Battery and electric device

Abstract

The utility model relates to a battery and an electric device. The battery (100) comprises a plurality of battery monomers (20), the plurality of battery monomers (20) comprise a first battery monomer (31) and a second battery monomer (32) which are arranged along a first direction, the first battery monomer (31) comprises a first wall (311) and a second wall (312) which are oppositely arranged along the first direction, and the second wall (312) is closer to the second battery monomer (32) relative to the first wall (311); wherein the maximum thickness of the second wall (312) is smaller than the maximum thickness of the first wall (311). According to the battery and the power utilization device provided by the invention, expansion of the battery in the use process can be reduced, and the safety performance of the battery is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to batteries and electrical devices. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] A battery consists of a casing and multiple individual battery cells. Each battery cell includes an electrode assembly and a housing, with the electrode assembly housed within the housing. During charging and discharging, the battery cells bulge outwards. Additionally, the charging and discharging process generates a certain amount of gas inside the housing, which also causes the battery cells to expand, affecting the battery's safety performance. Summary of the Invention

[0004] In view of the above problems, this application provides a battery and an electrical device that can reduce battery swelling during use and improve battery safety performance.

[0005] In a first aspect, this application provides a battery comprising:

[0006] Multiple battery cells, including a first battery cell and a second battery cell arranged along a first direction, the first battery cell including a first wall and a second wall arranged opposite to each other along the first direction, the second wall being closer to the second battery cell than the first wall;

[0007] The maximum thickness of the second wall is less than the maximum thickness of the first wall.

[0008] In the technical solution of this application embodiment, during battery cycling, both the first and second battery cells expand outwards. Since they are arranged along a first direction, the outward expansion force in the first direction is more pronounced. The first battery cell generates an outward expansion force within itself along the first direction. This expansion force includes a force F1 moving away from the second battery cell and a force F2 moving towards the second battery cell. When F1 acts on the first wall, it points from the inner wall surface to the outer wall surface; when F2 acts on the second wall, it points from the inner wall surface to the outer wall surface. The second battery cell also generates another outward expansion force within itself along the first direction. This expansion force includes a force F3 moving away from the first battery cell and a force F4 moving towards the first battery cell. Since the first and second battery cells are arranged along the first direction, and the second wall is closer to the second battery cell than the first wall, force F4 originates from the inside of the second battery cell and points towards the first battery cell. Since forces F2 and F4 are in opposite directions, the force F2 acting on the second wall—that is, from the inner surface of the second wall towards the outer surface of the first wall—can be balanced by force F4 generated within the second battery cell. However, there is no additional structure to balance force F1 on the first wall. Therefore, the maximum thickness of the second wall is set to be less than the maximum thickness of the first wall; that is, the first wall is thickened compared to the second wall, providing better restraint against the expansion caused by force F1. Conversely, thinning the second wall compared to the first wall compensates for the increased thickness of the first wall, reducing the increased volume space occupied by the first battery cell within the battery, thus improving the overall energy density of the battery. This reduces expansion during battery use, improves battery safety, and simultaneously results in a higher energy density.

[0009] In one embodiment, the second battery cell includes a third wall and a fourth wall disposed opposite to each other along a first direction, wherein the fourth wall is closer to the first battery cell than the third wall;

[0010] The maximum thickness of the fourth wall is less than that of the third wall. During battery cycling, the second battery cell generates an outward expansion force, which includes a force F3 moving away from the first battery cell and a force F4 moving towards the first battery cell. The force F4 acting on the fourth wall can be balanced by the force F2 of the first battery cell. However, there is no additional structure to balance the force F3 acting on the third wall. Therefore, the maximum thickness of the fourth wall is set to be less than that of the third wall, i.e., the third wall is thickened, so that the third wall has a better restraining effect on the expansion caused by the force F3. Compared to the third wall, thinning the fourth wall can compensate for the increased wall thickness of the third wall, reducing the increased volume space occupied by the second battery cell in the battery after the fourth wall is thickened, improving the overall energy density of the battery. This reduces the expansion during battery use, improves battery safety performance, and results in a higher energy density for the battery.

[0011] In one embodiment, the first direction is the thickness direction of the first battery cell and / or the second battery cell. The first and second battery cells are arranged along the thickness direction of the first and / or second battery cells. The first wall and the second wall are the walls of the large surface of the first battery cell, or the third wall and the fourth wall are the walls of the large surface of the second battery cell. During battery use, the battery cells generate more expansion force on the large surface walls. In this case, the thickening treatment of the first wall or the third wall has a better effect on confining expansion. Alternatively, while the first wall and the second wall are the walls of the large surface of the first battery cell, the third wall and the fourth wall are the walls of the large surface of the second battery cell. In this case, the first and second battery cells are arranged in a flat position, and the simultaneous thickening treatment of the first wall and the third wall has a confining expansion effect.

[0012] In one embodiment, at least one of the first and second battery cells includes an electrode assembly, with the first direction being the stacking direction of the electrode assembly. During charging and discharging, the insertion and extraction of lithium ions in the electrode active material will cause the battery to expand and contract. Ideally, the volume change of the material during insertion and extraction should be reversible. However, in reality, some lithium ions cannot be completely extracted from the anode due to changes in battery balance, or they may deposit as insoluble byproducts on the anode surface during cycling, resulting in expansion. The expansion in the stacking direction is the most significant. Thickening the first or third wall has a better effect on confining expansion and reducing battery safety issues caused by expansion during battery use.

[0013] In one embodiment, the electrode assembly is a wound electrode assembly and is flat. The electrode assembly includes a straight portion and a corner portion, which are connected to each other. A first direction is perpendicular to the stacking direction of the straight portion. When the electrode assembly is a wound electrode assembly, the first battery cell and the second battery cell are arranged along the stacking direction perpendicular to the straight portion, and the first wall and the third wall play a role in restraining expansion.

[0014] In some embodiments, the electrode assembly is a stacked electrode assembly. When the electrode assembly is a stacked electrode assembly, the internal resistance of the stacked electrode assembly is lower than that of the wound electrode assembly battery, the charge and discharge power of the stacked assembly is better, the stacked assembly utilization rate is higher, the electrode area is larger, and the energy density is improved.

[0015] In some embodiments, at least one of the first battery cell and the second battery cell includes at least two stacked electrode assemblies, with the first direction being the stacking direction of the at least two electrode assemblies. When the first direction is the stacking direction of the at least two electrode assemblies, the expansion in the stacking direction is more significant. The thickening treatment of the first wall or the third wall has a better effect on confining the expansion, effectively alleviating the safety problems caused by the expansion of at least one of the first battery cell and the second battery cell, reducing the expansion during battery use, and improving battery safety performance.

[0016] In some embodiments, the first battery cell and the second battery cell are directly connected through a second wall and a fourth wall. In a first direction, the first battery cell and the second battery cell are directly stacked, and the battery comprises at least two layers of flatly arranged battery cells. The flatly arranged battery has higher integration, improves the space utilization of the battery, reduces the overall thickness of the battery, saves space, and also saves the use of heat insulation material. The second wall and the fourth wall are in direct contact, and the contact surface of the second wall and the fourth wall is the direct contact surface of the first battery cell and the second battery cell. The second wall and the fourth wall are thinned to improve the energy density of the battery.

[0017] In one embodiment, the plurality of battery cells further includes a third battery cell located between the first and second battery cells. The third battery cell includes a fifth wall and a sixth wall disposed opposite each other along a first direction. The maximum thickness of at least one of the fifth and sixth walls is less than the maximum thickness of at least one of the first and third walls. When the battery has at least three battery cells, the third battery cell is located between the first and second battery cells along the first direction. The fifth and sixth walls serve as walls of the third battery cell close to the first or second battery cell. The expansion force generated by the third battery cell from the inside out along the first direction can be balanced by the force F2 of the first battery cell and the force F4 of the second battery cell. Therefore, by making the maximum thickness of at least one of the fifth and sixth walls less than the maximum thickness of at least one of the first and third walls, i.e., by thinning at least one of the fifth and sixth walls, the overall thickness and space occupied by the third battery cell can be reduced, the thickness of the plurality of battery cells in the first direction can be reduced, and the energy density of the battery can be improved.

[0018] In one embodiment, the first battery cell includes a seventh wall, one end of which is connected to the first wall and the other end to the second wall. The maximum thickness of the seventh wall is less than the maximum thickness of the first wall but greater than the maximum thickness of the second wall. Because the first and second battery cells are arranged along a first direction, the battery experiences greater expansion force in the first direction, but also expansion force in other directions. The seventh wall helps to restrain the expansion and deformation of the first battery cell, but its restraining direction is perpendicular to the first direction, thereby improving the restraint on the first battery cell, reducing expansion during battery use, and enhancing battery safety performance.

[0019] In some embodiments, the battery further includes at least one restraint member;

[0020] Along a first direction, a restraining member is provided on the side of the first battery cell away from the second battery cell, and / or, along the first direction, a restraining member is provided on the side of the second battery cell away from the first battery cell, wherein the first direction is configured as the thickness direction of the restraining member. The restraining member acts to restrain the battery cell from expansion and deformation, thereby reducing battery safety issues caused by expansion during battery use.

[0021] In one embodiment, the battery includes a housing, and a restraining member is configured as at least one of a base plate or a top cover of the housing. The base plate or top cover, as part of the housing, restrains the individual battery cells within the battery structure during battery assembly, resulting in a more compact battery structure, limiting battery expansion and deformation, and reducing battery safety issues caused by expansion during battery use.

[0022] In one embodiment, the battery includes at least two battery cell groups, and at least one of the at least two battery cell groups includes a first battery cell and a second battery cell.

[0023] At least two adjacent battery cell packs are separated by a separator, with the base plate and top cover connected to the separator. The separator connects the base plate and top cover, ensuring a stable connection and improving their containment within the battery. Simultaneously, the separator, positioned between the two battery cell packs, provides additional containment. Furthermore, the separator has thermal conductivity and dissipation properties, preventing direct heat transfer between adjacent battery cell packs and avoiding thermal failure. This ensures safe and reliable battery operation, maximizes the battery's charge and discharge capabilities, and extends its lifespan.

[0024] In one embodiment, the battery cell assembly includes a module housing, and a restraining element is configured as one of an end plate, side plate, or end cap of the module housing. As part of the module housing, the end plate, side plate, or end cap restrains the battery cells within the battery cell assembly during assembly, resulting in a more compact battery cell assembly structure, limiting expansion and deformation of the battery cells, and reducing battery safety issues caused by expansion during battery use.

[0025] In one embodiment, the battery includes a housing, and the restraining member is configured as a partition beam within the housing. As part of the housing, the partition beam, during battery assembly, restrains the individual battery cells within the battery structure, resulting in a more compact battery structure, limiting battery expansion and deformation, and reducing battery safety issues caused by expansion during use.

[0026] A battery module in which at least a portion of the surface of a restraining member facing a first or second battery cell is configured as a plane. This planar configuration allows the restraining member to provide a better restraining effect.

[0027] Secondly, this application provides an electrical device that includes the battery described in the above embodiments. The battery provides electrical energy to the electrical device. The electrical device has a high energy density, which improves its safety performance. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or conventional technology, the drawings used in the description of the embodiments or conventional technology will be briefly introduced below. Obviously, the drawings described below are merely embodiments of this application. For those skilled in the art, other drawings can be obtained based on the disclosed drawings without creative effort. In the drawings:

[0029] Figure 1This is a schematic diagram of the vehicle structure in some embodiments of this application;

[0030] Figure 2 This is a schematic diagram showing the exploded structure of the battery in some embodiments of this application;

[0031] Figure 3 This is a schematic diagram showing the exploded structure of a single battery cell in some embodiments of this application;

[0032] Figure 4 This is an exploded structural diagram of a battery having two individual cells along the first direction in some embodiments of this application.

[0033] Figure 5 This is a cross-sectional view of a battery having two individual cells along a first direction in some embodiments of this application;

[0034] Figure 6 This is a schematic diagram illustrating the force on the walls of the first and second battery cells in some embodiments of this application;

[0035] Figure 7 This is a cross-sectional view of a battery having three individual cells along a first direction in some embodiments of this application;

[0036] Figure 8 This is a cross-sectional view of a battery having two battery cell groups along a first direction in some other embodiments of this application;

[0037] Figure 9 This is a schematic diagram of the structure of the battery separator in some embodiments of this application.

[0038] The reference numerals in the detailed embodiments are as follows:

[0039] 1000, vehicles;

[0040] 100. Battery; 200. Controller; 300. Motor;

[0041] 10. Housing; 11. First part; 12. Second part; 121. Base plate; 20. Battery cell; 21. End cap; 21a. Electrode terminal; 22. Housing; 23. Cell assembly; 231. Electrode assembly; 30. Battery cell group; 31. First battery cell; 311. First wall; 312. Second wall; 313. Seventh wall; 32. Second battery cell; 321. Third wall; 322. Fourth wall; 33. Third battery cell; 331. Fifth wall; 332. Sixth wall; 40. Separator beam. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] The embodiments of the technical solution of this application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of this application, and are therefore merely examples and should not be used to limit the scope of protection of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and the foregoing description of the accompanying drawings, are intended to cover non-exclusive inclusion.

[0044] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0045] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0046] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0047] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0048] In the description of the embodiments of this application, the technical terms "center", "length", "width", "thickness", "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0049] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "connection" and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0050] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0051] The inventors have observed that during the charge-discharge cycles of the battery, as ions are inserted into or extracted from the positive and negative electrode active materials, the accumulation thickness of side reactions in the cell system and the peeling of graphite sheets cause the cell to expand. For the cell, the internal pressure increases, leading to a decrease in cell performance and lifespan. For the battery module, if the expansion force is not properly managed, it can cause the module dimensions to exceed tolerances, or even damage the structural framework, affecting the battery's safety performance.

[0052] Based on the above considerations, in order to alleviate the problem of battery expansion during use and improve battery safety performance, the inventors, after in-depth research, designed a battery cell that can thicken the walls of multiple battery cells that are far apart from each other during battery assembly to improve the effect of restraining expansion, and thin the walls of multiple battery cells that are close to each other to improve the energy density of the battery.

[0053] In such a battery, because the wall thickness of the battery cell is set to be non-uniform, the thickened wall plays a role in confining expansion during the cycle of the battery cell, while the thinned wall can increase the energy density. This results in a high-energy-density battery with high safety performance that can restrain the expansion and deformation of the battery cell, thereby reducing expansion during battery use and improving battery safety performance.

[0054] Against the backdrop of increasing demand for battery energy density, the battery cell of this application can make full use of the wall thickness variation of the battery cell itself, and achieve a better confinement effect without changing the overall volume occupied by the battery cell.

[0055] The batteries disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using batteries disclosed in this application. This helps reduce battery expansion during use, improves battery safety, enhances battery performance stability, and extends battery life.

[0056] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0057] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0058] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery 100 is disposed inside the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0059] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0060] Please refer to Figure 2 , Figure 2This is an exploded structural diagram of a battery 100 provided in some embodiments of this application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, jointly defining a space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 jointly define the space. Alternatively, the first portion 11 and the second portion 12 may both be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0061] In battery 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, battery 100 can also be composed of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 10. Battery 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0062] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0063] Please refer to Figure 3 , Figure 3 This is an exploded structural diagram of a battery cell 20 provided in some embodiments of this application. The battery cell 20 refers to the smallest unit that makes up a battery. Figure 3 The battery cell 20 includes an end cap 21, a housing 22, a cell assembly 23, and other functional components.

[0064] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21 can be adapted to the shape of housing 22 to fit it. End cap 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 21 is not easily deformed under pressure and impact, allowing battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 21a can be provided on end cap 21. Electrode terminals 21a can be used for electrical connection with cell assembly 23 to output or input electrical energy to battery cell 20. In some embodiments, end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold. The material of end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0065] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can accommodate the cell assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and the housing 22 can be integrated. Specifically, the end cap 21 and the housing 22 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 22, the end cap 21 closes the housing 22. The housing 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the cell assembly 23. The material of the housing 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0066] The cell assembly 23 is the component in the battery cell 20 where the electrochemical reaction occurs. The casing 22 may contain one or more cell assemblies 23. The cell assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the cell assembly, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals 21a to form a current loop.

[0067] According to some embodiments of this application, see [link / reference]. Figure 4 Please refer to further information. Figures 4 to 9 , Figure 4 This is an exploded structural diagram of a battery 100 having two battery cells 20 along a first direction according to some embodiments of this application. Figure 5 This is a cross-sectional view of a battery 100 having two battery cells 20 along a first direction according to some embodiments of this application. Figure 6 This is a schematic diagram illustrating the stress conditions on the walls of the first battery cell 31 and the second battery cell 32 in some embodiments of this application. Figure 7 This is a cross-sectional view of a battery 100 having three battery cells 20 along a first direction according to other embodiments of this application. Figure 8 This is a schematic diagram of the structure of the battery 100 having two battery cells 20 along a first direction according to other embodiments of this application. Figure 9 This is a schematic diagram of the structure of the separator of the battery 100 according to some embodiments of this application. This application provides a battery 100 including a plurality of battery cells 20. The plurality of battery cells 20 includes a first battery cell 31 and a second battery cell 32 arranged along a first direction. The first battery cell 31 includes a first wall 311 and a second wall 312 arranged opposite to each other along the first direction. The second wall 312 is closer to the second battery cell 32 than the first wall 311. The maximum thickness of the second wall 312 is less than the maximum thickness of the first wall 311. For example... Figure 4 As shown in the figure, the Y direction is the width direction of the battery cell 20, the X direction is the length direction of the battery cell 20, and the Z direction is the thickness direction of the battery cell 20.

[0068] See Figure 4 , Figure 5 and Figure 6In the technical solution of this application embodiment, during the cycling process, both the first battery cell 31 and the second battery cell 32 will expand outward. Since they are arranged along a first direction, the outward expansion force in the first direction will be more obvious. The first battery cell 31 will generate an outward expansion force along the first direction inside the first battery cell 31. This expansion force includes a force F1 moving away from the second battery cell 32 and a force F2 moving towards the second battery cell 32. When F1 acts on the first wall 311, it points from the inner wall surface of the first wall 311 to the outer wall surface of the first wall 311; when F2 acts on the second wall 312, it points from the inner wall surface of the second wall 312 to the outer wall surface of the first wall 311. The second battery cell 32 will generate another outward expansion force along the first direction inside the second battery cell 32. This expansion force includes a force F3 moving away from the first battery cell 31 and a force F4 moving towards the first battery cell 31. Since the first battery cell 31 and the second battery cell 32 are arranged along the first direction, and the second wall 312 is closer to the second battery cell 32 than the first wall 311, the force F4 is a force from the inside of the second battery cell 32 towards the first battery cell 31. The directions of forces F2 and F4 are exactly opposite. The force F2 acting on the second wall 312, that is, the force from the inner wall surface of the second wall 312 towards the outer wall surface of the first wall 311, can be balanced by the force F4 generated inside the second battery cell 32. However, there is no additional structure to balance the force F1 on the first wall 311. Therefore, the maximum thickness of the second wall 312 is set to be less than the maximum thickness of the first wall 311. That is, compared to the second wall 312, the first wall 311 is thickened, so that the first wall 311 has a better restraining effect on the expansion caused by force F1. Compared to the first wall 311, the second wall 312 is thinned. The reduced wall thickness of the second wall 312 can compensate for the increased wall thickness of the first wall 311, reducing the increased volume space occupied by the first battery cell 31 in the battery 100 after the first wall 311 is thickened. This improves the overall energy density of the battery 100, reduces the expansion of the battery 100 during use, improves the safety performance of the battery 100, and makes the battery 100 have a high energy density.

[0069] According to some embodiments of the present application, the maximum thickness of the first wall 311 is D1, the maximum thickness of the second wall 312 is D2, and the maximum thickness of the seventh wall 313 is D3. D1, D3, and D2 satisfy: 1:1:1 < D1:D3:D2 ≤ 8:3:2, and D3 is 0.2 millimeters (mm) - 4 millimeters. In some embodiments, D3 is 0.2 mm - 4 mm, that is, the maximum thickness of the seventh wall 313 is 0.2 mm - 4 mm. When the seventh wall 313 is the conventional wall thickness of the battery cell 20, when the first wall 311 is thickened, the maximum thickness of the first wall 311 can be set up to four times the conventional wall thickness of the battery cell 20 at most, and when the second wall 312 is thinned, the maximum thickness of the second wall 312 can be set to at least two-thirds of the conventional wall thickness of the battery cell 20 at least. Such a limitation can enable the battery cell 20 to have a good effect of restraining expansion force and a high energy density while ensuring easy processing in terms of technology and moderate cost.

[0070] Refer to Figure 8 , according to some embodiments of the present application, the wall thickness of the first wall 311 is set to be non-uniform. The wall thickness of the first wall 311 gradually increases from the center of the first wall 311 to the edge direction of the first wall 311, and the inner wall surface of the first wall 311 is set to a concave arc surface structure. The thinnest part of the first wall 311, that is, the minimum thickness of the first wall 311, is still greater than the maximum thickness of the second wall 312, and the first wall 311 still has the effect of restraining expansion force. At the same time, after the inner wall surface of the first wall 311 is set to a concave arc surface structure, an expansion gap is left between the center of the first wall 311 and the built-in electrode assembly 231, playing a certain role in expansion buffering. It can be understood that, of course, the first wall 311 can also be set to other non-uniform structures, such as the inner wall being wavy, etc., which will not be elaborated here.

[0071] Refer to Figure 5 , according to some embodiments of the present application, the second battery cell 32 includes a third wall 321 and a fourth wall 322 arranged opposite to each other in the first direction. The fourth wall 322 is closer to the first battery cell 31 than the third wall 321. Among them, the maximum thickness of the fourth wall 322 is less than the maximum thickness of the third wall 321.

[0072] The first battery cell 31 and the second battery cell 32 are arranged along the first direction. The third wall 321 serves as the wall of the second battery cell 32 away from the first battery cell 31. The third wall 321 is thickened compared to the fourth wall 322, so that the third wall 321 plays a restraining role in the expansion of the first battery cell 31 and the second battery cell 32 during cycling in the first direction. It can restrain the expansion and deformation of the second battery cell 32 and indirectly restrain the expansion and deformation of the first battery cell 31. The fourth wall 322 serves as the wall of the second battery cell 32 close to the first battery cell 31. The maximum thickness of the fourth wall 322 is set to be less than the maximum thickness of the third wall 321, that is, the fourth wall 322 is thinned. The thinned wall thickness of the fourth wall 322 can compensate for the thickened wall thickness of the third wall 321, reducing the volume space occupied by the second battery cell 32 in the battery 100 after the thickening of the fourth wall 322, thereby improving the overall energy density of the battery 100. While having a high energy density, the battery 100 can reduce the safety problems caused by the expansion of the battery 100 during use.

[0073] According to some embodiments of this application, the first direction is the thickness direction of the first battery cell 31 and / or the second battery cell 32.

[0074] The first battery cell 31 and the second battery cell 32 are arranged along the thickness direction of the first battery cell 31 and / or the second battery cell 32. The first wall 311 and the second wall 312 are the walls of the large surface of the first battery cell 31, or the third wall 321 and the fourth wall 322 are the walls of the large surface of the second battery cell 32. During use, the battery cell 20 generates more expansion force on the large surface wall. In this case, the thickening treatment of the first wall 311 or the third wall 321 has a better effect on restraining the expansion force. Alternatively, while the first wall 311 and the second wall 312 are the walls of the large surface of the first battery cell 31, the third wall 321 and the fourth wall 322 are the walls of the large surface of the second battery cell 32. In this case, the first battery cell 31 and the second battery cell 32 are arranged in a flat position. When arranged in a flat position, the battery 100 is more likely to expand. The simultaneous thickening treatment of the first wall 311 and the third wall 321 has a further effect on restraining the expansion force.

[0075] According to some embodiments of this application, at least one of the first battery cell 31 and the second battery cell 32 includes an electrode assembly 231, and the first direction is the stacking direction of the electrode assembly 231.

[0076] During the charging and discharging process, the insertion and extraction of lithium ions in the electrode active material of battery 100 will cause the battery 100 to expand and contract. Ideally, the volume change of the material during insertion and extraction should be reversible. However, in reality, some lithium ions will always be unable to be completely inserted or extracted from the anode due to changes in the balance of battery 100, or they will be deposited on the anode surface as insoluble byproducts during cycling, thus causing expansion. The expansion in the stacking direction is the most obvious. The thickening treatment of the first wall 311 or the third wall 321 has a better effect on restraining the expansion force, further reducing the safety problems of battery 100 caused by expansion during battery 100 use.

[0077] According to some embodiments of this application, the electrode assembly 231 is a wound electrode assembly 231 and is flat. The electrode assembly 231 includes a straight portion and a corner portion, which are connected to each other. The first direction is perpendicular to the stacking direction of the straight portion.

[0078] When the electrode assembly 231 is a wound electrode assembly 231, the first battery cell 31 and the second battery cell 32 are arranged along a stacking direction perpendicular to the straight portion, and the first wall 311 and the third wall 321 play a role in restraining the expansion force. The winding process of the battery 100 involves winding up the four layers of cathode sheet, separator, anode sheet, and separator together. The winding structure is mostly used to make cylindrical or cuboid batteries 100, and the process is relatively mature with low batch cost.

[0079] According to some embodiments of this application, the electrode assembly 231 is a stacked electrode assembly 231. When the electrode assembly 231 is a stacked electrode assembly 231, the internal resistance of the stacked electrode assembly 231 is lower than that of the wound electrode assembly 231 battery 100, the charging and discharging power of the stacked assembly is better, the stacked assembly utilization rate is higher, the electrode area is larger, and the energy density is further improved.

[0080] According to some embodiments of this application, at least one of the first battery cell 31 and the second battery cell 32 includes at least two stacked electrode assemblies 231, and the first direction is the stacking direction of the at least two electrode assemblies 231.

[0081] When the first direction is the stacking direction of at least two electrode components 231, the expansion in the stacking direction is more obvious. The thickening treatment of the first wall 311 or the third wall 321 has a better effect on restraining the expansion force, effectively alleviating the safety problems caused by the expansion of at least one of the first battery cell 31 and the second battery cell 100, further reducing the expansion of the battery 100 during use, and improving the safety performance of the battery 100.

[0082] See Figure 5According to some embodiments of this application, the first battery cell 31 and the second battery cell 32 are directly connected in contact through the second wall 312 and the fourth wall 322.

[0083] In the first direction, the first battery cell 31 and the second battery cell 32 are directly stacked, and the battery 100 includes at least two layers of flatly arranged battery cells 20. The flatly arranged battery 100 has a higher integration, improves the space utilization of the battery 100, reduces the overall thickness of the battery 100, saves space, and also saves the use of heat insulation materials. The second wall 312 and the fourth wall 322 are in direct contact, and the contact surface of the second wall 312 and the fourth wall 322 is the direct contact surface of the first battery cell 31 and the second battery cell 32. The second wall 312 and the fourth wall 322 are thinned to further improve the energy density of the battery 100.

[0084] See Figure 7 According to some embodiments of this application, the plurality of battery cells 20 further includes a third battery cell 33, which is located between the first battery cell 31 and the second battery cell 32. The third battery cell 33 includes a fifth wall 331 and a sixth wall 332 disposed opposite to each other along a first direction. The maximum thickness of at least one of the fifth wall 331 and the sixth wall 332 is less than the maximum thickness of at least one of the first wall 311 and the third wall 321.

[0085] When the battery 100 has at least three battery cells 20, the third battery cell 33 is located between the first battery cell 31 and the second battery cell 32 along the first direction. The fifth wall 331 and the sixth wall 332 serve as the walls of the third battery cell 33 that are close to the first battery cell 31 or the second battery cell 100. The expansion force generated by the third battery cell 33 from the inside to the outside along the first direction can be balanced by the force F2 of the first battery cell 31 and the force F4 of the second battery cell 32. Therefore, by making the maximum thickness of at least one of the fifth wall 331 and the sixth wall 332 less than the maximum thickness of at least one of the first wall 311 and the third wall 321, that is, by reducing the thickness of at least one of the fifth wall 331 and the sixth wall 332, the overall thickness and space occupied by the third battery cell 33 can be reduced, the thickness of multiple battery cells 20 in the first direction can be reduced, and the energy density of the battery 100 can be further improved.

[0086] See Figure 4 According to some embodiments of this application, the battery 100 further includes at least one restraining member; the restraining member is provided on the side of the first battery cell 31 away from the second battery cell 32 along a first direction, and / or the restraining member is provided on the side of the second battery cell 32 away from the first battery cell 31 along a first direction, the first direction being configured as the thickness direction of the restraining member.

[0087] See Figure 5According to some embodiments of this application, the first battery cell 31 includes a seventh wall 313, one end of which is connected to the first wall 311 and the other end is connected to the second wall 312. The maximum thickness of the seventh wall 313 is less than the maximum thickness of the first wall 311 and greater than the maximum thickness of the second wall 312.

[0088] According to some embodiments of this application, the seventh wall 313 is located at both ends of the length direction of the first battery cell 31 and also has a certain binding effect. It is understood that the second battery cell 32 may also have an eighth wall, one end of which is connected to the third wall 321 and the other end is connected to the fourth wall 322. The maximum thickness of the eighth wall is less than the maximum thickness of the third wall 321 and greater than the maximum thickness of the fourth wall 322.

[0089] During battery cycling, the second battery cell 32 generates an outward expansion force, which includes a force F3 moving away from the first battery cell 31 and a force F4 moving towards the first battery cell 31. The force F4 acting on the fourth wall 322 can be balanced by the force F2 of the first battery cell 31. However, the force F3 acting on the third wall 321 does not have an additional structure to balance it. Therefore, the maximum thickness of the fourth wall 322 is set to be less than the maximum thickness of the third wall 321, that is, the third wall 321 is thickened, so that the third wall 321 has a better restraining effect on the expansion generated by the force F3. Compared to the third wall 321, the fourth wall 322 is thinned. The reduced wall thickness of the fourth wall 322 can compensate for the increased wall thickness of the third wall 321. This reduces the overall volume space occupied by the second battery cell 32 in the battery 100 after the fourth wall 322 is thickened, thereby increasing the overall energy density of the battery 100. This also reduces the expansion of the battery 100 during use, improves the safety performance of the battery 100, and makes the battery 100 have a high energy density.

[0090] The restraint component on the outside of the battery cell 20 restrains the battery cell 20, further restrains the expansion and deformation of the battery 100, and further reduces the safety problems of the battery 100 caused by the expansion during the use of the battery 100.

[0091] According to some embodiments of this application, the battery 100 includes a housing 10, and the restraint is configured as at least one of the bottom plate 121 or the top cover of the housing 10.

[0092] The use of pressure plates and other structures is reduced, and the bottom plate 121 or top cover of the housing 10 is directly selected as the binding component. As part of the housing 10, the bottom plate 121 or top cover binds the battery cells 20 inside the battery 100 during battery assembly, making the battery 100 structure more compact, further restricting the expansion and deformation of the battery 100, and further reducing the safety issues of the battery 100 caused by expansion during use.

[0093] According to some embodiments of this application, the battery 100 includes at least two battery cell groups 30, at least one of the at least two battery cell groups 30 including a first battery cell 31 and a second battery cell 32; a separator is provided between two adjacent battery cell groups 30, and a base plate 121 and a top cover are connected to the separator. The separator serves to connect the base plate 121 and the top cover, making the connection between the base plate 121 and the top cover stable and improving the restraining effect of the base plate 121 and the top cover within the battery 100; at the same time, the separator, placed between the two battery cell groups 30, can further restrain the battery cell groups 30. In addition, the separator has a certain heat conduction and heat dissipation effect, avoiding direct heat transfer between two adjacent battery cell groups 30, which could lead to thermal failure of the battery 100, ensuring the safe and reliable use of the battery 100, fully utilizing the charging and discharging capacity of the battery 100, and extending the service life of the battery 100.

[0094] According to some embodiments of this application, the battery cell pack 30 includes a module housing 22, and a restraining member is configured as one of an end plate, side plate, or end cap 21 of the module housing 22. As part of the module housing 22, the end plate, side plate, or end cap 21 restrains the battery cells 20 within the battery cell pack 30 during assembly, making the battery cell pack 30 structure more compact, restraining the expansion and deformation of the battery cell pack 30, and further reducing battery safety issues caused by expansion during battery use.

[0095] See Figure 9 According to some embodiments of this application, the battery 100 includes a housing 10, and the restraint is configured as a partition beam 40 of the housing 10.

[0096] As part of the housing 10, the partition beam 40 plays a binding role on the battery cells 20 inside the battery 100 during battery assembly, making the battery 100 structure more compact, further restricting the expansion and deformation of the battery 100, and further reducing the safety problems of the battery 100 caused by expansion during use.

[0097] According to some embodiments of this application, the partition beam 40 is provided with a cooling structure, which includes a cold plate with cooling channels connected to an external cooling circulation mechanism. The partition beam 40 is also provided with an exhaust structure, and a pressure relief mechanism is provided on the side of the battery cell 20 closest to the partition beam 40. The exhaust structure includes an exhaust channel and an exhaust port. The exhaust channel penetrates the partition beam 40 and has an exhaust outlet connected to the inner cavity of the housing 10. An exhaust hole is located on the side wall of the partition beam 40 and connects to the exhaust channel. The pressure relief mechanism is positioned opposite the exhaust hole.

[0098] The separator beam 40 not only restrains the battery cell 20, but also serves as a water-cooling and venting mechanism. It integrates components such as the water-cooling plate, venting channel, and intermediate structural beam from traditional technologies, thereby improving the overall performance of the battery 100.

[0099] According to some embodiments of this application, at least a portion of the surface of the restraint member facing the first battery cell 31 or the second battery cell 32 is configured as a plane.

[0100] See Figure 4 When the restraining component is the top cover of the housing 10, the bottom wall of the top cover faces the first battery cell 31, and the bottom wall of the top cover is configured as a plane. The plane setting makes the top cover have a better restraining effect.

[0101] According to some embodiments of this application, this application also provides an electrical device that includes the battery 100 described in the above embodiments. The battery 100 is used to provide electrical energy to the electrical device. The electrical device can be any of the aforementioned devices or systems that utilize the battery 100. The electrical device has a high energy density, improving its safety performance.

[0102] According to some embodiments of this application, see Figure 4 and Figure 5This application provides a battery 100, which includes a housing 10. Two battery cell groups 30 are disposed within the housing 10. Each battery cell group 30 includes multiple first battery cells 31 and second battery cells 32. The first battery cells 31 and second battery cells 32 are arranged along their thickness direction and are directly connected by a second wall 312 and a fourth wall 322. The maximum thickness of the second wall 312 is less than the maximum thickness of the first wall 311, and the maximum thickness of the fourth wall 322 is less than the maximum thickness of the third wall 321. The maximum thickness of the first wall 311 is equal to the maximum thickness of the third wall 321, and the maximum thickness of the second wall 312 is equal to the maximum thickness of the fourth wall 322. The top cover and bottom plate 121 of the housing 10 serve as restraining elements. A partition beam 40 disposed between the two battery cell groups 30 not only restrains the battery cells 20 but also provides water cooling and ventilation.

[0103] In some embodiments of this application, the battery 100 and the power-consuming device have non-uniform wall thicknesses for the battery cells 20. The wall thickness of the walls of adjacent cells that are far apart is increased to provide a binding effect, while the wall thickness of the walls of adjacent cells that are close to each other is reduced to increase the energy density of the battery 100. By relying on the thick shell 22 for binding, the use of structures such as pressure plates can be reduced, thereby improving space utilization. At the same time, the shell 22 of the contact surface of adjacent battery cells 20 is thinned to maintain the energy density of the cells in a fixed quantity. This increases the power capacity while meeting the reliability requirements of use throughout the life cycle, resulting in a high-energy-density battery 100 with high safety performance that has the effect of restraining cell expansion and deformation.

[0104] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery, wherein, include: Multiple battery cells (20), the multiple battery cells (20) include a first battery cell (31) and a second battery cell (32) arranged along a first direction, the first battery cell (31) includes a first wall (311) and a second wall (312) arranged opposite to each other along the first direction, the second wall (312) is closer to the second battery cell (32) than the first wall (311); The maximum thickness of the second wall (312) is less than the maximum thickness of the first wall (311).

2. The battery according to any one of claims 1, wherein, The second battery cell (32) includes a third wall (321) and a fourth wall (322) disposed opposite to each other along the first direction, wherein the fourth wall (322) is closer to the first battery cell (31) than the third wall (321); The maximum thickness of the fourth wall (322) is less than the maximum thickness of the third wall (321).

3. The battery according to any one of claims 1-2, wherein, The first direction is the thickness direction of the first battery cell (31) and / or the second battery cell (32).

4. The battery according to any one of claims 1-3, wherein, At least one of the first battery cell (31) and the second battery cell (32) includes an electrode assembly (231), and the first direction is the stacking direction of the electrode assembly (231).

5. The battery according to claim 4, wherein, The electrode assembly (231) is a wound electrode assembly (231) and is flat. The electrode assembly (231) includes a straight portion and a corner portion, the straight portion and the corner portion are connected to each other, and the first direction is perpendicular to the stacking direction of the straight portion.

6. The battery according to claim 4, wherein, The electrode assembly (231) is a stacked electrode assembly (231).

7. The battery according to any one of claims 1-3, wherein, At least one of the first battery cell (31) and the second battery cell (32) includes at least two stacked electrode assemblies (231), and the first direction is the stacking direction of the at least two electrode assemblies (231).

8. The battery according to any one of claims 1-7, wherein, The first battery cell (31) and the second battery cell (32) are directly connected in contact through the second wall (312) and the fourth wall (322).

9. The battery according to any one of claims 1-7, wherein, The plurality of battery cells (20) further includes a third battery cell (33), which is located between the first battery cell (31) and the second battery cell (32). The third battery cell (33) includes a fifth wall (331) and a sixth wall (332) disposed opposite to each other along the first direction. The maximum thickness of at least one of the fifth wall (331) and the sixth wall (332) is less than the maximum thickness of at least one of the first wall (311) and the third wall (321).

10. The battery according to claim 1, wherein, The first battery cell (31) includes a seventh wall (313), one end of which is connected to the first wall (311) and the other end is connected to the second wall (312). The maximum thickness of the seventh wall (313) is less than the maximum thickness of the first wall (311) and greater than the maximum thickness of the second wall (312).

11. The battery according to any one of claims 1-10, wherein, The battery (100) also includes at least one restraint member; Along the first direction, the first battery cell (31) is provided with the restraint member on the side away from the second battery cell (32), and / or, along the first direction, the second battery cell (32) is provided with the restraint member on the side away from the first battery cell (31), wherein the first direction is configured as the thickness direction of the restraint member.

12. The battery according to claim 11, wherein, The battery (100) includes a housing (10), and the restraint is configured as at least one of the base plate (121) or the top cover of the housing (10).

13. The battery according to claim 11 or 12, wherein, The battery (100) includes at least two battery cell groups (30), at least one of the at least two battery cell groups (30) includes the first battery cell (31) and the second battery cell (32); A separator is provided between two adjacent battery cell groups (30) in the at least two battery cell groups (30), and the bottom plate (121) and the top cover are connected to the separator.

14. The battery according to claim 11, wherein, The battery cell assembly (30) includes a module housing (22), and the restraint is configured as one of an end plate, a side plate, or an end cap (21) of the module housing (22).

15. The battery according to claim 11, wherein, The battery (100) includes a housing (10), and the restraint is configured as a partition beam (40) of the housing (10).

16. The battery according to any one of claims 13-15, wherein, At least a portion of the surface of the restraint member facing the first battery cell (31) or the second battery cell (32) is configured as a plane.

17. An electrical appliance, wherein, The electrical device includes a battery (100) as described in any one of claims 1 to 16, the battery (100) being used to provide electrical energy to the electrical device.

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