mechanism 24 by foreign objects outside the battery cell 20 and ensuring the safety performance of the battery cell 20.

[0119] To facilitate the installation of the pressure release mechanism 24, the diameter of the third hole 2244 may be larger than the diameter of the second hole 2242.

[0120] In some selectable embodiments, the battery cell 20 further comprises a protective film 25, which is located on the side of the pressure relief mechanism 24 away from the electrode assembly 23, and is spaced apart from the pressure relief mechanism 24, with a chamber 27 formed between the protective film 25, the hole wall of the through hole 224, and the pressure relief mechanism 24.

[0121] The protective film 25 may be made of a material such as PET, and may be located inside the through hole 224, or of course outside the through hole 224.

[0122] By providing the protective film 25, the pressure release mechanism 24 is protected, preventing foreign matter from outside the battery cell 20 from damaging the pressure release mechanism 24. At the same time, a chamber is formed between the protective film 25, the wall of the through hole 224, and the pressure release mechanism 24, which facilitates the operation of the pressure release mechanism 24 when the internal pressure of the battery cell 20 reaches a threshold, and prevents the protective film 25 from affecting the operation of the pressure release mechanism 24.

[0123] In several selectable embodiments, the protective film 25 is attached to a surface of the first wall 221 away from the electrode assembly 23, and a communication mechanism 26 is provided on the surface of the first wall 221 away from the electrode assembly 23, with one end of the communication mechanism 26 communicating with the chamber and the other end communicating with the external space.

[0124] The communication mechanism 26 may be a communication hole, communication groove, communication pipe, or the like, provided in at least one of the protective film 25, the first wall 221, or the like.

[0125] By providing the communication mechanism 26, it is possible to connect the chamber 27 with the external space of the battery cell 20 using the communication mechanism 26. Furthermore, the air pressure on the side of the pressure release mechanism 24 away from the electrode assembly 23 can be matched with the external air pressure, and when the gas pressure inside the case 22 reaches a threshold, the pressure release mechanism 24 can be activated in a timely manner to release the pressure.

[0126] In some selectable embodiments, the through-hole 224 further comprises a fourth hole segment 2246 and a third stepped surface 2247, wherein the fourth hole segment 2246 is located on the side of the third hole segment 2244 away from the second hole segment 2242, and the third stepped surface 2247 is connected to the third hole segment 2244 and the fourth hole segment 2246. The third stepped surface 2247 is provided with a communication mechanism 26, one end of which communicates with the chamber 27 and the other end of which communicates with the external space.

[0127] The communication mechanism 26 may be a communication groove, communication hole, or the like provided in the third stepped surface 2247.

[0128] By providing the fourth hole segment 2246, the protective film 25 can be positioned within the fourth hole segment 2246, preventing the protective film 25 from protruding from the surface away from the electrode assembly 23 of the first wall 221, and further preventing the protective film 25 from being rubbed off during the movement of the battery cell 20.

[0129] In another embodiment, the embodiments of the present application further provide a battery comprising the battery cells 20 according to each of the above embodiments.

[0130] As shown in Figure 10, the battery according to the embodiment of the present invention optionally further comprises a cooling member 30 for cooling the battery cell 20.

[0131] The cooling member 30 may cover and contact at least one of the first wall 221 and the second wall 222, and if the battery cell 20 has a third wall 223, the cooling member 30 may cover the third wall 223 and contact the third wall 223.

[0132] By providing the cooling element 30, the cooling requirement for the battery cell 20 can be met, and thermal runaway of the battery cell 20 can be avoided.

[0133] In some embodiments, the battery according to the embodiment of the present invention is provided such that at least a portion of the cooling member 30 is positioned opposite the first wall 221 with a gap in the thickness direction of the first wall 221, and the cover assembly 21 is positioned between the cooling member 30 and the first wall 221. With this arrangement, it is possible to install the cooling member 30, the first wall 221 and the cover assembly 21 on different surfaces, thereby avoiding interference between the electrode terminals 21a of the cover assembly 21 and the cooling member 30, increasing the contact area between the cooling member 30 and the battery cell 20, and improving the cooling effect of the cooling member 30 on the battery cell 20.

[0134] As one possible embodiment, in the battery according to the embodiment of the present application, the cooling member 30 comprises a first cooling plate 31 and a second cooling plate 32 provided at intervals in the thickness direction of the first wall 221, the second cooling plate 32 is provided with relief holes 321, the second cooling plate 32 covers the first wall 221 where the pressure release mechanism 24 is located, and the relief holes 321 are for releasing the pressure release mechanism 24, and the first cooling plate 31 covers the side of the case 22 away from the pressure release mechanism 24.

[0135] The cover assembly 21 is positioned between the first wall 221 and the first cooling plate 31 of the cooling member 30. With this arrangement, the cooling member 30 can exchange heat by contacting the first wall 221 and the wall surface provided opposite the first wall 221, thereby optimizing the cooling effect.

[0136] Although the present application has been described above with reference to preferred embodiments, various modifications can be made to them and their components can be replaced with equivalents without departing from the scope of the application. In particular, each technical feature described in each embodiment can be combined in any way, provided that there is no structural inconsistency. The present application is not limited to the specific embodiments disclosed herein, but includes all technical concepts included in the claims.

Claims

1. Electrode assembly and A case for housing the electrode assembly, The case comprises a cover assembly that closes the opening of the case, The case comprises a first wall and two opposing second walls, the first wall connecting the two second walls, the thickness of the first wall being greater than the thickness of the second walls, and the first wall being provided with a pressure release mechanism that operates to release the pressure when the gas pressure inside the case reaches a threshold. The case has openings at both ends, and each of the openings is closed off by the cover assembly. The battery cell is characterized in that the case further comprises a third wall for connecting the two second walls, the third wall being provided opposite the first wall, and the thickness of the third wall being greater than the thickness of the second wall.

2. The battery cell according to claim 1, characterized in that the thickness of the first wall is D1, the thickness of the second wall is D2, and D1 and D2 satisfy the condition 0.05 mm ≤ D1 - D2 ≤ 3 mm.

3. The battery cell according to claim 1 or 2, characterized in that the thickness of the first wall is 0.5 mm or more.

4. The battery cell according to any one of claims 1 to 3, characterized in that, in the width direction of the first wall, the minimum distance d between the edge of the first wall and the pressure release mechanism is greater than 2 mm.

5. The battery cell according to any one of claims 1 to 4, characterized in that the pressure release mechanism has a length dimension L and a width dimension D, and L and D satisfy L / D ≤ ​​8.

6. The battery cell according to any one of claims 1 to 5, characterized in that the dimension of the pressure release mechanism in the longitudinal direction of the first wall is the length dimension L, and the dimension of the pressure release mechanism in the width direction of the first wall is D, and L and D satisfy L > D.

7. The battery cell according to any one of claims 1 to 6, characterized in that the area of ​​the first wall is smaller than the area of ​​the second wall.

8. The battery cell according to any one of claims 1 to 7, characterized in that the first wall has a through hole extending along the thickness direction of the first wall, the pressure release mechanism is provided inside the through hole, and at least one of the surface of the first wall facing the electrode assembly and the surface away from the electrode assembly is spaced apart from the pressure release mechanism in the thickness direction.

9. The battery cell according to claim 8, wherein the through hole is a stepped hole, and the through hole comprises a first hole segment, a second hole segment, and a first stepped surface connected between the first hole segment and the second hole segment, the hole diameter of the first hole segment is smaller than the hole diameter of the second hole segment, the second hole segment is located on the side of the first hole segment away from the electrode assembly, the pressure release mechanism is provided in the second hole segment, and the first stepped surface is used to support the pressure release mechanism.

10. The battery cell according to claim 9, wherein the through hole further comprises a third hole segment and a second stepped surface, the third hole segment being provided on the side of the second hole segment away from the first hole segment, and the second stepped surface being connected to the second hole segment and the third hole segment.

11. The battery cell according to claim 10, further comprising a protective film, wherein the protective film is provided on the side of the pressure release mechanism away from the electrode assembly and spaced apart from the pressure release mechanism, and a chamber is formed between the protective film, the hole wall of the through hole, and the pressure release mechanism.

12. The battery cell according to claim 11, characterized in that the protective film is attached to a surface of the first wall away from the electrode assembly, and a communication mechanism is provided on the surface of the first wall away from the electrode assembly, with one end communicating with the chamber and the other end communicating with the external space.

13. The through hole further comprises a fourth hole segment and a third stepped surface, the fourth hole segment being provided on the side of the third hole segment away from the second hole segment, and the third stepped surface being connected to the third hole segment and the fourth hole segment. The battery cell according to claim 11, characterized in that the third stepped surface is provided with a communication mechanism having one end in communication with the chamber and the other end in communication with the external space.

14. A battery cell according to any one of claims 1 to 13, A cooling member that covers at least a portion of the case and cools the battery cell, A battery characterized by having the following features.

15. The battery according to claim 14, characterized in that, in the thickness direction of the first wall, the cooling member is provided facing the first wall at least partially with a gap between them, and the cover assembly is located between the cooling member and the first wall.

16. The battery according to claim 14, wherein the cooling member comprises a first cooling plate and a second cooling plate provided at intervals in the thickness direction of the first wall, the first cooling plate is provided with relief holes, the first cooling plate covers the first wall where the pressure release mechanism is located and the relief holes allow the pressure release mechanism to escape, and the second cooling plate covers the side of the case away from the pressure release mechanism.

17. A power consumption device characterized by comprising a battery according to any one of claims 14 to 16 for supplying electrical energy.

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