Battery case, battery cell, battery device, and electric device

Abstract

The application discloses a battery shell, a battery monomer, a battery device and a power utilization device. The battery shell comprises a shell body and an insulating coating. The shell body comprises a first side wall, a second side wall and a connecting part. The first side wall is arranged at an angle with the second side wall. The connecting part connects the first side wall and the second side wall. The insulating coating is arranged on the outer surface of the shell body and comprises a first insulating part, a second insulating part and a third insulating part. The first insulating part is arranged on the first side wall. The second insulating part is arranged on the second side wall. The third insulating part is arranged on the connecting part. The thickness of the third insulating part is greater than the thickness of the first insulating part and / or the thickness of the third insulating part is greater than the thickness of the second insulating part. According to the battery shell, the insulating protection effect of the third insulating part on the connecting part can be improved, so that the risk of insulation failure at the connecting part can be effectively avoided, the insulating protection performance of the insulating coating is improved, and the safety performance of the battery shell is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery casing, a battery cell, a battery device, and an electrical device. Background Technology

[0002] With the continuous development of the new energy industry, the application fields of batteries are also increasing. To prevent short circuits during the use of multiple batteries, insulation structures are typically installed on the battery casing. However, the insulation structures in these technologies have a high risk of failure, directly affecting the safety of battery use. Utility Model Content

[0003] The first aspect of this application proposes a battery casing that has the advantage of high safety performance.

[0004] A battery casing according to a first aspect of this application includes: a casing body, the casing body including a first sidewall, a second sidewall, and a connecting portion, the first sidewall and the second sidewall being disposed at an angle, and the connecting portion connecting the first sidewall and the second sidewall; and an insulating coating disposed on the outer surface of the casing body and including a first insulating portion, a second insulating portion, and a third insulating portion, the first insulating portion being disposed on the first sidewall, the second insulating portion being disposed on the second sidewall, the third insulating portion being disposed on the connecting portion, and the thickness of the third insulating portion being greater than the thickness of the first insulating portion and / or the thickness of the third insulating portion being greater than the thickness of the second insulating portion.

[0005] According to the battery casing of the first aspect of this application, the thickness of the third insulating portion is greater than the thickness of the first insulating portion and / or the thickness of the third insulating portion is greater than the thickness of the second insulating portion. This can improve the insulation protection effect of the third insulating portion at the connection portion, thereby effectively avoiding the risk of insulation failure at the connection portion, improving the insulation protection performance of the insulating coating, and thus improving the safety performance of the battery casing.

[0006] In some embodiments of this application, the thickness of the first insulating portion is T1, the thickness of the second insulating portion is T2, and the thickness of the third insulating portion is T3; wherein, 2≤T3 / T1≤10; and / or, 2≤T3 / T2≤10; and / or, 30μm≤T3-T1≤300μm; and / or, 30μm≤T3-T2≤300μm.

[0007] In some embodiments of this application, 3≤T3 / T1≤5; and / or, 3≤T3 / T2≤5; and / or, 40μm≤T3-T1≤150μm; and / or, 40μm≤T3-T2≤150μm.

[0008] In some embodiments of this application, the thickness T0 of the insulating coating satisfies: 50μm≤T0≤5000μm; and / or, the thickness T1 of the first insulating portion satisfies: 50μm≤T1≤200μm; and / or, the thickness T2 of the second insulating portion satisfies: 50μm≤T2≤200μm; and / or, the thickness T3 of the third insulating portion satisfies: 80μm≤T3≤450μm; and / or, the thickness t0 of the shell body satisfies: 100μm≤t0≤800μm.

[0009] In some embodiments of this application, the thickness T0 of the insulating coating satisfies: 75μm≤T0≤2500μm; and / or, the thickness T1 of the first insulating portion satisfies: 75μm≤T1≤100μm; and / or, the thickness T2 of the second insulating portion satisfies: 75μm≤T2≤100μm; and / or, the thickness T3 of the third insulating portion satisfies: 100μm≤T3≤225μm; and / or, the thickness t0 of the shell body satisfies: 125μm≤t0≤400μm.

[0010] In some embodiments of this application, the maximum thickness of the insulating coating is T01, and the minimum thickness of the insulating coating is T02; wherein, T01 and T02 satisfy: 0 < T01 - T02 ≤ 5000 μm; and / or, T01 and T02 satisfy: T01 / T02 ≤ 3.

[0011] In some embodiments of this application, T01 and T02 satisfy: 0 < T01 - T02 ≤ 2500 μm; and / or, T01 / T02 ≤ 1.5.

[0012] In some embodiments of this application, the third insulating portion includes an underlayer coating, the underlayer coating connecting the first insulating portion and the second insulating portion, and the first insulating portion, the second insulating portion and the underlayer coating each include an attachment layer and an outer insulating layer, wherein, in any one of the first insulating portion, the second insulating portion and the underlayer coating, the attachment layer is located between the shell body and the outer insulating layer.

[0013] In some embodiments of this application, the adhesion layer comprises at least one of polyurethane, methyl acrylate, ethyl acrylate, and butyl acrylate; and / or, the outer insulating layer comprises at least one of epoxy resin and acrylate.

[0014] In some embodiments of this application, the thickness of the attachment layer is t1, and the thickness of the outer insulation layer is t2; wherein t1 and t2 satisfy: 10μm≤|t2—t1|≤150μm; and / or, the thickness of the shell body is t0, and t0, t1 and t2 satisfy: 0.0125≤|t2—t1| / t0≤1.5.

[0015] In some embodiments of this application, t1 and t2 satisfy: 15μm≤|t2—t1|≤75μm; and / or, the thickness of the shell body is t0, and t0, t1 and t2 satisfy: 0.015≤|t2—t1| / t0≤0.75.

[0016] In some embodiments of this application, the third insulating portion further includes an insulating reinforcement layer disposed on the side of the bottom coating away from the shell body and covering at least a portion of the connecting portion.

[0017] In some embodiments of this application, the insulating reinforcement layer is made of the same material as the outer insulating layer.

[0018] In some embodiments of this application, the insulating reinforcement layer is made of a different material than the outer insulating layer.

[0019] In some embodiments of this application, the insulating reinforcement layer is an adhesive layer; and / or, the insulating reinforcement layer and the underlying coating are an integral structure.

[0020] In some embodiments of this application, the insulating reinforcement layer at least covers a portion of the first insulating portion; and / or, the insulating reinforcement layer at least covers a portion of the second insulating portion; and / or, the first insulating portion, the second insulating portion, and the bottom coating are integrally coated on the outer surface of the shell body.

[0021] In some embodiments of this application, the shell body is cylindrical, the outer peripheral wall of the shell body constitutes the second sidewall, a limiting groove is formed on the outer peripheral surface of the second sidewall, the insulating coating further includes an insulating filling portion, the insulating filling portion is disposed in the limiting groove, and the second insulating portion is located on the outer peripheral side of the insulating filling portion and covers the insulating filling portion.

[0022] In some embodiments of this application, the insulating filler is an adhesive layer; and / or, the insulating filler and the second insulating part are an integral structure; and / or, the thickness T2 of the second insulating part and the thickness T4 of the insulating filler satisfy: 300μm≤T2+T4≤4000μm; and / or, along the radial direction of the shell body, the depth of the insulating filler is the same as the depth of the limiting groove, and the outer peripheral surface of the insulating filler is flush with the outer peripheral surface of the shell body.

[0023] In some embodiments of this application, the thickness T2 of the second insulating portion and the thickness T4 of the insulating filling portion satisfy: 400μm≤T2+T4≤2000μm.

[0024] In some embodiments of this application, the connecting portion is one of a right-angle structure, an obtuse-angle structure, an acute-angle structure, or a circular arc structure.

[0025] The second aspect of this application proposes a battery cell.

[0026] A battery cell according to a second aspect of this application includes: a battery casing as described in the first aspect of the application; and an electrode assembly disposed within the battery casing.

[0027] According to the battery cell of the second aspect of this application, the thickness of the third insulating portion is greater than the thickness of the first insulating portion and / or the thickness of the third insulating portion is greater than the thickness of the second insulating portion. This can improve the insulation protection effect of the third insulating portion at the connection portion, thereby effectively avoiding the risk of insulation failure at the connection portion, improving the insulation protection performance of the insulating coating, and thus improving the safety performance of the battery casing. The third aspect of this application proposes a battery device.

[0028] A battery device according to a third aspect of this application includes: a housing; and a plurality of battery cells described in the second aspect of the present application, wherein the battery cells are disposed within the housing.

[0029] According to the battery device of the third aspect of this application, the thickness of the third insulating portion is greater than the thickness of the first insulating portion and / or the thickness of the third insulating portion is greater than the thickness of the second insulating portion. This can improve the insulation protection effect of the third insulating portion at the connection portion, thereby effectively avoiding the risk of insulation failure at the connection portion, improving the insulation protection performance of the insulating coating, and thus improving the safety performance of the battery casing.

[0030] The fourth aspect of this application discloses an electrical device.

[0031] The electrical device according to the fourth aspect of this application includes: the battery device described in the third aspect of the present application.

[0032] According to the electrical device of the fourth aspect of this application, the thickness of the third insulating part is greater than the thickness of the first insulating part and / or the thickness of the third insulating part is greater than the thickness of the second insulating part. This can improve the insulation protection effect of the third insulating part at the connection part, thereby effectively avoiding the risk of insulation failure at the connection part, improving the insulation protection performance of the insulating coating, and thus improving the safety performance of the battery casing.

[0033] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a battery casing according to an embodiment of this application; Figure 2 This is a cross-sectional view of the battery casing according to an embodiment of this application; Figure 3 yes Figure 2 Enlarged view of region A in the middle; Figure 4 yes Figure 2 Enlarged view of region B in the middle; Figure 5 This is a schematic diagram of the insulating coating and the casing body of the battery casing according to an embodiment of this application; Figure 6 This is a schematic diagram of a battery cell according to an embodiment of this application; Figure 7 This is a schematic diagram of a battery device according to an embodiment of this application.

[0035] Figure label: 1000, Battery device; 100. Battery cell; 200. Housing; 10. Battery casing; 1. Casing body; 11. First sidewall; 12. Second sidewall; 13. Connecting part; 14. Limiting groove; 2. Insulating coating; 20a. Adhesive layer; 20b. Outer insulating layer; 21. First insulating part; 22. Second insulating part; 23. Third insulating part; 231. Undercoat coating; 232. Insulating reinforcement layer; 24. Insulating filling part; 20. Terminal post. Detailed Implementation

[0036] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0037] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0038] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0039] In the description of this application, "multiple" means two or more.

[0040] The battery casing 10 according to a first aspect embodiment of the present application is described below with reference to the accompanying drawings.

[0041] like Figures 1 to 3 As shown, the battery casing 10 according to a first aspect embodiment of this application includes: a casing body 1 and an insulating coating 2. The casing body 1 includes a first sidewall 11, a second sidewall 12, and a connecting portion 13. The first sidewall 11 and the second sidewall 12 are arranged at an angle, and the connecting portion 13 connects the first sidewall 11 and the second sidewall 12. That is, one end of the connecting portion 13 is connected to the first sidewall 11, and the other end of the connecting portion 13 is connected to the second sidewall 12. The first sidewall 11 and the second sidewall 12 are connected as a whole through the connecting portion 13. The insulating coating 2 is disposed on the outer surface of the casing body 1 and includes a first insulating portion 21, a second insulating portion 22, and a third insulating portion 23. The thickness of the third insulating portion 23 is greater than the thickness of the first insulating portion 21 and / or the thickness of the third insulating portion 23 is greater than the thickness of the second insulating portion 22.

[0042] In related technologies, during the coating process of the insulating coating, the shape of the outer surface of the connecting part can affect the third insulating part, which may result in gaps (i.e., exposed outer surface of the casing body), leading to the risk of insulation failure. In other words, the thickness of the portion of the insulating coating 2 located at the connecting part 13 is greater than the thickness of the portion of the insulating coating 2 located on the first sidewall 11 and / or greater than the thickness of the portion of the insulating coating 2 located on the second sidewall 12. The greater thickness can improve the insulation protection effect of the third insulating part 23 at the connecting part 13, thereby effectively avoiding the risk of insulation failure at the connecting part 13, improving the insulation protection performance of the insulating coating 2, and ultimately improving the safety performance of the battery casing 10.

[0043] It should be noted that the thickness of the third insulating part 23 may be greater than the thickness of the first insulating part 21; or the thickness of the third insulating part 23 may be greater than the thickness of the second insulating part 22; or the thickness of the third insulating part 23 may be greater than the thickness of the first insulating part 21 and the thickness of the third insulating part 23 may be greater than the thickness of the second insulating part 22.

[0044] According to the battery casing 10 of the first aspect of this application, the thickness of the third insulating portion 23 is greater than the thickness of the first insulating portion 21 and / or the thickness of the third insulating portion 23 is greater than the thickness of the second insulating portion 22. This can improve the insulation protection effect of the third insulating portion 23 on the connection portion 13, thereby effectively avoiding the risk of insulation failure at the connection portion 13, improving the insulation protection performance of the insulating coating 2, and thus improving the safety performance of the battery casing 10.

[0045] In some embodiments of this application, the thickness of the first insulating portion 21 is T1, the thickness of the second insulating portion 22 is T2, and the thickness of the third insulating portion 23 is T3, wherein 2≤T3 / T1≤10; and / or, 2≤T3 / T2≤10; and / or, 30μm≤T3-T1≤300μm; and / or, 30μm≤T3-T2≤300μm. This avoids the risk of breakage or even detachment at the connection between the third insulating portion 23 and the first insulating portion 21 and the second insulating portion 22 due to excessive thickness differences. Simultaneously, it avoids the risk that insufficient thickness of the third insulating portion 23 will affect the insulation protection effect on the connecting portion 13, thereby improving the insulation protection performance of the third insulating portion 23.

[0046] In some embodiments of this application, 3≤T3 / T1≤5; and / or, 3≤T3 / T2≤5; and / or, 40μm≤T3-T1≤150μm; and / or, 40μm≤T3-T2≤150μm. Therefore, the thickness difference between the third insulating portion 23 and the first insulating portion 21 and the second insulating portion 22 can be effectively controlled to avoid the risk of breakage or even detachment at the connection between the third insulating portion 23 and the first insulating portion 21 and the second insulating portion 22, thereby ensuring a firm connection between the insulating coating 2 and the shell body 1.

[0047] In some embodiments of this application, the thickness T0 of the insulating coating 2 satisfies: 50μm ≤ T0 ≤ 5000μm. If the insulating coating 2 is too thin, its voltage withstand capability is too low, making it susceptible to breakdown and puncture, thus increasing the risk of failure. Conversely, if the insulating coating 2 is too thick, it occupies more space in the thickness direction of the casing body 1, resulting in an excessively large overall size of the battery casing 10, which is detrimental to controlling the size of the battery casing 10 and also increases production costs. Therefore, by controlling the thickness of the insulating coating 2 within the range of 50μm to 5000μm, the risk of insulation failure due to an excessively thin insulating coating 2 can be avoided, while the excessive size of the battery casing 10 and increased production costs due to an excessively thick insulating coating 2 can also be avoided. This allows for control of the size and production cost of the battery casing 10 while ensuring the insulating protective performance of the insulating coating 2. The thickness of the insulating coating 2 can be 50μm, 100μm, 200μm, 500μm, 1000μm, 2000μm, 3000μm, 4000μm, 5000μm, etc., and no specific limitation is made here.

[0048] In some embodiments of this application, the thickness T1 of the first insulating portion 21 satisfies: 50μm ≤ T1 ≤ 200μm. If the thickness of the first insulating portion 21 is too thin, its voltage withstand capability is too low, making it susceptible to breakdown and puncture, thus increasing the risk of failure. Conversely, if the thickness of the first insulating portion 21 is too thick, the space occupied in the thickness direction of the casing body 1 increases, resulting in an excessively large overall size of the battery casing 10, which is detrimental to controlling the size of the battery casing 10 and also increases production costs. Therefore, by controlling the thickness of the first insulating portion 21 within the range of 50μm to 200μm, the risk of insulation failure due to an excessively thin first insulating portion 21 can be avoided, while the excessive size of the battery casing 10 and increased production costs due to an excessively thick first insulating portion 21 can be avoided. This allows for control of the size and production cost of the battery casing 10 while ensuring the insulation protection performance of the first insulating portion 21. The thickness of the first insulating part 21 can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 120μm, 150μm, 180μm, 200μm, etc., and no specific limitation is made here.

[0049] In some embodiments of this application, the thickness T2 of the second insulating portion 22 satisfies: 50μm ≤ T2 ≤ 200μm. If the thickness of the second insulating portion 22 is too thin, its voltage withstand capability is too low, making it susceptible to breakdown and puncture, thus increasing the risk of failure. Conversely, if the thickness of the second insulating portion 22 is too thick, the space occupied in the thickness direction of the casing body 1 increases, resulting in an excessively large overall size of the battery casing 10. This is detrimental to controlling the size of the battery cell 100 and also increases production costs. Therefore, by controlling the thickness of the second insulating portion 22 within the range of 50μm to 200μm, the risk of insulation failure due to an excessively thin second insulating portion 22 can be avoided. Simultaneously, the excessively large size of the battery casing 10 and increased production costs due to an excessively thick second insulating portion 22 can be avoided. Thus, while ensuring the insulation protection performance of the second insulating portion 22, the size and production cost of the battery casing 10 can be controlled. The thickness of the second insulating part 22 can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 120μm, 150μm, 180μm, 200μm, etc., and no specific limitation is made here.

[0050] In some embodiments of this application, the thickness T3 of the third insulating portion 23 satisfies: 80μm≤T3≤450μm. When the thickness of the third insulating portion 23 is too small, the voltage withstand capability of the portion of the insulating coating 2 located at the connection portion 13 is too low, making it susceptible to breakdown, puncture, or gaps, thus increasing the risk of insulation failure at the connection portion 13. Conversely, when the thickness of the third insulating portion 23 is too large, the space occupied in the thickness direction of the shell body 1 increases, resulting in an excessively large overall size of the battery shell 10, which is detrimental to controlling the size of the battery cell 100 and also increases production costs. Therefore, by controlling the thickness of the third insulating portion 23 within the range of 80μm to 450μm, the risk of insulation failure at the connection portion 13 can be reduced, while avoiding excessive thickness leading to an excessively large size of the battery shell 10 and increased production costs. This allows for control of the size and production cost of the battery shell 10 while ensuring the insulating protective performance of the insulating coating 2. The thickness of the third insulating part 23 can be 80μm, 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, etc., and no specific limitation is made here.

[0051] In some embodiments of this application, the thickness t0 of the shell body 1 satisfies: 100μm ≤ t0 ≤ 800μm. If the shell body 1 is too thin, its mechanical strength is insufficient, and its resistance to deformation and corrosion is poor; if the shell body 1 is too thick, its weight is excessive, its cost increases, and it is detrimental to heat dissipation. Therefore, by controlling the thickness of the shell body 1 within the range of 100μm to 800μm, the shell body 1 has a certain thickness, improving its mechanical strength, resistance to deformation, and corrosion resistance, while avoiding excessive thickness, thereby controlling the weight and production cost of the shell body 1 and improving its heat dissipation performance. The thickness of the shell body 1 can be 100μm, 150μm, 200μm, 250μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, etc., and no specific limitation is made here.

[0052] It should be noted that the thickness values ​​in this application can be measured using methods such as eddy current thickness measurement and ultrasonic thickness measurement, referring to the GB / T4957-2003 standard. The aforementioned range of T0 refers to the thickness of the insulating coating 2, where testing at any location ensures that the thickness falls within the specified range. In other words, even if the thicknesses at different locations of the insulating coating 2 differ, they all conform to the range of T0: for example, even if 50μm ≤ T1 ≤ 200μm, T2 and T3 still satisfy the range of T0.

[0053] In some embodiments of this application, the thickness T0 of the insulating coating 2 satisfies: 75μm≤T0≤2500μm. This increases the lower limit of the insulating coating 2's thickness, ensuring sufficient thickness to guarantee insulation performance. Furthermore, it allows for better control of the maximum thickness of the insulating coating 2, reducing its fabrication difficulty and decreasing the required materials, thus lowering its fabrication cost.

[0054] In some embodiments of this application, the thickness T1 of the first insulating portion 21 satisfies: 75μm≤T1≤100μm. Therefore, by increasing the lower limit of the thickness of the first insulating portion 21, the insulation performance of the first insulating portion 21 can be improved; furthermore, by reducing the upper limit of the thickness of the first insulating portion 21, while ensuring the insulation performance of the first insulating portion 21, the thickness of the first insulating portion 21 and the materials required for its fabrication can be effectively controlled, thereby reducing the fabrication difficulty and cost of the first insulating portion 21.

[0055] In some embodiments of this application, the thickness T1 of the second insulating portion 22 satisfies: 75μm≤T2≤100μm. Therefore, by increasing the lower limit of the thickness of the second insulating portion 22, the insulation performance of the second insulating portion 22 can be improved; furthermore, by reducing the upper limit of the thickness of the second insulating portion 22, while ensuring the insulation performance of the second insulating portion 22, the thickness of the second insulating portion 22 and the materials required for its fabrication can be effectively controlled, thereby reducing the fabrication difficulty and cost of the second insulating portion 22.

[0056] In some embodiments of this application, the thickness T1 of the third insulating portion 23 satisfies: 100μm≤T3≤225μm. Therefore, by increasing the lower limit of the thickness of the third insulating portion 23, the insulation performance of the third insulating portion 23 can be improved; furthermore, by reducing the upper limit of the thickness of the third insulating portion 23, while ensuring the insulation performance of the third insulating portion 23, the thickness of the third insulating portion 23 and the materials required for its fabrication can be effectively controlled, thereby reducing the fabrication difficulty and cost of the third insulating portion 23.

[0057] In some embodiments of this application, the thickness t0 of the shell body 1 satisfies: 125μm≤t0≤400μm. Therefore, by increasing the lower limit of the shell body 1's thickness, the mechanical strength, deformation resistance, and corrosion resistance of the shell body 1 can be improved; furthermore, the upper limit requirement for the shell body 1's thickness can be reduced, thereby controlling the weight and production cost of the shell body 1 and improving its heat dissipation performance.

[0058] In some embodiments of this application, the maximum thickness of the insulating coating 2 is T01, and the minimum thickness of the insulating coating 2 is T02, where T01 and T02 satisfy: 0 < T01 - T02 ≤ 5000 μm. That is, the maximum thickness difference at different locations of the insulating coating 2 is controlled within a range not exceeding 5000 μm. This avoids large height differences on the outer surface of the insulating coating 2, thereby preventing the risk of localized breakage or even detachment of the insulating coating 2 due to excessive thickness differences, thus ensuring the reliability of the connection between the insulating coating 2 and the shell body 1. The maximum thickness difference at different locations of the insulating coating 2 can be 50 μm, 100 μm, 200 μm, 500 μm, 1000 μm, 2000 μm, 3000 μm, 4000 μm, 5000 μm, etc., and no specific limitation is made here.

[0059] In some embodiments, the first insulating portion 21 and the second insulating portion 22 have the same thickness. The minimum thickness of the insulating coating 2 is the thickness of the first insulating portion 21 and the second insulating portion 22, and the maximum thickness of the insulating coating 2 is the sum of the thicknesses of the insulating filler portion 24 and the second insulating portion 22.

[0060] In some embodiments of this application, T01 and T02 satisfy: 0 < T01 - T02 ≤ 2500 μm. This effectively reduces the thickness difference at different locations of the insulating coating 2, thereby avoiding the risk of localized breakage or even detachment of the insulating coating 2 due to excessive thickness differences, thus ensuring the reliability of the connection between the insulating coating 2 and the shell body 1.

[0061] In some embodiments of this application, T01 and T02 satisfy: T01 / T02≤3. That is, the maximum thickness of the insulating coating 2 is controlled to be within three times the minimum thickness of the insulating coating 2. Thus, while ensuring the consistency of insulation between different locations of the shell body 1 through multiple locations with different thicknesses of the insulating coating 2, the risk of local breakage or even detachment of the insulating coating 2 due to excessive thickness differences can be avoided, thereby ensuring the reliability of the connection between the insulating coating 2 and the shell body 1.

[0062] In some embodiments of this application, T01 and T02 satisfy: T01 / T02≤1.5. This effectively reduces the thickness difference at different locations of the insulating coating 2, thereby avoiding the risk of localized breakage or even detachment of the insulating coating 2 due to excessive thickness differences, thus ensuring the reliability of the connection between the insulating coating 2 and the shell body 1.

[0063] In some embodiments of this application, such as Figure 5 As shown, the third insulating part 23 includes a bottom coating 231, which connects the first insulating part 21 and the second insulating part 22. The first insulating part 21, the second insulating part 22, and the bottom coating 231 each include an adhesion layer 20a and an outer insulating layer 20b. In any one of the first insulating part 21, the second insulating part 22, and the bottom coating 231, the adhesion layer 20a is located between the shell body 1 and the outer insulating layer 20b. That is, the outer insulating layer 20b of the first insulating part 21, the second insulating part 22, and the bottom coating 231 are respectively attached to the outer surface of the corresponding adhesion layer 20a and connected to the shell body 1 through the corresponding adhesion layer 20a. In other words, the insulating coating 2 is attached to the shell body 1 through the adhesion layer 20a. The adhesion layer 20a effectively enhances the adhesion of the insulating coating 2 to the shell body 1, preventing the insulating coating 2 from falling off the shell body 1, thereby ensuring the insulating protective effect of the insulating coating 2 on the shell body 1.

[0064] In some embodiments, the adhesion layer 20a may be made of a flexible material with high adhesion and high insulation, such as polyurethane, methyl acrylate, ethyl acrylate, and butyl acrylate, which can improve the adhesion of the insulating coating 2 to the surface of the shell body 1. The outer insulation layer 20b may be made of a weather-resistant material, such as epoxy resin and acrylate, which can improve the insulation effect and service life of the insulating coating 2.

[0065] In some embodiments of this application, the thickness of the adhesion layer 20a is t1, and the thickness of the outer insulating layer 20b is t2; wherein t1 and t2 satisfy: 10μm≤|t2—t1|≤150μm. It should be noted that the thicknesses of the adhesion layer 20a and the outer insulating layer 20b of the first insulating portion 21, the second insulating portion 22, and the bottom coating 231 all satisfy the above relationship.

[0066] In other words, the thickness difference between the adhesion layer 20a and the outer insulating layer 20b is controlled within the range of 10μm to 150μm. Taking a fixed thickness for the adhesion layer 20a and an outer insulating layer 20b thickness greater than that for the adhesion layer 20a as an example, if the thickness difference between the adhesion layer 20a and the outer insulating layer 20b is too large (i.e., the outer insulating layer 20b is too thick), it may lead to stress concentration at the interface, reducing the bonding force between the adhesion layer 20a and the outer insulating layer 20b, and increasing the risk of peeling off the outer insulating layer 20b. Conversely, if the thickness difference between the adhesion layer 20a and the outer insulating layer 20b is too small (i.e., the outer insulating layer 20b is too thin), it will result in reduced insulation performance of the outer insulating layer 20b. Therefore, by controlling the thickness difference between the adhesion layer 20a and the outer insulating layer 20b within the range of 10μm to 150μm, the bonding force between the adhesion layer 20a and the outer insulating layer 20b can be guaranteed, as well as the insulation performance of the outer insulating layer 20b. The thickness difference between the adhesion layer 20a and the outer insulating layer 20b can be 10μm, 20μm, 30μm, 50μm, 70μm, 90μm, 100μm, 120μm, 150μm, etc., and no specific limitation is imposed here.

[0067] In some embodiments of this application, the thickness of the shell body 1 is t0, and t0, t1, and t2 satisfy: 0.0125 ≤ |t2—t1| / t0 ≤ 1.5. Since the wall thickness, rigidity, and deformation range of different shell bodies 1 vary, by designing the ratio of the thickness difference between the attachment layer 20a and the outer insulating layer 20b to the thickness of the shell body 1, the deformation stress of the shell body 1 can be adapted to while also considering the safety margin for damage to the insulating coating 2 due to stress, thus ensuring the insulation performance of the insulating coating 2. For example, |t2—t1| / t0 can be 0.0125, 0.025, 0.05, 0.1, 0.2, 0.3, 0.5, 0.7, 0.9, 1.0, 1.2, 1.4, 1.5, etc.

[0068] In some embodiments of this application, t1 and t2 satisfy: 15μm≤|t2—t1|≤75μm. This reduces the thickness difference between the attachment layer 20a and the outer insulating layer 20b, thereby reducing process defects caused by an excessive thickness difference between the attachment layer 20a and the outer insulating layer 20b, and improving the yield of the battery casing 10.

[0069] In some embodiments of this application, t0, t1, and t2 satisfy: 0.015 ≤ |t2—t1| / t0 ≤ 0.75. Therefore, while adapting to the deformation stress of the shell body 1, it also takes into account the safety margin of the insulating coating 2 in case of stress damage, thus ensuring the insulation performance of the insulating coating 2.

[0070] In some embodiments of this application, the third insulating portion 23 further includes an insulating reinforcing layer 232, which is disposed on the side of the bottom coating 231 away from the shell body 1 and covers at least a portion of the connecting portion 13. Thus, by providing the insulating reinforcing layer 232 on the outer side of the bottom coating 231, i.e., the side of the bottom coating 231 away from the shell body 1, the insulating reinforcing layer 232 can cover areas on the bottom coating 231 that are blank, have uneven thickness, or poor adhesion. In other words, the insulating reinforcing layer 232 can cover defective areas on the bottom coating 231 where there is a risk of insulation failure. Therefore, the bottom coating 231 and the insulating reinforcing layer 232 jointly provide insulating protection for the connecting portion 13, thereby improving the insulating protection performance of the insulating coating 2 on the shell body 1, and consequently improving the safety performance of the battery casing 10.

[0071] It should be noted that in the battery casing 10 with rounded corners, because the sprayed material is not easily maintained at the rounded corners in a liquid state, the thickness of the adhesion layer 20a in the bottom coating 231 of the third insulating part 23 is less than the thickness of the adhesion layer 20a in the first insulating part 21 and the second insulating part 22. Similarly, the thickness of the outer insulating layer 20b in the bottom coating 231 of the third insulating part 23 is less than the thickness of the outer insulating layer 20b in the first insulating part 21 and the second insulating part 22. Therefore, by providing an insulating reinforcing layer 232 on the outside of the bottom coating 231, the rounded corners on the casing body 1 can be reinforced, preventing exposed white areas.

[0072] In some embodiments of this application, the insulating reinforcement layer 232 is a dispensing layer, that is, the insulating reinforcement layer 232 can be formed on the insulating coating layer 2 by dispensing process, which is convenient for local application.

[0073] In some embodiments of this application, the insulating reinforcing layer 232 and the underlying coating 231 are an integral structure. That is, after the insulating coating 2 is cured, the insulating reinforcing layer 232 and the underlying coating 231 are connected to form an integral structure. This ensures the stability of the connection between the insulating reinforcing layer 232 and the underlying coating 231 and improves the reliability of the overall structure of the insulating coating 2.

[0074] In some embodiments of this application, the insulating reinforcement layer 232 at least partially covers the first insulating portion 21. That is, while the insulating reinforcement layer 232 covers the outer surface of the underlying coating 231, a portion of the insulating reinforcement layer 232 extends to the first sidewall 11 to at least cover the connection point between the first insulating portion 21 and the underlying coating 231. Therefore, the coverage area of ​​the insulating reinforcement layer 232 on the insulating coating 2 can be significantly increased, thereby increasing the insulating protection area of ​​the insulating reinforcement layer 232 on the shell body 1. This avoids the risk of insulation failure at the connecting portion 13 and the connection point between the connecting portion 13 and the first sidewall 11, thus improving the insulating protection performance of the insulating coating 2.

[0075] In some embodiments of this application, the insulating reinforcement layer 232 at least partially covers the second insulating portion 22. That is, while the insulating reinforcement layer 232 covers the outer surface of the underlying coating 231, a portion of the insulating reinforcement layer 232 extends to the second sidewall 12 to at least cover the connection point between the second insulating portion 22 and the underlying coating 231. Therefore, the coverage area of ​​the insulating reinforcement layer 232 on the insulating coating 2 can be significantly increased, thereby increasing the insulating protection area of ​​the insulating reinforcement layer 232 on the shell body 1. This avoids the risk of insulation failure at the connecting portion 13 and the connection point between the connecting portion 13 and the second sidewall 12, thus improving the insulating protection performance of the insulating coating 2.

[0076] In some embodiments of this application, the first insulating portion 21, the second insulating portion 22, and the undercoat 231 are integrally coated on the outer surface of the shell body 1. That is, the first insulating portion 21, the second insulating portion 22, and the undercoat 231 can be formed simultaneously in a single process. For example, the coating can be simultaneously applied to the outer surfaces of the first sidewall 11, the connecting portion 13, and the second sidewall 12, and then cured to simultaneously form the first insulating portion 21, the second insulating portion 22, and the undercoat 231. This eliminates the need for sequential production of the first insulating portion 21, the second insulating portion 22, and the undercoat 231, thus significantly reducing the production steps of the insulating coating 2 and improving the efficiency of coating the insulating coating 2 on the outer surface of the shell body 1. Furthermore, the connection strength between the undercoat 231 and the first insulating portion 21 and the second insulating portion 22 can be guaranteed, thereby reducing the risk of the undercoat 231 detaching and ensuring the insulating effect of the undercoat 231 at the connecting portion 13.

[0077] It should be noted that the coatings of the first insulating part 21, the second insulating part 22 and the bottom coating 231 can be sprayed on the outer surface of the shell body 1, and the coatings of the first insulating part 21, the second insulating part 22 and the bottom coating 231 can also be printed on the outer surface of the shell body 1. Here, there are no specific restrictions on the way the first insulating part 21, the second insulating part 22 and the bottom coating 231 are coated on the outer surface of the shell body 1.

[0078] In some embodiments of this application, such as Figure 4 As shown, the shell body 1 is cylindrical, and the outer peripheral wall of the shell body 1 forms a second side wall 12. A limiting groove 14 is formed on the outer peripheral surface of the second side wall 12. The insulating coating 2 also includes an insulating filling part 24, which is disposed in the limiting groove 14. The second insulating part 22 is located on the outer peripheral side of the insulating filling part 24 and covers the insulating filling part 24. That is, the insulating filling part 24 is located inside the part of the second insulating part 22 that is opposite to the limiting groove 14. The insulating filling part 24 can fill at least part of the space of the limiting groove 14. The insulating filling part 24 can support the part of the second insulating part 22 that is opposite to the limiting groove 14 and the inner bottom wall of the limiting groove 14, thereby reducing the deformation of the part of the second insulating part 22 that is opposite to the limiting groove 14 toward the limiting groove 14, thereby improving the insulating protection performance of the insulating coating 2 at the limiting groove 14.

[0079] The limiting groove 14 can be an annular shape extending circumferentially along the shell body 1, or the limiting groove 14 can be an arc shape extending circumferentially along the shell body 1 and have multiple grooves arranged at intervals along the circumferential direction of the shell body 1. No specific restrictions are made here.

[0080] In some embodiments of this application, the insulating filler 24 is a dispensing layer. That is, the insulating filler 24 can be formed in the limiting groove 14 by a dispensing process, which facilitates local application.

[0081] In some embodiments of this application, the insulating filler portion 24 and the second insulating portion 22 are an integral structure. That is, after the insulating coating 2 is cured, the insulating filler portion 24 and the second insulating portion 22 are connected to form an integral structure. This ensures the stability of the connection between the insulating filler portion 24 and the second insulating portion 22 and improves the reliability of the overall structure of the insulating coating 2.

[0082] In some embodiments, the insulating reinforcing layer 232 is made of the same material as the insulating filler 24 and the outer insulating layer 20b. This improves the adhesion of the insulating reinforcing layer 232 to the outer insulating layer 20b and reduces the variety of materials required to prepare the insulating coating 2, thereby simplifying material management.

[0083] In some embodiments, the insulating reinforcing layer 232 and the insulating filler 24 are made of different materials than the outer insulating layer 20b. That is, the insulating reinforcing layer 232 and the insulating filler 24 can be made of different materials than the outer insulating layer 20b, as long as the insulating performance and adhesion of the insulating reinforcing layer 232 and the insulating filler 24 are guaranteed. For example, resins, etc., are used. There are no specific limitations on the materials of the insulating reinforcing layer 232 and the insulating filler 24.

[0084] In some embodiments of this application, the thickness T2 of the second insulating portion 22 and the thickness T4 of the insulating filling portion 24 satisfy: 300μm≤T2+T4≤4000μm; wherein, when the sum of the thicknesses of the second insulating portion 22 and the insulating filling portion 24 is too small, the voltage withstand performance of the portion of the insulating coating 2 located at the connection portion 13 is too low and easily broken down and punctured, which increases the risk of insulation failure at the limiting groove 14; conversely, when the sum of the thicknesses of the second insulating portion 22 and the insulating filling portion 24 is too large, the space occupied in the thickness direction of the shell body 1 increases, resulting in an excessively large overall size of the battery shell 10, which is not conducive to controlling the size of the battery cell 100, and the production cost also increases accordingly. Therefore, by controlling the sum of the thicknesses of the second insulating portion 22 and the insulating filling portion 24 within the range of 1000μm to 4000μm, the risk of insulation failure at the limiting groove 14 can be reduced. Simultaneously, excessive thickness can be avoided, preventing the battery casing 10 from becoming too large and increasing production costs. Thus, while ensuring the insulating protective performance of the insulating coating 2, the size and production cost of the battery casing 10 can be controlled. The sum of the thicknesses of the second insulating portion 22 and the insulating filling portion 24 can be 300μm, 500μm, 1000μm, 1500μm, 2000μm, 2500μm, 3000μm, 3500μm, 4000μm, etc., without specific limitations.

[0085] In some embodiments of this application, the thickness T2 of the second insulating portion 22 and the thickness T4 of the insulating filling portion 24 satisfy: 400μm≤T2+T4≤2000μm. Therefore, by increasing the lower limit of the thickness of the portion of the insulating coating 2 opposite to the limiting groove 14, the insulating protection performance of the insulating coating 2 for the area of ​​the limiting groove 14 can be improved. Furthermore, by reducing the upper limit of the thickness of the portion of the insulating coating 2 opposite to the limiting groove 14, while ensuring the insulating protection performance of the insulating coating 2 for the area of ​​the limiting groove 14, the thickness of the insulating coating 2 and the materials required for its preparation can be effectively controlled, thereby reducing the difficulty and cost of preparing the insulating coating 2.

[0086] In some embodiments of this application, the depth of the insulating filling portion 24 along the radial direction of the shell body 1 is the same as the depth of the limiting groove 14, and the outer peripheral surface of the insulating filling portion 24 is flush with the outer peripheral surface of the shell body 1. That is, the insulating filling portion 24 can better fill the limiting groove 14 and avoid the insulating filling portion 24 occupying the space on the outer peripheral side of the shell body 1, thereby improving the supporting effect of the insulating filling portion 24 on the second insulating portion 22, that is, ensuring the straightness of the second insulating portion 22 along the axial direction of the shell body 1, and reducing the space occupied by the insulating coating 2 on the outer peripheral side of the shell body 1.

[0087] In some embodiments of this application, the connecting portion 13 is one of a right-angle structure, an obtuse-angle structure, an acute-angle structure, or a circular arc structure. This allows the connecting portion 13 to flexibly adjust the included angle between the first sidewall 11 and the second sidewall 12. For example, when the included angle between the first sidewall 11 and the second sidewall 12 is an acute angle, the connecting portion 13 can be an acute-angle structure; when the included angle between the first sidewall 11 and the second sidewall 12 is a right angle, the connecting portion 13 can be a right-angle structure or a circular arc structure, etc. Examples will not be provided here.

[0088] The following description, with reference to the accompanying drawings, describes a battery cell 100 according to a second aspect of this application.

[0089] like Figure 6 As shown, a battery cell 100 according to a second aspect embodiment of this application includes: a battery casing 10 and an electrode assembly, the electrode assembly being disposed within the battery casing 10. The battery casing 10 is provided with terminal posts 20.

[0090] According to the battery cell 100 of the second aspect embodiment of this application, the thickness of the third insulating portion 23 is greater than the thickness of the first insulating portion 21 and / or the thickness of the third insulating portion 23 is greater than the thickness of the second insulating portion 22. This can improve the insulation protection effect of the third insulating portion 23 on the connection portion 13, thereby effectively avoiding the risk of insulation failure at the connection portion 13, improving the insulation protection performance of the insulating coating 2, and further improving the safety performance of the battery casing 10.

[0091] A battery device 1000 according to a third aspect embodiment of this application is described below with reference to the accompanying drawings.

[0092] like Figure 7 As shown, a battery device 1000 according to a third aspect embodiment of this application includes: a housing 200 and a plurality of battery cells 100, wherein the battery cells 100 are disposed within the housing 200.

[0093] According to the battery device 1000 of the third aspect embodiment of this application, the thickness of the third insulating portion 23 is greater than the thickness of the first insulating portion 21 and / or the thickness of the third insulating portion 23 is greater than the thickness of the second insulating portion 22. This can improve the insulation protection effect of the third insulating portion 23 on the connection portion 13, thereby effectively avoiding the risk of insulation failure at the connection portion 13, improving the insulation protection performance of the insulating coating 2, and further improving the safety performance of the battery casing 10.

[0094] An electrical device according to a fourth aspect of this application includes a battery device 1000.

[0095] According to the electrical device of the fourth aspect of this application, the thickness of the third insulating part 23 is greater than the thickness of the first insulating part 21 and / or the thickness of the third insulating part 23 is greater than the thickness of the second insulating part 22. This can improve the insulation protection effect of the third insulating part 23 on the connection part 13, thereby effectively avoiding the risk of insulation failure at the connection part 13, improving the insulation protection performance of the insulating coating 2, and further improving the safety performance of the battery casing 10.

[0096] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0097] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery casing, characterized in that, include: A shell body, the shell body including a first sidewall, a second sidewall and a connecting part, the first sidewall and the second sidewall being arranged at an angle, and the connecting part connecting the first sidewall and the second sidewall; An insulating coating is provided on the outer surface of the shell body and includes a first insulating portion, a second insulating portion and a third insulating portion. The first insulating portion is provided on the first side wall, the second insulating portion is provided on the second side wall, and the third insulating portion is provided on the connecting portion and connects the first insulating portion and the second insulating portion. The thickness of the third insulating portion is greater than the thickness of the first insulating portion and / or the thickness of the third insulating portion is greater than the thickness of the second insulating portion.

2. The battery casing according to claim 1, characterized in that, The thickness of the first insulating part is T1, the thickness of the second insulating part is T2, and the thickness of the third insulating part is T3; wherein, 2≤T3 / T1≤10; and / or, 2≤T3 / T2≤10; and / or, 30μm≤T3-T1≤300μm; and / or, 30μm≤T3-T2≤300μm.

3. The battery casing according to claim 2, characterized in that, 3≤T3 / T1≤5; and / or, 3≤T3 / T2≤5; and / or, 40μm≤T3-T1≤150μm; and / or, 40μm≤T3-T2≤150μm.

4. The battery casing according to claim 1, characterized in that, The thickness T0 of the insulating coating satisfies: 50μm≤T0≤5000μm; And / or, the thickness T1 of the first insulating portion satisfies: 50μm≤T1≤200μm; And / or, the thickness T2 of the second insulating portion satisfies: 50μm≤T2≤200μm; And / or, the thickness T3 of the third insulating portion satisfies: 80μm≤T3≤450μm; And / or, the thickness t0 of the shell body satisfies: 100μm≤t0≤800μm.

5. The battery casing according to claim 4, characterized in that, The thickness T0 of the insulating coating satisfies: 75μm≤T0≤2500μm; And / or, the thickness T1 of the first insulating portion satisfies: 75μm≤T1≤100μm; And / or, the thickness T2 of the second insulating portion satisfies: 75μm≤T2≤100μm; And / or, the thickness T3 of the third insulating portion satisfies: 100μm≤T3≤225μm; And / or; the thickness t0 of the shell body satisfies: 125μm≤t0≤400μm.

6. The battery casing according to claim 1, characterized in that, The maximum thickness of the insulating coating is T01, and the minimum thickness of the insulating coating is T02; Wherein, T01 and T02 satisfy: 0 < T01 - T02 ≤ 5000 μm; and / or, T01 and T02 satisfy: T01 / T02 ≤ 3.

7. The battery casing according to claim 6, characterized in that, T01 and T02 satisfy: 0 < T01 - T02 ≤ 2500 μm; and / or, T01 / T02 ≤ 1.

5.

8. The battery casing according to claim 1, characterized in that, The third insulating portion includes a bottom coating that connects the first insulating portion and the second insulating portion. The first insulating portion, the second insulating portion, and the bottom coating each include an attachment layer and an outer insulating layer. In any one of the first insulating portion, the second insulating portion, and the bottom coating, the attachment layer is located between the shell body and the outer insulating layer.

9. The battery casing according to claim 8, characterized in that, The adhesion layer comprises one of polyurethane, methyl acrylate, ethyl acrylate, and butyl acrylate; and / or, the outer insulation layer comprises one of epoxy resin and acrylate.

10. The battery casing according to claim 8, characterized in that, The thickness of the adhesion layer is t1, and the thickness of the outer insulation layer is t2; Where t1 and t2 satisfy: 10μm≤|t2—t1|≤150μm; And / or, the thickness of the shell body is t0, and t0, t1 and t2 satisfy: 0.0125≤|t2—t1| / t0≤1.

5.

11. The battery casing according to claim 10, characterized in that, t1 and t2 satisfy: 15μm≤|t2—t1|≤75μm; And / or, the thickness of the shell body is t0, and t0, t1 and t2 satisfy: 0.015≤|t2—t1| / t0≤0.

75.

12. The battery casing according to claim 8, characterized in that, The third insulating portion further includes an insulating reinforcement layer, which is disposed on the side of the bottom coating away from the shell body and covers at least a portion of the connecting portion.

13. The battery casing according to claim 12, characterized in that, The insulating reinforcement layer is made of the same material as the outer insulating layer.

14. The battery casing according to claim 12, characterized in that, The insulating reinforcement layer is made of a different material than the outer insulating layer.

15. The battery casing according to claim 12, characterized in that, The insulating reinforcement layer is an adhesive layer; and / or, the insulating reinforcement layer and the underlying coating are an integral structure.

16. The battery casing according to claim 12, characterized in that, The insulating reinforcement layer at least covers a portion of the first insulating part; and / or, the insulating reinforcement layer at least covers a portion of the second insulating part; and / or, the first insulating part, the second insulating part, and the bottom coating are integrally coated on the outer surface of the shell body.

17. The battery casing according to claim 1, characterized in that, The shell body is cylindrical, and the outer peripheral wall of the shell body forms the second side wall. A limiting groove is formed on the outer peripheral surface of the second side wall. The insulating coating also includes an insulating filling part, which is disposed in the limiting groove. The second insulating part is located on the outer peripheral side of the insulating filling part and covers the insulating filling part.

18. The battery casing according to claim 17, characterized in that, The insulating filling part is an adhesive layer; And / or, the insulating filling portion and the second insulating portion are an integral structure; And / or, the thickness T2 of the second insulating portion and the thickness T4 of the insulating filling portion satisfy: 300μm≤T2+T4≤4000μm; And / or, along the radial direction of the shell body, the depth of the insulating filling portion is the same as the depth of the limiting groove, and the outer peripheral surface of the insulating filling portion is flush with the outer peripheral surface of the shell body.

19. The battery casing according to claim 18, characterized in that, The thickness T2 of the second insulating part and the thickness T4 of the insulating filling part satisfy: 400μm≤T2+T4≤2000μm.

20. The battery casing according to claim 1, characterized in that, The connecting part is one of a right-angle structure, an obtuse-angle structure, an acute-angle structure, or a circular arc structure.

21. A single battery cell, characterized in that, include: Battery casing according to any one of claims 1-20; The electrode assembly is located inside the battery casing.

22. A battery device, characterized in that, include: Box; Multiple battery cells according to claim 21, wherein the battery cells are disposed within the housing.

23. An electrical appliance, characterized in that, include: The battery device according to claim 22.

Images