Battery and electric device

Abstract

The utility model discloses a battery and an electric device. The battery comprises a battery cell and at least one cooling component, the battery cell comprises a shell, at least one electrode assembly and at least one buffer piece, the electrode assembly and the buffer piece are arranged in the shell, the buffer piece is arranged on at least part of the surface of the electrode assembly and / or inside the electrode assembly, and the cooling component is arranged in the shell. The at least one electrode assembly and the at least one buffer piece are arranged in a stacked mode in the first direction; a cooling member is provided on at least one side of the battery cells in the first direction.

Description

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] As an energy storage device, batteries are widely used in various fields. Take lithium-ion batteries as an example. They 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 stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, and ships, as well as military equipment and aerospace and other fields. With the development of the current society, people's requirements for batteries are getting higher and higher. Utility Model Content

[0003] In view of the technical problems existing in the background technology, the present application provides a battery, aiming to shorten the heat conduction path and improve the cooling efficiency of the battery.

[0004] In order to achieve the above-mentioned object, the first aspect of the present application provides a battery, comprising:

[0005] A battery cell, comprising: a shell, at least one electrode assembly and at least one buffer, wherein the electrode assembly and the buffer are placed in the shell, the buffer is arranged on at least a 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 are stacked along a first direction;

[0006] At least one cooling member is disposed on at least one side of the battery cell along the first direction.

[0007] 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 the insulating film, which is not only beneficial to shorten the heat conduction path between the electrode assembly and the shell, but also beneficial to increase the contact heat exchange area between the electrode assembly and the shell, improve the heat dissipation effect of the battery cell itself, and thus improve 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-heat dissipation of the battery cell and the heat conduction efficiency with the cooling component, and improving the heat dissipation effect of the battery.

[0008] 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.

[0009] 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.

[0010] In some embodiments of the present application, the battery includes a first battery cell group, and 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 battery cells along the first direction. This is beneficial to improving the heat dissipation efficiency and effect of the battery.

[0011] In some embodiments of the present application, the battery includes: at least one second battery cell group, the second battery cell group includes a plurality of the battery cells stacked along a second direction, and the second direction intersects with the first direction.

[0012] In some embodiments of the present application, the battery includes a second battery cell group, and 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 the plurality of battery cells along the first direction.

[0013] In some embodiments of the present application, the battery cell includes two first surfaces arranged opposite to each other 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. Meeting the given conditions is conducive to 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.

[0014] 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 is beneficial to further improve the fit between the electrode assembly and the housing on the basis of increasing the total heat exchange area between the battery cell and the cooling member, and further improve the heat dissipation efficiency of the battery cell.

[0015] In some embodiments of the present application, in the first direction, the cooling member is disposed between each of the plurality of battery cells. 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, and improving the heat dissipation efficiency and effect of the battery.

[0016] In some embodiments of the present application, the first group margin of the battery cell is ≥95%, and can be ≥100%; the second group margin of the battery cell is ≥90%, and can be ≥95%. The first group margin refers to: in the first direction, the ratio of the sum of the total thickness of the buffer in the free state in the battery cell and the maximum total size of the electrode assembly in the fully charged state to the distance between the inner wall surface of the shell; the second group margin refers to: in the first direction, the ratio of the maximum total size of the electrode assembly in the fully charged state in the battery cell to the distance between the inner wall surface of the shell. Meeting the given conditions is conducive to improving the fit between the electrode assembly and the shell, improving the heat exchange efficiency and effect, and taking into account the energy density of the battery.

[0017] 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.

[0018] In some embodiments of the present application, a cooling medium flow channel is provided inside the cooling member, the cooling medium flow channel includes an inlet and an outlet, and the first group margin of the battery cells located on the outlet side is greater than or equal to the first group margin of the battery cells located on the inlet side. Meeting the given conditions is conducive to compensating for the lack of cooling effect on the battery cells near the outlet side of the cooling medium flow channel caused by the temperature rise of the cooling medium, and is further conducive to maintaining the uniformity of the overall temperature of each battery cell in the battery.

[0019] In some embodiments of the present application, the difference between the first group margin of the battery cells located at the outlet side and the first group margin of the battery cells located at the inlet side is less than or equal to 5%. Meeting the given condition is conducive to maintaining the uniformity of the overall temperature of each battery cell in the battery and taking into account the overall volume stability of the battery.

[0020] In some embodiments of the present application, the difference between the second group margin of the battery cells located at the outlet side and the second group margin of the battery cells located at the inlet side is less than or equal to 1%, and may be 0;

[0021] 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 margin and the second group margin of the battery cells located on the outlet side is greater than the difference between the first group margin and the second group margin of the battery cells located on the inlet side. 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.

[0022] In some embodiments of the present application, it includes: a plurality of the cooling components, and the cooling medium flow channels of the plurality of cooling components are arranged in parallel and / or in series.

[0023] In some embodiments of the present application, a plurality of the cooling members are connected by a connector, and the cooling medium flow channels of two adjacent and spaced cooling members in the first direction can be connected by the connector. Meeting the given conditions is not only conducive to the filling and flow of the cooling medium in different cooling medium flow channels, but also conducive to further increasing the contact area between the battery cell and the cooling medium, and improving the heat dissipation effect.

[0024] In some embodiments of the present application, the battery cell includes two second surfaces arranged 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 the heat dissipation efficiency and effect.

[0025] 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 area of ​​the second surface, and may be 80% to 100% of the area of ​​the second surface, and may be 90% to 100% of the area of ​​the second surface. Meeting the given conditions is conducive to further improving the heat dissipation efficiency and effect.

[0026] 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 the given conditions is conducive to further improving the heat dissipation efficiency and effect.

[0027] In some embodiments of the present application, in the battery cell, the buffer is provided between a part of the surface of the electrode assembly and the shell. Meeting the given conditions is conducive to increasing the fit and contact area between the electrode assembly and the shell, and improving the heat dissipation efficiency and effect of the battery.

[0028] In some embodiments of the present application, the thermal conductivity of the buffer disposed between the electrode assembly and the housing is ≥3W / (m·°C), and may be ≥5W / (m·°C). Meeting the given conditions can improve the thermal conductivity of the buffer and the heat dissipation effect of the battery cell.

[0029] In some embodiments of the present application, in the battery cell, the buffer is provided between two adjacent electrode assemblies. Meeting the given conditions is conducive to increasing the fit between the electrode assembly and the shell, and improving the heat dissipation efficiency and effect of the battery.

[0030] In some embodiments of the present application, the thermal conductivity of the buffer provided between two adjacent electrode assemblies is ≤0.05W / (m·℃), and may be ≤0.03W / (m·℃). Meeting the given conditions 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.

[0031] 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. Meeting the given conditions is conducive to improving the heat dissipation efficiency and effect of the battery.

[0032] In some embodiments of the present application, the battery cell further includes: an insulating film, the insulating film wrapping at least a portion of the surface of the electrode assembly, and in the first direction, each electrode assembly is stacked with at least one layer of the insulating film, and the thermal conductivity of the insulating film is greater than or equal to the thermal conductivity of the buffer. Meeting the given conditions is beneficial to reducing the risk of leakage and improving the heat dissipation efficiency and effect of the battery.

[0033] In some embodiments of the present application, the third group margin of the battery cell is ≥95%, and 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 a free state, the maximum total size of the electrode assembly in a fully charged state, and the total thickness of the insulating film to the distance between the inner wall of the shell. Meeting the given conditions is conducive to further improving the heat dissipation efficiency and effect of the battery.

[0034] 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 the given conditions is conducive to improving the heat dissipation efficiency and effect of the battery.

[0035] In some embodiments of the present application, the battery cell includes two third surfaces arranged opposite to each other along the first direction, and the orthographic projection of the buffer member stacked and adjacent to the electrode assembly along the first direction on the third surface is located within the area of ​​the orthographic projection of the electrode assembly on the third surface. Meeting the given conditions is not only conducive to improving the heat dissipation efficiency and effect of the battery, but also conducive to taking into account the energy density of the battery cell.

[0036] In some embodiments of the present application, the area of ​​the positive 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 positive projection of the electrode assembly on the third surface. Meeting the given conditions is conducive to improving the heat dissipation efficiency of the battery cell and the volume stability during the cycle.

[0037] 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

[0038] 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:

[0039] Figure 1 It is a schematic diagram of the cross-sectional structure of a battery according to one embodiment of the present application.

[0040] Figure 2 It is a schematic diagram of the cross-sectional structure of a prismatic battery cell according to one embodiment of the present application.

[0041] Figure 3 It is a schematic cross-sectional structure diagram of a prismatic battery cell according to another embodiment of the present application.

[0042] Figure 4It is a schematic cross-sectional structure diagram of a prismatic battery cell according to yet another embodiment of the present application.

[0043] Figure 5 It is a schematic cross-sectional structure diagram of a prismatic battery cell according to yet another embodiment of the present application.

[0044] Figure 6 It is a schematic diagram of the cross-sectional structure of a cylindrical battery cell according to one embodiment of the present application.

[0045] Figure 7 It is a schematic structural diagram of a prismatic battery cell according to one embodiment of the present application.

[0046] Figure 8 It is a schematic diagram of the cross-sectional structure of a battery according to another embodiment of the present application.

[0047] Fig. 9 It is a schematic diagram of the cross-sectional structure of a battery according to another embodiment of the present application.

[0048] Fig.10 It is a schematic diagram of the cross-sectional structure of a battery according to another embodiment of the present application.

[0049] Fig.11 It is a schematic diagram of the cross-sectional structure of a battery according to another embodiment of the present application.

[0050] Fig.12 It is a schematic diagram of the cross-sectional structure of a battery according to another embodiment of the present application.

[0051] Fig.13 It is a schematic structural diagram of a battery module according to one embodiment of the present application.

[0052] Fig.14 It is a schematic diagram of the structure of a battery pack according to one embodiment of the present application.

[0053] Fig.15 is an exploded view of a battery pack according to one embodiment of the present application.

[0054] Fig.16 It is a schematic diagram of an electrical device using a battery as a power source according to one embodiment of the present application.

[0055] Reference numerals:

[0056] 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

[0057] The present application is further described below in conjunction with specific implementations. It should be understood that these specific implementations are only used to illustrate the present application and are not used to limit the scope of the present application.

[0058] Below, the embodiments of the positive electrode active material and its preparation method, positive electrode sheet, battery and electric device of the present application are specifically disclosed with appropriate reference to the drawings. However, there are 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 descriptions 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.

[0059] The "range" disclosed in the present 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 value, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form an unambiguous range, and any lower limit can be combined with other lower limits to form an unambiguous range, and any upper limit can be combined with any other upper limit to form an unambiguous range. In addition, each individually 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 unambiguous range. For example, if a range of 60 to 120 and 80 to 110 is listed for a specific parameter, it is understood that the range of 60 to 110 and 80 to 120 is also expected. 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 expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range "a-b" represents an abbreviation of any real number combination 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 of 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 of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0060] If not otherwise specified, all embodiments and optional embodiments of the present application may be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of the present application.

[0061] Unless otherwise specified, all technical features and optional technical features of the present application may be combined with each other to form a new technical solution, and such a technical solution should be deemed to be included in the disclosure of the present application.

[0062] If there is no special explanation, 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 also 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.

[0063] If there is no special explanation, the "include" and "comprising" mentioned in this application represent open-ended or closed-ended expressions. For example, the "include" and "comprising" may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0064] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": 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).

[0065] If there is no special explanation, in this application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0066] In the present application, the terms "plurality" and "multiple" refer to two or more.

[0067] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in this application are only for the purpose of describing specific embodiments 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 figure descriptions 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 embodiments of this application).

[0068] With the continuous advancement of the green environmental protection theme, the application of batteries has penetrated into all aspects of life, including vehicles, electronic equipment, energy storage devices, etc. However, with the continuous promotion of battery applications, people's requirements for batteries are getting higher and higher. Among them, the battery will be accompanied by heat during the charge and discharge cycle, but long-term excessive heat will easily lead to rapid attenuation of battery capacity on the one hand, and increase the risk of battery bulging and thermal runaway on the other hand, affecting the battery's service life and the normal operation of electrical devices.

[0069] 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.

[0070] 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, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys may include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.

[0071] A first aspect of the present application provides a battery, comprising: a battery cell and at least one cooling component, the battery cell comprising a shell, at least one electrode assembly and at least one buffer, the electrode assembly and the buffer are placed in the shell, the buffer is arranged on at least a portion 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 are stacked along a first direction; the cooling component is arranged on at least one side of the battery cell along the first direction.

[0072] For example, refer to Figures 1 to 6 It is understood that 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 arranged on at least a portion of the surface of the electrode assembly 12 and / or inside the electrode assembly 12, at least one electrode assembly 12 and at least one buffer 13 are stacked along a first direction, and the cooling member 6 is arranged on at least one side of the battery cell 1 along the first direction (reference Figure 1 For example, the buffer 13 may be disposed between the electrode assembly 12 and the housing 11 (see Figure 2 Understanding), and / or can be provided between two adjacent electrode assemblies 12 (reference Figure 3 Understanding), and / or may be provided inside the electrode assembly (reference Figure 4 The buffer member 13 may be disposed between the electrode assembly 12 and the housing 11, which may be understood as being disposed in at least one of the regions between the electrode assembly 12 and the side wall of the housing 11, between the electrode assembly 12 and the bottom wall of the housing 11, and between the electrode assembly 12 and the top wall of the housing 11. Optionally, refer to Figure 5 It is understood that the buffer member 13 can be provided between the electrode assembly 12 and the housing 11 and between two adjacent electrode assemblies 12; alternatively, refer to Figure 2 , Figure 3 It is understood that the buffer member 13 may be provided on a partial surface of the electrode assembly 12. For example, the buffer member 13 may be provided only 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 provided only on one side of the electrode assembly 12 in the first direction (see Figure 2 As some specific examples, when the battery cell 1 includes a plurality of electrode assemblies 12, the buffer 13 can be directly arranged only on two adjacent electrode assemblies 12 in the first direction, and the electrode assemblies 12 and the buffer 13 are alternately stacked in the first direction (refer to Figure 3 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 (reference Figure 6When the wound electrode assembly is used in a prismatic battery cell, the electrode assembly includes a straight portion and a corner portion after molding, and the first direction may be the thickness direction of the straight portion (refer to Figure 4 In actual operation, both sides of the buffer 13 along its thickness direction can be arranged in affixed relation with the electrode assembly 12, or one side can be arranged in affixed relation with the electrode assembly 12 and the other side can be arranged in affixed relation with the inner wall of the housing 11.

[0073] Optionally, the thickness direction of at least one electrode assembly 12 is the same as the first direction (refer to Figures 2 to 5 Alternatively, 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 understand).

[0074] 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 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 just next to each other. Exemplarily, the cooling member can be provided on the surface of the battery cell along the first direction, or spaced 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, the buffer refers to a structural member that can undergo elastic deformation.

[0075] 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 arranged on at least one side of the battery cell along the first direction, wherein the buffer is arranged to 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 to fit the inner wall of the shell through the buffer or the 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 beneficial to shortening the heat conduction path between the electrode assembly and the shell, but also beneficial to increasing the heat dissipation between the electrode assembly and the shell. The contact heat exchange area between the battery body is increased to improve the heat dissipation effect of the battery cell itself, thereby improving the cooling efficiency; further, the structure of stacking at least one electrode assembly and at least one buffer member 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 setting 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 shortened portion of the heat conduction path in the first direction, thereby further improving the cooling efficiency. It can be understood that setting 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 position 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.

[0076] 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-heat dissipation of the battery cell and the heat conduction efficiency with the cooling component, and improving the heat dissipation effect of the battery.

[0077] 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.

[0078] Furthermore, the battery of the first aspect of the present application can further improve the heat dissipation effect of the battery cell by further improving the relative position relationship between the cooling member and the battery cell, the group margin of the battery cell, the group margin difference between the battery cells, the contact area between the battery cell and the cooling member, the thermal conductivity of the buffer and its size relationship with other structural parts, the setting area of ​​the buffer, etc. on the basis of satisfying the above conditions. That is, on the basis of satisfying the above conditions, one or more of the following conditions can also be optionally satisfied.

[0079] 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.

[0080] In some embodiments of the present application, the battery cell may be cylindrical or prismatic, and may be prismatic; wherein the prismatic battery cell may be a wound structure or a laminated structure, see Figure 6 It is understood that when the battery cell is cylindrical, the first direction may be the radial direction of the electrode assembly; Figure 7 It is understood that when the battery cell is prismatic, the first direction may be at least one of the x-direction, the y-direction, and the z-direction, that is, it may be at least one of the length direction, the thickness direction, and the height direction of the shell. Figures 2 to 4 For example, the first direction can be understood as the thickness direction of the housing 11. Figure 5 For example, the first direction can be understood as the length direction of the housing 11. Figure 5 For example, it can be understood that 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 can be stacked with at least one electrode assembly 12 along a first direction, optionally, the first direction can be the same as the thickness direction of the electrode assembly 12.

[0081] 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.

[0082] refer to Figure 8It is understood that in the battery cell, 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, and the cooling efficiency and heat dissipation effect of the battery cell in the first direction are relatively good. By stacking multiple battery cells along the first direction, the surfaces of multiple battery cells with relatively good cooling efficiency and heat dissipation effect can be concentrated in the first direction. Then, combined with the design of setting a cooling member on at least one side of the battery cell along the first direction, such as setting a cooling member on at least one side of each battery cell along the first direction, it is not only conducive to further shortening the heat conduction path between the electrode assembly and the cooling member in the first direction, and increasing 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, but also conducive to further increasing 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 the relative position relationship between the cooling member and the battery cell in the first direction, and taking into account the overall integration of the battery cell and the cooling member. Optionally, in the first direction, a cooling member can be set between any two battery cells stacked and adjacently arranged along the first direction, thereby facilitating further increasing the total relative heat exchange area between the entire first battery cell group and the cooling member and providing cooling efficiency.

[0083] In some embodiments of the present application, a plurality of first battery cell groups A may be stacked along a second direction, and the second direction may intersect the first direction.

[0084] refer to Fig. 9 or Fig.10 It is understood that the method of stacking multiple first battery cell groups along the second direction is also conducive to realizing the arrangement method of stacking a single cooling member with multiple battery cells along the first direction at the same time, thereby not only facilitating the improvement of the total heat exchange area between a single cooling member and a battery cell, and the total heat exchange area between all battery cells in the entire battery and the cooling member, but also facilitating the overall integration of the battery cell and the cooling member. Optionally, the second direction can be perpendicular or substantially perpendicular to the first direction, and the substantially perpendicular means that the angle between the second direction and the first direction can be 80 to 100 degrees, optionally 85 to 95 degrees, and further optionally 88 to 92 degrees.

[0085] In some embodiments of the present application, the battery includes a first battery cell group A, and in a first direction, the cooling member 6 may be disposed between two adjacent battery cells 1 , and / or the cooling member 6 may be disposed on one side of the plurality of battery cells 1 along the first direction.

[0086] Exemplary, reference Figure 8 or Fig. 9It is understood that for the battery structure with the first battery cell group A, in the first direction, the cooling member 6 can be arranged between two adjacent battery cells 1, which is conducive to heat exchange between both sides of each cooling member distributed along the first direction and the battery cell surface, thereby facilitating the increase of the total heat exchange area between the entire first battery cell group and the cooling member. Optionally, in the first direction, the cooling member 6 and the plurality of battery cells 1 can be alternately stacked, and each cooling member 6 can be independently distributed between two adjacent battery cells 1. This method is conducive to increasing the total heat exchange area between the entire first battery cell group and the cooling member, shortening the heat conduction path, improving the heat dissipation efficiency of the battery, and simplifying the battery structure.

[0087] Exemplary, reference Fig.10 It is understood that for a battery structure having a first battery cell group A, in a first direction, the cooling component 6 can be arranged on one side of the multiple 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 component, shorten the heat conduction path, and improve the heat dissipation efficiency of the battery.

[0088] Exemplary, combined Figures 8 to 10 It is understood that for the battery structure with the first battery cell group A, in the first direction, a portion of the cooling member 6 can be arranged between two adjacent battery cells 1, and another portion of the cooling member 6 can be arranged on one side of the plurality of battery cells 1 along the first direction. This method is conducive to realizing an arrangement in which both sides of each battery cell distributed along the first direction exchange heat with the cooling member, thereby facilitating 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.

[0089] For the battery structure including a first battery cell group A, and a plurality of first battery cell groups A stacked along the second direction, the relative position relationship between the cooling component and the battery cell satisfies the given conditions, which is beneficial to increase the total heat exchange area between the entire first battery cell group and the cooling component, shorten the heat conduction path, and improve the heat dissipation efficiency and effect of the battery.

[0090] 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, the second direction intersecting the first direction. Fig.11 It is understood that the battery may include only one second battery cell group B. For example, referring to Fig.12It is understood that 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 conducive to taking into account both the heat dissipation efficiency of the battery cell and the integration of the battery cell. 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.

[0091] 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.

[0092] Exemplary, reference Fig.11 It is understood that when the battery includes only one second battery cell group B, only one cooling member 6 may be provided, so that the cooling member 6 is located on one side of the second battery cell group B along the first direction, or two cooling members 6 may be provided, so that the two cooling members 6 are respectively provided on both sides of the second battery cell group B along the first direction. In the above arrangement, each of the cooling members 6 is independently provided on one side of the plurality of battery cells 1 along the first direction.

[0093] Exemplary, reference Fig.12 It is understood that 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 independently distributed between two adjacent second battery cell groups B. This is beneficial for both sides of each cooling member distributed along the first direction to exchange heat with the surfaces of multiple battery cells, which is beneficial for increasing the total heat exchange area between the entire second battery cell group and the cooling member, and is also beneficial for simplifying the battery structure.

[0094] Exemplary, combined Fig.11 and Fig.12 It is understood that when the battery includes multiple second battery cell groups B, in the first direction, a portion of the cooling member 6 can be arranged between two adjacent battery cells 1, and another portion of the cooling member 6 can be arranged on one side of the multiple battery cells 1 along the first direction. This method is conducive to realizing an arrangement in which both sides of each battery cell distributed along the first direction exchange heat with the cooling member, thereby further increasing the total heat exchange area between the entire second battery cell group and the cooling member, and improving the heat dissipation efficiency of the battery.

[0095] 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 .

[0096] Combination Figure 1 and Figure 7 It is understood that, taking a 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 two first surfaces 11a of the battery cell relatively arranged along a 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 relative to or in contact with the cooling component can be maximized compared with 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.

[0097] 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 .

[0098] Exemplary, combined Figure 1 and Figure 7 It is understood that the area of ​​the positive projection of the buffer 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 the present application, the area of ​​the first surface can be understood as the area of ​​the side of the first surface facing the inside of the shell. Among them, the area of ​​the first surface and the area of ​​the positive projection of the buffer on the first surface can be measured independently by conventional methods. For example, the area of ​​the first surface can be measured by direct measurement or colorimetry, and the area of ​​the positive projection of the buffer on the first surface can be measured by direct measurement, segmentation and summation, projection area formula or three-dimensional modeling software. The projection area of ​​the buffer on the first surface reflects to a certain extent the area where the electrode assembly can be relatively set or can be fitted with the first surface. The increase in the projection area is conducive to increasing the area where the electrode assembly can be relatively set or can be fitted with the first surface, and improving the fit between the electrode assembly and the shell.

[0099] Making the positive projection area of ​​the buffer on the first surface satisfy the given conditions is beneficial to further improve 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, which is beneficial to further improve the heat dissipation efficiency of the battery cell.

[0100] 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. Figure 8 or Fig.12 It is understood that adopting this arrangement is beneficial to further increase the total heat exchange area between all battery cells in the entire battery and the cooling component, thereby improving the heat dissipation efficiency and effect of the battery.

[0101] In some embodiments of the present application, the first group margin of the battery cell 1 can be ≥95%, and can be optionally ≥100%; the second group margin of the battery cell 1 can be ≥90%, and can be optionally ≥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 battery cell 1 in the fully charged state to the distance between the inner wall surface of the shell 11.

[0102] Exemplarily, the first group margin of the battery cell 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 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 first group margin of the battery cell to meet the given range conditions is conducive to further obtaining higher heat dissipation efficiency and effect. Exemplarily, the second group margin of the battery cell 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 the battery cell 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 the battery cell to meet the given range, the fit between the electrode assembly and the shell can be further improved on the basis of taking into account the energy density of the battery, and the heat exchange efficiency and effect can be improved.

[0103] 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 tested by conventional instruments and conventional methods in the field, such as using a Mitutoyo ID-C112MX micrometer thickness gauge (or an instrument of the same type), and testing under a test force less than or equal to 1.8N, and randomly measuring multiple points (such as 5, 10, etc.) to take the average value. The thickness test of the buffer under stress state can be obtained by using two parallel plates, with the buffer located in the middle of the plates, using the plates to apply a preset pressure to the buffer and measuring the distance between the plates. The instruments used to measure the distance between the 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.

[0104] In the 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 wall surfaces of the shell in the first direction refers to the distance between the inner wall surfaces of the shell in the free state (i.e., the state without any external force) along the first direction, wherein, when the battery unit is a prismatic battery, the distance between the inner wall surfaces of the shell along the first direction can be understood as the average distance, and when the battery cell is cylindrical, the distance between the inner wall surfaces of the shell along the first direction can be understood as the maximum distance, exemplary:

[0105] by Figure 3 For example, the battery cell is a prismatic battery, and the interior of the shell only includes two electrode assemblies and a buffer component stacked along a first direction. The total thickness of the buffer component in the free state in the first direction refers to the thickness d1 of the single buffer component 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 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 oppositely arranged 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%.

[0106] by Figure 5For example, the battery cell is a prismatic battery, and the interior of the shell includes two electrode assemblies and three buffer members, wherein the two electrode assemblies and the two second buffer members 13b are stacked along the first direction, and the total thickness of the buffer members in the free state in the first direction refers to the sum d1′ of the thicknesses of the two second buffer members in the free state; the maximum total size of the electrode assembly in the fully charged state in the first direction is the total projection length d2′ of the two electrode assemblies in the first direction (when the projection 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 that are oppositely arranged 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%.

[0107] by Figure 6 For example, when the battery cell is cylindrical, the first direction is the radial direction of the electrode assembly, the distance between the inner wall surfaces of the shell along the first direction is the inner cavity diameter of the shell in a free state, and the diameter can be the average value of multiple measurements.

[0108] The dimensions of the electrode assembly in the first direction under full charge can be measured by conventional methods or conventional 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 of a single electrode assembly in the first direction can be tested by the following method: using two parallel flat plates, the electrode assembly is located in the middle of the flat plates, and a pressure of 0.1 MPa is applied to the electrode assembly by the flat plates. The thickness of the electrode assembly is obtained by measuring the distance between the flat plates. The Yinghaoda PPG1200 battery thickness measuring instrument can be used for testing. The distance between the inner wall surfaces of the shell in the first direction can also be tested by conventional instruments and conventional methods in the art.

[0109] 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%.

[0110] 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 battery cells is beneficial to improving the volume stability of battery cells 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.

[0111] Exemplarily, the second group margin of the battery cell 1 can be 100%, 99%, 98%, 97%, 96%, 95%, etc. The second group margin of the battery cell that meets the given conditions is conducive to the battery assembly into the shell and the battery cell assembly. Optionally, the second group margin can be ≤98%. This is conducive to further taking into account the assembly of the battery cell.

[0112] 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.

[0113] Optionally, the margin of the first group of battery cells 1 located on the outlet 62 side may be greater than the margin of the first group of battery cells 1 located on the inlet 61 side. Fig. 9 It is understood that in the flow direction of the cooling medium, as the cooling medium continues to flow and continuously exchanges heat, the temperature of the cooling medium gradually increases, and in the direction from the inlet 61 to the outlet 62, the cooling effect on the battery cell will decrease to a certain extent. By making the first group margin of the battery cell 1 located on the side of the outlet 62 greater than the first group margin of the battery cell 1 located on the side of the inlet 61, it is beneficial to further increase the fit between the electrode assembly and the shell in the battery cell near the outlet, and then it is beneficial to increase the heat exchange area and contact time between the battery cell near the outlet and the cooling member, and make up for the cooling effect of the cooling member on the battery cell near the outlet 62 due to the temperature rise of the cooling medium. Therefore, it is not only beneficial to further improve the heat dissipation effect of the battery, but also beneficial to maintain the uniformity of the overall temperature of each battery cell in the battery, and reduce the risk of significantly higher temperature in a local area.

[0114] In some embodiments of the present application, the difference between the first group margin of the battery cells 1 located at the outlet 62 side and the first group margin of the battery cells 1 located at the inlet 61 side may be less than or equal to 5%.

[0115] Exemplary, reference Fig. 9 It is understood that the difference between the first group margin of the battery cell 1 located on the side of the outlet 62 and the first group margin of the battery cell 1 located on the side of the inlet 61 can be 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, 0.5%, etc. Reducing the difference in the group margin of the battery cells located on the side of the outlet 62 and the side of the inlet 61 is conducive to reducing the risk of uneven stress distribution and decreased volume stability of the battery due to different expansion forces of battery cells at different positions during the charging and discharging process. By controlling the first group margin distribution of the battery cells to meet the given conditions, it is not only conducive to improving the overall heat dissipation effect of the battery and maintaining the uniformity of the overall temperature of each battery cell in the battery, but also taking into account the overall volume stability of the battery.

[0116] In some embodiments of the present application, the difference between the second group margin of the battery cells 1 located on the outlet 62 side and the second group margin of the battery cells 1 located on the inlet 61 side may be less than or equal to 1%, and may be 0. Fig. 9 It is understood that the difference between the second group margin of the battery cell 1 located on the side of the outlet 62 and the second group margin of the battery cell 1 located on the side of the inlet 61 can be 1%, 0.5%, 0.1%, 0, etc. The second group margins of each battery cell that meets the given conditions are basically the same, which is conducive to controlling the change of the first group margin of each battery cell distributed along the cooling medium flow channel by adjusting the thickness change of the buffer member, and realizing a structural design in which the first group margins of multiple battery cells distributed along the inlet toward the outlet are gradually increased or equal.

[0117] 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. Fig. 9 It is understood that satisfying 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 first group margin of the plurality of battery cells 1 distributed along the inlet 61 toward the outlet 62 can be gradually increased, and the second group margin remains unchanged or basically the same (that is, the difference in the second group margin of any two battery cells is ≤1%).

[0118] 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.

[0119] It should be noted that the parallel arrangement means that the cooling medium flow channels of the multiple cooling components 6 are independent of each other and not connected to each other; the series arrangement means that the inlets and outlets of the cooling medium flow channels of the multiple cooling components 6 are connected at the end and are directly or indirectly connected to each other. The arrangement of the direct cooling flow channels of the multiple cooling components can be flexibly adjusted according to the stacking method of the battery cells, for example, Fig. 9 Taking the first direction and the second direction shown in as an example, if the number of battery cells stacked in the second direction is large, it is possible to consider adopting a method of arranging the cooling medium flow channels of multiple cooling components in parallel; if the number of battery cells stacked in the second direction is small, it is possible to consider adopting a method of arranging the cooling medium flow channels of multiple cooling components in series; in addition, it is also possible to adopt a method of arranging the cooling medium flow channels of some cooling components in series and the cooling medium flow channels of the remaining cooling components in parallel according to the specific arrangement of the battery cells. This is more conducive to taking into account both the cooling effect of the battery and the reuse of the cooling medium.

[0120] In some embodiments of the present application, a plurality of cooling components 6 may be connected via a connector (not shown), and cooling medium channels of two cooling components 6 adjacent and spaced apart in the first direction may be connected via the connector.

[0121] 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 be independently a delivery pipe or a delivery panel, the inlets of the cooling medium flow channels of the multiple cooling components 6 may be independently connected to the cooling medium supply end, and / or the outlets of the cooling medium flow channels of the multiple cooling components 6 may be independently connected to the cooling medium output end; and / or, the connector may be a delivery pipe or a delivery panel for connecting the cooling medium flow channels of two different cooling components end to end. The above arrangement is beneficial to the filling and flow of the cooling medium in different cooling medium flow channels on the one hand, and to further increase the contact area between the battery cell and the cooling medium on the other hand, and to improve the heat dissipation effect.

[0122] 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.

[0123] Exemplary, reference Figure 7 and Figure 8 It is understood that the second surface may be in contact with the cooling member; optionally, both second surfaces may be in contact with the cooling member. Compared with radiation heat dissipation, making the surface of the battery cell directly contact with the cooling member can further shorten the heat conduction path and improve the heat dissipation efficiency and effect of the battery cell.

[0124] Exemplarily, the contact area between the second surface and the cooling member 6 may 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 may be measured by conventional methods, such as direct measurement or colorimetry. Increasing the contact area between the battery cell surface and the cooling member may 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 may 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 facilitating 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.

[0125] 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.

[0126] 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 may be greater than or equal to 25% of the total surface area of ​​the battery cell.

[0127] Exemplarily, the total contact area between a single battery cell 1 and the cooling member 6 can be 20%, 25%, 30%, 35%, 40%, etc. of the total surface area of ​​the battery cell, or can be a range consisting of any of the above values. 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 can increase the heat exchange area, shorten the heat conduction path, and improve the heat dissipation efficiency and effect.

[0128] 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.

[0129] 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 shell 11 .

[0130] Among them, the buffer 13 is arranged between the electrode assembly 12 and the shell 11, so that the surface of the electrode assembly in contact with the buffer 13 can be indirectly in contact with the shell, buffering the expansion force of the electrode assembly during the charge and discharge process, and improving the volume stability of the battery during the charge and discharge cycle. If the electrode assembly is in direct contact with the shell, it is further beneficial to improve the heat dissipation effect of the battery cell. The buffer is only arranged between part of the surface of the electrode assembly and the shell, which is conducive to better fit and contact area between the electrode assembly and the shell, and improves the heat dissipation efficiency and effect. Optionally, refer to Figure 2 It is understood that when there is only one electrode assembly 12 in the battery cell 1, the buffer 13 can be provided on only one side of the two sides of the electrode assembly 12 arranged opposite to each other along the first direction, and the cooling member 6 can be provided on the other side of the battery cell 1 along the first direction where the buffer 13 is not provided; alternatively, refer to Figure 3 It is understood that when the battery cell 1 includes a plurality of electrode assemblies 12, the buffer 13 may be provided only between two electrode assemblies 12 adjacently arranged along the first direction, and no buffer may be provided between the electrode assembly 12 and the housing 11 in the first direction, and in this case, the cooling member 6 may be provided on at least one of the two sides of the battery cell 1 that are arranged oppositely along the first direction. This is conducive to ensuring that the electrode assembly always has a good fit with the housing during the charge and discharge cycle, thereby further facilitating the increase of the heat dissipation area, shortening the heat conduction path, and improving the heat dissipation efficiency and effect of the battery.

[0131] In some embodiments of the present application, the thermal conductivity of the buffer member 13 disposed between the electrode assembly 12 and the shell 11 may be ≥3 W / (m·° C.), and may optionally be ≥5 W / (m·° C.).

[0132] Exemplarily, the thermal conductivity of the buffer 13 provided between the electrode assembly 12 and the shell 11 may be ≥3W / (m·℃), ≥5W / (m·℃), ≥10W / (m·℃), ≥15W / (m·℃), ≥20W / (m·℃), ≥25W / (m·℃), ≥30W / (m·℃), ≥35W / (m·℃), and the like, and may be optionally ≥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 / T10295. Meeting the given range conditions can improve the thermal conductivity efficiency of the buffer and improve the heat dissipation effect of the battery cell.

[0133] In some embodiments of the present application, a buffer member 13 may be provided between two adjacent electrode assemblies 12 in the battery cell 1. Optionally, when the battery cell 1 includes a plurality of electrode assemblies 12, the buffer member 13 may be provided only between two adjacent electrode assemblies 12. Figure 3It is understood that adopting this arrangement is further beneficial to ensure that the electrode assembly always has a good fit with the shell during the charge and discharge cycle, which not only helps to shorten the heat conduction path between the electrode assembly and the shell, but also increases the relative heat dissipation area between the electrode assembly and the shell in the portion where the heat conduction path is shortened, thereby improving the heat dissipation efficiency and effect of the battery.

[0134] 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 may optionally be ≤0.03 W / (m·° C.).

[0135] Exemplarily, the thermal conductivity of the buffer 13 disposed between two adjacent electrode assemblies 12 may be ≤0.05W / (m·℃), ≤0.04W / (m·℃), ≤0.03W / (m·℃), ≤0.02W / (m·℃), ≤0.01W / (m·℃), ≤0.005W / (m·℃), and so on, and may be ≤0.03W / (m·℃). A lower thermal conductivity is conducive to isolating heat conduction between battery assemblies and reducing the risk of failure of a single electrode assembly causing failure of other electrode assemblies. Therefore, the above-mentioned configuration is conducive to reducing the probability of thermal runaway of battery cells.

[0136] In some embodiments of the present application, the electrode assembly 12 may further include a separator (not shown), and the thermal conductivity of the separator may be greater than or equal to the thermal conductivity of the buffer 13 .

[0137] 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 shell, the use of a diaphragm that meets the given conditions is conducive to further improving the efficiency of heat generation and outward transfer of the electrode assembly. Moreover, even if a buffer is provided between the electrode assembly and the shell, the use of a diaphragm that meets the given conditions is also conducive to improving the thermal conduction of the electrode assembly itself. Therefore, making the thermal conductivity of the diaphragm meet the given conditions is conducive to improving the heat dissipation efficiency and effect of the battery.

[0138] 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 part of the surface of the electrode assembly, and in the 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 shell (such as a metal shell), and further making the thermal conductivity of the insulating film greater than or equal to the thermal conductivity of the buffer is also conducive to improving the efficiency of heat generation of the electrode assembly to transfer to the outside, and reducing heat conduction between battery components, and improving the heat dissipation efficiency and effect of the battery.

[0139] 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.

[0140] Exemplarily, 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 the field. Optionally, the third group margin can be greater than or equal to the first group margin, and can be greater than the first group margin. Optionally, the third group margin can be ≤108%, and can be ≤105%, and can be 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.

[0141] In some embodiments of the present application, the battery cell 1 may include at least two electrode assemblies 12, and each buffer 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 is not only conducive to improving the fit between the electrode assembly and the shell, but also conducive to achieving direct contact between the electrode assembly and the inner wall of the shell, thereby facilitating shortening the heat conduction path and improving the heat dissipation efficiency and effect of the battery.

[0142] 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, and the orthographic projections of the buffer and the electrode assembly on the third surface satisfying the given conditions can be achieved by controlling the large surface area of ​​the buffer to be less than or equal to the surface area 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, improve the heat dissipation efficiency and effect of the battery, but also beneficial to take into account the energy density of the battery cell.

[0143] In some embodiments of the present application, the area of ​​the orthographic projection of the buffer 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. Exemplarily, the area of ​​the orthographic projection of the buffer 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%, etc. of 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, and the increase in the overlapping area is conducive to improving the fit between the electrode assembly and the shell. Making the orthographic projections of the buffer and the electrode assembly on the third surface meet the given conditions is not only conducive to improving the fit between the electrode assembly and the shell, but also conducive to improving the uniformity of stress distribution of the battery cell during the charging and discharging process, and thus conducive to further improving the heat dissipation efficiency of the battery cell and the volume stability during the cycle process. 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 relatively set or fitted with the cooling component compared to the other surfaces, which is not only beneficial for further improving the fit between the electrode assembly and the shell, but also beneficial for further increasing the heat exchange area between the battery cell and the cooling component, thereby improving the heat dissipation efficiency and effect.

[0144] 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.

[0145] Exemplarily, the buffer 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, and the like.

[0146] Exemplarily, the buffer may be a multilayer structure, specifically including an elastic buffer layer and a support layer, and the support layer may be provided on at least one of the two sides of the elastic buffer layer along the thickness direction thereof. Optionally, the elastic modulus of the elastic buffer layer is smaller than the elastic modulus of the support layer, and / or, the compression rate of the elastic buffer layer along the thickness direction thereof under the same pressure is greater than the compression rate of the support layer along the thickness direction thereof, and / or, the porosity of the elastic buffer layer may be greater than the porosity 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 again, 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 a 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; the elastic buffer layer and the support layer may be bonded together. Among them, the composite of the support layer and the elastic buffer layer can provide support to the elastic buffer layer, which can not only inhibit the thermal shrinkage of the elastic buffer layer (such as thermal shrinkage during vacuum baking), but also optionally inhibit the thermal shrinkage of the elastic buffer layer in a two-dimensional direction perpendicular to its thickness direction, thereby improving the problem of losing its original function due to thermal shrinkage, and at the same time improving the problem of material damage of the buffer due to mechanical stress in the later stage of battery use. Furthermore, placing the buffer inside the battery cell is conducive to further improving the volume stability of the battery during long-term use and improving long-term performance.

[0147] In some embodiments of the present application, the electrode assembly 12 may include a positive electrode sheet, a negative electrode sheet, and a separator, and the positive electrode sheet, the negative electrode sheet, and the separator may be wound to form an electrode assembly. During the battery charging and discharging process, active ions are embedded and removed 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 play a role of 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 choose according to actual needs.

[0148] 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.

[0149] The battery of the first aspect of the present application may include a battery cell 1 (refer to Figure 7Understanding) and cooling member 6, may also include a battery module 2 composed of battery cells 1 (reference Fig.13 Understanding) and cooling member 6, or may include a battery pack 3 composed of battery cells 1 (reference Fig.14 Understanding) and cooling member 6.

[0150] 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. Fig.13 2 is an example of a battery module 2. Fig.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, they may also be arranged in any other manner. The plurality of battery cells 1 may further be fixed by fasteners. Optionally, the battery module 2 may further include a housing having a housing space, and the plurality of battery cells 1 are accommodated in the housing space. It is understood that the cooling member 6 is also accommodated in the housing space.

[0151] In some embodiments, the battery modules described above may also be assembled into a battery pack, and the number of battery modules contained in the battery pack may be adjusted according to the application and capacity of the battery pack. Fig.14 or Fig.15 ( Fig.14 and Fig.15 As an example, a battery pack 3 is shown, in which a battery box and a plurality of battery modules 2 disposed in the battery box may be included. The battery box may include an upper box body 4 and a lower box body 5, wherein the upper box body 4 can be covered on the lower box body 5 and form a closed space for accommodating the battery modules 2. The plurality of battery modules 2 may be arranged in the battery box in any manner.

[0152] 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. Reference Fig.15 It is understood that, as a specific example, the electric device may be a vehicle. The electric device may select a specific type of battery according to its usage requirements, such as a battery having a battery cell, a battery module or a battery pack.

[0153] 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.

[0154] As another example, the electric device may be a mobile phone, a tablet computer, or a laptop computer. The electric device is usually required to be thin and light, and a battery cell and a cooling member may be used as a power source.

[0155] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0156] Example 1

[0157] (I) Preparation of lithium secondary batteries

[0158] (1) Preparation of positive electrode sheet

[0159] 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 and mixed 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.

[0160] (2) Negative electrode sheet preparation

[0161] 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 and mixed 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.

[0162] (3) Preparation of electrolyte

[0163] 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.

[0164] (4) Preparation of diaphragm

[0165] A polyethylene porous film with a thickness of 7 μm was used as the separator.

[0166] (5) Preparation of buffer parts

[0167] Polypropylene with a thickness of 3 mm and a porosity of 94% in a free state is used as the buffer.

[0168] (6) Preparation of lithium secondary battery monomers

[0169] The positive electrode sheet, the separator, and the negative electrode sheet are stacked in order, so that the separator is placed between the positive and negative electrode sheets to play a role of isolation, and then wound and formed to obtain an electrode assembly. Two electrode assemblies and a buffer are stacked along the thickness direction of the electrode assembly and placed in the battery housing. The buffer is sandwiched between the two electrode assemblies. The thickness direction of the electrode assembly and the buffer in the electrode monomer is consistent with the y direction. The prepared electrolyte is injected and packaged to obtain a battery as shown in FIG. Figure 7 The lithium secondary battery shown.

[0170] refer to Figure 7 and Fig.10 , with the y direction as the first direction and the x direction as the second direction, 16 lithium secondary battery cells are arranged in a Fig. 9 The battery cells are stacked in the manner shown, and a cooling member is sandwiched between two layers of battery cells stacked in the y direction, and the cooling member is attached to 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 inner cavity of the cooling member is filled with cooling medium.

[0171] Examples 2 to 13 and Comparative Examples 1 to 3

[0172] The differences between Examples 2 to 13 and Comparative Examples 1 to 3 are detailed in Table 1. Compared with Example 1, the remaining Examples and Comparative Examples change the first group margin of the battery cells by changing the thickness of the point buffer; Figure 7 It is understood that the remaining embodiments and comparative examples change the percentage of the contact area between a single surface of the battery cell and the cooling member in the first direction to the area of ​​the single surface by changing the distance of the cooling member in the z direction.

[0173] (II) Battery temperature rise test method

[0174] Take the z direction of the lithium secondary battery cell as the height direction, make the top cover of the battery cell face upward, refer to Fig. 9 , set a temperature sensing line at the center of the top cover of one of the two battery cells on the outlet side of the cooling member to test the temperature of the battery cell, control the cooling medium inlet temperature to 25°C, and the cooling medium flow rate to 10L / min. At 25°C, after 0.33C discharge to 2.5V, make the battery temperature consistent with the ambient temperature and charge according to the following process: 3C charge for 5min, 2C charge for 10min, 1C charge for 15min, 0.33C charge to the upper limit voltage, record the highest temperature of the process, the temperature rise of the lithium secondary battery cell = maximum temperature - temperature before charging.

[0175] Relevant tests were carried out on Examples 1 to 13 and Comparative Examples 1 to 3, and the test results are shown in Table 1.

[0176]

[0177]

[0178] Results and Conclusions:

[0179] Based on Examples 1 to 13, Comparative Examples 1 to 3 and Table 1, it can be seen that, relative to a battery without a cooling member and a buffer member, a buffer member is provided in a battery cell so that it is stacked with an electrode assembly, and a cooling member is provided on one side of the battery cell along the stacking direction, so as to 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 member, or increasing the group margin of the cooling member within a suitable range, or gradually increasing the first group margin of multiple battery cells distributed along the flow direction of the cooling medium (from the inlet to the outlet) within a suitable range, or increasing the number of cooling members and adjusting the setting position of the cooling members.

[0180] 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 is described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate 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 description 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.

[0181] The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery, wherein: include: A battery cell, comprising: a shell, at least one electrode assembly and at least one buffer, wherein the electrode assembly and the buffer are placed in the shell, the buffer is arranged on at least a 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 are stacked along a first direction; At least one cooling member is disposed on at least one side of the battery cell along the first direction.

2. The battery according to claim 1, wherein include: At least one first battery cell group, the first battery cell group including 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 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 battery cells along the first direction.

5. The battery according to claim 1, wherein include: At least one second battery cell group, the second battery cell group including a plurality of the battery cells stacked along a second direction, the second direction intersecting 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 battery cells along the first direction.

7. The battery according to any one of claims 1 to 6, wherein The battery cell includes two first surfaces that are opposite to each other, 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.

8. The battery according to claim 7, wherein An area of ​​an 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 an area of ​​the first surface.

9. The battery according to any one of claims 2 to 6, wherein In the first direction, the cooling member is disposed between each of the plurality of battery cells.

10. The battery according to any one of claims 1 to 6, wherein The margin of the first group of battery cells is ≥ 95%; the margin of the second group of battery cells is ≥ 90%, 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 battery cell in a free state, the maximum total size of the electrode assembly in a fully charged state, and the distance between the inner wall surface of the shell; The second group margin refers to: in the first direction, the ratio of the maximum total size of the electrode assembly in the battery cell in a fully charged state to the distance between the inner wall surface of the shell.

11. The battery according to claim 10, wherein The first group margin of the battery cells is ≥100%.

12. The battery according to claim 10, wherein The second group margin of the battery cells is ≥95%.

13. The battery according to claim 10, wherein The first group margin of the battery cells is ≤108%; and / or the second group margin is ≤100%.

14. The battery according to claim 13, wherein The first group margin of the battery cells is ≤105%.

15. The battery according to claim 13, wherein The second group margin is ≤98%.

16. The battery according to any one of claims 1 to 6, wherein A cooling medium flow channel is provided inside the cooling component, and the cooling medium flow channel includes an inlet and an outlet, and the first group margin of the battery cells located on the outlet side is greater than or equal to the first group margin of the battery cells located on the inlet side.

17. The battery according to claim 16, wherein: At least one of the following conditions is met: The difference between the first group margin of the battery cells located at the outlet side and the first group margin of the battery cells located at the inlet side is less than or equal to 5%; The difference between the second group margin of the battery cells located at the outlet side and the second group margin of the battery cells located at the inlet side is less than or equal to 1%; 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.

18. The battery according to claim 17, wherein A difference between the second group margin of the battery cells located at the outlet side and the second group margin of the battery cells located at the inlet side is equal to zero.

19. The battery according to claim 16, wherein: include: A plurality of the cooling components, wherein the cooling medium channels of the plurality of the cooling components are arranged in parallel and / or in series; and / or, The plurality of cooling components are connected via a connector, and the cooling medium flow channels of two cooling components that are adjacent and spaced apart in the first direction can be connected via the connector.

20. The battery according to any one of claims 1 to 6, wherein The battery cell includes two second surfaces oppositely arranged along the first direction, at least one of the two second surfaces is in contact with the cooling member, and a contact area between the second surface and the cooling member is greater than or equal to 80% of an area of ​​the second surface.

21. The battery according to claim 20, wherein The contact area between the second surface and the cooling member is greater than or equal to 80% to 100% of the area of ​​the second surface.

22. The battery according to claim 21, wherein The contact area between the second surface and the cooling member is greater than or equal to 90% to 100% of the area of ​​the second surface.

23. The battery according to any one of claims 1 to 6, wherein A total contact area between a single battery cell and the cooling member is greater than or equal to 20% of a total surface area of ​​the battery cell.

24. The battery according to claim 23, wherein A total contact area between a single battery cell and the cooling member is greater than or equal to 25% of a total surface area of ​​the battery cell.

25. The battery according to any one of claims 1 to 6, wherein In the battery cell, the buffer is disposed between a portion of the surface of the electrode assembly and the shell.

26. The battery according to claim 25, wherein The thermal conductivity of the buffer member disposed between the electrode assembly and the housing is ≥3 W / (m·° C.).

27. The battery according to claim 26, wherein The thermal conductivity of the buffer member disposed between the electrode assembly and the housing is ≥5 W / (m·° C.).

28. The battery according to any one of claims 1 to 6, wherein In the battery cell, the buffer member is disposed between two adjacent electrode assemblies.

29. The battery according to claim 28, wherein The thermal conductivity of the buffer member disposed between two adjacent electrode assemblies is ≤0.05 W / (m·°C).

30. The battery according to claim 29, wherein The thermal conductivity of the buffer member disposed between two adjacent electrode assemblies is ≤0.03 W / (m·°C).

31. The battery according to any one of claims 1 to 6, wherein The electrode assembly includes a diaphragm, the thermal conductivity of the diaphragm is greater than or equal to the thermal conductivity of the buffer member; and / or, The battery cell also includes: an insulating film, which wraps at least a portion of the surface of the electrode assembly, and in the first direction, each electrode assembly is stacked with at least one layer of the insulating film, and the thermal conductivity of the insulating film is greater than or equal to the thermal conductivity of the buffer.

32. The battery according to claim 31, wherein The third group margin of the battery cell is ≥95%, and 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 a free state, the maximum total size of the electrode assembly in a fully charged state, and the total thickness of the insulating film to the distance between the inner wall surface of the shell.

33. The battery according to claim 32, wherein The third group margin of the battery cells is ≥100%.

34. The battery according to any one of claims 1 to 6, wherein The battery cell includes at least two electrode assemblies. Each buffer member in the battery cell is independently disposed between two adjacent electrode assemblies and is stacked with the electrode assemblies along the first direction.

35. The battery according to any one of claims 1 to 6, wherein The battery cell includes two third surfaces arranged opposite to each other along the first direction, and the orthographic projection of the buffer member stacked and adjacent to the electrode assembly along the first direction on the third surface is located within the area of ​​the orthographic projection of the electrode assembly on the third surface.

36. The battery according to claim 35, wherein 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.

37. An electrical device, wherein: A battery comprising the battery according to any one of claims 1 to 36.

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