Battery cells, batteries and power consuming devices

Abstract

The present application relates to a battery cell, a battery, and a power consumption device, the battery cell comprising an electrode assembly, a case for accommodating the electrode assembly, and a cover assembly for closing an opening of the case, the case comprising 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 operable to release pressure when the gas pressure inside the case reaches a threshold value. The battery cell of the present application can meet the internal gas release requirements of the battery cell and ensure the safety performance of the battery cell. Figure 4

Description

[Technical Field]

[0001] This application relates to the field of energy storage technology, and in particular to battery cells, batteries and power consuming devices. [Background technology]

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric scooters, electric cars, electric planes, electric boats, toy electric cars, toy electric boats, toy electric planes, and power tools.

[0003] In the development of battery technology, in addition to improving the performance of battery cells, safety issues must also be considered. Therefore, how to improve the safety of battery cells is a challenge that needs to be solved in battery technology. Summary of the Invention

[0004] The embodiments of the present application provide a battery cell, a battery, and a power consumption device that can meet the internal gas release requirements of the battery cell and ensure the safety performance of the battery cell.

[0005] According to one aspect, an embodiment of the present application provides a battery cell comprising an electrode assembly, a case that houses the electrode assembly, and a cover assembly that closes an opening of the case, the case comprising 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 pressure when gas pressure inside the case reaches a threshold.

[0006] According to one aspect of the present invention, the thickness of the first wall is D1, the thickness of the second wall is D2, and D1 and D2 satisfy 0.05 mm≦D1−D2≦3 mm.

[0007] According to one aspect of the present invention, the thickness of the first wall is 0.5 mm or more.

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

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

[0010] According to one aspect of the present invention, the dimension of the pressure release mechanism in the longitudinal direction of the first wall is length dimension L, and the dimension of the pressure release mechanism in the width direction of the first wall is D, where L and D satisfy L>D.

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

[0012] According to one aspect of the embodiment of the present application, an opening is formed at both ends of the case, and each opening is closed by a cover assembly, and the case further includes a third wall for connecting the two second walls, the third wall being opposite the first wall, the thickness of the first wall being equal to or greater than 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 aspect of the present embodiment, the first wall has a through hole extending along the thickness direction of the first wall, and 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 in the thickness direction is provided at a distance from the pressure release mechanism.

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

[0015] According to one aspect of the present embodiment, the through hole further comprises a third hole segment and a second step surface, the third hole segment being located on a side of the second hole segment away from the first hole segment, and the second step surface being connected to the second hole segment and the third hole segment.

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

[0017] According to one aspect of the present embodiment, 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, one end of which is connected to the chamber and the other end of which is connected to the external space.

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

[0019] According to another aspect, an embodiment of the present application provides a battery including the above-described battery cell and a cooling member covering at least a portion of the case for cooling the battery cell.

[0020] According to another aspect of the present embodiment, the cooling member is at least partially The first wall and the cover assembly is located between the cooling member and the first wall.

[0021] According to another aspect of the present embodiment, the cooling member includes a first cooling plate and a second cooling plate spaced apart in a thickness direction, the first cooling plate has a relief hole, the first cooling plate covers a first wall where the pressure release mechanism is located and the relief hole allows the pressure release mechanism to escape, and the second cooling plate covers a side of the case away from the pressure release mechanism.

[0022] According to yet another aspect, embodiments of the present application provide a power consuming device comprising the above-described battery for supplying electrical energy.

[0023] According to the battery cell, battery, and power consumption device according to the embodiments of the present application, the battery cell includes an electrode assembly, a case, and a cover assembly. The case houses the electrode assembly, and the cover assembly closes the opening of the case. The case includes a first wall and two opposing second walls. The first wall connects the two second walls, and the first wall is provided with a pressure release mechanism. When the gas pressure inside the case reaches a threshold, the pressure release mechanism is activated to release the pressure, thereby ensuring the safety of the battery cell. Furthermore, by making the thickness of the first wall greater than that of the second wall, the increased thickness of the first wall strengthens 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 of the battery cell.

[0024] The above description is only a summary of the technical solution of the present application, which can be implemented according to the contents of the specification in order to more clearly understand the technical solution of the present application. In order to facilitate a clearer understanding of the above and other objectives, features and advantages of the present application, specific embodiments of the present application are listed below. [Brief explanation of the drawings]

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

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

[0027] [Figure 2] FIG. 1 is an exploded view of a battery according to some embodiments of the present application.

[0028] [Figure 3] 1 is an exploded structural schematic diagram of a battery cell according to some embodiments of the present application. FIG.

[0029] [Figure 4] FIG. 2 is a structural schematic diagram of a case according to one embodiment of the present application;

[0030] [Figure 5] 1 is a bottom view of a battery according to one embodiment of the present application;

[0031] [Figure 6] 1 is an exploded view of a case according to one embodiment of the present application;

[0032] [Figure 7] FIG. 2 is a partial cross-sectional view of a case according to one embodiment of the present application.

[0033] [Figure 8] FIG. 2 is a schematic diagram illustrating a combination of a case, a pressure release mechanism, and a protective film according to one embodiment of the present invention.

[0034] [Figure 9] FIG. 9 is a partial enlarged view of a portion A in FIG. 8.

[0035] [Figure 10] FIG. 2 is an exploded view of a battery according to another embodiment of the present application.

[0036] 1000 vehicles

[0037] 100 batteries 200 Controller 300 motor

[0038] 10. Cabinet 11 First Part 12 Second Part 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 Second Wall 223 The Third Wall 224 Through hole 2241 First hole segment 2242 Second hole segment 2243 First step surface 2244 Third hole segment 2245 Second step surface 2246 Fourth hole segment 2247 Third step surface

[0042] 23 Electrode assembly

[0043] 24 Pressure release mechanism

[0044] 25 Protective film

[0045] 26 Communication mechanism

[0046] 27 Chamber

[0047] 30 Cooling member 31 First cooling plate 32 Second cooling plate 321 Relief hole

[0048] In the drawings, identical elements are designated by identical reference numerals. The drawings are not drawn to scale. DETAILED DESCRIPTION OF THE INVENTION

[0049] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without any creative work fall within the scope of protection of the present application.

[0050] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art, and the terms used in this application are only for describing specific embodiments and are not intended to limit the application, and the terms "comprise" and "have" and any variations thereof in the specification and claims of this application and the accompanying drawings are intended to cover, but not exclusively include. The terms "first," "second," etc. in the specification and claims of this application or the above drawings are intended to distinguish different objects and are not intended to describe a specific order or subordinate relationship.

[0051] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described with reference to the embodiment may be included in at least one embodiment of the present application. The appearances of the phrase in various places in this specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, independent, or alternative embodiments of other embodiments.

[0052] In the description of this application, unless otherwise clearly specified or limited, the terms "mounted," "connected," "coupled," and "attached" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, an integral connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. Those skilled in the art can understand the specific meanings of the above terms in this application according to specific circumstances.

[0053] The term "and / or" in this application is merely a relational relationship that describes related objects, and indicates that three relationships may exist, for example, A and / or B may indicate three situations: A exists alone, A and B exist simultaneously, and B exists alone. Also, 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 the present application, the same reference numerals denote the same elements, and for the sake of brevity, detailed descriptions of the same elements in different embodiments will be omitted. Note that the dimensions such as thickness, length, and width of various elements in the embodiments of the present application and the overall dimensions such as thickness, length, and width of the integrated device shown in the drawings are merely illustrative and do not limit the present application in any way.

[0055] As used herein, "plurality" refers to two or more (including two).

[0056] In this application, the battery cell may include, but is not limited to, a lithium ion secondary battery, a lithium ion primary battery, a lithium-sulfur battery, a sodium lithium ion battery, a sodium ion battery, or a magnesium ion battery. The battery cell may be, but is not limited to, a flat, rectangular, or other shape.

[0057] The battery described in the embodiments of this application refers to a single physical module that includes one or more battery cells and 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 includes a housing for packaging one or more battery cells. The housing can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0058] The battery cell includes an electrode assembly including a positive electrode sheet, a negative electrode sheet, and a separator, and a case for housing the electrode assembly. The battery cell operates primarily through the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes 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. The positive electrode current collector without the positive electrode active material layer protrudes from the positive electrode current collector with the positive electrode active material layer coated thereon, and the positive electrode current collector without the positive electrode active material layer is referred to as a positive electrode tab. In the case of a lithium-ion battery, for example, the positive electrode current collector may be made of aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, a ternary lithium, or lithium manganese oxide. The negative electrode sheet includes 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. The negative electrode current collector without the negative electrode active material layer protrudes from the negative electrode current collector with the negative electrode active material layer coated thereon. The negative electrode current collector without the negative electrode active material layer is referred to as a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon. To ensure that the electrode does not melt under high current, multiple positive electrode tabs are stacked, and multiple negative electrode tabs are stacked. The separator may be made of polypropylene (PP) or polyethylene (PE). The electrode assembly may have a wound structure or a stacked structure, but the present disclosure is not limited thereto.

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

[0060] In a battery cell, after multiple charge / discharge cycles, side reactions occur and gas is continuously generated, resulting in a certain air pressure inside the battery cell. As the air pressure increases, the gas between the sheets cannot be released in a timely manner, affecting the insertion and desorption of lithium ions and even posing a risk of lithium precipitation. To ensure the safety of the battery cell, a pressure release mechanism is generally provided on the battery cell case, which can release the gas generated inside the battery cell and ensure the safety of the battery cell.

[0061] The inventor discovered that during the use of the battery cell, the wall portion of the case corresponding to the pressure release mechanism is insufficient in supporting the pressure release mechanism, which affects the service life of the pressure release mechanism and poses a potential risk to the safety performance of the battery cell.

[0062] After extensive research, the inventors found that existing battery cell cases generally have side walls with equal thickness, and the side walls are generally designed to be thin in order to ensure the available space of the battery cell and improve its energy density, which reduces the connection area between the pressure release mechanism and the corresponding side wall of the case, which is unfavorable for the connection between the pressure release mechanism and the side wall of the case, weakens the support ability of the side wall for the pressure release mechanism, and further affects the service life of the pressure release mechanism.

[0063] In view of this, an embodiment of the present application provides a battery cell comprising an electrode assembly, a case that houses the electrode assembly, and a cover assembly that closes an opening of the case, wherein the case comprises a first wall and two opposing second walls, the first wall is for connecting the two second walls, the thickness of the first wall is greater than the thickness of the second walls, and 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 value.

[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 ensuring the safety performance of the battery cell.

[0065] The battery cells described in the embodiments of the present application are applied to batteries, power consuming devices and appliances that use batteries.

[0066] The power consuming devices and equipment may be vehicles, mobile phones, mobile devices, laptops, ships, spacecraft, electric toys, power tools, etc. The vehicles may be engine-driven vehicles, natural gas vehicles, or new energy vehicles, and the new energy vehicles may be pure electric vehicles, hybrid vehicles, or range-extender vehicles, etc. The spacecraft may include airplanes, rockets, spaceplanes, and spaceships, etc. The electric toys may include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc. The 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, etc. In the embodiments of the present application, the power consuming devices are not particularly limited to the above.

[0067] In the following embodiment, for convenience of explanation, the power consuming device is a vehicle.

[0068] Referring to FIG. 1, FIG. 1 is a structural schematic diagram 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, a range-extender vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head, or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, and the controller 200 is configured to control the battery 100 to supply power to the motor 300, for example, for operating power needs during startup, navigation, and driving of the vehicle 1000.

[0069] In some embodiments of the present application, the battery 100 is used not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, and can replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0070] Referring to FIG. 2, FIG. 2 is an exploded view of a battery 100 according to some embodiments of the present application. The battery 100 includes 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 have various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which are fitted over each other and together define a housing space 13 for housing the battery cells 20. The second portion 12 may have a hollow structure with one end open, and the first portion 11 may have a plate-like structure. The first portion 11 may cover the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define the housing space 13. The first portion 11 and the second portion 12 each have a hollow structure with one side open, and the open side of the first portion 11 may cover the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 may have various shapes, such as a cylindrical body or a rectangular parallelepiped.

[0071] The battery 100 may include a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, parallel, or a mixed connection. A mixed connection refers to the plurality of battery cells 20 being connected in series and in parallel. The plurality of battery cells 20 are directly connected in series, parallel, or series-parallel, and the entire battery cell set is housed within the housing 10. Of course, the battery 100 may be configured in the form of a battery module in which the plurality of battery cells 20 are first connected in series, parallel, or series-parallel, and the plurality of battery modules may then be further connected in series, parallel, or series-parallel to be integrated and housed within the housing 10. The battery 100 may further include other structures, for example, the battery 100 may further include bus members for achieving electrical connection between the plurality of 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 cells 20 may be flat, rectangular, or have other shapes.

[0073] 3 and 4, a battery cell 20 refers to the smallest unit constituting a battery. The battery cell 20 includes a case 22, an electrode assembly 23, and a cover assembly 21. The case 22 is configured to house the electrode assembly 23. The cover assembly 21 is configured to close an opening 22a of the case 22. The case 22 includes a first wall 221 and two opposing second walls 222. The first wall 221 is configured to connect the two second walls 222. 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. The pressure release mechanism 24 is activated to release pressure when the gas pressure inside the case 22 reaches a threshold.

[0074] Optionally, the case 22 has an accommodation space, and the first wall 221 and the second wall 222 included in the case 22 may be disposed so as to intersect with each other or may be disposed perpendicular to each other. The distance between the two second walls 222 may be set according to the size of the electrode assembly 23, and the electrode assembly 23 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 point 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 point of the second wall 222 in a direction perpendicular to the surface of the second wall 222 facing the internal storage space of the case 22 .

[0077] Of course, the thickness 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 the case 22 may be one or two, and if there are two openings 22a, the two openings 22a may be provided facing each other with a gap between them.

[0079] Optionally, the cover assembly 21 is a member 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 cover assembly 21 may be engaged with the case 22 so that its shape matches the shape of the case 22.

[0080] Optionally, the cover assembly 21 may be manufactured from a material (e.g., aluminum alloy) having a certain hardness and strength. In this way, the cover assembly 21 is less likely to deform when pressed and hit, 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 assemblies 23 to output or input electrical energy to the battery cells 20. The cover assembly 21 may be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic, but the embodiments of the present application are not particularly limited thereto.

[0081] 3 and 4, the case 22 is a component that cooperates with the cover assembly 21 to form an internal environment of the battery cell 20, and the formed internal environment is used to accommodate the electrode assembly 23, the electrolyte, and other components. The case 22 and the cover assembly 21 may be separate components, or 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 form a common connection surface before other components are inserted into the case, and when it is necessary to seal the interior of the case 22, the cover assembly 21 is placed over 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 depending on the specific shape and size of the electrode assembly 23. The case 22 may be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic, but the embodiments of the present 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 include one or more electrode assemblies 23. The electrode assembly 23 is typically formed by winding or stacking a positive electrode sheet and a negative electrode sheet, with a separator typically 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 form 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 form tabs, respectively. The positive electrode tab and the negative electrode tab may both be located at one end of the main body, or may be located at both ends of the main body. During the charge and discharge 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 terminal 21a to form an electrical circuit.

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

[0085] The pressure release mechanism 24 and the first wall 221 of the case 22 may be an integral structure, or of course, the two may be processed separately and then connected together. For example, if the two are provided separately, they may be connected to each other by welding or other methods.

[0086] A battery cell 20 according to an embodiment of the present application includes a case 22 that houses an electrode assembly 23, and a cover assembly 21 that closes an opening 22a of the case 22. The case 22 includes a first wall 221 and two opposing second walls 222. The first wall 221 is used to connect the two second walls 222. A pressure release mechanism 24 is provided in the first wall 221. When the gas pressure inside the case 22 reaches a threshold, the pressure release mechanism 24 operates to release the pressure, thereby ensuring the safety of the battery cell 20. In addition, by making the thickness of the first wall 221 greater than the thickness of the second wall 222, the thickness of the first wall 221 is increased, which strengthens the support of the explosion-proof valve by the first wall 221 and increases the connection area between the pressure release mechanism 24 and the first wall 221. This avoids damage to the pressure release mechanism 24 due to insufficient connection strength between the pressure release mechanism 24 and the first wall 221 when the pressure release mechanism 24 is activated, improves the service life of the pressure release mechanism 24, and further ensures the safety performance of the battery cell 20.

[0087] In some preferred embodiments, the thickness of the first wall 221 is D1, the thickness of the second wall 222 is D2, and 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, including the 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 thickness of the second wall 222 within an appropriate range, and while ensuring the connection and support requirements of the first wall 221 for the pressure release mechanism 24, it is possible to avoid an increase in the difficulty of processing the case 22 due to an excessive difference in thickness between the first wall 221 and the second wall 222. In addition, it is possible to ensure the required storage space of the case 22 and improve the energy density of the battery cell 20.

[0090] In some alternative embodiments, D1 and D2 may satisfy 0.1 mm≦D1−D2≦0.7 mm, which is advantageous for processing the case 22 and ensures the energy density of the battery cell 20.

[0091] In some alternative 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, and the like.

[0092] The first wall 221 adopts the above-mentioned structural form, so that the first wall 221 has a sufficient thickness, which is advantageous for connection with and support for the pressure release mechanism 24, and improves the service life of the pressure release mechanism 24.

[0093] As shown in FIGS. 3 to 5, in some alternative 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 edge of the first wall 221 may be understood as the outermost contour of the first wall 221. When the shape of the first wall 221 is rectangular, the edge of the first wall 221 is 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 guaranteed during the process of connecting them together after the pressure release mechanism 24 is integrally molded with the first wall 221 or provided separately, and it is possible to avoid the difficulty of molding or connecting the two in a molding or connection form due to the minimum distance d between them being too small.

[0096] In some alternative embodiments, pressure relief mechanism 24 has a length dimension L and a width dimension D, where L and D satisfy L / D≦8.

[0097] The longitudinal direction and width direction 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 molded integrally with the first wall 221 or is installed separately and is therefore less likely to deform during the process of connecting the two. If the internal pressure of the battery cell 20 exceeds a preset threshold, the pressure release mechanism 24 can be activated to reduce pressure fluctuations, thereby improving the safety performance of the battery cell 20.

[0099] In one alternative embodiment, the dimension of the pressure relief mechanism 24 in the length direction of the first wall 221 is length dimension L, and the dimension of the pressure relief mechanism 24 in the width direction of the first wall 221 is D, where L and D satisfy L>D.

[0100] The length direction of the first wall 221 may be aligned with the length direction of the pressure release mechanism 24, and the width direction of the first wall 221 may be aligned with the width direction of the pressure release mechanism 24. With the above arrangement, the shape of the pressure release mechanism 24 is adapted to the shape of the first wall 221, the connection requirements between the pressure release mechanism 24 and the first wall 221 are ensured, and when the pressure of the gas inside the case 22 reaches a threshold, the pressure release mechanism 24 is activated to help release the pressure.

[0101] In some alternative 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 orthogonal projection of the first wall 221 in its thickness direction; for example, if the orthogonal projection of the first wall 221 in its thickness direction is a rectangle, the area is the area of ​​the outer shape of the outer ring of the rectangle.

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

[0104] By making the area of ​​the first wall 221 smaller than the area of ​​the second wall 222, when the same pressure is applied, the area of ​​the first wall 221 is smaller than the area of ​​the second wall 222, so that the strength of the pressure applied to the first wall 221 is greater, which is advantageous in that the pressure release mechanism 24 located on the first wall 221 is activated to release the pressure.

[0105] 3 to 6 , in some 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 includes a third wall 223 for connecting the two second walls 222, the third wall 223 being disposed opposite the first wall 221, and the thickness of the first wall 221 being equal to or greater than the thickness of the third wall 223, which is greater than the thickness of the second wall 222.

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

[0107] Optionally, the third wall 223 may be arranged symmetrically and spaced apart from the first wall 221, and 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] Alternatively, the thickness of the third wall 223 may be understood as the thickness of each point of the third wall 223 in a direction perpendicular to the surface of the third wall 223 facing the storage space inside the case 22.

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

[0110] The above-described structural form of the case 22 is advantageous for extending the electrode terminals 21a to both sides. Furthermore, the thickness of the first wall 221 is equal to or greater than the thickness of the third wall 223, which is greater than the thickness of the second wall 222. By appropriately thickening the third wall 223, the strength of the case 22 is reinforced, which is advantageous for improving the safety performance of the case 22. At the same time, the asymmetry between the top and bottom of the case 22 is improved, which solves the problem of cracks caused by inconsistent material flow rates during the extrusion process.

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

[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 remote from the electrode assembly 23 may be spaced apart from the pressure release mechanism 24. Of course, in some embodiments, both the surface of the first wall 221 facing the electrode assembly 23 and the surface remote 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 due to foreign matter inside and / or outside the battery cell 20, and improves 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 has a first hole segment 2241, a second hole segment 2242, and a first step surface 2243 connected between the first hole segment 2241 and the second hole segment 2242, where the hole diameter of the first hole segment 2241 is smaller than the hole diameter of the second hole segment 2242, and the second hole segment 2242 is located on the side of the first hole segment 2241 away from the electrode assembly 23, and the pressure release mechanism 24 is provided in the second hole segment 2242, and the first step 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 when the first hole segment 2241 and the second hole segment 2242 are polygonal, the hole diameter of the first hole segment 2241 and the hole diameter of the second hole segment 2242 may be the hole diameter of both the circumscribing circle or the inscribing circle.

[0116] With this installation, the position of the pressure release mechanism 24 can be limited by the first stepped surface 2243. At the same time, the pressure release mechanism 24 can be installed at a distance from the surface of the first wall 221 that faces the electrode assembly 23, which makes it possible to prevent damage to the pressure release mechanism 24 by components inside the battery cell 20, such as the electrode assembly 23.

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

[0118] With this installation, the surface of the first wall 221 away from the electrode assembly 23 and the pressure release mechanism 24 are spaced apart, which further prevents damage to the pressure release mechanism 24 due to foreign objects outside the battery cell 20 and ensures the safety performance of the battery cell 20.

[0119] Optionally, the diameter of the third hole 2244 may be larger than the diameter of the second hole 2242 to facilitate attachment of the pressure relief mechanism 24 .

[0120] In some alternative embodiments, the battery cell 20 further includes a protective membrane 25, which is provided on the side of the pressure release mechanism 24 away from the electrode assembly 23, and which is spaced apart from the pressure release mechanism 24, such that a chamber 27 is formed between the protective membrane 25, the wall of the through-hole 224, and the pressure release mechanism 24.

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

[0122] The protective film 25 protects the pressure release mechanism 24 and prevents foreign objects outside the battery cell 20 from scratching or otherwise 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 operation of the pressure release mechanism 24 when the internal pressure of the battery cell 20 reaches a threshold value, and prevents the protective film 25 from affecting the operation of the pressure release mechanism 24.

[0123] In some alternative 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 configured as a communication hole, a communication groove, a 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 use the communication mechanism 26 to communicate between the chamber 27 and the external space of the battery cell 20, and furthermore, the air pressure on the side of the pressure release mechanism 24 away from the electrode assembly 23 can be made to match the external air pressure, so that when the gas pressure inside the case 22 reaches a threshold value, the pressure release mechanism 24 can be activated in a timely manner to release the pressure.

[0126] In some alternative embodiments, the through hole 224 further comprises a fourth hole segment 2246 and a third step surface 2247, the fourth hole segment 2246 being provided on a side of the third hole segment 2244 away from the second hole segment 2242, and the third step surface 2247 being connected to the third hole segment 2244 and the fourth hole segment 2246. The third step surface 2247 is provided with a communication mechanism 26 having one end communicating with the chamber 27 and the other end communicating with the external space.

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

[0128] By providing the fourth hole segment 2246, the protective film 25 can be positioned within the fourth hole segment 2246, so that the protective film 25 does not protrude from the surface of the first wall 221 away from the electrode assembly 23, and further, the protective film 25 can be prevented from being rubbed and falling off when the battery cell 20 moves.

[0129] In another aspect, the present embodiment further provides a battery, the battery including the battery cell 20 according to any of the above embodiments.

[0130] As shown in FIG. 10, the battery according to the embodiment of the present application may optionally further include a cooling member 30 for cooling the battery cells 20.

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

[0132] By providing the cooling member 30, the temperature reduction requirement for the battery cells 20 can be realized, and thermal runaway of the battery cells 20 can be avoided.

[0133] In some embodiments, in a battery according to an embodiment of the present application, at least a portion of the cooling member 30 is provided facing the first wall 221 with a gap in between in the thickness direction of the first wall 221, and the cover assembly 21 is located between the cooling member 30 and the first wall 221. This arrangement makes it possible to install the cooling member 30, the first wall 221, and the cover assembly 21 on different surfaces, which prevents the electrode terminals 21a of the cover assembly 21 from interfering with the cooling member 30 and increases the contact area between the cooling member 30 and the battery cells 20, thereby improving the cooling effect of the cooling member 30 on the battery cells 20.

[0134] As one alternative embodiment, in the battery according to the embodiment of the present application, the cooling member 30 includes a first cooling plate 31 and a second cooling plate 32 spaced apart in the thickness direction of the first wall 221, Second cooling plate 32 A relief hole 321 is provided in Second cooling plate 32 covers the first wall 221 where the pressure release mechanism 24 is located, and the relief hole 321 is for venting the pressure release mechanism 24; First cooling plate 31 covers the side of the case 22 away from the pressure relief mechanism 24.

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

[0136] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and equivalents may be substituted for the components thereof without departing from the scope of the present application. In particular, the technical features described in each embodiment may be arbitrarily combined as long as there is no structural contradiction. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. an electrode assembly; a case that accommodates the electrode assembly; a cover assembly for closing the opening of the case; the case includes a first wall and two second walls arranged opposite to each other, the first wall connects the two second walls, the thickness of the first wall is greater than the thickness of the second walls, and the first wall is provided with a pressure release mechanism that operates to release gas pressure inside the case when the gas pressure reaches a threshold; The openings are formed at both ends of the case, and the cover assemblies are provided to close the openings, The battery cell is characterized in that the case further includes a third wall for connecting two of the second walls, the third wall being disposed opposite the first wall, and the thickness of the first wall being equal to or greater than the thickness of the third wall.

2. 2. The battery cell according to claim 1, wherein the thickness of the first wall is D1, the thickness of the second wall is D2, and D1 and D2 satisfy 0.05 mm≦D1−D2≦3 mm.

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

4. 4. The battery cell according to claim 1, wherein a minimum distance d between the edge of the first wall and the pressure release mechanism in the width direction of the first wall is greater than 2 mm.

5. 5. The battery cell according to claim 1, wherein the pressure release mechanism has a length dimension L and a width dimension D, and L and D satisfy the relationship L / D≦8.

6. 6. The battery cell according to claim 1, wherein the dimension of the pressure release mechanism in the longitudinal direction of the first wall is a length dimension L, 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. 7. The battery cell according to claim 1, wherein the area of ​​the first wall is smaller than the area of ​​the second wall.

8. 8. The battery cell according to claim 1, wherein the thickness of the third wall is greater than the thickness of the second wall.

9. 9. The battery cell according to claim 1, wherein the first wall has a through hole extending along a thickness direction of the first wall, the pressure release mechanism is provided inside the through hole, and at least one of a surface of the first wall facing the electrode assembly and a surface remote from the electrode assembly in the thickness direction is provided with a gap between it and the pressure release mechanism.

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

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

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

13. 13. The battery cell according to claim 12, wherein the protective film is attached to a surface of the first wall away from the electrode assembly, and the surface of the first wall away from the electrode assembly is provided with a communication mechanism having one end communicating with the chamber and the other end communicating with an external space.

14. the through hole further comprises a fourth hole segment and a third step surface, the fourth hole segment being disposed on a side of the third hole segment away from the second hole segment, and the third step surface being connected to the third hole segment and the fourth hole segment; 13. The battery cell according to claim 12, wherein the third step surface is provided with a communication mechanism having one end communicating with the chamber and the other end communicating with an external space.

15. The battery cell according to any one of claims 1 to 14; a cooling member that covers at least a portion of the case and cools the battery cells; A battery comprising:

16. 16. The battery of claim 15, wherein the cooling member is at least partially opposed to the first wall with a gap in the thickness direction of the first wall, and the cover assembly is located between the cooling member and the first wall.

17. 16. The battery of claim 15, wherein the cooling member comprises a first cooling plate and a second cooling plate spaced apart in a thickness direction of the first wall, the first cooling plate having a relief hole, the first cooling plate covering the first wall where the pressure release mechanism is located and the relief hole allows the pressure release mechanism to escape, and the second cooling plate covering the side of the case away from the pressure release mechanism.

18. 18. An electrical power consuming device comprising a battery according to any one of claims 15 to 17 for supplying electrical energy thereto.

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