Battery and electric device

Abstract

Disclosed in the present application are a battery and an electric device. The battery comprises a battery cell and at least one cooling component. The battery cell comprises a casing, at least one electrode assembly and at least one buffer member, wherein the electrode assembly and the buffer member are arranged in the casing; the buffer member is arranged on at least part of the surface of the electrode assembly and / or inside the electrode assembly; and the at least one electrode assembly and the at least one buffer member are stacked in a first direction. The cooling component is arranged on at least one side of the battery cell in the first direction.

Description

Batteries and electrical devices Technical Field

[0001] The present application belongs to the field of battery technology, and in particular, relates to batteries and electrical devices. Background Art

[0002] Batteries, as energy storage devices, are widely used in various fields. Lithium-ion batteries, for example, are green, environmentally friendly, high-energy, and low-carbon. They are not only used in energy storage power systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric vehicles, and ships, as well as in military equipment and aerospace. With the development of today's society, people's demands for batteries are also becoming increasingly higher.

[0003] Public content

[0004] In view of the technical problems existing in the background technology, the present application provides a battery, which aims to shorten the heat conduction path and improve the cooling efficiency of the battery.

[0005] In order to achieve the above objectives, the first aspect of the present application provides a battery, comprising:

[0006] A battery cell comprising: a housing, at least one electrode assembly, and at least one buffer member, wherein the electrode assembly and the buffer member are disposed within the housing, the buffer member being disposed on at least a portion of a surface of and / or within the electrode assembly, and wherein the at least one electrode assembly and the at least one buffer member are stacked along a first direction;

[0007] At least one cooling member is provided on at least one side of the battery cell along the first direction.

[0008] The battery of the first aspect of the present application has the following beneficial effects: on the one hand, the provision of a buffer can improve the fit between the electrode assembly and the shell, and even if the buffer is not over-compressed, it is beneficial to achieve direct fit between the electrode assembly and the inner wall of the shell, or fit between the electrode assembly and the inner wall of the shell through the buffer or insulating film, which is not only beneficial to shortening the heat conduction path between the electrode assembly and the shell, but also beneficial to increasing the contact heat exchange area between the electrode assembly and the shell, improving the heat dissipation effect of the battery cell itself, and thus improving the cooling efficiency; further, the structure in which at least one electrode assembly and at least one buffer are stacked along the first direction makes the electrode assembly and the inner wall of the shell have a further improved fit and a further shortened heat conduction path in the first direction. On this basis, by providing a cooling component on at least one side of the battery cell along the first direction, it is not only beneficial to further shorten the heat conduction path between the electrode assembly and the cooling component in the first direction, but also beneficial to increase the relative heat exchange area between the electrode assembly and the cooling component in the portion where the heat conduction path is shortened in the first direction, thereby further improving the cooling efficiency. In summary, the above structure is conducive to improving the fit between the electrode assembly and the shell, shortening the heat conduction path, improving the self-heating efficiency of the battery cell and the heat conduction efficiency with the cooling component, and improving the heat dissipation effect of the battery.

[0009] In some embodiments of the present application, the battery includes: at least one first battery cell group, the first battery cell group including a plurality of the battery cells stacked along the first direction.

[0010] In some embodiments of the present application, a plurality of the first battery cell groups are stacked along a second direction, and the second direction intersects with the first direction.

[0011] In some embodiments of the present application, the battery includes a first battery cell group, and the cooling member is disposed between two adjacent battery cells in the first direction, and / or the cooling member is disposed on one side of a plurality of battery cells along the first direction. This helps improve the heat dissipation efficiency and effect of the battery.

[0012] In some embodiments of the present application, the battery includes: at least one second battery cell group, the second battery cell group including a plurality of the battery cells stacked along a second direction, and the second direction intersects with the first direction.

[0013] In some embodiments of the present application, the battery includes a second battery cell group, and in the first direction, the cooling member is arranged between two adjacent battery cells, and / or the cooling member is arranged on one side of the plurality of battery cells along the first direction.

[0014] In some embodiments of the present application, the battery cell includes two first surfaces disposed opposite each other along the first direction, and the area of ​​the first surfaces is greater than or equal to the area of ​​a single surface among the other surfaces of the battery cell. Meeting this condition further increases the total heat exchange area between the battery cell and the cooling member, thereby improving the heat dissipation efficiency and effectiveness of the battery.

[0015] In some embodiments of the present application, the area of ​​the orthographic projection of the buffer member stacked with the electrode assembly along the first direction on the first surface is greater than or equal to 80% of the area of ​​the first surface. This helps to further improve the fit between the electrode assembly and the housing while increasing the total heat exchange area between the battery cell and the cooling member, thereby further improving the heat dissipation efficiency of the battery cell.

[0016] In some embodiments of the present application, the cooling member is provided between each of the plurality of battery cells in the first direction. Meeting the given conditions is conducive to further increasing the total heat exchange area between all battery cells in the entire battery and the cooling member, thereby improving the heat dissipation efficiency and effect of the battery.

[0017] In some embodiments of the present application, the first group margin of the battery cells is ≥95%, and may be ≥100%; the second group margin of the battery cells is ≥90%, and may be ≥95%. The first group margin refers to the ratio of the sum of the total thickness of the buffer member in the battery cell in the free state and the maximum total dimension of the electrode assembly in the fully charged state to the distance between the inner wall surface of the housing in the first direction; the second group margin refers to the ratio of the maximum total dimension of the electrode assembly in the battery cell in the fully charged state to the distance between the inner wall surface of the housing in the first direction. Meeting these conditions is beneficial to improving the fit between the electrode assembly and the housing, improving heat exchange efficiency and effect, and taking into account the energy density of the battery.

[0018] In some embodiments of the present application, the first group margin of the battery cells is ≤108%, optionally ≤105%; and / or the second group margin is ≤100%, optionally ≤98%. Meeting the given conditions is also beneficial to taking into account the volume stability of the battery during the charge and discharge cycle.

[0019] In some embodiments of the present application, a cooling medium flow channel is provided within the cooling member, the cooling medium flow channel including an inlet and an outlet, and the margin of the first group of battery cells located on the outlet side is greater than or equal to the margin of the first group of battery cells located on the inlet side. Meeting this condition helps to compensate for the reduced cooling effect on battery cells near the outlet side of the cooling medium flow channel caused by the temperature rise of the cooling medium, thereby helping to maintain the overall temperature uniformity of the battery cells in the battery.

[0020] In some embodiments of the present application, the difference between the first group margin of the battery cells located on the outlet side and the first group margin of the battery cells located on the inlet side is less than or equal to 5%. Meeting this condition is beneficial for maintaining the overall temperature uniformity of the battery cells and also takes into account the overall volume stability of the battery.

[0021] In some embodiments of the present application, a difference between the second group margin of the battery cells located on the outlet side and the second group margin of the battery cells located on the inlet side is less than or equal to 1%, and may be 0.

[0022] In some embodiments of the present application, the first group margins of the plurality of battery cells distributed along the inlet toward the outlet gradually increase, and the difference between the first group margins and the second group margins of the battery cells located on the outlet side is greater than the difference between the first group margins and the second group margins of the battery cells located on the inlet side. Meeting these conditions further improves the overall heat dissipation of the battery and maintains overall temperature uniformity among the battery cells.

[0023] In some embodiments of the present application, the cooling components are multiple, and the cooling medium flow channels of the multiple cooling components are arranged in parallel and / or in series.

[0024] In some embodiments of the present application, multiple cooling members are connected by a connector, and the cooling medium flow channels of two adjacent cooling members spaced apart in the first direction are interconnected via the connector. Meeting this condition not only facilitates the filling and flow of the cooling medium in the different cooling medium flow channels, but also further increases the contact area between the battery cells and the cooling medium, thereby improving heat dissipation.

[0025] In some embodiments of the present application, the battery cell includes two second surfaces disposed opposite to each other along the first direction, and at least one of the two second surfaces is in contact with the cooling member. Meeting the given conditions can further shorten the heat conduction path and improve heat dissipation efficiency and effect.

[0026] In some embodiments of the present application, in the battery cell, the contact area between the second surface and the cooling member is greater than or equal to 80% of the second surface area, optionally 80% to 100% of the second surface area, and further optionally 90% to 100% of the second surface area. Meeting these conditions is conducive to further improving heat dissipation efficiency and effects.

[0027] In some embodiments of the present application, the total contact area between a single battery cell and the cooling member is greater than or equal to 20% of the total surface area of ​​the battery cell, and optionally greater than or equal to 25% of the total surface area of ​​the battery cell. Meeting this condition is conducive to further improving heat dissipation efficiency and effect.

[0028] In some embodiments of the present application, in the battery cell, the buffer member is provided between a portion of the surface of the electrode assembly and the housing. Meeting the given conditions is beneficial for increasing the fit and contact area between the electrode assembly and the housing, and improving the heat dissipation efficiency and effect of the battery.

[0029] In some embodiments of the present application, the thermal conductivity of the buffer member disposed between the electrode assembly and the housing is ≥3 W / (m·°C), and may be ≥5 W / (m·°C). Meeting this condition can improve the thermal conductivity of the buffer member and enhance the heat dissipation effect of the battery cell.

[0030] In some embodiments of the present application, in the battery cell, a buffer is provided between two adjacent electrode assemblies. Meeting the given conditions is conducive to increasing the fit between the electrode assembly and the housing, and improving the heat dissipation efficiency and effect of the battery.

[0031] In some embodiments of the present application, the thermal conductivity of the buffer member disposed between two adjacent electrode assemblies is ≤0.05 W / (m·°C), and optionally ≤0.03 W / (m·°C). Meeting this condition helps isolate heat conduction between battery assemblies and reduces the risk of failure of other electrode assemblies due to failure of a single electrode assembly.

[0032] In some embodiments of the present application, the electrode assembly includes a diaphragm, and the thermal conductivity of the diaphragm is greater than or equal to the thermal conductivity of the buffer member. Meeting the given conditions is conducive to improving the heat dissipation efficiency and effect of the battery.

[0033] In some embodiments of the present application, the battery cell further includes an insulating film that wraps at least a portion of the surface of the electrode assembly. Each electrode assembly is stacked with at least one layer of the insulating film in the first direction, and the thermal conductivity of the insulating film is greater than or equal to the thermal conductivity of the buffer component. Meeting this condition not only reduces the risk of electrical leakage but also improves the heat dissipation efficiency and effectiveness of the battery.

[0034] In some embodiments of the present application, the third group margin of the battery cell is ≥95%, and optionally ≥100%. The third group margin refers to the ratio, in the first direction, of the sum of the total thickness of the buffer member in the battery cell in the free state, the maximum total dimension of the electrode assembly in the fully charged state, and the total thickness of the insulating film to the distance to the inner wall of the housing. Meeting this condition further improves the heat dissipation efficiency and effectiveness of the battery.

[0035] In some embodiments of the present application, the battery cell includes at least two electrode assemblies, and each buffer member in the battery cell is independently disposed between two adjacent electrode assemblies and stacked with the electrode assemblies along the first direction. Meeting these conditions is beneficial for improving the heat dissipation efficiency and effect of the battery.

[0036] In some embodiments of the present application, the battery cell includes two third surfaces disposed opposite each other along the first direction, and the orthographic projection of the buffer member, which is stacked and adjacent to the electrode assembly along the first direction, on the third surfaces is located within the area of ​​the orthographic projection of the electrode assembly on the third surfaces. Meeting this condition not only improves the heat dissipation efficiency and effect of the battery, but also helps to balance the energy density of the battery cell.

[0037] In some embodiments of the present application, the area of ​​the orthographic projection of the buffer member stacked and adjacent to the electrode assembly along the first direction on the third surface is greater than or equal to 80% of the area of ​​the orthographic projection of the electrode assembly on the third surface. Meeting this condition is beneficial for improving the heat dissipation efficiency of the battery cell and the volume stability during cycling.

[0038] The second aspect of the present application provides an electrical device, which includes: the battery described in the first aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0040] FIG1 is a schematic diagram of a cross-sectional structure of a battery according to one embodiment of the present application.

[0041] FIG2 is a schematic cross-sectional view of a prismatic battery cell according to one embodiment of the present application.

[0042] FIG3 is a schematic cross-sectional view of a prismatic battery cell according to another embodiment of the present application.

[0043] FIG4 is a schematic cross-sectional view of a prismatic battery cell according to another embodiment of the present application.

[0044] FIG5 is a schematic cross-sectional view of a prismatic battery cell according to another embodiment of the present application.

[0045] FIG6 is a schematic cross-sectional view of a cylindrical battery cell according to one embodiment of the present application.

[0046] FIG. 7 is a schematic structural diagram of a prismatic battery cell according to one embodiment of the present application.

[0047] FIG8 is a schematic cross-sectional view of a battery according to another embodiment of the present application.

[0048] FIG9 is a schematic cross-sectional view of a battery according to another embodiment of the present application.

[0049] FIG10 is a schematic cross-sectional view of a battery according to another embodiment of the present application.

[0050] FIG11 is a schematic cross-sectional view of a battery according to another embodiment of the present application.

[0051] FIG12 is a schematic diagram of the cross-sectional structure of a battery according to yet another embodiment of the present application.

[0052] FIG13 is a schematic structural diagram of a battery module according to one embodiment of the present application.

[0053] FIG14 is a schematic structural diagram of a battery pack according to one embodiment of the present application.

[0054] FIG. 15 is an exploded view of a battery pack according to one embodiment of the present application.

[0055] FIG16 is a schematic diagram of an electric device using a battery as a power source according to an embodiment of the present application.

[0056] Reference numerals:

[0057] 11: Shell; 12: Electrode assembly; 13: Buffer; 13a: First buffer; 13b: Second buffer; 1: Battery cell; 2: Battery module; 3: Battery pack; 4: Upper case; 5: Lower case; 6: Cooling member; 61: Cooling medium flow channel inlet; 62: Cooling medium flow channel outlet; A: First battery cell group; B: Second battery cell group. DETAILED DESCRIPTION

[0058] The present application will be further described below in conjunction with specific embodiments. It should be understood that these specific embodiments are only used to illustrate the present application and are not used to limit the scope of the present application.

[0059] Below, with appropriate reference to the accompanying drawings, the embodiments of the positive electrode active material and its preparation method, the positive electrode sheet, the battery and the electric device of the present application are described in detail. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0060] The "range" disclosed in this application is defined in the form of a lower limit and / or an upper limit, and a given range is defined by selecting a lower limit and / or an upper limit, and the selected lower limit and / or upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form an unspecified range, and any lower limit can be combined with other lower limits to form an unspecified range, and similarly any upper limit can be combined with any other upper limit to form an unspecified range. In addition, each separately disclosed point or single value itself can be combined with any other point or single value as a lower limit or upper limit or with other lower limits or upper limits to form an unspecified range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also contemplated. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4, and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise specified, the numerical range "a-b" is an abbreviation for any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in this document, and "0-5" is just an abbreviation for these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0061] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present application.

[0062] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of this application.

[0063] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps S1 and S2, which means that the method may include steps S1 and S2 performed sequentially, or may include steps S2 and S1 performed sequentially. For example, the method may further include step S3, which means that step S3 may be added to the method in any order, for example, the method may include steps S1, S2, and S3, or may include steps S1, S3, and S2, or may include steps S3, S1, and S2, etc.

[0064] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0065] Unless otherwise specified, the term "or" is used in this application to be inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied if any of the following conditions are met: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0066] Unless otherwise specified, the term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0067] In this application, the terms "plurality" and "multiple" refer to two or more.

[0068] 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 to which this application belongs; the terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned description of the drawings and any variations thereof are intended to cover non-exclusive inclusions. Unless otherwise specified, the terms used in this application have the well-known meanings commonly understood by those skilled in the art. Unless otherwise specified, the numerical values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the examples of this application).

[0069] With the continued advancement of green environmental protection, batteries have become increasingly ubiquitous in everyday life, including vehicles, electronic devices, and energy storage devices. However, as battery applications continue to expand, so too do people's expectations for batteries. Batteries generate heat during the charge and discharge cycle. Prolonged excessive heating can lead to rapid capacity degradation and increase the risk of battery bulging and thermal runaway, impacting both the battery's service life and the proper functioning of electrical devices.

[0070] In the present application, by arranging a buffer member in the battery cell, and stacking at least one electrode assembly and at least one buffer member located in the battery cell shell along a first direction, and at the same time arranging a cooling component on at least one side of the battery cell along the first direction, it is beneficial to improve the fit between the electrode assembly and the shell, improve the thermal conductivity efficiency of the battery cell and the cooling component, and improve the heat dissipation effect of the battery.

[0071] The battery disclosed in the embodiments of the present application can be used in electrical devices that use the battery as a power source or various energy storage systems that use the battery as an energy storage element. Electrical devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery cars, electric cars, ships, spacecraft, and the like. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0072] A first aspect of the present application provides a battery, comprising: a battery cell and at least one cooling member, the battery cell comprising a shell, at least one electrode assembly and at least one buffer, the electrode assembly and the buffer being placed in the shell, the buffer being arranged on at least a portion of the surface of the electrode assembly and / or inside the electrode assembly, the at least one electrode assembly and the at least one buffer being stacked along a first direction; the cooling member being arranged on at least one side of the battery cell along the first direction.

[0073] For example, referring to Figures 1 to 6, the battery of the first aspect of the present application includes a battery cell 1 and at least one cooling member 6. The battery cell 1 includes a housing 11, at least one electrode assembly 12, and at least one buffer 13. The electrode assembly 12 and the buffer 13 are placed in the housing 11. The buffer 13 can be provided on at least a portion of the surface of the electrode assembly 12 and / or inside the electrode assembly 12. The at least one electrode assembly 12 and the at least one buffer 13 are stacked along a first direction. The cooling member 6 is provided on at least one side of the battery cell 1 along the first direction (refer to Figure 1 for understanding). Exemplarily, the buffer 13 can be provided between the electrode assembly 12 and the housing 11 (refer to Figure 2 for understanding), and / or can be provided between two adjacent electrode assemblies 12 (refer to Figure 3 for understanding), and / or can be provided inside the electrode assembly (refer to Figure 4 for understanding). Among them, the buffer member 13 can be provided between the electrode assembly 12 and the shell 11, which can be understood as being provided in at least one of the areas between the electrode assembly 12 and the side wall of the shell 11, between the electrode assembly 12 and the bottom wall of the shell 11, and between the electrode assembly 12 and the top wall of the shell 11. Optionally, referring to FIG5 , it is understood that the buffer member 13 can be provided simultaneously between the electrode assembly 12 and the shell 11 and between two adjacent electrode assemblies 12; further optionally, referring to FIG2 and FIG3 , it is understood that the buffer member 13 can be provided on a partial surface of the electrode assembly 12, for example, only A buffer member 13 is provided on one side of the electrode assembly 12 along the first direction. As some specific examples, when the battery cell 1 includes only one electrode assembly 12, the buffer member 13 may be optionally provided on only one side of the electrode assembly 12 in the first direction (refer to FIG2 for understanding); as some other specific examples, when the battery cell 1 includes multiple electrode assemblies 12, the buffer member 13 may be optionally provided directly on only two adjacent electrode assemblies 12 in the first direction, and the electrode assemblies 12 and the buffer member 13 may be alternately stacked in the first direction (refer to FIG3 for understanding). The buffer 13 can be arranged inside the electrode assembly. It can be understood that when the electrode assembly 12 is a laminated structure, the buffer 13 can be located in the middle area of ​​the electrode assembly 12, that is, in the first direction, laminated units are distributed on both sides of the buffer 13, and the laminated units include positive electrode sheets, negative electrode sheets and diaphragms; when the electrode assembly 12 is a wound structure, the buffer 13 can be located in the central area of ​​the electrode assembly, that is, the buffer 13 can be used as the winding center, and the positive electrode sheets, negative electrode sheets and diaphragms can be stacked and wound around the buffer 13 to form. At this time, when the wound electrode assembly is used in a cylindrical battery cell, the first direction can be the radial direction of the electrode assembly (refer to Figure 6 for understanding). When the wound electrode assembly is used in a prismatic battery cell, the electrode assembly includes a straight portion and a corner portion after forming. The first direction can be the thickness direction of the straight portion (refer to Figure 4 for understanding) or the length direction, and can be optionally the thickness direction of the straight portion.In actual operation, both sides of the buffer member 13 along its thickness direction can be fitted with the electrode assembly 12 , or one side can be fitted with the electrode assembly 12 and the other side can be fitted with the inner wall of the shell 11 .

[0074] Optionally, the thickness direction of at least one electrode assembly 12 is the same as the first direction (refer to Figures 2 to 5 for understanding), and further optionally, the thickness direction of at least one buffer member 13 is the same as the thickness direction of the electrode assembly 12 (refer to Figures 2 to 5 for understanding).

[0075] In addition, it is understood that when the cooling member is provided on at least one side of the battery cell along the first direction, the cooling member can be provided in contact with or spaced apart from at least one side of the battery cell along the first direction, and the contact setting can include a situation where the two are in close contact (with a strong effect) or a situation where they are just adjacent. Exemplarily, the cooling member can be provided on the surface of the battery cell along the first direction, or spaced apart from the battery cell, that is, other components or battery cells can be provided between the cooling member and the battery cell, and the other components can include but are not limited to fixing glue (the cooling member and the battery cell can be fixed by gluing) and other components. In addition, a buffer refers to a structural member that can undergo elastic deformation.

[0076] In the battery cell of the present application, at least one electrode assembly and at least one buffer are stacked along a first direction, and a cooling member is provided on at least one side of the battery cell along the first direction, wherein the provision of the buffer can improve the fit between the electrode assembly and the shell, and even if the buffer is not over-compressed, it is conducive to achieving direct fit between the electrode assembly and the inner wall of the shell, or fit to the inner wall of the shell through the buffer or insulating film, thereby facilitating that the electrode assembly always has a high fit with the inner wall of the shell during the charge and discharge cycle. Improving the fit between the electrode assembly and the shell is not only conducive to shortening the heat conduction path between the electrode assembly and the shell, but also conducive to increasing the heat dissipation between the electrode assembly and the shell. The contact heat exchange area between the battery cells is increased, improving the heat dissipation effect of the battery cells themselves, thereby improving the cooling efficiency; further, the structure of at least one electrode assembly and at least one buffer member stacked along the first direction allows the electrode assembly and the inner wall of the shell to have a further improved fit and a further shortened heat conduction path in the first direction. On this basis, by arranging a cooling member on at least one side of the battery cell along the first direction, it is not only beneficial to further shorten the heat conduction path between the electrode assembly and the cooling member in the first direction, but also beneficial to increase the relative heat exchange area between the electrode assembly and the cooling member in the portion where the heat conduction path is shortened in the first direction, thereby further improving the cooling efficiency. It can be understood that the provision of a buffer member in the battery cell is also beneficial to improving the volume change of the battery cell during the charge and discharge cycle and improving the cycle stability. Among them, the relative positional relationship between the battery cell and the cooling member, as well as the internal structure of the battery cell, can be determined by disassembling the battery.

[0077] The battery of the first aspect of the present application has the following beneficial effects: it is conducive to improving the fit between the electrode assembly and the shell, shortening the heat conduction path, improving the self-heating of the battery cell and the heat conduction efficiency with the cooling component, and improving the heat dissipation effect of the battery.

[0078] It can be understood that in the embodiments of the present application, battery cells include but are not limited to shells, electrode assemblies and buffers. For example, battery cells may also include electrolytes; in the embodiments of the present application, battery cells include but are not limited to secondary battery cells, primary battery cells, etc.; in the embodiments of the present application, battery cells include but are not limited to lithium-ion battery cells, sodium-ion battery cells, magnesium-ion battery cells, etc.; in the embodiments of the present application, battery cells include but are not limited to hard battery cells, soft-pack battery cells, etc., and hard battery cells include but are not limited to metal battery shell cells, etc.

[0079] Furthermore, the battery of the first aspect of the present application, while meeting the aforementioned conditions, can further improve the heat dissipation effect of the battery cells by further improving the relative positional relationship between the cooling member and the battery cells, the group margin of the battery cells, the difference in group margin between the battery cells, the contact area between the battery cells and the cooling member, the thermal conductivity of the buffer and its size relationship with other structural components, and the area where the buffer is installed. That is, in addition to meeting the aforementioned conditions, one or more of the following conditions can also be optionally met.

[0080] In some embodiments of the present application, the cooling component 6 includes but is not limited to commonly used cooling structural components. For example, the cooling component may include but is not limited to a cooling plate, a radiator, and the like.

[0081] In some embodiments of the present application, a battery cell may be cylindrical or prismatic, or optionally prismatic. A prismatic battery cell may have a wound or laminated structure. Referring to FIG6 , when the battery cell is cylindrical, the first direction may be the radial direction of the electrode assembly. Referring to FIG7 , when the battery cell is prismatic, the first direction may be at least one of the x-, y-, and z-directions, that is, at least one of the length, thickness, and height directions of the housing. For example, in FIG2-4 , the first direction may be the thickness direction of the housing 11. For example, in FIG5 , the first direction may be the length direction of the housing 11. Furthermore, in FIG5 , the prismatic battery cell may include at least one first buffer member 13a and / or at least one second buffer member 13b. At least one of the first buffer member 13a and the second buffer member 13b may be stacked with at least one electrode assembly 12 along a first direction. Optionally, the first direction may be the same as the thickness direction of the electrode assembly 12.

[0082] In some embodiments of the present application, the battery may include: at least one first battery cell group A, the first battery cell group A including a plurality of battery cells 1 stacked along a first direction.

[0083] Referring to FIG8 , it can be understood that in a battery cell, the electrode assembly and the inner wall of the housing have a further improved fit and a further shortened heat conduction path in the first direction. This results in relatively good cooling efficiency and heat dissipation of the battery cell in the first direction. By stacking multiple battery cells along the first direction, the surfaces of the multiple battery cells with relatively good cooling efficiency and heat dissipation can be concentrated in the first direction. Furthermore, combined with the design of providing cooling members on at least one side of the battery cell along the first direction, such as providing cooling members on at least one side of each battery cell along the first direction, this not only further shortens the heat conduction path between the electrode assembly and the cooling member in the first direction and increases the relative heat exchange area between the electrode assembly and the cooling member in the portion of the shortened heat conduction path in the first direction, but also further increases the total relative heat exchange area between the entire first battery cell group and the cooling member by optimizing the number of cooling members and their relative positional relationship with the battery cell in the first direction, while also ensuring the overall integration of the battery cell and the cooling member. Optionally, a cooling member can be provided between any two adjacent battery cells stacked in the first direction in the first direction, thereby further increasing the total relative heat exchange area between the entire first battery cell group and the cooling member, improving cooling efficiency.

[0084] In some embodiments of the present application, the plurality of first battery cell groups A may be stacked along a second direction, and the second direction may intersect with the first direction.

[0085] With reference to Figures 9 and 10 , it can be understood that employing a stacked arrangement of multiple first battery cell groups along the second direction can also facilitate the simultaneous stacking of a single cooling member with multiple battery cells along the first direction. This, in turn, increases both the total heat exchange area between a single cooling member and a battery cell, as well as the total heat exchange area between all battery cells in the entire battery and the cooling member, while also balancing the overall integration of the battery cells and the cooling member. Optionally, the second direction can be perpendicular or substantially perpendicular to the first direction, where the angle between the second direction and the first direction can be 80 to 100 degrees, optionally 85 to 95 degrees, or even more optionally 88 to 92 degrees.

[0086] In some embodiments of the present application, the battery includes a first battery cell group A. In the first direction, the cooling member 6 can be arranged between two adjacent battery cells 1, and / or the cooling member 6 can be arranged on one side of the plurality of battery cells 1 along the first direction.

[0087] For example, referring to Figures 8 or 9 , for a battery structure having a first battery cell group A, the cooling member 6 can be positioned between two adjacent battery cells 1 in the first direction. This facilitates heat exchange between both sides of each cooling member along the first direction and the battery cell surface, thereby increasing the total heat exchange area between the entire first battery cell group and the cooling member. Optionally, the cooling members 6 and multiple battery cells 1 can be alternately stacked in the first direction, with each cooling member 6 independently positioned between two adjacent battery cells 1. This approach not only increases the total heat exchange area between the entire first battery cell group and the cooling member, shortens the heat conduction path, improves the heat dissipation efficiency of the battery, but also facilitates a simplified battery structure.

[0088] For example, referring to FIG10 , for a battery structure having a first battery cell group A, in a first direction, the cooling member 6 can be arranged on one side of the plurality of battery cells 1 along the first direction. This arrangement is beneficial to further increase the total heat exchange area between the battery cells distributed on both sides of the first direction and the cooling member, shorten the heat conduction path, and improve the heat dissipation efficiency of the battery.

[0089] For example, as understood in conjunction with Figures 8 to 10 , for a battery structure having a first battery cell group A, a portion of the cooling member 6 can be positioned between two adjacent battery cells 1 in the first direction, and another portion of the cooling member 6 can be positioned on one side of the plurality of battery cells 1 along the first direction. This arrangement facilitates heat exchange between both sides of each battery cell along the first direction, thereby further increasing the total heat exchange area between the entire first battery cell group and the cooling member, and improving the heat dissipation efficiency of the battery.

[0090] For a battery structure including a first battery cell group A and a structure including multiple first battery cell groups A stacked along a second direction, the relative positional relationship between the cooling component and the battery cell satisfies the given conditions, which is beneficial to increasing the total heat exchange area between the entire first battery cell group and the cooling component, shortening the heat conduction path, and improving the heat dissipation efficiency and effect of the battery.

[0091] In some embodiments of the present application, the battery may include: at least one second battery cell group B, the second battery cell group B may include a plurality of battery cells 1 stacked along a second direction, and the second direction intersects with the first direction. Exemplarily, with reference to Figure 11, the battery may include only one second battery cell group B. Exemplarily, with reference to Figure 12, the battery may include a plurality of second battery cell groups B, and optionally, the plurality of second battery cell groups B may be stacked along the first direction. The battery structure design with one or more second battery cell groups is also beneficial for taking into account both the heat dissipation efficiency of the battery cells and the integration of the battery cells. Optionally, the battery may include a plurality of first battery cell groups A and a plurality of second battery cell groups B at the same time. Optionally, as mentioned above, the second direction may be perpendicular or substantially perpendicular to the first direction.

[0092] In some embodiments of the present application, the battery includes a second battery cell group B, and in the first direction, the cooling member 6 can be arranged between two adjacent battery cells 1, and / or, the cooling member 6 can be arranged on one side of the plurality of battery cells 1 along the first direction.

[0093] For example, referring to FIG11 , when the battery includes only one second battery cell group B, only one cooling member 6 may be provided, with the cooling member 6 being located on one side of the second battery cell group B along the first direction. Alternatively, two cooling members 6 may be provided, with the two cooling members 6 being located on both sides of the second battery cell group B along the first direction. In the above arrangement, each cooling member 6 is independently provided on one side of the plurality of battery cells 1 along the first direction.

[0094] Exemplarily, referring to Figure 12, when the battery includes multiple second battery cell groups B, in the first direction, the cooling member 6 can be arranged between two adjacent battery cells 1. For example, in the first direction, the cooling member 6 can be alternately stacked with the multiple second battery cell groups B, and each cooling member 6 can be distributed independently between two adjacent second battery cell groups B. This is beneficial for each cooling member to exchange heat with the surfaces of multiple battery cells on both sides distributed along the first direction, thereby facilitating an increase in the total heat exchange area between the entire second battery cell group and the cooling member, and also facilitating a simplification of the battery structure.

[0095] For example, as understood in conjunction with Figures 11 and 12 , when the battery includes multiple second battery cell groups B, in the first direction, a portion of the cooling members 6 can be positioned between two adjacent battery cells 1, and another portion of the cooling members 6 can be positioned on one side of the multiple battery cells 1 along the first direction. This arrangement facilitates heat exchange between both sides of each battery cell along the first direction, thereby further increasing the total heat exchange area between the entire second battery cell group and the cooling member, thereby improving the heat dissipation efficiency of the battery.

[0096] In some embodiments of the present application, the battery cell 1 may include two first surfaces 11 a oppositely disposed along a first direction, and an area of ​​the first surface 11 a may be greater than or equal to an area of ​​a single surface among other surfaces of the battery cell 1 .

[0097] In combination with Figures 1 and 7, taking the prismatic battery cell 1 as an example, the battery cell 1 may include multiple surfaces. When the area of ​​a single first surface 11a of the two first surfaces 11a of the battery cell opposite to each other along the first direction is greater than or equal to the area of ​​a single surface of the remaining other surfaces in the battery cell 1 where it is located, the area of ​​the first surface 11a that can be arranged opposite to or in contact with the cooling component can be maximized compared with the other surfaces, thereby facilitating further increasing the total heat exchange area between the battery cell and the cooling component and improving the heat dissipation efficiency and effect of the battery.

[0098] In some embodiments of the present application, the area of ​​the orthographic projection of the buffer member 13 stacked with the electrode assembly 12 along the first direction on the first surface 11 a may be greater than or equal to 80% of the area of ​​the first surface 11 a .

[0099] For example, in conjunction with Figures 1 and 7 , the area of ​​the orthographic projection of the buffer member 13 stacked with the electrode assembly 12 along the first direction on the first surface 11a can be 80%, 85%, 90%, 95%, 98%, etc. of the area of ​​the first surface 11a. In this application, the area of ​​the first surface can be understood as the area of ​​the side of the first surface facing the interior of the housing. The area of ​​the first surface and the area of ​​the orthographic projection of the buffer member on the first surface can be measured independently using conventional methods. For example, the area of ​​the first surface can be measured using direct measurement or colorimetry, and the area of ​​the orthographic projection of the buffer member on the first surface can be measured using direct measurement, segmentation and summation, projection area formula, or 3D modeling software. The projected area of ​​the buffer member on the first surface reflects, to a certain extent, the area where the electrode assembly can be positioned relative to or in contact with the first surface. Increasing this projected area helps increase the area where the electrode assembly can be positioned relative to or in contact with the first surface, thereby improving the fit between the electrode assembly and the housing.

[0100] Ensuring that the positive projection area of ​​the buffer member on the first surface meets the given conditions is beneficial to further improving the fit between the electrode assembly and the shell on the basis of increasing the total heat exchange area between the battery cell and the cooling component, thereby further improving the heat dissipation efficiency of the battery cell.

[0101] In some embodiments of the present application, in the first direction, a cooling member 6 may be provided between each of the plurality of battery cells 1. Referring to FIG. 8 or FIG. 12 , it can be understood that this arrangement further increases the total heat exchange area between all battery cells and the cooling member in the entire battery, thereby improving the heat dissipation efficiency and effectiveness of the battery.

[0102] In some embodiments of the present application, the first group margin of the battery cell 1 can be ≥95%, and can optionally be ≥100%; the second group margin of the battery cell 1 can be ≥90%, and can optionally be ≥95%. The first group margin refers to: in the first direction, the ratio of the sum of the total thickness of the buffer 13 in the free state in the battery cell 1 and the maximum total size of the electrode assembly 12 in the fully charged state to the distance between the inner wall surface of the shell 11; the second group margin refers to: in the first direction, the ratio of the maximum total size of the electrode assembly 12 in the fully charged state in the battery cell 1 to the distance between the inner wall surface of the shell 11.

[0103] Exemplarily, the first group margin of battery cells 1 can be 95%, 97%, 100%, 102%, 105%, 108%, 110%, etc., or can be a range consisting of any of the above values. Improving the group margin of battery cells is conducive to further improving the fit between the electrode assembly and the shell, and improving the heat dissipation efficiency and effect. Controlling the first group margin of battery cells to meet the given range conditions is conducive to further achieving higher heat dissipation efficiency and effect. Exemplarily, the second group margin of battery cells 1 can be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc., or can be a range consisting of any of the above values. Improving the second group margin of battery cells is conducive to further improving the energy density of the battery. In addition, by comprehensively controlling the first group margin and the second group margin of battery cells to meet the given range, the fit between the electrode assembly and the shell can be further improved, and the heat exchange efficiency and effect can be improved while taking into account the energy density of the battery.

[0104] Among them, the free state of the buffer refers to the state in which the buffer is not subjected to any external force. The thickness test of the buffer in the free state can be carried out using conventional instruments and conventional methods in this field. For example, a Mitutoyo ID-C112MX micrometer thickness gauge (or similar instrument) can be used to test when the test force is less than or equal to 1.8N, and multiple points (such as 5, 10, etc.) are randomly measured to obtain the average value. The thickness test of the buffer under stress state can be carried out using two parallel flat plates, with the buffer located in the middle of the flat plates, and the flat plates are used to apply a preset pressure to the buffer and measure the distance between the flat plates. The instruments used to measure the distance between the flat plates may include but are not limited to conventional instruments such as vernier calipers. The fully charged state refers to the state of charging at room temperature with a constant current of 0.33C of the rated capacity of the battery cell to the upper limit of the cut-off voltage, and then charging at a constant voltage until the current is 0.05C, or charging under this condition until the SOC of the battery no longer changes.

[0105] In a battery cell, the total thickness of the buffer in the free state in the first direction refers to the cumulative value of the thickness of one or more buffers stacked with the electrode assembly along the first direction; the maximum total size of the electrode assembly in the fully charged state in the first direction refers to the maximum extension distance of all electrode assemblies in the battery cell in the first direction when the battery cell is fully charged at room temperature; the distance between the inner walls of the shell in the first direction refers to the distance between the inner walls of the shell in the free state (i.e., the state without any external force). When the battery unit is a prismatic battery, the distance between the inner walls of the shell along the first direction can be understood as the average distance. When the battery cell is cylindrical, the distance between the inner walls of the shell along the first direction can be understood as the maximum distance. For example:

[0106] Taking Figure 3 as an example, the battery cell is a prismatic battery, and the interior of the shell only includes two electrode assemblies and a buffer stacked along the first direction. The total thickness of the buffer in the free state in the first direction refers to the thickness d1 of the single buffer in the free state; the maximum total size of the electrode assembly in the fully charged state in the first direction is the sum d2 of the distances between the two electrode assemblies in the first direction, and the distance between the inner walls of the shell in the first direction refers to the average distance d3 between the inner surfaces of the two side walls of the shell opposite to each other in the first direction in the free state. At this time, the first group margin is (d1+d2) / d3×100%, and the second group margin is d2 / d3×100%.

[0107] Taking Figure 5 as an example, the battery cell is a prismatic battery, and the interior of the shell includes two electrode assemblies and three buffers, wherein the two electrode assemblies and the two second buffers 13b are stacked along the first direction, and the total thickness of the buffer in the free state in the first direction refers to the sum d1′ of the thickness of the two second buffers in the free state; the maximum total size of the electrode assembly in the fully charged state in the first direction is the total projected length d2′ of the two electrode assemblies in the first direction (when the projected lengths of the two electrode assemblies in the first direction are the same, d2′ can also be regarded as the distance of a single electrode assembly in the first direction), and the distance between the inner wall surfaces of the shell in the first direction refers to the average distance d3′ between the inner surfaces of the two side walls of the shell arranged opposite to each other along the first direction in the free state. At this time, the first group margin is (d1′+d2′) / d3′×100%, and the second group margin is d2′ / d3′×100%.

[0108] Taking Figure 6 as an example, when the battery cell is cylindrical, the first direction is the radial direction of the electrode assembly, and the distance between the inner wall surfaces of the shell along the first direction is the inner cavity diameter of the shell in the free state. The diameter can be the average value of multiple measurements.

[0109] The dimensions of the electrode assembly in the first direction in a fully charged state can be measured using conventional methods or instruments in the art. For example, taking the thickness direction of the electrode assembly (when the electrode assembly is a wound structure and includes a straight portion and a corner portion, the thickness of the electrode assembly can be understood as the thickness of the straight portion) as the same as the first direction, the distance between a single electrode assembly in the first direction can be tested using the following method: using two parallel flat plates, with the electrode assembly located between the plates, applying a pressure of 0.1 MPa to the electrode assembly using the plates, and measuring the distance between the plates to obtain the thickness of the electrode assembly. The Yinghaoda PPG1200 battery thickness gauge can be optionally used for testing. The distance between the inner wall surfaces of the shell in the first direction can also be tested using conventional instruments and methods in the art.

[0110] In some embodiments of the present application, the margin of the first group of battery cells 1 is ≤108%, optionally ≤105%; and / or the margin of the second group of battery cells 1 is ≤100%, optionally ≤98%.

[0111] Exemplarily, the first group margin of battery cell 1 can be 108%, 107%, 106%, 105%, 104%, 103%, 102%, and so on. Reducing the group margin of the battery cell is beneficial to improving the volume stability of the battery cell during the charge and discharge cycle. Controlling the first group margin to meet the given conditions is beneficial to reducing the expansion force of the electrode assembly during the charge and discharge process, improving the volume stability of the battery during the charge and discharge cycle, and reducing the risk of affecting the battery cycle stability due to excessive expansion force of the electrode assembly during the charge and discharge process. Optionally, the first group margin can be ≤105%, and further optionally, the first group margin can be 95% to 105%, and further optionally, the first group margin can be 100% to 105%. Meeting the given conditions is beneficial to further taking into account both the heat dissipation efficiency and cycle stability of the battery.

[0112] For example, the second group margin of battery cell 1 can be 100%, 99%, 98%, 97%, 96%, 95%, and so on. Meeting the given conditions for the second group margin of battery cells facilitates the insertion of the battery assembly into the housing and facilitates the assembly of the battery cells. Alternatively, the second group margin can be ≤ 98%, thereby further facilitating the assembly of the battery cells.

[0113] In some embodiments of the present application, a cooling medium flow channel (not shown) may be provided inside the cooling component 6, and the cooling medium flow channel may include an inlet 61 and an outlet 62, and the first group margin of the battery cells 1 located on the side of the outlet 62 is greater than or equal to the first group margin of the battery cells 1 located on the side of the inlet 61.

[0114] Optionally, the margin of the first group of battery cells 1 located on the side of outlet 62 can be greater than the margin of the first group of battery cells 1 located on the side of inlet 61. As can be understood from Figure 9 , as the cooling medium continues to flow and exchange heat, the temperature of the cooling medium gradually increases. As the cooling medium moves from inlet 61 to outlet 62, the cooling effect on the battery cells decreases to a certain extent. However, by making the margin of the first group of battery cells 1 located on the side of outlet 62 greater than the margin of the first group of battery cells 1 located on the side of inlet 61, the fit between the electrode assembly and the casing of the battery cells near the outlet is further improved. This, in turn, increases the heat exchange area and contact time between the battery cells near the outlet and the cooling member, compensating for the reduced cooling effect of the cooling member on the battery cells near the outlet 62 caused by the temperature rise of the cooling medium. This not only further improves the heat dissipation of the battery, but also helps maintain the overall temperature uniformity of the battery cells in the battery, reducing the risk of significantly higher temperatures in local areas.

[0115] In some embodiments of the present application, a difference between the first group margin of battery cells 1 located on the outlet 62 side and the first group margin of battery cells 1 located on the inlet 61 side may be less than or equal to 5%.

[0116] For example, referring to FIG9 , the difference between the first group margin of the battery cells 1 located on the outlet 62 side and the first group margin of the battery cells 1 located on the inlet 61 side can be 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, 0.5%, and so on. Reducing the difference in group margin between the battery cells located on the outlet 62 side and the inlet 61 side helps reduce the risk of uneven battery stress distribution and decreased volume stability due to different expansion forces of battery cells at different positions during charging and discharging. By controlling the first group margin distribution of battery cells to meet the given conditions, it is not only beneficial to improve the overall heat dissipation effect of the battery and maintain the uniformity of the overall temperature of each battery cell in the battery, but also to take into account the overall volume stability of the battery.

[0117] In some embodiments of the present application, the difference between the second group margin of the battery cells 1 located on the side of the outlet 62 and the second group margin of the battery cells 1 located on the side of the inlet 61 can be less than or equal to 1%, and can be optionally 0. For example, with reference to FIG9 , the difference between the second group margin of the battery cells 1 located on the side of the outlet 62 and the second group margin of the battery cells 1 located on the side of the inlet 61 can be 1%, 0.5%, 0.1%, 0, and so on. The second group margins of the battery cells that meet the given conditions are basically the same, which is conducive to controlling the change in the first group margin of the battery cells distributed along the cooling medium flow channel by adjusting the thickness change of the buffer member, thereby realizing a structural design in which the first group margins of the plurality of battery cells distributed along the inlet toward the outlet gradually increase or become equal.

[0118] In some embodiments of the present application, the margins of the first group of multiple battery cells 1 distributed along the inlet 61 toward the outlet 62 may gradually increase, and the difference between the margins of the first group of battery cells 1 located on one side of the outlet 62 and the margins of the second group may be greater than the difference between the margins of the first group of battery cells 1 located on one side of the inlet 61 and the margins of the second group. With reference to FIG9 , it is understood that meeting the given conditions is conducive to further improving the overall heat dissipation effect of the battery and maintaining the uniformity of the overall temperature of each battery cell in the battery. Optionally, the margins of the first group of multiple battery cells 1 distributed along the inlet 61 toward the outlet 62 may gradually increase, and the margins of the second group may remain unchanged or substantially the same (i.e., the difference between the margins of the second group of any two battery cells is ≤1%).

[0119] In some embodiments of the present application, the battery may include: a plurality of cooling components 6 , and the cooling medium flow channels of the plurality of cooling components 6 may be arranged in parallel and / or in series.

[0120] It should be noted that the parallel arrangement refers to the cooling medium flow channels of multiple cooling components 6 being independent and disconnected from each other, while the series arrangement refers to the cooling medium flow channels of multiple cooling components 6 being connected at their inlets and outlets, and being directly or indirectly connected to each other. The arrangement of the direct cooling flow channels of multiple cooling components can be flexibly adjusted based on the stacking arrangement of the battery cells. For example, taking the first and second directions shown in FIG9 as an example, if the number of battery cells stacked in the second direction is large, the cooling medium flow channels of multiple cooling components can be arranged in parallel. If the number of battery cells stacked in the second direction is small, the cooling medium flow channels of multiple cooling components can be arranged in series. In addition, depending on the specific arrangement of the battery cells, the cooling medium flow channels of some cooling components can be arranged in series, while the cooling medium flow channels of the remaining cooling components can be arranged in parallel. This is more conducive to achieving both the cooling effect of the battery and the reuse of the cooling medium.

[0121] In some embodiments of the present application, multiple cooling components 6 can be connected by a connector (not shown), and the cooling medium flow channels of two cooling components 6 adjacent and spaced apart in the first direction can be connected by the connector.

[0122] Exemplarily, the connector may be a cooling medium supply end and / or a cooling medium output end. The supply end and the output end may each independently be a delivery pipe or delivery panel. The inlets of the cooling medium flow channels of the multiple cooling components 6 may each independently be connected to the cooling medium supply end, and / or the outlets of the cooling medium flow channels of the multiple cooling components 6 may each independently be connected to the cooling medium output end. Alternatively, the connector may be a delivery pipe or delivery panel for connecting the cooling medium flow channels of two different cooling components end to end. This arrangement facilitates the filling and flow of the cooling medium in the different cooling medium flow channels, while also further increasing the contact area between the battery cells and the cooling medium, improving heat dissipation.

[0123] In some embodiments of the present application, the battery cell 1 may include two second surfaces arranged opposite to each other along a first direction, at least one of the two second surfaces may be in contact with the cooling member 6, and the contact area between the second surface and the cooling member 6 may be greater than or equal to 80% of the area of ​​the second surface, optionally 80% to 100% of the area of ​​the second surface, and further optionally 90% to 100% of the area of ​​the second surface.

[0124] For example, as understood with reference to Figures 7 and 8 , the second surface can be in contact with the cooling member; alternatively, both second surfaces can be in contact with the cooling member. Compared to radiative heat dissipation, direct contact between the surface of the battery cell and the cooling member can further shorten the heat conduction path and improve the heat dissipation efficiency and effectiveness of the battery cell.

[0125] Exemplarily, the contact area between the second surface and the cooling member 6 can be 80%, 85%, 90%, 95%, 100%, and so on, of the area of ​​the second surface. The contact area between the second surface and the cooling member 6 can be measured by conventional methods, such as direct measurement or colorimetry. Increasing the contact area between the battery cell surface and the cooling member can increase the heat exchange area, shorten the heat conduction path, and improve the heat dissipation efficiency and effect. Optionally, the area of ​​a single second surface can be greater than or equal to the area of ​​a single surface among the other remaining surfaces in the battery cell in which it is located, thereby maximizing the area of ​​the second surface that can be fitted with the cooling member compared to other surfaces, thereby further increasing the heat exchange area between the battery cell and the cooling member and improving the heat dissipation efficiency and effect of the battery.

[0126] Controlling the contact area between the second surface and the cooling member to meet a given range is beneficial to further improving the heat dissipation efficiency and effect.

[0127] In some embodiments of the present application, the total contact area between a single battery cell 1 and the cooling member 6 may be greater than or equal to 20% of the total surface area of ​​the battery cell, and optionally greater than or equal to 25% of the total surface area of ​​the battery cell.

[0128] For example, the total contact area between a single battery cell 1 and the cooling member 6 can be 20%, 25%, 30%, 35%, 40%, or the like, of the total surface area of ​​the battery cell, or any range thereof. The total contact area between a single battery cell 1 and the cooling member 6 refers to the sum of the contact areas between all surfaces of the battery cell and each cooling member. Increasing the total contact area between a single battery cell 1 and the cooling member 6 increases the heat exchange area, shortens the heat conduction path, and improves heat dissipation efficiency and effectiveness.

[0129] Controlling the total contact area between a single battery cell and the cooling member to meet a given range is beneficial to further improving the heat dissipation efficiency and effect.

[0130] In some embodiments of the present application, in the battery cell 1 , a buffer member 13 may be provided between a portion of the surface of the electrode assembly 12 and the housing 11 .

[0131] The buffer member 13 is provided between the electrode assembly 12 and the housing 11, allowing the surface of the electrode assembly in contact with the buffer member 13 to indirectly contact the housing, buffering the electrode assembly's expansion force during charge and discharge, thereby improving the battery's volume stability during charge and discharge cycles. Direct contact between the electrode assembly and the housing further improves the heat dissipation of the battery cells. Providing the buffer member only between a portion of the electrode assembly's surface and the housing facilitates better contact and abutment between the two, improving heat dissipation efficiency and effectiveness. Alternatively, as understood with reference to FIG2 , when a battery cell 1 contains only one electrode assembly 12, a buffer 13 may be provided only on one of the two opposing sides of the electrode assembly 12 arranged in the first direction. In this case, the cooling member 6 may be provided on the other side of the battery cell 1 in the first direction where the buffer 13 is not provided. Alternatively, as understood with reference to FIG3 , when a battery cell 1 contains multiple electrode assemblies 12, a buffer 13 may be provided only between two adjacent electrode assemblies 12 arranged in the first direction, with no buffer provided between the electrode assembly 12 and the housing 11 in the first direction. In this case, the cooling member 6 may be provided on at least one of the two opposing sides of the battery cell 1 in the first direction. This facilitates ensuring that the electrode assembly maintains a good fit with the housing during the charge and discharge cycles, thereby further increasing the heat dissipation area, shortening the heat conduction path, and improving the heat dissipation efficiency and effect of the battery.

[0132] In some embodiments of the present application, the thermal conductivity of the buffer member 13 disposed between the electrode assembly 12 and the housing 11 may be ≥3 W / (m·°C), and optionally may be ≥5 W / (m·°C).

[0133] Exemplarily, the thermal conductivity of the buffer 13 provided between the electrode assembly 12 and the shell 11 can be ≥3W / (m·℃), ≥5W / (m·℃), ≥10W / (m·℃), ≥15W / (m·℃), ≥20W / (m·℃), ≥25W / (m·℃), ≥30W / (m·℃), ≥35W / (m·℃), and so on, and can optionally be ≥5W / (m·℃). A higher thermal conductivity is conducive to quickly transferring heat from the battery cell and improving the heat dissipation effect of the battery cell. The thermal conductivity of the buffer can be measured with reference to GB / T 10295. Meeting the given range conditions can improve the thermal conductivity efficiency of the buffer and improve the heat dissipation effect of the battery cell.

[0134] In some embodiments of the present application, a buffer member 13 may be provided between two adjacent electrode assemblies 12 in a battery cell 1. Optionally, when a battery cell 1 includes multiple electrode assemblies 12, a buffer member 13 may be provided only between two adjacent electrode assemblies 12. With reference to FIG3 , this arrangement further facilitates ensuring that the electrode assembly always has a good fit with the housing during the charge and discharge cycle, thereby not only shortening the heat conduction path between the electrode assembly and the housing, but also increasing the relative heat dissipation area between the electrode assembly and the housing in the portion of the shortened heat conduction path, thereby improving the heat dissipation efficiency and effect of the battery.

[0135] In some embodiments of the present application, the thermal conductivity of the buffer member 13 disposed between two adjacent electrode assemblies 12 may be ≤0.05 W / (m·°C), and optionally may be ≤0.03 W / (m·°C).

[0136] For example, the thermal conductivity of the buffer member 13 provided between two adjacent electrode assemblies 12 can be ≤0.05W / (m·℃), ≤0.04W / (m·℃), ≤0.03W / (m·℃), ≤0.02W / (m·℃), ≤0.01W / (m·℃), ≤0.005W / (m·℃), and so on, and can optionally be ≤0.03W / (m·℃). A lower thermal conductivity is conducive to isolating heat conduction between battery assemblies and reducing the risk of failure of other electrode assemblies caused by failure of a single electrode assembly. Therefore, the above-mentioned setting is conducive to reducing the probability of thermal runaway of battery cells.

[0137] In some embodiments of the present application, the electrode assembly 12 may further include a diaphragm (not shown), and the thermal conductivity of the diaphragm may be greater than or equal to the thermal conductivity of the buffer member 13 .

[0138] Optionally, the thermal conductivity of the diaphragm can be greater than the thermal conductivity of the buffer. The outermost layer of the electrode assembly 12 is covered with a diaphragm. When no buffer is provided between the electrode assembly and the housing, the use of a diaphragm that meets the given conditions can further improve the efficiency of heat transfer from the electrode assembly to the outside. Moreover, even if a buffer is provided between the electrode assembly and the housing, the use of a diaphragm that meets the given conditions can also improve the thermal conduction of the electrode assembly itself. Therefore, ensuring that the thermal conductivity of the diaphragm meets the given conditions can help improve the heat dissipation efficiency and effect of the battery.

[0139] In some embodiments of the present application, the battery cell 1 may further include an insulating film (not shown). The insulating film may wrap at least a portion of the surface of the electrode assembly. In a first direction, each electrode assembly 12 is stacked with at least one layer of insulating film, and the thermal conductivity of the insulating film is greater than or equal to the thermal conductivity of the buffer. Providing an insulating film on the outer surface of the electrode assembly can reduce the risk of leakage caused by direct contact between the electrode assembly and the housing (such as a metal housing). Further, ensuring that the thermal conductivity of the insulating film is greater than or equal to the thermal conductivity of the buffer can also help improve the efficiency of heat transfer from the electrode assembly to the outside, reduce heat conduction between battery components, and improve the heat dissipation efficiency and effectiveness of the battery.

[0140] In some embodiments of the present application, the third group margin of the battery cell 1 can be ≥95%, and optionally can be ≥100%. The third group margin refers to: in the first direction, the ratio of the sum of the total thickness of the buffer in the battery cell in the free state, the maximum total size of the electrode assembly in the fully charged state, and the total thickness of the insulating film to the distance between the inner wall surface of the shell.

[0141] For example, the third group margin of the battery cell 1 can be 95%, 97%, 100%, 102%, 105%, 108%, 110%, and so on. Improving the third group margin of the battery cell is conducive to further improving the fit between the electrode assembly and the shell, and improving the heat dissipation efficiency and effect. Controlling the third group margin to meet the given range is conducive to further obtaining higher heat dissipation efficiency and effect on the basis of reducing the risk of battery cell leakage. Among them, the total thickness of the insulating film in the first direction can be obtained by determining the number of stacked layers of the insulating film in the first direction and the thickness of the insulating film. The thickness test of the insulating film can be tested using conventional instruments and conventional methods in this field. Optionally, the third group margin can be greater than or equal to the first group margin, and further optionally greater than the first group margin. Optionally, the third group margin can be ≤108%, further optionally ≤105%, and further optionally 100% to 105%. Meeting the given conditions is also conducive to taking into account the volume stability of the battery cell during the charge and discharge cycle.

[0142] In some embodiments of the present application, a battery cell 1 may include at least two electrode assemblies 12. Each buffer member 13 in the battery cell 1 may be independently disposed between two adjacent electrode assemblies 12 and stacked with the electrode assemblies 12 along a first direction. This arrangement not only improves the fit between the electrode assembly and the housing, but also facilitates direct contact between the electrode assembly and the inner wall of the housing, thereby shortening the heat conduction path and improving the heat dissipation efficiency and effect of the battery.

[0143] In some embodiments of the present application, the battery cell 1 may include two third surfaces arranged opposite to each other along the first direction, and the orthographic projection of the buffer 13 stacked and adjacent to the electrode assembly 12 along the first direction on the third surface may be located within the area of ​​the orthographic projection of the electrode assembly 12 on the third surface. The relative position and projection area of ​​the orthographic projection of the buffer 13 on the third surface and the orthographic projection of the electrode assembly 12 on the third surface reflect the overlapping area between the buffer 13 and the electrode assembly. The orthographic projections of the buffer and the electrode assembly on the third surface can be made to meet the given conditions by controlling the large surface area of ​​the buffer to be less than or equal to the area of ​​the surface of the electrode assembly stacked therewith. As a result, it is not only beneficial to improve the fit between the electrode assembly and the shell, shorten the heat conduction path, and improve the heat dissipation efficiency and effect of the battery, but also beneficial to take into account the energy density of the battery cell.

[0144] In some embodiments of the present application, the area of ​​the orthographic projection of the buffer member 13 stacked and adjacent to the electrode assembly 12 along the first direction on the third surface is greater than or equal to 80% of the area of ​​the orthographic projection of the electrode assembly 12 on the third surface. For example, the area of ​​the orthographic projection of the buffer member 13 stacked and adjacent to the electrode assembly 12 along the first direction on the third surface is greater than or equal to 80%, 85%, 90%, 95%, 100%, or so forth, of the area of ​​the orthographic projection of the electrode assembly 12 on the third surface. The relative position and projected area of ​​the orthographic projection of the buffer member 13 on the third surface and the orthographic projection of the electrode assembly 12 on the third surface reflect the overlap area between the buffer member 13 and the electrode assembly. Increasing this overlap area helps improve the fit between the electrode assembly and the housing. Ensuring that the orthographic projections of the buffer member and the electrode assembly on the third surface meet the given conditions not only improves the fit between the electrode assembly and the housing, but also improves the uniformity of stress distribution in the battery cells during charge and discharge, thereby further improving the heat dissipation efficiency and volume stability of the battery cells during cycling. Optionally, the area of ​​a single third surface can be greater than or equal to the area of ​​a single surface among the other remaining surfaces of the battery cell, thereby maximizing the area of ​​the third surface that can be set relative to or in contact with the cooling component compared to the other surfaces. This not only helps to further improve the fit between the electrode assembly and the shell, but also helps to further increase the heat exchange area between the battery cell and the cooling component, thereby improving the heat dissipation efficiency and effect.

[0145] It can be understood that in the battery cell of the first aspect of the present application, the structure and material of the buffer 13 are not particularly limited, as long as it can undergo elastic deformation. For example, at least one of the material, porosity and pore size of the buffer can be adjusted to obtain buffers with different stress-strain relationships, so as to achieve different compression rates of the buffer along its thickness direction under different stresses.

[0146] Exemplarily, the buffer component may be a single-layer structure, and its material may include but is not limited to at least one of foamed polyethylene, polypropylene, polyurethane, silicone rubber, etc.

[0147] Exemplarily, the buffer may be a multi-layer structure, specifically including an elastic buffer layer and a support layer, wherein the support layer may be provided on at least one of the two sides of the elastic buffer layer along its thickness direction. Optionally, the elastic modulus of the elastic buffer layer is smaller than that of the support layer, and / or, under the same pressure, the compressibility of the elastic buffer layer along its thickness direction is greater than that of the support layer along its thickness direction, and / or, the porosity of the elastic buffer layer may be greater than that of the support layer. For example, the porosity of the elastic buffer layer may be 40% to 95%, optionally 55% to 90%, and further optionally 70% to 85%, and the porosity of the support layer may be less than or equal to 5%. Optionally, the elastic buffer layer may include at least one of foamed polyethylene, polypropylene, polyurethane, and silicone rubber, and the support layer may include, but is not limited to, at least one of high-density polyethylene, polymethacrylate, polyethylene terephthalate, and polytetrafluoroethylene. Optionally, at least one of the following conditions may be met: the thickness of the elastic buffer layer may be greater than the thickness of the support layer; in a single buffer, the ratio of the total thickness of the support layer to the free thickness of the elastic buffer layer may be 0.005 to 0.1, such as 0.02 to 0.05; the thickness of the elastic buffer layer in its natural state may be 0.2 mm to 10 mm, and the thickness of a single support layer may be 30 μm to 200 μm; and the elastic buffer layer and the support layer may be bonded together. The composite support layer and the elastic buffer layer provide support for the elastic buffer layer, which not only inhibits thermal shrinkage of the elastic buffer layer (such as thermal shrinkage during vacuum baking), but also optionally inhibits thermal shrinkage of the elastic buffer layer in a two-dimensional direction perpendicular to its thickness, thereby alleviating the problem of loss of its original function due to thermal shrinkage. It also improves the problem of material damage caused by mechanical stress in the buffer component during the later stages of battery use. Furthermore, placing the buffer component inside the battery cell can further improve the volume stability of the battery during long-term use, enhancing long-term performance.

[0148] In some embodiments of the present application, the electrode assembly 12 may include a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet, the negative electrode sheet, and the separator may be wound to form an electrode assembly. During the charge and discharge process of the battery, active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet. The separator is arranged between the positive electrode sheet and the negative electrode sheet to serve as an isolation. Among them, the specific structure, raw material composition, and thickness of the positive electrode sheet, the negative electrode sheet, and the separator can all be conventional choices in the field, and those skilled in the art can make choices based on actual needs.

[0149] The battery mentioned in the first aspect of the present application may be a secondary battery, for example, the battery may be a lithium-ion secondary battery.

[0150] The battery of the first aspect of the present application may include a battery cell 1 (refer to Figure 7 for understanding) and a cooling component 6, or may include a battery module 2 composed of battery cells 1 (refer to Figure 13 for understanding) and a cooling component 6, or may include a battery pack 3 composed of battery cells 1 (refer to Figure 14 for understanding) and a cooling component 6.

[0151] In some embodiments, the number of battery cells contained in the battery module may be one or more, and the specific number may be adjusted according to the application and capacity of the battery module. Figure 13 is a battery module 2 as an example. Referring to Figure 13, in the battery module 2, a plurality of battery cells 1 may be arranged in sequence along the length direction of the battery module 2, and the first direction may be one of the length direction, width direction and height direction of the battery module 2. Of course, it can also be arranged in any other manner. The plurality of battery cells 1 can further be fixed by fasteners. Optionally, the battery module 2 may further include a housing having a accommodating space, and a plurality of battery cells 1 are accommodated in the accommodating space. It is understandable that the cooling member 6 is also accommodated in the accommodating space.

[0152] In some embodiments, the battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack. Referring to Figure 14 or Figure 15 (Figures 14 and 15 are battery packs 3 as an example), the battery pack 3 may include a battery box and a plurality of battery modules 2 disposed in the battery box. The battery box may include an upper box body 4 and a lower box body 5. The upper box body 4 can be covered on the lower box body 5 and form an enclosed space for accommodating the battery modules 2. The plurality of battery modules 2 can be arranged in the battery box in any manner.

[0153] In addition, the present application also provides an electrical device, which includes: the battery of the first aspect of the present application. The battery can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device. The electrical device may include but is not limited to mobile devices (such as mobile phones, laptops), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, and energy storage systems. With reference to Figure 15, as a specific example, the electrical device can be a vehicle. The electrical device can select the specific type of battery according to its usage requirements, such as a battery with a battery cell, a battery module or a battery pack.

[0154] As an example, the electric device may be a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. In order to meet the electric device's requirements for high power and high energy density of the battery, a battery having a battery pack or a battery module may be used.

[0155] As another example, the electrical device may be a mobile phone, a tablet computer, or a laptop computer. Such an electrical device is generally required to be lightweight and thin, and may use a battery cell in combination with a cooling member as a power source.

[0156] Below, the embodiment of the present application is described. The embodiment described below is exemplary and is only used to explain the present application, and is not to be construed as limiting the present application. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used that do not specify the manufacturer are conventional products that can be obtained commercially.

[0157] Example 1

[0158] (1) Preparation of lithium secondary batteries

[0159] (1) Preparation of positive electrode sheet

[0160] The positive electrode active material LiNi 0.6 Co 0.1 Mn 0.3 O2, superconducting carbon black (SuperP), and polyvinylidene fluoride (PVDF) were mixed in a weight ratio of 96:2:2, and N-methylpyrrolidone (NMP) was added. The mixture was stirred thoroughly to obtain a positive electrode slurry, which was then coated on both surfaces of a positive electrode current collector aluminum foil with a thickness of 13 μm. The coating surface density of the positive electrode slurry on one side of the aluminum foil was 20 mg / cm 2 , then dried and cold pressed to obtain the positive electrode sheet.

[0161] (2) Preparation of negative electrode sheet

[0162] The negative electrode active material artificial graphite, SuperP, styrene-butadiene rubber, and thickener sodium carboxymethyl cellulose were mixed in a weight ratio of 96:0.5:2:1.5, deionized water was added, and the mixture was stirred thoroughly to obtain a negative electrode slurry, which was then coated on both surfaces of a negative electrode current collector copper foil with a thickness of 6 μm. The coating surface density of the negative electrode slurry on one side of the copper foil was 11 mg / cm 2 , then dried and cold pressed to obtain the negative electrode sheet.

[0163] (3) Preparation of electrolyte

[0164] In an argon atmosphere glove box with a water content of <10ppm, solvents EC (ethylene carbonate), EMC (ethylene methyl carbonate), and DMC (dimethyl carbonate) are mixed in a volume ratio of 1:1:1, and then fully dried lithium salt LiPF6 is dissolved in the above mixed organic solvents. After stirring evenly, an electrolyte is obtained, in which the concentration of the lithium salt is 1 mol / L.

[0165] (4) Preparation of diaphragm

[0166] A polyethylene porous film with a thickness of 7 μm was used as the separator.

[0167] (5) Preparation of buffer parts

[0168] Polypropylene with a thickness of 3 mm and a porosity of 94% in a free state is used as the buffer.

[0169] (6) Preparation of lithium secondary battery monomers

[0170] The positive electrode sheet, separator, and negative electrode sheet are stacked in order, with the separator positioned between the positive and negative electrode sheets to provide separation. The electrodes are then wound and formed to form an electrode assembly. Two electrode assemblies and a buffer are stacked along their thickness and placed in the battery casing, with the buffer sandwiched between the two electrode assemblies. The thickness of the electrode assembly and buffer within the electrode cell aligns with the y-direction. The prepared electrolyte is then injected and packaged to produce the lithium secondary battery shown in Figure 7.

[0171] Referring to Figures 7 and 10, with the y-direction as the first direction and the x-direction as the second direction, 16 lithium secondary battery cells are stacked as shown in Figure 9. A cooling member is sandwiched between two layers of battery cells stacked along the y-direction, and the cooling member is in contact with the surface of each battery cell and covers the entire large surface of the cooling member (i.e., 11a). The cooling member has a cooling medium inlet and outlet, and the cooling medium is filled in the cooling member cavity.

[0172] Examples 2 to 13 and Comparative Examples 1 to 3

[0173] The differences between Examples 2-13 and Comparative Examples 1-3 are detailed in Table 1. Compared to Example 1, the remaining Examples and Comparative Examples alter the first group margin of the battery cells by changing the thickness of the point buffer. Referring to Figure 7 , the remaining Examples and Comparative Examples alter the percentage of the contact area between a single surface of the battery cell and the cooling member in the first direction relative to the area of ​​that single surface by changing the distance of the cooling member in the z-direction.

[0174] (2) Battery temperature rise test method

[0175] With the z-axis of the lithium secondary battery cell as the height, position the cell top cap upward. Referring to Figure 9, place a temperature sensor at the center of the top cap of one of the two cells located on the outlet side of the cooling element to measure the cell temperature. Maintain the cooling medium inlet temperature at 25°C and the cooling medium flow rate at 10 L / min. At 25°C, discharge the cell at 0.33C to 2.5V. Then, align the battery temperature with the ambient temperature and charge according to the following process: 3C for 5 minutes, 2C for 10 minutes, 1C for 15 minutes, and finally 0.33C to the upper voltage limit. Record the highest temperature during this process. The temperature rise of the lithium secondary battery cell = maximum temperature - pre-charge temperature.

[0176] Relevant tests were performed on Examples 1 to 13 and Comparative Examples 1 to 3. The test results are shown in Table 1.

[0177]

[0178]

[0179] Results and Conclusions:

[0180] From Examples 1 to 13, Comparative Examples 1 to 3 and Table 1, it can be seen that, relative to batteries without cooling components and buffer components, providing buffer components in the battery cells so that they are stacked with the electrode assembly, and providing cooling components on one side of the battery cells along the stacking direction, can further exert a better heat dissipation effect; further, the heat dissipation effect of the battery can be further improved by increasing the total relative heat exchange area between the battery cell surface and the cooling components, or increasing the group margin of the cooling components within an appropriate range, or gradually increasing the margin of the first group of multiple battery cells distributed along the flow direction of the cooling medium (from the inlet to the outlet) within an appropriate range, or increasing the number of cooling components and adjusting the setting position of the cooling components.

[0181] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery, wherein, Comprising: A battery cell, comprising: a housing, at least one electrode assembly, and at least one buffer member, wherein the electrode assembly and the buffer member are disposed within the housing, the buffer member is provided on at least a part of the surface of the electrode assembly and / or inside the electrode assembly, and at least one of the electrode assemblies and at least one of the buffer members are stacked along a first direction; At least one cooling member, provided on at least one side of the battery cell along the first direction.

2. The battery according to claim 1, wherein, Comprising: At least one first battery cell group, the first battery cell group comprising a plurality of the battery cells stacked along the first direction.

3. The battery according to claim 2, wherein, A plurality of the first battery cell groups are stacked along a second direction, and the second direction intersects the first direction.

4. The battery according to claim 2 or 3, wherein, In the first direction, the cooling member is disposed between two adjacent battery cells, and / or the cooling member is disposed on one side of a plurality of the battery cells along the first direction.

5. The battery according to claim 1, wherein, Comprising: At least one second battery cell group, the second battery cell group comprising a plurality of the battery cells stacked along a second direction, and the second direction intersects the first direction.

6. The battery according to claim 5, wherein, In the first direction, the cooling member is disposed between two adjacent battery cells, and / or the cooling member is disposed on one side of a plurality of the battery cells along the first direction.

7. The battery according to any one of claims 1 to 6, wherein, The battery cell comprises two first surfaces oppositely disposed along the first direction, and the area of the first surface is greater than or equal to the area of a single surface among the other surfaces of the battery cell.

8. The battery according to claim 7, wherein, The area of the orthographic projection of the buffer member stacked with the electrode assembly along the first direction on the first surface is greater than or equal to 80% of the area of the first surface.

9. The battery according to any one of claims 2 to 8, wherein, In the first direction, the cooling member is disposed between every two of the plurality of battery cells.

10. The battery according to any one of claims 1 to 9, wherein, The first group margin of the battery cell ≥ 95%, optionally ≥ 100%; the second group margin of the battery cell ≥ 90%, optionally ≥ 95%. The first group margin refers to: in the first direction, the ratio of the sum of the total thickness of the buffer member in the free state and the maximum total dimension of the electrode assembly in the fully charged state in the battery cell to the distance between the inner wall surface of the housing. The second group margin refers to: in the first direction, the ratio of the maximum total dimension of the electrode assembly in the fully charged state in the battery cell to the distance between the inner wall surface of the housing.

11. The battery according to claim 10, wherein, The first group margin of the battery cell ≤ 108%, optionally ≤ 105%; and / or the second group margin ≤ 100%, optionally ≤ 98%.

12. The battery according to any one of claims 1 to 11, wherein, A cooling medium flow channel is provided inside the cooling member, the cooling medium flow channel comprising an inlet and an outlet, and the first group margin of the battery cell on the side of the outlet is greater than or equal to the first group margin of the battery cell on the side of the inlet.

13. The battery according to claim 12, wherein, Satisfying at least one of the following conditions: The difference between the first group margin of the battery cell on the side of the outlet and the first group margin of the battery cell on the side of the inlet is less than or equal to 5%. The difference between the second group margin of the battery cell located on the outlet side and the second group margin of the battery cell located on the inlet side is less than or equal to 1%, and can be optionally 0; The first group margin of the plurality of battery cells distributed in the direction from the inlet to the outlet gradually increases, and the difference between the first group margin of the battery cell located on the outlet side and the second group margin is greater than the difference between the first group margin of the battery cell located on the inlet side and the second group margin.

14. The battery according to claim 12 or 13, wherein Comprising: A plurality of the cooling members, and the cooling medium flow channels of the plurality of cooling members are arranged in parallel and / or in series; and / or, The plurality of cooling members are connected by a connecting member, and the cooling medium flow channels of two adjacent and spaced cooling members in the first direction can be connected through the connecting member.

15. The battery according to any one of claims 1 to 14, wherein, The battery cell includes two second surfaces oppositely arranged in the first direction, and at least one of the two second surfaces is in contact with the cooling member, and the contact area between the second surface and the cooling member is greater than or equal to 80% of the area of the second surface, and can be optionally 80% - 100% of the area of the second surface, and further optionally 90% - 100% of the area of the second surface.

16. The battery according to any one of claims 1 to 15, wherein, The total contact area of a single battery cell and the cooling member is greater than or equal to 20% of the total surface area of the battery cell, and can be optionally greater than or equal to 25% of the total surface area of the battery cell.

17. The battery according to any one of claims 1 to 16, wherein, In the battery cell, a buffer member is provided between a partial surface of the electrode assembly and the housing.

18. The battery according to claim 17, wherein, The thermal conductivity of the buffer member provided between the electrode assembly and the housing is ≥ 3 W / (m·°C), and can be optionally ≥ 5 W / (m·°C).

19. The battery according to any one of claims 1 to 18, wherein, In the battery cell, a buffer member is provided between two adjacent electrode assemblies.

20. The battery according to claim 19, wherein, The thermal conductivity of the buffer member provided between two adjacent electrode assemblies is ≤ 0.05 W / (m·°C), and can be optionally ≤ 0.03 W / (m·°C).

21. The battery according to any one of claims 1 to 20, wherein, The electrode assembly includes a separator, and the thermal conductivity of the separator is greater than or equal to the thermal conductivity of the buffer member; and / or, The battery cell further includes: an insulating film, the insulating film wraps at least a partial surface of the electrode assembly, and in the first direction, each electrode assembly and at least one layer of the insulating film are stacked, and the thermal conductivity of the insulating film is greater than or equal to the thermal conductivity of the buffer member.

22. The battery according to claim 21, wherein, The third group margin of the battery cell is ≥ 95%, and can be optionally ≥ 100%. The third group margin refers to the ratio of the sum of the total thickness of the buffer member in the free state, the maximum total size of the electrode assembly in the fully charged state, and the total thickness of the insulating film in the battery cell in the first direction to the distance between the inner wall surface of the housing.

23. The battery according to any one of claims 1 to 22, wherein, The battery cell includes at least two electrode assemblies, and each buffer member in the battery cell is independently provided between two adjacent electrode assemblies and is stacked with the electrode assemblies in the first direction.

24. The battery according to any one of claims 1 to 23, wherein, The battery cell includes two third surfaces oppositely arranged along the first direction, and a positive projection of the buffer member stacked and adjacently arranged with the electrode assembly along the first direction on the third surface is located within an area of a positive projection of the electrode assembly on the third surface.

25. The battery according to claim 24, wherein, An area of a positive projection of the buffer member stacked and adjacently arranged with the electrode assembly along the first direction on the third surface is greater than or equal to 80% of an area of a positive projection of the electrode assembly on the third surface.

26. An electrical device, wherein, A battery including any one of claims 1 to 25.

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