Battery and electrical apparatus

Abstract

Disclosed in the present application are a battery and an electrical apparatus. The charge rate of the present battery is greater than or equal to 2C; the battery comprises a battery unit, and the battery unit comprises a housing, at least one electrode assembly, and at least one impact reduction member; the battery electrode and the impact reduction member are arranged within the housing, and the impact reduction member is arranged on at least a portion of surfaces of the electrode assembly and / or within the electrode assembly, wherein the at least one electrode assembly and the at least one impact reduction member are arranged as stacked in a first direction.

Description

Batteries and electrical devices Technical Field

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

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

[0003] Public content

[0004] In view of the technical problems existing in the background technology, the present application provides a battery, aiming to improve the cooling efficiency of a fast-charging battery.

[0005] In order to achieve the above-mentioned objectives, the first aspect of the present application provides a battery, wherein the charging rate of the battery is greater than or equal to 2C; the battery includes a battery cell, and the battery cell includes a shell, at least one electrode assembly and at least one buffer member, the electrode assembly and the buffer member are placed in the shell, and the buffer member is provided on at least a portion of the surface of the electrode assembly and / or inside the electrode assembly; wherein, along a first direction, at least one electrode assembly and at least one buffer member are stacked.

[0006] At present, fast-charging batteries usually have a serious problem of heat generation during the charging and discharging process, and have a high demand for heat dissipation, especially for batteries with a charging rate of 2C or above. The battery of the first aspect of the present application has the following beneficial effects: by providing a buffer, even if the buffer is not over-compressed, it is conducive to achieving direct adhesion between the electrode assembly and the inner wall of the shell, or adhesion to the inner wall of the shell through the buffer or insulating film, thereby not only shortening the heat conduction path between the electrode assembly and the shell, but also increasing the relative heat dissipation area between the electrode assembly and the shell in the shortened part of the heat conduction path, that is, the contact heat exchange area between the electrode assembly and the shell can be increased, improving the heat dissipation effect of the battery cell, thereby improving the cooling efficiency; further, the structure in which at least one electrode assembly and at least one buffer are stacked along the first direction makes the electrode assembly and the inner wall of the shell have a further improved fit and a further shortened heat conduction path in the first direction, 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, and improving the heat dissipation efficiency and effect of the fast-charging battery.

[0007] In some embodiments of the present application, the battery has a charge rate greater than or equal to 4 C. Fast-charge batteries with a charge rate above 4 C have higher heat dissipation requirements, and meeting the given battery structure is conducive to improving the heat dissipation efficiency and effect of such fast-charge batteries.

[0008] In some embodiments of the present application, the buffer member is provided between a portion of the surface of the electrode assembly and the housing. Meeting the given conditions is conducive to increasing the fit and contact area between the electrode assembly and the housing, and improving the heat dissipation efficiency and effect.

[0009] In some embodiments of the present application, the thermal conductivity of the buffer member disposed between the electrode assembly and the housing is ≥3 W / (m·°C), and may be ≥5 W / (m·°C). Meeting this range can improve the thermal conductivity of the buffer member and enhance the heat dissipation effect of the battery cell.

[0010] In some embodiments of the present application, the buffer member is provided between two adjacent electrode assemblies in the battery cell. Meeting the given conditions is conducive to further increasing the fit and contact area between the electrode assembly and the housing, and improving the heat dissipation efficiency and effect.

[0011] In some embodiments of the present application, the thermal conductivity of the buffer member disposed between two adjacent electrode assemblies is ≤0.05 W / (m·°C), and optionally ≤0.03 W / (m·°C). Meeting this condition helps isolate heat conduction between battery assemblies and reduces the risk of failure of other electrode assemblies due to failure of a single electrode assembly.

[0012] In some embodiments of the present application, the battery cell includes at least two electrode assemblies, and each buffer member in the battery cell is independently disposed between two adjacent electrode assemblies and stacked with the electrode assemblies along the first direction. Meeting these conditions is beneficial for improving the heat dissipation efficiency and effect of the battery.

[0013] In some embodiments of the present application, the electrode assembly further comprises a diaphragm, the thermal conductivity of the housing is greater than or equal to the thermal conductivity of the diaphragm, and the thermal conductivity of the diaphragm is greater than or equal to the thermal conductivity of the buffer. Meeting these conditions is beneficial to improving the heat dissipation efficiency and effect of the battery.

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

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

[0016] In some embodiments of the present application, the orthographic projection of the buffer member stacked and adjacent to the electrode assembly along the first direction on the first surface is within the area of ​​the orthographic projection of the electrode assembly on the first surface, and the area of ​​the orthographic projection of the buffer member on the first surface is greater than or equal to 80% of the area of ​​the orthographic projection of the electrode assembly on the first surface. Meeting these conditions is beneficial for improving the heat dissipation efficiency and volume stability of the battery during cycling.

[0017] In some embodiments of the present application, the battery includes: at least one cooling member, the cooling member being provided on at least one side of the battery cell along the first direction. Meeting the given conditions is conducive to further improving the heat dissipation efficiency and effect of the battery.

[0018] 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.

[0019] 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.

[0020] In some embodiments of the present application, the battery includes a first battery cell group, and the cooling member is disposed between two adjacent battery cells in the first direction, and / or the cooling member is disposed on one side of a plurality of battery cells along the first direction. This helps improve the heat dissipation efficiency and effect of the battery.

[0021] In some embodiments of the present application, the battery includes: at least one second battery cell group, the second battery cell group including a plurality of the battery cells stacked along a second direction, and the second direction intersects with the first direction.

[0022] In some embodiments of the present application, the battery includes a second battery cell group, and in the first direction, the cooling member is arranged between two adjacent battery cells, and / or the cooling member is arranged on one side of the plurality of battery cells along the first direction.

[0023] In some embodiments of the present application, in the first direction, the cooling member is provided between each of the plurality of battery cells. Meeting the given conditions is conducive to increasing the heat exchange area between the battery cells and the cooling member, and improving the heat dissipation efficiency and effect of the battery.

[0024] In some embodiments of the present application, a cooling medium flow channel is provided inside the cooling member, and the cooling medium flow channels of multiple cooling members are arranged in parallel and / or in series. This is more conducive to balancing the cooling effect on the battery and the reuse of the cooling medium.

[0025] In some embodiments of the present application, multiple cooling members are connected by a connector, and the cooling medium flow channels of two adjacent cooling members spaced apart in the first direction are interconnected via the connector. Meeting this condition facilitates the filling and flow of the cooling medium in the different cooling medium flow channels, while also further increasing the contact area between the battery cells and the cooling medium, thereby improving heat dissipation.

[0026] In some embodiments of the present application, the battery cell includes two second surfaces disposed opposite each other along the first direction, at least one of the two second surfaces contacts the cooling member, and the contact area between the second surface and the cooling member is greater than or equal to 80% of the area of ​​the second surface, optionally 80-100% of the area of ​​the second surface, and further optionally 90-100% of the area of ​​the second surface. Meeting this range is conducive to further improving heat dissipation efficiency and effect.

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

[0028] 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

[0029] 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:

[0030] FIG1 is a schematic structural diagram of a prismatic battery cell according to one embodiment of the present application.

[0031] FIG2 is a schematic cross-sectional view of a prismatic battery cell according to one embodiment of the present application.

[0032] FIG3 is a schematic cross-sectional view of a prismatic battery cell according to another embodiment of the present application.

[0033] FIG4 is a schematic cross-sectional view of a prismatic battery cell according to another embodiment of the present application.

[0034] FIG5 is a schematic cross-sectional view of a prismatic battery cell according to another embodiment of the present application.

[0035] FIG6 is a schematic cross-sectional view of a cylindrical battery cell according to one embodiment of the present application.

[0036] FIG7 is a schematic diagram of a cross-sectional structure of a battery according to one embodiment of the present application.

[0037] FIG8 is a schematic diagram of the cross-sectional structure of a battery according to another embodiment of the present application.

[0038] FIG9 is a schematic cross-sectional view of a battery according to another embodiment of the present application.

[0039] FIG10 is a schematic cross-sectional view of a battery according to another embodiment of the present application.

[0040] FIG11 is a schematic cross-sectional view of a battery according to another embodiment of the present application.

[0041] FIG12 is a schematic diagram of the cross-sectional structure of a battery according to yet another embodiment of the present application.

[0042] FIG13 is a schematic structural diagram of a battery module according to one embodiment of the present application.

[0043] FIG14 is a schematic structural diagram of a battery pack according to one embodiment of the present application.

[0044] FIG. 15 is an exploded view of a battery pack according to one embodiment of the present application.

[0045] FIG16 is a schematic diagram of an electric device using a battery as a power source according to an embodiment of the present application.

[0046] Figure numerals: 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

[0047] The present application will be further described below in conjunction with specific embodiments. It should be understood that these specific embodiments are only used to illustrate the present application and are not used to limit the scope of the present application.

[0048] Below, with appropriate reference to the accompanying drawings, the embodiments of the positive electrode active material and its preparation method, the positive electrode sheet, the battery and the electric device of the present application are described in detail. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0049] The "range" disclosed in this application is defined in the form of a lower limit and / or an upper limit, and a given range is defined by selecting a lower limit and / or an upper limit, and the selected lower limit and / or upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form an unspecified range, and any lower limit can be combined with other lower limits to form an unspecified range, and similarly any upper limit can be combined with any other upper limit to form an unspecified range. In addition, each separately disclosed point or single value itself can be combined with any other point or single value as a lower limit or upper limit or with other lower limits or upper limits to form an unspecified range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also contemplated. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4, and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise specified, the numerical range "a-b" is an abbreviation for any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in this document, and "0-5" is just an abbreviation for these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0050] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present application.

[0051] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of this application.

[0052] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps S1 and S2, which means that the method may include steps S1 and S2 performed sequentially, or may include steps S2 and S1 performed sequentially. For example, the method may further include step S3, which means that step S3 may be added to the method in any order, for example, the method may include steps S1, S2, and S3, or may include steps S1, S3, and S2, or may include steps S3, S1, and S2, etc.

[0053] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0054] Unless otherwise specified, the term "or" is used in this application to be inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied if any of the following conditions are met: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0055] Unless otherwise specified, the term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0056] In this application, the terms "plurality" and "multiple" refer to two or more.

[0057] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned description of the drawings and any variations thereof are intended to cover non-exclusive inclusions. Unless otherwise specified, the terms used in this application have the well-known meanings commonly understood by those skilled in the art. Unless otherwise specified, the numerical values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the examples of this application).

[0058] With the continuous advancement of the theme of green environmental protection, 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, such as fast charging performance. Fast charging shortens the charging time by increasing the charging power by increasing the voltage and / or current, for example, it can be achieved by increasing the charging current. However, the high-voltage and high-current charging method will produce a large thermal effect, which may cause a certain degree of damage to the battery, including aging, performance degradation and safety risks. Among them, the thermal effect will aggravate aging, and excessively high temperatures may damage the internal structure of the battery, resulting in problems such as degradation of battery performance (such as rapid decay of capacity), affecting the battery's service life and the normal operation of electrical devices.

[0059] In the present application, for fast-charging batteries with a charging rate greater than or equal to 2C, by optimizing the internal structure of the battery cell, that is, arranging a buffer member in the battery cell and stacking at least one electrode assembly and at least one buffer member in a first direction, it is beneficial to improve the fit between the electrode assembly and the shell, shorten the heat conduction path, and improve the heat dissipation efficiency and effect of the battery.

[0060] The battery disclosed in the embodiments of the present application can be used in electrical devices that use the battery as a power source or various energy storage systems that use the battery as an energy storage element. Electrical devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery cars, electric cars, ships, spacecraft, and the like. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0061] A first aspect of the present application provides a battery having a charge rate greater than or equal to 2C; the battery includes a battery cell, the battery cell includes a shell, at least one electrode assembly and at least one buffer component, the electrode assembly and the buffer component are placed in the shell, and the buffer component is provided on at least a portion of the surface of the electrode assembly and / or inside the electrode assembly, wherein, along a first direction, at least one electrode assembly and at least one buffer component are stacked.

[0062] Among them, the charging rate is a measure of charging speed, which refers to the current value required for the battery to be charged to its rated capacity within a specified time. Exemplarily, the charging rate of the battery can be greater than or equal to 2C, 3C, 4C, 5C, 6C, and so on. In actual operation, for batteries with unknown charging rates, the following methods can be used to determine whether the battery is a fast-charging battery and the charging rate of the fast-charging battery. Taking a battery with a charging rate of 2C as an example, the battery can be fast-charged according to the following method (the test environment temperature is 25°C): (ⅰ) Let the battery stand for 10 minutes, and then charge the battery to 97% SOC (State Of Charge) with an equivalent 2C current. (ii) let the battery stand for 30 minutes, and then discharge the battery to 3% SOC at a constant current of 1C; (iii) repeat steps (i) and (ii) 50 times; (iv) charge the battery to 97% SOC at an equivalent current of 2C; (v) disassemble the battery, take lithium-ion battery as an example, observe the lithium deposition on the surface of the negative electrode, and judge whether the battery meets the 2C fast charging requirement based on the degree of lithium deposition on the surface of the negative electrode. For example, the negative electrode can be flattened and the negative electrode can be measured. The total area of ​​the negative electrode active material layer on one side (or both sides) is S1; the area of ​​each lithium deposition point region on this negative electrode active material layer (there is no lithium deposition around the lithium deposition point region) is measured to obtain the sum of the areas of all lithium deposition point regions S2. If S2 / S1≤5%, it is considered that the battery meets the 2C fast charging requirement (it can be understood that the ratio of S2 / S1 can be calculated by randomly sampling multiple negative electrode sheets and taking the average value, or by testing all negative electrode sheets in the battery and taking the average value). For another example, taking a battery with a charging rate of 4C as an example, in steps (i) to (iv), the charging current used is 4C, and the other operations and judgment criteria of the test method remain unchanged. Among them, the lithium deposition point area on the negative electrode active material layer and the area of ​​the lithium deposition point area can be identified and calculated by conventional technical means in this field. For example, the lithium deposition point area on the negative electrode active material layer can be judged in combination with naked eye observation and / or a magnifying display device (such as a microscope, an electronic camera and other conventional instruments). The area of ​​each lithium deposition point area can be measured by flattening the negative electrode sheet and measuring the maximum dimension a of each lithium deposition point (no lithium is deposited around the lithium deposition point) along the length direction of the negative electrode sheet, and the maximum dimension b along the width direction of the negative electrode sheet. A / 2 is used as the median value of the lithium deposition point area in the length direction of the negative electrode sheet, and b / 2 is used as the median value of the lithium deposition point area in the width direction of the negative electrode sheet. The area of ​​each lithium deposition point area is calculated by a×b / 4 to obtain the sum S2 of the areas of all lithium deposition point areas (the S2 value measured by this method is generally larger than the actual area of ​​the lithium deposition point area, tested); it can also be obtained by one or more conventional area measurement methods such as electronic scanning measurement method and grid estimation method.

[0063] It can be understood that when determining whether a battery is a fast-charging battery, the type of power supply device used is not particularly limited, as long as the power supply device can convert the external power supply into a power supply that is suitable for charging the battery. For example, taking an electronic device (such as a mobile phone, etc.) that uses the battery of the first aspect of this application as a power source as an example, the charging device may include but is not limited to the original charger of the electronic device; taking a vehicle (such as a car, etc.) that uses the battery of the first aspect of this application as a power source as an example, the charging device may include but is not limited to a charging pile.

[0064] In addition, with reference to Figures 1 to 6, the battery of the first aspect of the present application includes a battery cell 1, which includes a housing 11, at least one electrode assembly 12, and at least one buffer 13. The electrode assembly 12 and the buffer 13 are placed in the housing 11. The buffer 13 can be provided on at least a portion of the surface of the electrode assembly 12 and / or inside the electrode assembly 12. The at least one electrode assembly 12 and the at least one buffer 13 are stacked along a first direction. Exemplarily, the buffer 13 can be provided between the electrode assembly 12 and the housing 11 (for reference to Figure 2), and / or can be provided between two adjacent electrode assemblies 12 (for reference to Figure 3), and / or can be provided inside the electrode assembly (for reference to Figure 4). Among them, the buffer member 13 can be provided between the electrode assembly 12 and the shell 11, which can be understood as being provided in at least one of the areas between the electrode assembly 12 and the side wall of the shell 11, between the electrode assembly 12 and the bottom wall of the shell 11, and between the electrode assembly 12 and the top wall of the shell 11. Optionally, referring to FIG5 , it is understood that the buffer member 13 can be provided simultaneously between the electrode assembly 12 and the shell 11 and between two adjacent electrode assemblies 12; further optionally, referring to FIG2 and FIG3 , it is understood that the buffer member 13 can be provided on a partial surface of the electrode assembly 12, for example, only A buffer member 13 is provided on one side of the electrode assembly 12 along the first direction. As some specific examples, when the battery cell 1 includes only one electrode assembly 12, the buffer member 13 may be optionally provided on only one side of the electrode assembly 12 in the first direction (refer to FIG2 for understanding); as some other specific examples, when the battery cell 1 includes multiple electrode assemblies 12, the buffer member 13 may be optionally provided directly on only two adjacent electrode assemblies 12 in the first direction, and the electrode assemblies 12 and the buffer member 13 may be alternately stacked in the first direction (refer to FIG3 for understanding). The buffer 13 can be arranged inside the electrode assembly. It can be understood that when the electrode assembly 12 is a laminated structure, the buffer 13 can be located in the middle area of ​​the electrode assembly 12, that is, in the first direction, laminated units are distributed on both sides of the buffer 13, and the laminated units include a positive electrode sheet, a negative electrode sheet and a separator; 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, so that the positive electrode sheet, the negative electrode sheet and the separator are stacked and wound around the buffer 13 and formed. At this time, when the wound electrode assembly is used in a cylindrical battery cell, the first direction can be the radial direction of the electrode assembly (refer to Figure 6 for understanding). When the wound electrode assembly is used in a prismatic battery cell, the electrode assembly includes a straight portion and a corner portion after forming. The first direction can be the thickness direction of the straight portion (refer to Figure 4 for understanding) or the length direction, and can be optionally the thickness direction of the straight portion. In this application, the buffer 13 refers to a structural member that can undergo elastic deformation.In actual operation, both sides of the buffer member 13 along the thickness direction can be fitted with the electrode assembly 12 , or one side can be fitted with the electrode assembly 12 and the other side can be fitted with the inner wall of the shell 11 .

[0065] For fast-charging batteries with a charging rate greater than or equal to 2C, especially high-capacity fast-charging batteries, a large thermal effect will be generated during the charging process, and the heat dissipation demand is high. By setting a buffer, even if the buffer is not over-compressed, it is beneficial to achieve direct adhesion between the electrode assembly and the inner wall of the shell, or adhesion to the inner wall of the shell through the buffer or insulating film, which is not only beneficial to shortening the heat conduction path between the electrode assembly and the shell, but also beneficial to increase the relative heat dissipation area between the electrode assembly and the shell in the shortened part of the heat conduction path, that is, the contact heat exchange area between the electrode assembly and the shell can be increased, and the heat dissipation effect of the battery cell can be improved, thereby improving the cooling efficiency; further, the structure of at least one electrode assembly 12 and at least one buffer 13 in the battery cell 1 is stacked along the first direction, so that 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, thereby helping to further improve the cooling efficiency.

[0066] 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, and improving the heat dissipation efficiency and effect of the fast-charging battery.

[0067] 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.

[0068] Furthermore, the battery of the first aspect of the present application, while meeting the aforementioned conditions, may further improve the heat dissipation of the battery cells by further improving the buffer's placement and thermal conductivity, the relationship between the buffer's thermal conductivity and that of other structural components, and the placement of the cooling member. That is, in addition to meeting the aforementioned conditions, one or more of the following conditions may also be optionally met.

[0069] In some embodiments of the present application, a battery cell may be cylindrical or prismatic, or optionally prismatic. A prismatic battery cell may have a wound or laminated structure. Referring to FIG6 , when the battery cell is cylindrical, the first direction may be the radial direction of the electrode assembly. Referring to FIG7 , when the battery cell is prismatic, the first direction may be at least one of the x-, y-, and z-directions, that is, at least one of the length, thickness, and height directions of the housing. For example, in FIG2-4 , the first direction may be the thickness direction of the housing 11. For example, in FIG5 , the first direction may be the length direction of the housing 11. Furthermore, in FIG5 , the prismatic battery cell may include at least one first buffer member 13a and / or at least one second buffer member 13b. At least one of the first buffer member 13a and the second buffer member 13b may be stacked with at least one electrode assembly 12 along a first direction. Optionally, the first direction may be the same as the thickness direction of the electrode assembly 12.

[0070] In some embodiments of the present application, the charge rate of the battery may be greater than or equal to 4C.

[0071] For batteries with different fast charging capabilities, the thermal effects during the charge and discharge cycle are also different. Under the same charging capacity, the shorter the required charging time, the higher the charging heat generation, and the higher the requirements for battery heat dissipation. For fast-charging batteries with a charging rate greater than or equal to 4C, by building a buffer into the battery cell shell and providing the buffer on at least part of the surface of the electrode assembly and / or inside the electrode assembly, and at the same time stacking at least one electrode assembly and at least one buffer along a first direction, the fit between the electrode assembly and the shell can be significantly improved, the heat dissipation area can be increased, the heat conduction path of the electrode assembly can be shortened, and the heat dissipation efficiency and effect of the battery can be improved.

[0072] In some embodiments of the present application, a buffer member 13 may be provided between a portion of the surface of the electrode assembly 12 and the shell 11 .

[0073] Disposing a buffer 13 between the electrode assembly 12 and the housing 11 allows the surface of the electrode assembly in contact with the buffer 13 to indirectly contact the housing, buffering the electrode assembly's expansion force during charge and discharge, improving the battery's volumetric stability during charge and discharge cycles. Direct contact between the electrode assembly and the housing further improves heat dissipation within the battery cell. Disposing a buffer only between a portion of the electrode assembly's surface and the housing facilitates better contact and contact area between the electrode assembly and the housing, improving heat dissipation efficiency and effectiveness. Alternatively, as shown in FIG2 , when a battery cell 1 contains only one electrode assembly 12, the buffer 13 may be disposed only on one of the two opposing sides of the electrode assembly 12 along the first direction. In this case, the cooling member 6 may be disposed on the other side of the battery cell 1 along the first direction where the buffer 13 is not disposed. Alternatively, as shown in FIG3 , when a battery cell 1 contains multiple electrode assemblies 12, the buffer 13 may be disposed only between two adjacent electrode assemblies 12 along the first direction, with no buffer disposed between the electrode assembly 12 and the housing 11 along the first direction. This helps ensure that the electrode assembly always has a good fit with the shell during the charge and discharge cycle, which is further beneficial to increasing the heat dissipation area, shortening the heat conduction path, and improving the heat dissipation efficiency and effect of the battery.

[0074] In some embodiments of the present application, the thermal conductivity of the buffer member 13 disposed between the electrode assembly 12 and the housing 11 may be ≥3 W / (m·°C), and optionally may be ≥5 W / (m·°C).

[0075] Exemplarily, the thermal conductivity of the buffer 13 provided between the electrode assembly 12 and the shell 11 can be ≥3W / (m·℃), ≥5W / (m·℃), ≥10W / (m·℃), ≥15W / (m·℃), ≥20W / (m·℃), ≥25W / (m·℃), ≥30W / (m·℃), ≥35W / (m·℃), and so on, and can optionally be ≥5W / (m·℃). A higher thermal conductivity is conducive to quickly transferring heat from the battery cell and improving the heat dissipation effect of the battery cell. The thermal conductivity of the buffer can be measured with reference to GB / T 10295. Meeting the given range conditions can improve the thermal conductivity efficiency of the buffer and improve the heat dissipation effect of the battery cell.

[0076] In some embodiments of the present application, a buffer member 13 may be provided between two adjacent electrode assemblies 12 in a battery cell 1. Optionally, when a battery cell 1 includes multiple electrode assemblies 12, a buffer member 13 may be provided only between two adjacent electrode assemblies 12. With reference to FIG3 , this arrangement further facilitates ensuring that the electrode assembly always has a good fit with the housing during the charge and discharge cycle, thereby not only shortening the heat conduction path between the electrode assembly and the housing, but also increasing the relative heat dissipation area between the electrode assembly and the housing in the portion of the shortened heat conduction path, thereby improving the heat dissipation efficiency and effect of the battery.

[0077] In some embodiments of the present application, the thermal conductivity of the buffer member provided between two adjacent electrode assemblies 12 may be ≤0.05 W / (m·°C), and optionally may be ≤0.03 W / (m·°C).

[0078] For example, the thermal conductivity of the buffer member 13 provided between two adjacent electrode assemblies 12 can be ≤0.05W / (m·℃), ≤0.04W / (m·℃), ≤0.03W / (m·℃), ≤0.02W / (m·℃), ≤0.01W / (m·℃), ≤0.005W / (m·℃), and so on, and can optionally be ≤0.03W / (m·℃). A lower thermal conductivity is conducive to isolating heat conduction between battery assemblies and reducing the risk of failure of other electrode assemblies caused by failure of a single electrode assembly. Therefore, the above-mentioned setting is conducive to reducing the probability of thermal runaway of battery cells.

[0079] In some embodiments of the present application, a battery cell 1 may include at least two electrode assemblies 12. Each buffer member 13 in the battery cell 1 is independently disposed between two adjacent electrode assemblies 12 and is stacked with the electrode assemblies 12 along a first direction. This arrangement not only improves the fit between the electrode assembly and the housing, but also facilitates direct contact between the electrode assembly and the housing. This, in turn, not only shortens the heat conduction path between the electrode assembly and the housing, but also increases the contact and heat dissipation area between the electrode assembly and the housing in the portion of the heat conduction path that is shortened, thereby improving the heat dissipation efficiency and effectiveness of the battery.

[0080] In some embodiments of the present application, the electrode assembly 12 may further include a diaphragm, the thermal conductivity of the shell 11 may be greater than or equal to the thermal conductivity of the diaphragm, and the thermal conductivity of the diaphragm may be greater than or equal to the thermal conductivity of the buffer 13 .

[0081] Optionally, the thermal conductivity of the shell 11 can be greater than that of the diaphragm; further optionally, the thermal conductivity of the diaphragm can be greater than that of the buffer 13. The outermost layer of the electrode assembly is covered with a diaphragm. When no buffer is provided between the electrode assembly and the shell, the use of a shell and diaphragm that meet the given conditions can further improve the efficiency of heat transfer from the electrode assembly to the outside. Moreover, even if a buffer is provided between the electrode assembly and the shell, the use of a shell and diaphragm that meet the given conditions can also help improve the heat conduction between the electrode assembly and the shell itself. When a buffer is provided between the electrode assemblies, the use of a diaphragm that meets the given conditions can also help reduce heat conduction between battery assemblies, reducing the risk of failure of a single electrode assembly causing failure of other electrode assemblies. Therefore, ensuring that the thermal conductivity of the shell and diaphragm meets the given conditions is conducive to improving the heat dissipation efficiency and effect of the battery.

[0082] In some embodiments of the present application, the battery cell 1 may include two first surfaces 11a arranged opposite to each other along a first direction, and the area of ​​the first surface 11a is greater than or equal to the area of ​​a single surface among the other surfaces of the battery cell 1. In conjunction with Figure 1 , 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 the two first surfaces 11a arranged opposite to each other along the first direction is greater than or equal to the area of ​​a single surface among the remaining surfaces of the battery cell 1 on which it is located, the area of ​​the first surface 11a that can be arranged opposite to or in contact with the electrode assembly can be maximized compared to the other surfaces. This means that the total area of ​​the heat conduction path between the electrode assembly and the housing can be shortened to a larger area, thereby further increasing the total contact heat exchange area between the electrode assembly and the housing, and improving the heat dissipation efficiency and effect of the battery.

[0083] 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 is greater than or equal to 80% of the area of ​​the first surface 11 a .

[0084] For example, in conjunction with Figures 1 to 3, the area of ​​the orthographic projection of the buffer member 13 stacked with the electrode assembly 12 along the first direction on the first surface 11a can be 80%, 85%, 90%, 95%, 98%, etc. of the area of ​​the first surface 11a. In 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 orthographic projection of the buffer member on the first surface can be measured independently using conventional methods. For example, the area of ​​the first surface can be measured using direct measurement or colorimetry, and the area of ​​the orthographic projection of the buffer member on the first surface can be measured using direct measurement, segmentation and summation, projection area formula, or three-dimensional modeling software. The projected area of ​​the buffer on the first surface reflects, to a certain extent, the area in which the electrode assembly and the first surface can be arranged relative to or in contact with each other. The increase in the projected area is beneficial to increasing the area in which the electrode assembly and the first surface can be arranged relative to or in contact with each other, improving the fit between the electrode assembly and the shell, shortening the heat conduction path between the electrode assembly and the shell, and increasing the contact and heat dissipation area between the electrode assembly and the shell in the portion where the heat conduction path is shortened, so that the positive projection area of ​​the buffer on the first surface meets the given conditions, which is beneficial to further improve the heat dissipation efficiency and effect of the battery cell.

[0085] In some embodiments of the present application, the orthographic projection of the buffer member 13 stacked and adjacent to the electrode assembly 12 along the first direction on the first surface 11a can be located within the area of ​​the orthographic projection of the electrode assembly 12 on the first surface 11a, and the area of ​​the orthographic projection of the buffer member 13 on the first surface 11a can be greater than or equal to 80% of the area of ​​the orthographic projection of the electrode assembly 12 on the first surface 11a.

[0086] For example, referring to Figures 1-2 , the orthographic projection area of ​​the buffer member 13 stacked and adjacent to the electrode assembly 12 along the first direction on the first surface 11a can be greater than or equal to 80%, 85%, 90%, 95%, 100%, etc., of the orthographic projection area of ​​the electrode assembly 12 on the first surface 11a. Ensuring that the orthographic projections of the buffer member and the electrode assembly on the first surface meet the given conditions can be achieved by controlling the large surface area of ​​the buffer member and the relative positional relationship between the buffer member and the electrode assembly. Optionally, the large surface area of ​​the buffer member can be controlled to be less than or equal to the surface area of ​​the electrode assembly stacked therewith. The relative position and projected area of ​​the orthographic projection of the buffer member 13 on the first surface 11a and the orthographic projection of the electrode assembly 12 on the first surface reflect the overlap area between the buffer member 13 and the electrode assembly. Increasing this overlap area improves the fit between the electrode assembly and the housing, shortens the thermal path between the electrode assembly and the housing, and increases the contact and heat dissipation area between the electrode assembly and the housing in the portion of the shortened thermal path.

[0087] Ensuring that the orthographic projections of the buffer member and electrode assembly on the first surface meet the given conditions not only improves the fit between the electrode assembly and the housing, but also improves the uniformity of stress distribution within the battery cell during charge and discharge, thereby further improving the heat dissipation efficiency and volume stability of the battery cell during cycling. Furthermore, when the area of ​​a single first surface is greater than or equal to the area of ​​a single surface among the remaining surfaces of the battery cell in which it resides, it also helps maximize the area over which the electrode assembly and the housing are positioned relative to or in contact with each other. This shortens the heat conduction path between the electrode assembly and the housing, increasing the total area of ​​the shortened heat conduction path between the electrode assembly and the housing, thereby further increasing the total contact heat exchange area between the electrode assembly and the housing and improving the heat dissipation efficiency and effectiveness of the battery.

[0088] In some embodiments of the present application, the battery may include at least one cooling member 6, which may be disposed on at least one side of the battery cell along the first direction. It is understood that when the cooling member is disposed on at least one side of the battery cell along the first direction, the cooling member may be disposed in contact with or spaced apart from the at least one side of the battery cell along the first direction. The contact arrangement may include a situation where the two are in close contact (forceful interaction) or simply adjacent to each other. For example, the cooling member may be disposed on the surface of the battery cell along the first direction or spaced apart from the battery cell. That is, other components or the battery cell may be disposed between the cooling member and the battery cell. These other components may include, but are not limited to, adhesive (the cooling member and the battery cell may be fixed by adhesive). With reference to FIG7 , it can be understood that disposing the cooling member on at least one side of the battery cell along the first direction not only further shortens the heat conduction path between the electrode assembly and the cooling member in the first direction, but also increases the relative heat exchange area between the electrode assembly and the cooling member in the portion of the shortened heat conduction path in the first direction, thereby further improving the heat dissipation efficiency and effectiveness of the battery cell.

[0089] 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.

[0090] In some embodiments of the present application, a 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.

[0091] Referring to FIG8 , it can be understood that in a battery cell, the electrode assembly and the inner wall of the housing have a further improved fit and a further shortened heat conduction path in the first direction. This results in relatively good cooling efficiency and heat dissipation of the battery cell in the first direction. By stacking multiple battery cells along the first direction, the surfaces of the multiple battery cells with relatively good cooling efficiency and heat dissipation can be concentrated in the first direction. Furthermore, combined with the design of providing cooling members on at least one side of the battery cell along the first direction, such as providing cooling members on at least one side of each battery cell along the first direction, this not only further shortens the heat conduction path between the electrode assembly and the cooling member in the first direction and increases the relative heat exchange area between the electrode assembly and the cooling member in the portion of the shortened heat conduction path in the first direction, but also further increases the total relative heat exchange area between the entire first battery cell group and the cooling member by optimizing the number of cooling members and their relative positional relationship with the battery cell in the first direction, while also ensuring the overall integration of the battery cell and the cooling member. Optionally, a cooling member can be provided between any two adjacent battery cells stacked in the first direction in the first direction, thereby further increasing the total relative heat exchange area between the entire first battery cell group and the cooling member, improving cooling efficiency.

[0092] In some embodiments of the present application, the plurality of first battery cell groups A may be stacked along a second direction, where the second direction intersects the first direction.

[0093] With reference to Figures 9 and 10 , it can be understood that employing a stacked arrangement of multiple first battery cell groups along the second direction can also facilitate the simultaneous stacking of a single cooling member with multiple battery cells along the first direction. This, in turn, increases both the total heat exchange area between a single cooling member and a battery cell, as well as the total heat exchange area between all battery cells in the entire battery and the cooling member, while also balancing the overall integration of the battery cells and the cooling member. Optionally, the second direction can be perpendicular or substantially perpendicular to the first direction, where the angle between the second direction and the first direction can be 80 to 100 degrees, optionally 85 to 95 degrees, or even more optionally 88 to 92 degrees.

[0094] In some embodiments of the present application, the battery includes a first battery cell group A, and in the first direction, the cooling member 6 is disposed between two adjacent battery cells 1, and / or the cooling member 6 can be disposed on one side of the plurality of battery cells 1 along the first direction.

[0095] For example, referring to Figures 8 or 9 , for a battery structure having a first battery cell group A, the cooling member 6 can be positioned between two adjacent battery cells 1 in the first direction. This facilitates heat exchange between both sides of each cooling member along the first direction and the battery cell surface, thereby increasing the total heat exchange area between the entire first battery cell group and the cooling member. Optionally, the cooling members 6 and multiple battery cells 1 can be alternately stacked in the first direction, with each cooling member 6 independently positioned between two adjacent battery cells 1. This approach not only increases the total heat exchange area between the entire first battery cell group and the cooling member, shortens the heat conduction path, improves the heat dissipation efficiency of the battery, but also facilitates a simplified battery structure.

[0096] For example, referring to FIG10 , for a battery structure having a first battery cell group A, in a first direction, the cooling member 6 can be arranged on one side of the plurality of battery cells 1 along the first direction. This arrangement is beneficial to further increase the total heat exchange area between the battery cells distributed on both sides of the first direction and the cooling member, shorten the heat conduction path, and improve the heat dissipation efficiency of the battery.

[0097] For example, as understood in conjunction with Figures 8 to 10 , for a battery structure having a first battery cell group A, a portion of the cooling member 6 can be positioned between two adjacent battery cells 1 in the first direction, and another portion of the cooling member 6 can be positioned on one side of the plurality of battery cells 1 along the first direction. This arrangement facilitates heat exchange between both sides of each battery cell along the first direction, thereby further increasing the total heat exchange area between the entire first battery cell group and the cooling member, and improving the heat dissipation efficiency of the battery.

[0098] For battery structures including a single first battery cell group A, and structures including multiple first battery cell groups A stacked along the second direction, ensuring that the relative positional relationship between the cooling member and the battery cells satisfies the given conditions can help increase the total heat exchange area between the entire first battery cell group and the cooling member, shorten the heat conduction path, and improve the heat dissipation efficiency and effectiveness of the battery. Furthermore, when the battery cell includes two first surfaces arranged opposite each other along the first direction, and the area of ​​a single first surface is greater than or equal to the area of ​​a single surface among the other surfaces of the battery cell in which it is located, this can further help increase the total heat exchange area between the entire first battery cell group and the cooling member, particularly the total heat exchange area between the electrode assembly region, where the heat conduction path is shortened, and the cooling member, thereby further improving the heat dissipation efficiency and effectiveness of the battery.

[0099] 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 including a plurality of battery cells 1 stacked along a second direction, the second direction intersecting the first direction. Exemplarily, with reference to FIG11 , the battery may include only one second battery cell group B. Exemplarily, with reference to FIG12 , the battery may include a plurality of second battery cell groups B, optionally, the plurality of second battery cell groups B may be stacked along the first direction. The battery structure design with one or more second battery cell groups is also beneficial for taking into account both the heat dissipation efficiency of the battery cells and the integration of the battery cells. Optionally, the battery may include a plurality of first battery cell groups A and a plurality of second battery cell groups B at the same time. Optionally, as mentioned above, the second direction may be perpendicular or substantially perpendicular to the first direction.

[0100] In some embodiments of the present application, the battery may include a second battery cell group B, and in the first direction, the cooling member 6 may be arranged between two adjacent battery cells 1, and / or, the cooling member 6 may be arranged on one side of the plurality of battery cells 1 along the first direction.

[0101] For example, referring to FIG11 , when the battery includes only one second battery cell group B, only one cooling member 6 may be provided, with the cooling member 6 being located on one side of the second battery cell group B along the first direction. Alternatively, two cooling members 6 may be provided, with the two cooling members 6 being located on both sides of the second battery cell group B along the first direction. In the above arrangement, each cooling member 6 is independently provided on one side of the plurality of battery cells 1 along the first direction.

[0102] Exemplarily, referring to Figure 12, when the battery includes multiple second battery cell groups B, in the first direction, the cooling member 6 can be arranged between two adjacent battery cells 1. For example, in the first direction, the cooling member 6 can be alternately stacked with the multiple second battery cell groups B, and each cooling member 6 can be distributed independently between two adjacent second battery cell groups B. This is beneficial for each cooling member to exchange heat with the surfaces of multiple battery cells on both sides distributed along the first direction, thereby facilitating an increase in the total heat exchange area between the entire second battery cell group and the cooling member, and also facilitating a simplification of the battery structure.

[0103] For example, as understood in conjunction with Figures 11 and 12 , when the battery includes multiple second battery cell groups B, in the first direction, a portion of the cooling members 6 can be positioned between two adjacent battery cells 1, and another portion of the cooling members 6 can be positioned on one side of the multiple battery cells 1 along the first direction. This arrangement facilitates heat exchange between both sides of each battery cell along the first direction, thereby further increasing the total heat exchange area between the entire second battery cell group and the cooling member, thereby improving the heat dissipation efficiency of the battery.

[0104] Furthermore, when the battery cell 1 includes two first surfaces 11a arranged opposite to each other along a first direction, and the area of ​​a single first surface 11a is greater than or equal to the area of ​​a single surface among the other surfaces in the battery cell in which it is located, it is also beneficial to further increase the total heat exchange area between the entire second battery cell group and the cooling component, especially the total heat exchange area between the electrode assembly area where the heat conduction path is shortened and the cooling component, which is beneficial to further improve the heat dissipation efficiency and effect of the battery.

[0105] In some embodiments of the present application, in the first direction, a cooling member 6 may be provided between each of the plurality of battery cells 1. Referring to FIG. 8 or FIG. 12 , it can be understood that this arrangement further increases the total heat exchange area between all battery cells and the cooling member in the entire battery, thereby improving the heat dissipation efficiency and effectiveness of the battery.

[0106] 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 channels of multiple cooling components 6 may be arranged in parallel and / or in series.

[0107] It should be noted that the parallel arrangement refers to the cooling medium flow channels of multiple cooling components 6 being independent and disconnected from each other, while the series arrangement refers to the cooling medium flow channels of multiple cooling components 6 being connected at their inlets and outlets, and being directly or indirectly connected to each other. The arrangement of the direct cooling flow channels of multiple cooling components can be flexibly adjusted based on the stacking arrangement of the battery cells. For example, taking the first and second directions shown in FIG9 as an example, if the number of battery cells stacked in the second direction is large, the cooling medium flow channels of multiple cooling components can be arranged in parallel. If the number of battery cells stacked in the second direction is small, the cooling medium flow channels of multiple cooling components can be arranged in series. In addition, depending on the specific arrangement of the battery cells, the cooling medium flow channels of some cooling components can be arranged in series, while the cooling medium flow channels of the remaining cooling components can be arranged in parallel. This is more conducive to balancing the cooling effect of the battery and the reuse of the cooling medium.

[0108] In some embodiments of the present application, multiple cooling components 6 can be connected by a connector (not shown), and the cooling medium flow channels of two cooling components 6 adjacent and spaced apart in the first direction can be connected by the connector.

[0109] Exemplarily, the connector may be a cooling medium supply end and / or a cooling medium output end. The supply end and the output end may each independently be a delivery pipe or delivery panel. The inlets of the cooling medium flow channels of the multiple cooling components 6 may each independently be connected to the cooling medium supply end, and / or the outlets of the cooling medium flow channels of the multiple cooling components 6 may each independently be connected to the cooling medium output end. Alternatively, the connector may be a delivery pipe or delivery panel for connecting the cooling medium flow channels of two different cooling components end to end. This arrangement facilitates the filling and flow of the cooling medium in the different cooling medium flow channels, while also further increasing the contact area between the battery cells and the cooling medium, improving heat dissipation.

[0110] 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.

[0111] Alternatively, as can be understood with reference to Figures 1 and 8 , the second surface can be in contact with the cooling member; alternatively, both second surfaces can be in contact with the cooling member. Compared to radiative heat dissipation, direct contact between the surface of the battery cell and the cooling member can further shorten the heat conduction path and improve the heat dissipation efficiency and effectiveness of the battery cell.

[0112] Exemplarily, the contact area between the second surface and the cooling member 6 can be 80%, 85%, 90%, 95%, 100%, and so on, of the area of ​​the second surface. The contact area between the second surface and the cooling member 6 can be measured by conventional methods, such as direct measurement or colorimetry. Increasing the contact area between the battery cell surface and the cooling member can increase the heat exchange area, shorten the heat conduction path, and improve the heat dissipation efficiency and effect. Optionally, the area of ​​a single second surface can be greater than or equal to the area of ​​a single surface among the other remaining surfaces in the battery cell in which it is located, thereby maximizing the area of ​​the second surface that can be fitted with the cooling member compared to other surfaces, thereby further increasing the heat exchange area between the battery cell and the cooling member and improving the heat dissipation efficiency and effect of the battery.

[0113] 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.

[0114] 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 1 , and optionally greater than or equal to 25% of the total surface area of ​​the battery cell 1 .

[0115] For example, the total contact area between a single battery cell 1 and the cooling member 6 can be 20%, 25%, 30%, 35%, 40%, or the like, of the total surface area of ​​the battery cell 1, or any range thereof. The total contact area between a single battery cell and the cooling member refers to the sum of the contact areas between all surfaces of the battery cell and each cooling member. Increasing the total contact area between a single battery cell 1 and the cooling member 6 increases the heat exchange area, shortens the heat conduction path, and improves heat dissipation efficiency and effectiveness.

[0116] 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.

[0117] 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.

[0118] Exemplarily, the buffer component may be a single-layer structure, and its material may include but is not limited to at least one of foamed polyethylene, polypropylene, polyurethane, silicone rubber, etc.

[0119] Exemplarily, the buffer may be a multi-layer 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 its thickness direction. Optionally, the elastic modulus of the elastic buffer layer is smaller than the elastic modulus of the support layer, and / or, under the same pressure, the compressibility of the elastic buffer layer along its thickness direction is greater than the compressibility of the support layer along its thickness direction, 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% (which may be measured using conventional methods in the art). 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. Alternatively, 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 member, the ratio of the total thickness of the support layer to the free thickness of the elastic buffer layer may be 0.005 to 0.1, such as 0.02 to 0.05; the thickness of the elastic buffer layer in its natural state may be 0.2 mm to 10 mm, and the thickness of a single support layer may be 30 μm to 200 μm (which may be measured using conventional methods in the art); and the elastic buffer layer and the support layer may be bonded together. The free thickness of the elastic buffer layer refers to the thickness of the elastic buffer layer in its natural state, i.e., the thickness when not subjected to any external force. This can be measured using conventional instruments and methods in the art. For example, a Mitutoyo ID-C112MX micrometer thickness gauge (or similar instrument) may be used for testing under a test force of less than or equal to 1.8 N, and a plurality of random measurement points (e.g., 5, 10, etc.) may be measured to obtain an average value. The composite support layer and elastic buffer layer provide support for the elastic buffer layer, not only suppressing thermal shrinkage of the elastic buffer layer (such as thermal shrinkage during vacuum baking), but also optionally suppressing thermal shrinkage of the elastic buffer layer in a two-dimensional direction perpendicular to its thickness, thereby improving the problem of loss of its original function due to thermal shrinkage. It also improves the problem of material damage caused by mechanical stress in the buffer component during the later stages of battery use. Furthermore, placing the buffer component inside the battery cell can further improve the battery's volume stability during long-term use and enhance long-term performance.

[0120] In some embodiments of the present application, the electrode assembly 12 may include a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet, the negative electrode sheet, and the separator may be wound to form an electrode assembly. During the charge and discharge process of the battery, active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet. The separator is arranged between the positive electrode sheet and the negative electrode sheet to serve as an isolation. Among them, the specific structure, raw material composition, and thickness of the positive electrode sheet, the negative electrode sheet, and the separator can all be conventional choices in the field, and those skilled in the art can make choices based on actual needs.

[0121] 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.

[0122] The battery of the first aspect of the present application may include a battery cell 1 (refer to Figure 1 for understanding), a battery module 2 composed of battery cells 1 (refer to Figure 13 for understanding), or a battery pack 3 composed of battery cells 1 (refer to Figure 14 for understanding).

[0123] In some embodiments, the number of battery cells contained in the battery module may be one or more, and the specific number may be adjusted according to the application and capacity of the battery module. Figure 13 is a battery module 2 as an example. Referring to Figure 13, in the battery module 2, a plurality of battery cells 1 may be arranged in sequence along the length direction of the battery module 2, and the first direction may be one of the length direction, width direction and height direction of the battery module 2. Of course, it 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 accommodating space, and a plurality of battery cells 1 are accommodated in the accommodating space. It will be understood that when a cooling member 6 is included, the cooling member 6 is also accommodated in the accommodating space.

[0124] In some embodiments, the battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack. Referring to Figure 14 or Figure 15 (Figures 14 and 15 are battery packs 3 as an example), the battery pack 3 may include a battery box and a plurality of battery modules 2 disposed in the battery box. The battery box may include an upper box body 4 and a lower box body 5. The upper box body 4 can be covered on the lower box body 5 and form an enclosed space for accommodating the battery modules 2. The plurality of battery modules 2 can be arranged in the battery box in any manner.

[0125] In addition, the present application also provides an electrical device, which includes: the battery of the first aspect of the present application. The battery can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device. The electrical device may include but is not limited to mobile devices (such as mobile phones, laptops), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, and energy storage systems. With reference to Figure 16, as a specific example, the electrical device can be a vehicle. The electrical device can select the specific type of battery according to its usage requirements, such as a battery with a battery cell, a battery module or a battery pack.

[0126] 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.

[0127] As another example, the electrical device may be a mobile phone, a tablet computer, or a laptop computer. Such an electrical device is generally required to be lightweight and thin, and may use a battery cell in combination with a cooling member as a power source.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery, wherein: The charging rate of the battery is greater than or equal to 2C; the battery includes a battery cell, the battery cell includes a shell, at least one electrode assembly and at least one buffer component, the electrode assembly and the buffer component are placed in the shell, and the buffer component is provided on at least a portion of the surface of the electrode assembly and / or inside the electrode assembly; wherein, along a first direction, at least one electrode assembly and at least one buffer component are stacked.

2. The battery according to claim 1, wherein The charging rate of the battery is greater than or equal to 4C.

3. The battery according to claim 1 or 2, wherein The buffer member is provided between a portion of the surface of the electrode assembly and the shell.

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

5. The battery according to any one of claims 1 to 4, wherein In the battery cell, the buffer member is provided between two adjacent electrode assemblies.

6. The battery according to claim 5, wherein The thermal conductivity of the buffer member provided between two adjacent electrode assemblies is ≤0.05W / (m·°C), and can be optionally ≤0.03W / (m·°C).

7. 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.

8. The battery according to any one of claims 1 to 7, wherein The electrode assembly further includes a diaphragm, the thermal conductivity of the shell is greater than or equal to the thermal conductivity of the diaphragm, and the thermal conductivity of the diaphragm is greater than or equal to the thermal conductivity of the buffer.

9. The battery according to any one of claims 1 to 8, wherein The battery cell includes two first surfaces oppositely disposed along the first direction, and an area of the first surfaces is greater than or equal to an area of a single surface among other surfaces of the battery cell.

10. The battery according to claim 9, 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.

11. The battery according to claim 9 or 10, wherein The orthographic projection of the buffer member stacked and adjacent to the electrode assembly along the first direction on the first surface is located within the area of the orthographic projection of the electrode assembly on the first surface, and the area of the orthographic projection of the buffer member on the first surface is greater than or equal to 80% of the area of the orthographic projection of the electrode assembly on the first surface.

12. The battery according to any one of claims 1 to 11, wherein include: At least one cooling member is provided on at least one side of the battery cell along the first direction.

13. The battery according to claim 12, wherein include: At least one first battery cell group includes a plurality of the battery cells stacked along the first direction.

14. The battery according to claim 13, wherein A plurality of the first battery cell groups are stacked along a second direction, and the second direction intersects the first direction.

15. The battery according to claim 13 or 14, 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 the plurality of battery cells along the first direction.

16. The battery according to claim 15, wherein include: At least one second battery cell group includes a plurality of the battery cells stacked along a second direction intersecting the first direction.

17. The battery according to claim 16, 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 the plurality of battery cells along the first direction.

18. The battery according to any one of claims 12 to 17, wherein In the first direction, the cooling member is disposed between each of the plurality of battery cells.

19. The battery according to any one of claims 12 to 18, wherein A cooling medium flow channel is provided inside the cooling member, and the cooling medium flow channels of the plurality of cooling members are arranged in parallel and / or in series; and / or, The plurality of cooling members are connected via a connector, and the cooling medium flow channels of two cooling members 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 12 to 19, wherein The battery cell includes two second surfaces arranged opposite to each other along the first direction, at least one of the two second surfaces is in contact with the cooling member, and the contact area between the second surface and the cooling member is greater than or equal to 80% of the area of the second surface, and can be optionally 80-100% of the area of the second surface, and can be further optionally 90-100% of the area of the second surface.

21. The battery according to any one of claims 12 to 20, wherein 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.

22. An electrical device, wherein: A battery comprising the battery according to any one of claims 1 to 21.

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