Battery casing, battery shell, battery monomer and power-consuming device

Abstract

The present application provides a battery case, a battery shell, a battery cell and an electric device. The battery case includes a cylindrical side wall, the cylindrical side wall includes at least one barrel opening, the cylindrical side wall includes a first end, a second end opposite to the first end, and a waist located between the first end and the second end, and one barrel opening is located at the first end; along the direction from the first end to the waist of the cylindrical side wall, the cylindrical side wall includes a first rigidity zone and a second rigidity zone, the first rigidity zone is closer to the first end than the second rigidity zone, and the first rigidity zone has a smaller rigidity than the second rigidity zone.

Description

Technical Field

[0001] The present application relates to the technical field of secondary batteries, and in particular to a battery casing, a battery shell, a battery cell and an electrical device. Background Art

[0002] In recent years, as the application scope of secondary batteries has become more and more extensive, secondary batteries are widely used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, as well as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields. As secondary batteries have made great progress, higher requirements have been put forward for their energy density, cycle performance and safety performance. Summary of the invention

[0003] The present application is made in view of the above-mentioned problems, and its purpose is to provide a battery casing, which is used for a secondary battery and can effectively improve the lithium deposition of the secondary battery.

[0004] The first aspect of the present application provides a battery housing, comprising:

[0005] A cylindrical side wall, the cylindrical side wall comprising at least one barrel opening, the cylindrical side wall comprising a first end, a second end opposite to the first end, and a waist portion located between the first end and the second end, one of the barrel openings being located at the first end;

[0006] The cylindrical side wall meets one or more of the following characteristics:

[0007] [1] Along the direction from the first end to the waist, the cylindrical side wall includes a first stiffness zone and a second stiffness zone, the first stiffness zone is closer to the first end than the second stiffness zone, and the first stiffness zone has a smaller stiffness than the second stiffness zone;

[0008] [2] Along the direction from the second end to the waist, the cylindrical side wall includes a fourth stiffness zone and a fifth stiffness zone, the fourth stiffness zone is closer to the second end than the fifth stiffness zone; the fourth stiffness zone has smaller stiffness than the fifth stiffness zone.

[0009] The battery casing based on the above solution is used for a secondary battery, which can effectively improve the lithium deposition of the secondary battery.

[0010] In some embodiments, the battery housing described in any of the above items has one or more of the following features:

[0011] [1] The material of the first stiffness zone is a first material, the material of the second stiffness zone is a second material, and the stiffness of the first material is less than that of the second material;

[0012] [2] The material of the fourth stiffness zone is a fourth material, the material of the fifth stiffness zone is a fifth material, and the stiffness of the fourth material is smaller than that of the fifth material.

[0013] The battery casing based on the above solution is used for a secondary battery, which can further effectively improve the lithium deposition situation of the secondary battery.

[0014] In some embodiments, any of the above battery casings has one or more of the following features:

[0015] [1] The first stiffness zone has a first thickness, the second stiffness zone has a second thickness, and the first thickness is smaller than the second thickness.

[0016] [2] The fourth stiffness zone has a fourth thickness, the fifth stiffness zone has a fifth thickness, and the fourth thickness is smaller than the fifth thickness.

[0017] The battery casing based on the above solution is used for a secondary battery, which can effectively improve the lithium deposition of the secondary battery.

[0018] In some embodiments, the battery housing of any of the above items has one or more of the following features:

[0019] [1] The first rigidity zone includes a groove structure located on the surface of the cylindrical side wall;

[0020] [2] The fourth rigidity zone includes a groove structure located on the surface of the cylindrical side wall.

[0021] The battery casing based on the above solution is used for a secondary battery, which can effectively improve the lithium deposition of the secondary battery.

[0022] In some embodiments, in any of the above battery casings, the groove structure includes a groove array, and an extension direction of the groove array is substantially parallel to an edge of the first end.

[0023] The battery casing based on the above solution is used for a secondary battery, which can effectively improve the lithium deposition of the secondary battery, and the battery casing has a satisfactory structural strength.

[0024] In some embodiments, in any of the above battery casings, the groove structure is filled with a support body.

[0025] The battery casing based on the above solution is used for a secondary battery, which can effectively improve the lithium deposition of the secondary battery and effectively fix the position of the electrode assembly in the battery casing.

[0026] In some embodiments, the battery housing of any of the above items has one or more of the following features:

[0027] [1] The first rigidity zone includes a hollow structure located in the core of the cylindrical side wall;

[0028] [2] The fourth rigidity zone includes a hollow structure located in the core of the cylindrical side wall.

[0029] The battery casing based on the above solution is used for a secondary battery, which can effectively improve the lithium deposition of the secondary battery.

[0030] In some embodiments, in any of the above battery casings, the hollow structure is filled with a support.

[0031] The battery casing based on the above solution is used for a secondary battery, which can effectively improve the lithium plating of the secondary battery, and the battery casing has a satisfactory structural strength.

[0032] In some embodiments, the battery housing of any of the above items has one or more of the following features:

[0033] [1] The support body is made of elastic material;

[0034] [2] The support body is made of a porous material.

[0035] The battery casing based on the above solution is used for a secondary battery, which can effectively improve the lithium deposition of the secondary battery. At the same time, the support body provides good support for the electrode assembly or the hollow structure.

[0036] In some embodiments, the battery housing of any of the above items has one or more of the following features:

[0037] [1] The cylindrical side wall further includes a third rigidity zone, the third rigidity zone connecting the first rigidity zone and the first end, the first rigidity zone having a smaller rigidity than the third rigidity zone;

[0038] [2] The cylindrical side wall further includes a sixth stiffness zone, wherein the sixth stiffness zone connects the fourth stiffness zone and the second end, and the fourth stiffness zone has a smaller stiffness than the sixth stiffness zone.

[0039] The battery casing based on the above solution is used for a secondary battery, which can effectively improve the lithium plating of the secondary battery, and at the same time the secondary battery exhibits satisfactory structural strength.

[0040] In some embodiments, the battery housing of any of the above items has one or more of the following features:

[0041] [1] The ratio of the stiffness of the first stiffness zone to the stiffness of the second stiffness zone is 0.2-0.75:0.8-1.2, and may be 0.6-0.7:0.8-1.2;

[0042] [2] The stiffness ratio of the fourth stiffness zone to the fifth stiffness zone is 0.2-0.75:0.8-1.2, and can be optionally 0.6-0.7:0.8-1.2.

[0043] The battery casing based on the above solution is used for a secondary battery, which can effectively improve the lithium deposition of the secondary battery.

[0044] A second aspect of the present application provides a battery housing, comprising any one of the battery shells described above, wherein the battery housing further comprises an end plate, and the end plate seals the first end.

[0045] A third aspect of the present application provides a battery cell, comprising an electrode assembly and any one of the above battery casings, wherein the electrode assembly is accommodated in the battery casing.

[0046] A fourth aspect of the present application provides an electrical device, comprising any one of the above-mentioned battery cells, wherein the battery cell is used as a power source for the electrical device.

[0047] Effects of the Invention

[0048] One or more embodiments of the present invention have one or more of the following beneficial effects:

[0049] (1) The battery housing is used for secondary batteries (especially lithium-ion batteries), which can effectively improve the lithium deposition of lithium-ion batteries;

[0050] (2) The battery housing also has satisfactory structural strength;

[0051] (3) The electrode assembly can be well fixed in the battery case. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 Schematic diagram of a battery casing according to some embodiments of the present application.

[0053] Figure 2 (a) shows a perspective view of a battery cell according to some embodiments of the present application, Figure 2 (b) shows an exploded view of a battery cell according to some embodiments of the present application.

[0054] Figure 3 (a) and (b) show cross-sectional views of a battery cell in a non-expanded state and in an expanded state, respectively.

[0055] Figure 4 A schematic diagram showing a single side surface of a cylindrical side wall according to some embodiments of the present application.

[0056] Figure 5 (a) is a schematic diagram showing a partial surface of a cylindrical side wall according to some embodiments of the present application. Figure 5(b) shows a cross-sectional view of the cylindrical sidewall of some embodiments. Figure 5 (c) shows a cross-sectional view of the cylindrical sidewall of some embodiments. Figure 5 (d) shows a cross-sectional view of the cylindrical sidewall of some embodiments.

[0057] Figure 6 (a) and (b) respectively show cross-sectional views of the cylindrical side wall of some embodiments.

[0058] Figure 7 A schematic diagram showing a single side surface of a cylindrical side wall according to some embodiments of the present application.

[0059] Figure 8 A schematic diagram showing an electrical device in which a battery cell according to some embodiments of the present application is used as a power source.

[0060] Description of reference numerals:

[0061] Battery housing 51; battery casing 10; battery cell 1; power-consuming device 8;

[0062] Cylindrical side wall 100; end plate 121; cylinder bottom 122; first end 125; second end 126; waist 110; first rigidity zone 101; second rigidity zone 102; third rigidity zone 103; fourth rigidity zone 104; fifth rigidity zone 105; sixth rigidity zone 106; groove structure 111; hollow structure 112; groove array 113; support body 114 DETAILED DESCRIPTION

[0063] Below, the battery casing, battery housing, battery cell, and electrical device of the present application are described in detail with appropriate reference to the accompanying 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 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.

[0064] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 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 scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are 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.

[0065] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0066] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0067] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0068] 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.

[0069] 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).

[0070] Figure 1 The battery housing in some embodiments of the present application is shown.

[0071] refer to Figure 1 In some embodiments, the present application provides a cylindrical sidewall 100, the cylindrical sidewall 100 comprising at least one barrel opening, the cylindrical sidewall comprising a first end 125, a second end 126 opposite to the first end, and a waist 110 located between the first end and the second end, and one barrel opening is located at the first end 125;

[0072] The cylindrical side wall meets one or more of the following characteristics:

[0073] [1] Along the direction from the first end 125 to the waist 110, the cylindrical side wall 10 includes a first stiffness zone 101 and a second stiffness zone 102, the first stiffness zone 101 is closer to the first end 125 than the second stiffness zone 102, and the first stiffness zone 101 has a smaller stiffness than the second stiffness zone 102;

[0074] [2] Along the direction from the second end 126 to the waist 110, the cylindrical side wall 100 includes a fourth stiffness zone 104 and a fifth stiffness zone 105, the fourth stiffness zone 104 is closer to the second end 126 than the fifth stiffness zone 105; the fourth stiffness zone 104 has smaller stiffness than the fifth stiffness zone 105.

[0075] Stiffness refers to the ability of an object to resist elastic deformation when subjected to force. This means that the first stiffness zone 101 corresponding to the end of the electrode assembly 20 is more likely to deform after being subjected to force, thereby alleviating the greater squeezing force of the first stiffness zone 101 on the end of the electrode assembly 20 caused by structural factors, thereby improving the problem of insufficient electrolyte infiltration at the end of the electrode assembly 20, thereby improving the problem of lithium deposition at the end of the electrode assembly 20. The fourth stiffness zone 104 is symmetrical with the first stiffness zone 101 relative to the waist 10. Therefore, it can be understood that the fourth stiffness zone 104 is more likely to deform after being subjected to force, thereby alleviating the greater squeezing force of the fourth stiffness zone 104 on the end of the electrode assembly 20 caused by structural factors, thereby improving the problem of insufficient electrolyte infiltration at the end of the electrode assembly 20, thereby improving the problem of lithium deposition at the end of the electrode assembly 20. In the above scheme, as long as the cylindrical side wall meets one of the above characteristics [1] and [2], the lithium deposition of the battery can be effectively improved. Of course, if the cylindrical side wall satisfies both characteristics [1] and [2], the lithium deposition of the battery can be improved more effectively. Figure 3 The beneficial effects of the technical solution of the present application are analyzed in more detail.

[0076] In some embodiments, the term "waist" refers to a position between the first end 125 and the second end 126, for example, the center position of the first end 125 and the second end 126. For example, the distance between the first end 125 and the second end 126 is L, then the distance from the waist 110 to the first end 125 is L1, L1 = 0.4 ~ 0.6L, and the distance from the waist 110 to the first end 125 is L2, L2 = L-L1. Optionally, L1 = 0.5L.

[0077] In some embodiments, the term "cylindrical sidewall" refers to a sidewall that surrounds the perimeter. The cross-sectional shape formed by the surrounding of the cylindrical sidewall can be any closed shape, such as a circle, an ellipse, a rectangle, a square, a quadrilateral, a pentagon, a hexagon, etc.

[0078] In some embodiments, the term "rigidity" refers to the ability of a material or structure to resist elastic deformation when subjected to force. It is a characterization of the ease of elastic deformation of a material or structure. The stiffness of a material is usually measured by the elastic modulus E. Within the macroscopic elastic range, stiffness is the proportional coefficient that the load of a part is proportional to the displacement, that is, the force required to cause a unit displacement. In this application, stiffness and elastic modulus have the same meaning and are used interchangeably. The test of stiffness can refer to the general standards in this field, such as GBT22315-2008 Elastic modulus and Poisson's ratio test method for metal materials.

[0079] In some embodiments, it is effective to arrange the first stiffness zone 101 and the second stiffness zone 102 (and / or the fourth stiffness zone 104 and the fifth stiffness zone 105) on one or more side surfaces of the cylindrical side wall. For example, the first stiffness zone 101 and the second stiffness zone 102 (and / or the fourth stiffness zone 104 and the fifth stiffness zone 105) are arranged on one side surface of the cylindrical side wall. Optionally, the first stiffness zone 101 and the second stiffness zone 102 (and / or the fourth stiffness zone 104 and the fifth stiffness zone 105) are arranged on both side surfaces of the cylindrical side wall. Optionally, the cross-sectional shape formed by the cylindrical side wall 100 is a rectangle, and for the two long sides of the rectangle, the cylindrical side wall 100 includes two large faces arranged in parallel, and the first stiffness zone 101 and the second stiffness zone 102 (and / or the fourth stiffness zone 104 and the fifth stiffness zone 105) are arranged on both large faces. Optionally, a first rigidity zone 101 and a second rigidity zone 102 (and / or a fourth rigidity zone 104 and a fifth rigidity zone 105 ) are provided on each side surface of the cylindrical side wall.

[0080] Figure 2 (a) shows a perspective view of a battery cell according to some embodiments of the present application, Figure 2 (b) shows an exploded view of a battery cell according to some embodiments of the present application.

[0081] In some embodiments, reference Figure 2 (a), the battery cell 1 includes a battery housing 10, and the battery housing 10 includes an end plate 121 and a battery housing 51. The end plate 121 and the battery housing 10 enclose a receiving cavity. The battery housing 51 of the present application is used for the battery cell 1, which can effectively improve the lithium precipitation phenomenon of 20, and thus can improve the working performance of the battery cell 1. The following is a detailed analysis of the internal structure of the battery cell 1.

[0082] In some embodiments, reference Figure 2 (b), the end plate 121 can cover the first end 125 of the battery housing 51, thereby sealing the barrel mouth of the cylindrical side wall 100 and forming a closed accommodation cavity. The accommodation cavity is used to accommodate the electrode assembly 20.

[0083] In some embodiments, reference Figure 2 (b), the electrode assembly 20 includes a positive electrode sheet, a negative electrode sheet and a separator. The electrode assembly 20 can be formed by a winding process or a lamination process. The electrolyte is infiltrated in the electrode assembly 20. The number of electrode assemblies 20 contained in the battery cell 1 can be one or more, and those skilled in the art can select according to specific actual needs.

[0084] Figure 3 (a) and (b) are cross-sectional views of a battery cell in a non-expanded state and in an expanded state, respectively. Figure 2AA' cross-sectional view of the battery cell of (a). Figure 3 As shown in (a), when the unexpanded electrode assembly 20 is located in the battery housing 10, the electrode assembly 20 is substantially not squeezed by the battery housing 10. Figure 3 As shown in (b), during the cyclic charge and discharge process of the electrode assembly 10, especially after lithium is inserted into the negative electrode of the electrode assembly 20, the volume of the electrode assembly 20 will expand. The expanded electrode assembly 20 will be squeezed by the battery housing 10. The degree of squeezing force on different positions of the electrode assembly 20 is different.

[0085] like Figure 3 As shown by the arrows in (b), since the first end 125 and the second end 126 of the cylindrical side wall 100 are circumferentially connected to the end plate 121 and the bottom 122, respectively, the area of ​​the cylindrical side wall 100 close to the first end 125 and the second end 126 is a restricted end. In contrast, the waist 110 of the cylindrical side wall 100 is a free end. The first rigidity zone 101 is closer to the first end 125 restricted end than the second rigidity zone 102, and accordingly, the second rigidity zone 102 is closer to the second end 126 free end than the first rigidity zone 101. In this case, considering only structural factors, when the electrode assembly 20 expands, the first rigidity zone 101 will exert a greater extrusion force on the electrode assembly 20. The area of ​​the electrode assembly 20 corresponding to the first rigidity zone 101 is the end area. When the end area of ​​the electrode assembly 20 is subjected to a greater extrusion force, it is easy to cause insufficient electrolyte infiltration in the end area of ​​the electrode assembly 20, thereby causing lithium deposition at the end of the electrode assembly 20.

[0086] Continue to refer Figure 3 (b), in some embodiments, on the cylindrical side wall 10 of the battery housing 51, the first rigidity zone 101 is closer to the first end 125 than the second rigidity zone 102, and the first rigidity zone 101 has a smaller rigidity than the second rigidity zone 102. Rigidity refers to the ability of an object to resist elastic deformation when subjected to force. This means that the first rigidity zone 101 is more likely to deform after being subjected to force, thereby alleviating the greater squeezing force of the first rigidity zone 101 on the electrode assembly 20 caused by structural factors, thereby improving the problem of insufficient electrolyte infiltration at the end of the electrode assembly 20, and thereby improving the problem of lithium deposition at the end of the electrode assembly 20.

[0087] Symmetrically, continue to refer to Figure 3(b), in some embodiments, the cylindrical side wall 10 of the battery housing 51 further includes a fourth rigidity zone 104 and a fifth rigidity zone 105, the fourth rigidity zone 104 is closer to the second end 126 than the fifth rigidity zone 105; the fourth rigidity zone 104 has a smaller rigidity than the fifth rigidity zone 105. According to the symmetric relationship, the fourth rigidity zone 104 is symmetrical with the first rigidity zone 101 relative to the waist 110 of the cylindrical side wall 100, and the fifth rigidity zone 105 is symmetrical with the second rigidity zone 102 relative to the waist 110 of the cylindrical side wall 100. Based on the above principle, the fourth rigidity zone 104 is more likely to deform after being subjected to force, so that the greater squeezing force of the fourth rigidity zone 104 on the electrode assembly 20 caused by structural factors is alleviated, thereby improving the problem of insufficient electrolyte infiltration at the end of the electrode assembly 20, thereby improving the problem of lithium deposition at the end of the electrode assembly 20.

[0088] In some embodiments, the cylindrical sidewall 100 includes two openings, one opening is located at the first end 125 , and the other opening is located at the second end 126 .

[0089] refer to Figure 3 (a) and (b), in some embodiments, the battery housing 51 further includes a cylinder bottom 122, and the cylinder bottom 122 is circumferentially sealed and connected to the second end 126 of the cylindrical side wall 100.

[0090] In some embodiments, the ratio of the stiffness of the first stiffness zone 101 to the stiffness of the second stiffness zone 102 is 0.2-0.75:0.8-1.2, and can be optionally 0.6-0.7:0.8-1.2.

[0091] Symmetrically, in some embodiments, the ratio of the stiffness of the fourth stiffness zone 104 to the fifth stiffness zone 105 is 0.2-0.75:0.8-1.2, and can be optionally 0.6-0.7:0.8-1.2.

[0092] In some embodiments, the stiffness ratio of the first stiffness zone 101, the second stiffness zone 102, the fourth stiffness zone 104 and the fifth stiffness zone 105 is 0.2-0.75:0.8-1.2:0.2-0.75:0.8-1.2, and can be optionally 0.6-0.7:0.8-1.2:0.6-0.7:0.8-1.2.

[0093] Figure 4 A schematic diagram showing a single side surface of a cylindrical sidewall of some embodiments.

[0094] In some embodiments, the first stiffness zone 101 and the fourth stiffness zone 104 are symmetrical with respect to the waist 110; the second stiffness zone 102 and the fifth stiffness zone 105 are symmetrical with respect to the waist 110. The following description of the relationship between the first stiffness zone 101 and the second stiffness zone 102 can be symmetrically mapped to the fourth stiffness zone 104 and the fifth stiffness zone 105.

[0095] refer to Figure 4 In some embodiments, along the direction from the first end 125 to the waist 110, the cylindrical side wall 10 includes a first stiffness zone 101 and a second stiffness zone 102, the first stiffness zone 101 is closer to the first end 125 than the second stiffness zone 102, and the first stiffness zone 101 has a smaller stiffness than the second stiffness zone 102.

[0096] refer to Figure 4 In some embodiments, the material of the first rigidity zone 101 is a first material, the material of the second rigidity zone 102 is a second material, the rigidity of the first material is less than that of the second material, and the rigidity of the first material is less than that of the second material. In this embodiment, by adjusting the composition of the first material and the second material, such as the alloy composition, the technician can obtain materials with different rigidities. In this embodiment, by adjusting the material composition to obtain regions with different rigidities, the first rigidity zone and the second rigidity zone can have the same thickness and structure, and the battery housing has better structural consistency and stability.

[0097] In some embodiments, when it is mentioned that "the stiffness of the first material is less than that of the second material", it should be understood that this is a description of the intrinsic properties of the material, which has nothing to do with the shape and structure of the material. However, when it is mentioned that "the stiffness of the first stiffness zone is less than that of the second stiffness zone", it should be understood that this is a description of the comprehensive properties of the structure / material, which is related to the material, structure, and shape of the first stiffness zone / second stiffness zone.

[0098] In some embodiments, the material of the fourth stiffness zone 104 is a fourth material, the material of the fifth stiffness zone 105 is a fifth material, and the stiffness of the fourth material is smaller than that of the fifth material.

[0099] In some embodiments, the material of the fourth stiffness zone 104 is a fourth material, the material of the fifth stiffness zone 105 is a fifth material, and the stiffness of the fourth material is smaller than that of the fifth material.

[0100] Figure 5 (a) is a schematic diagram showing a partial surface of a cylindrical side wall of some embodiments. Figure 5 (b) shows a cross-sectional view (FF' section) of the cylindrical side wall of some embodiments. Figure 5(c) shows a cross-sectional view (FF' section) of the cylindrical side wall of some embodiments. Figure 5 (d) shows a cross-sectional view (FF' section) of the cylindrical side wall of some embodiments.

[0101] refer to Figure 5 (a), in some embodiments, the battery housing 51 includes: a cylindrical side wall 100, wherein the cylindrical side wall 100 includes a first end 125, a second end 126 opposite to the first end, and a waist 110 located between the first end 125 and the second end 126.

[0102] refer to Figure 5 (b), in some embodiments, the first rigidity zone 101 of the cylindrical side wall 100 has a first thickness, and the second rigidity zone 102 has a second thickness, and the first thickness is less than the second thickness. Since the rigidity of the structure is positively correlated with the thickness of the structure, that is, the rigidity of the structure increases with the increase of the thickness. In this embodiment, the thickness of the first rigidity zone 101 is less than that of the second rigidity zone, so the rigidity of the first rigidity zone 101 is less than that of the second rigidity zone. The battery housing based on this scheme is used for secondary batteries, which can improve the lithium deposition of secondary batteries. In this scheme, the rigidity of the first rigidity zone and the second rigidity zone can be adjusted by processing the thickness of the two, and this scheme has the beneficial effect of simple process.

[0103] Symmetrically, in some embodiments, the fourth rigidity zone 104 has a fourth thickness, the fifth rigidity zone 105 has a fifth thickness, and the fourth thickness is less than the fifth thickness. The battery housing based on this solution is used for a secondary battery, which can improve the lithium deposition of the secondary battery.

[0104] In some embodiments, the ratio of the thickness of the second rigidity zone to the thickness of the first rigidity zone is 3-5:1.

[0105] In some embodiments, the ratio of the thickness of the fifth rigidity zone to the thickness of the fourth rigidity zone is 3-5:1.

[0106] refer to Figure 5 (c), in some embodiments, the first rigidity zone 101 includes a groove structure 111 located on the surface of the cylindrical side wall 100. Since the rigidity of the structure is positively correlated with the thickness of the structure, that is, the rigidity of the structure increases with the increase of the thickness. In this embodiment, the first rigidity zone includes a groove structure 111 with a smaller thickness, so the rigidity of the first rigidity zone 101 is less than that of the second rigidity zone. The battery housing based on this solution is used for a secondary battery, which can improve the lithium deposition of the secondary battery.

[0107] refer to Figure 5(c), in some embodiments, the groove structure 111 includes a groove array 113, and the extension direction of the groove array 113 is perpendicular to the barrel opening direction of the cylindrical side wall 100. The groove array 113 is easier to deform in the barrel opening direction parallel to the cylindrical side wall 100, and the groove array 113 is more difficult to deform in the barrel opening direction perpendicular to the cylindrical side wall 100. The battery shell based on this solution is used for a secondary battery. On the one hand, it can relieve the squeezing force on the end of the electrode assembly, and on the other hand, it also has a satisfactory structural strength in the barrel opening direction perpendicular to the cylindrical side wall 100.

[0108] refer to Figure 5 (d), in some embodiments, the groove structure 111 is filled with a support body 114. The support body 114 can fix the electrode assembly 20 to prevent the electrode assembly 20 from shaking in the battery housing 51. The material of the support body can be an elastic material, such as rubber. The material of the support body can also be a porous material, such as a foam material, a honeycomb material, etc.

[0109] Figure 6 (a) and (b) respectively show cross-sectional views (FF' cross section) of the cylindrical side wall of some embodiments.

[0110] refer to Figure 6 (a), in some embodiments, the first rigidity zone 101 of the cylindrical side wall 100 includes a hollow structure 112. Since the rigidity of the structure is positively correlated with the thickness of the structure, that is, the rigidity of the structure increases with the increase of the thickness. In this embodiment, the hollow structure 112 causes the first rigidity zone 101 to have material missing in the thickness direction, which is essentially equivalent to a reduction in the thickness of the first rigidity zone, so the rigidity of the first rigidity zone 101 is less than that of the second rigidity zone. The battery housing based on this solution is used for secondary batteries, which can improve the lithium deposition of secondary batteries.

[0111] Symmetrically, in some embodiments, the first rigidity zone 104 of the cylindrical side wall 100 includes a hollow structure 112. The battery housing based on this solution is used for a secondary battery, which can improve the lithium deposition of the secondary battery.

[0112] refer to Figure 6 (b), the hollow structure 112 is filled with a support body 114. The support body 114 can support the hollow structure 112 to prevent the hollow structure 112 from deforming. The material of the support body 114 can be an elastic material, such as rubber. The material of the support body 114 can also be a porous material, such as a foam material, a honeycomb material, etc.

[0113] In some embodiments, the elastic material may have an elastic modulus at least as low as 1 GPa, or at least as low as 0.1 GPa, or at least as low as 0.01 GPa. In other embodiments, the elastic modulus of the elastic material may be at least as low as that of rubber.

[0114] In some embodiments, the porous material is a foam metal, such as foam nickel. The porous material can also be a honeycomb metal, such as honeycomb aluminum.

[0115] Figure 7 Schematic diagram showing a single side surface of a cylindrical section of some embodiments.

[0116] refer to Figure 7 In some embodiments, the cylindrical side wall 100 further includes a third rigidity zone 103, and the third rigidity zone 103 connects the first rigidity zone 101 and the first end 125; the first rigidity zone 101 has a smaller rigidity than the third rigidity zone 103. The function of the third rigidity zone 103 is to enhance the structural strength of the battery housing 51. In this embodiment, the third rigidity zone 103 is a zone directly connected to the first end 125. When the end plate 121 and the first end 125 are circumferentially connected, such as circumferentially welded, the third rigidity zone 103 connecting the first rigidity zone 101 and the first end 125 has a greater rigidity than the first rigidity zone 101, so that the first rigidity zone 101 has a smaller rigidity, and the secondary battery as a whole has a satisfactory structural stability.

[0117] refer to Figure 7 In some embodiments, the cylindrical side wall 100 further includes a sixth stiffness zone 106 , wherein the sixth stiffness zone 106 connects the fourth stiffness zone 104 and the second end 126 ; the fourth stiffness zone 105 has a smaller stiffness than the sixth stiffness zone 106 .

[0118] refer to Figure 7 In some embodiments, along the opening direction of the cylindrical side wall 100, the size of the third stiffness zone 103 is 1-5 mm.

[0119] refer to Figure 7 In some embodiments, along the direction of the opening of the cylindrical side wall 100, the size of the sixth stiffness zone 106 is 1-5 mm.

[0120] In some embodiments, along the opening direction of the cylindrical side wall 100 , the size of the first rigidity zone 101 is 5-10 mm.

[0121] In some embodiments, along the direction of the opening of the cylindrical sidewall 100 , the size of the fourth rigidity zone 104 is 5-10 mm.

[0122] refer to Figure 2 (a) and b, in some embodiments, the present application provides a battery housing 10, comprising any of the battery housings described above, the battery housing further comprising an end plate 121, the end plate 121 sealing the first end 125. The battery housing based on this solution is used for a secondary battery, which can improve the lithium deposition of the secondary battery.

[0123] refer to Figure 2 (a), in some embodiments, the present application provides a battery cell 1, including an electrode assembly 20 and a battery housing 51 as described in any one of the above items, wherein the electrode assembly 20 is accommodated in the battery housing 51.

[0124] In some embodiments, the battery cell is a secondary battery (eg, a lithium-ion secondary battery). A secondary battery, also known as a rechargeable battery or storage battery, refers to a battery that can be recharged to activate the active material after being discharged and continue to be used.

[0125] Typically, a secondary battery (such as a lithium-ion battery) includes a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte. During the battery charge and discharge process, active ions (such as lithium 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, and mainly plays the role of preventing the positive and negative electrodes from short-circuiting, while allowing active ions to pass through. The electrolyte is between the positive electrode sheet and the negative electrode sheet, and mainly plays the role of conducting active ions.

[0126] [Positive electrode]

[0127] The positive electrode sheet generally includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material.

[0128] As an example, the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0129] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0130] In some embodiments, the positive electrode active material may adopt a positive electrode active material for a battery that is well known in the art. As an example, the positive electrode active material may include at least one of the following materials: a lithium-containing phosphate with an olivine structure, a lithium transition metal oxide, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and its modified compounds, etc. Examples of lithium-containing phosphates with an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0131] In some embodiments, the positive electrode film layer may also optionally include a binder. As an example, the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.

[0132] In some embodiments, the positive electrode film layer may further include a conductive agent, for example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.

[0133] In some embodiments, the positive electrode sheet can be prepared in the following manner: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.

[0134] [Negative electrode]

[0135] The negative electrode sheet includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode film layer includes a negative electrode active material.

[0136] As an example, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0137] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, a copper foil may be used. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0138] In some embodiments, the negative electrode active material may adopt the negative electrode active material for the battery known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0139] In some embodiments, the negative electrode film layer may further include a binder. As an example, the binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).

[0140] In some embodiments, the negative electrode film layer may further include a conductive agent. As an example, the conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0141] In some embodiments, the negative electrode film layer may optionally include other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).

[0142] In some embodiments, the negative electrode sheet can be prepared in the following manner: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode collector, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained.

[0143] [Electrolytes]

[0144] The electrolyte plays the role of conducting ions between the positive electrode and the negative electrode. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. For example, the electrolyte can be liquid, gel or all-solid.

[0145] In some embodiments, the electrolyte is liquid and includes an electrolyte salt and a solvent.

[0146] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0147] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane sulfone, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.

[0148] In some embodiments, the electrolyte may further include additives. As examples, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.

[0149] [Isolation film]

[0150] In some embodiments, the secondary battery further includes a separator. The present application has no particular limitation on the type of separator, and any known porous separator with good chemical stability and mechanical stability can be selected.

[0151] In some embodiments, the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The isolation membrane can be a single-layer film or a multi-layer composite film, without particular limitation. When the isolation membrane is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0152] In some embodiments, the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.

[0153] In some embodiments, the secondary battery may include a housing that can be used to encapsulate the electrode assembly and the electrolyte.

[0154] In some embodiments, the housing of the secondary battery may be a hard housing, such as a hard plastic housing, an aluminum housing, a steel housing, or the like.

[0155] Figure 8 A schematic diagram showing an electrical device in which a battery cell according to some embodiments of the present application is used as a power source.

[0156] refer to Figure 8 In some embodiments, the present application provides an electric device 8, wherein the electric device comprises any one of the battery cells 1 described above, and the battery cell is used as a power source for the electric device.

[0157] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A battery housing, characterized in that: include A cylindrical side wall (100), the cylindrical side wall (100) comprising at least one barrel opening, the cylindrical side wall comprising a first end (125), a second end (126) opposite to the first end, and a waist (110) located between the first end and the second end, one barrel opening being located at the first end (125); The cylindrical side wall (100) satisfies one or more of the following characteristics: [1] Along the direction from the first end (125) to the waist (110), the cylindrical side wall (100) includes a first stiffness zone (101) and a second stiffness zone (102), the first stiffness zone (101) being closer to the first end (125) than the second stiffness zone (102), and the first stiffness zone (101) having a stiffness smaller than that of the second stiffness zone (102); [2] Along the direction from the second end (126) to the waist (110), the cylindrical side wall (100) includes a fourth stiffness zone (104) and a fifth stiffness zone (105), wherein the fourth stiffness zone (104) is closer to the second end (126) than the fifth stiffness zone (105); and the fourth stiffness zone (104) has a smaller stiffness than the fifth stiffness zone (105).

2. The battery housing according to claim 1, characterized in that: Have one or more of the following characteristics: [1] The material of the first stiffness zone (101) is a first material, the material of the second stiffness zone (102) is a second material, and the stiffness of the first material is smaller than that of the second material; [2] The material of the fourth stiffness zone (104) is a fourth material, the material of the fifth stiffness zone (105) is a fifth material, and the stiffness of the fourth material is smaller than that of the fifth material.

3. The battery housing according to claim 1, characterized in that: Have one or more of the following characteristics: [1] The first stiffness zone (101) has a first thickness, the second stiffness zone (102) has a second thickness, and the first thickness is smaller than the second thickness; [2] The fourth stiffness zone (104) has a fourth thickness, the fifth stiffness zone (105) has a fifth thickness, and the fourth thickness is smaller than the fifth thickness.

4. The battery casing according to claim 2, characterized in that: Have one or more of the following characteristics: [1] The first stiffness zone (101) has a first thickness, the second stiffness zone (102) has a second thickness, and the first thickness is smaller than the second thickness; [2] The fourth stiffness zone (104) has a fourth thickness, the fifth stiffness zone (105) has a fifth thickness, and the fourth thickness is smaller than the fifth thickness.

5. The battery case according to any one of claims 1 to 4, characterized in that: Have one or more of the following characteristics: [1] The first rigidity zone (101) comprises a groove structure (111) located on the surface of the cylindrical side wall (100); [2] The fourth stiffness zone (104) includes a groove structure (111) located on the surface of the cylindrical side wall (100).

6. The battery casing according to claim 5, characterized in that: The groove structure (111) comprises a groove array (113), and the extension direction of the groove array (113) is substantially parallel to the edge of the first end (125).

7. The battery case according to claim 5, characterized in that: The groove structure (111) is filled with a support body (114).

8. The battery case according to claim 6, characterized in that: The groove structure (111) is filled with a support body (114).

9. The battery casing according to claim 1, characterized in that: Have one or more of the following characteristics: [1] The first rigidity zone (101) comprises a hollow structure (112) located in the core of the cylindrical side wall (100); [2] The fourth stiffness zone (104) includes a hollow structure (112) located in the core of the cylindrical side wall (100).

10. The battery casing according to claim 9, characterized in that: The hollow structure (112) is filled with a support body (114).

11. The battery housing according to claim 7, characterized in that: Have one or more of the following characteristics: [1] The support body (114) is made of elastic material; [2] The support body (114) is made of a porous material.

12. The battery casing according to claim 8, characterized in that: Have one or more of the following characteristics: [1] The support body (114) is made of elastic material; [2] The support body (114) is made of a porous material.

13. The battery housing according to claim 10, characterized in that: Have one or more of the following characteristics: [1] The support body (114) is made of elastic material; [2] The support body (114) is made of a porous material.

14. The battery casing according to claim 1, characterized in that: Have one or more of the following characteristics: [1] The cylindrical side wall (100) further comprises a third rigidity zone (103), wherein the third rigidity zone (103) connects the first rigidity zone (101) and the first end (125), and the first rigidity zone (101) has a smaller rigidity than the third rigidity zone (103); [2] The cylindrical side wall (100) further includes a sixth stiffness zone (106), wherein the sixth stiffness zone (106) connects the fourth stiffness zone (104) and the second end (126), and the fourth stiffness zone (104) has a smaller stiffness than the sixth stiffness zone (106).

15. The battery casing according to claim 1, characterized in that: Have one or more of the following characteristics: [1] A ratio of the stiffness of the first stiffness zone (101) to the stiffness of the second stiffness zone (102) is 0.2-0.75:0.8-1.2; [2] A ratio of the stiffness of the fourth stiffness zone (104) to that of the fifth stiffness zone (105) is 0.2~0.75:0.8~1.

2.

16. The battery casing according to claim 15, characterized in that: Have one or more of the following characteristics: [1] A ratio of stiffness of the first stiffness zone (101) to that of the second stiffness zone (102) is 0.6-0.7:0.8-1.2; [2] A ratio of the stiffness of the fourth stiffness zone (104) to that of the fifth stiffness zone (105) is 0.6-0.7:0.8-1.

2.

17. A battery casing, comprising the battery housing according to any one of claims 1 to 16, the battery casing further comprising an end plate (121), wherein the end plate (121) seals the first end (125).

18. A battery cell, comprising an electrode assembly (20) and a battery casing according to any one of claims 1 to 16, wherein the electrode assembly (20) is accommodated in the battery casing.

19. An electrical device, characterized in that: The invention comprises the battery cell (1) as claimed in claim 18, wherein the battery cell (1) is used as a power source for the electrical device (8).

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