Battery case, battery cell and battery device

Abstract

The present invention discloses a battery case, a battery cell and a battery device, the battery case comprises: a housing, the inner side of the housing defines an accommodating cavity, the housing comprises: a housing main body, an end cover and an insulating ring, the housing main body is provided with an opening in one side in a first direction, the end cover is connected with the housing main body and covers the opening, and the insulating ring is arranged in the housing main body; the insulating ring extends along the circumferential direction of the end cover to form a ring shape, and the insulating ring is arranged between the end cover and the shell, so that the end cover is insulated from the shell; and the insulating coating is arranged on the outer side surfaces of at least two of the shell main body, the end cover and the insulating ring. According to the battery shell disclosed by the invention, the insulating coating is arranged on the outer side surfaces of at least two of the shell main body, the end cover and the insulating ring, so that the covering area of the insulating coating on the outer surface of the battery shell can be increased, and the overall insulating property and the protective property of the battery shell are improved.

Description

Technical Field

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

[0002] Batteries are susceptible to damage from external environmental factors during transportation and use. Furthermore, the tens of thousands of cells tightly packed within a battery pack pose a significant safety risk due to contact between their metal casings and with internal metal structural components. Simultaneously, the high operating voltage of battery systems necessitates a high-dielectric-strength insulation structure to withstand internal potential differences and prevent high-voltage breakdown. Additionally, protection and abrasion resistance are crucial to prevent insulation damage and electrochemical corrosion caused by scratches during handling. Therefore, a protective layer integrating insulation, protection, and thermal conductivity is essential for the battery casing. However, the insulation and protective performance of existing battery casings requires further improvement. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention provides a battery casing that can improve the overall insulation and protective performance of the battery casing.

[0004] The present invention also proposes a battery cell having the above-mentioned battery casing.

[0005] According to a first aspect of the present invention, a battery casing includes: a housing, the inner side of which defines a receiving cavity and includes: a housing body, an end cap, and an insulating ring, the housing body having an opening formed on one side in a first direction, the end cap being connected to the housing body and sealing the opening, the insulating ring extending circumferentially along the end cap in an annular shape, the insulating ring being disposed between the end cap and the housing to insulate the end cap from the housing; and an insulating coating disposed on the outer surfaces of at least two of the housing body, the end cap, and the insulating ring.

[0006] According to the battery casing of the present invention, by providing an insulating coating on the outer surfaces of at least two of the casing body, end caps and insulating rings, the coverage area of ​​the insulating coating on the outer surface of the battery casing can be increased, thereby improving the overall insulation and protection performance of the battery casing.

[0007] In some embodiments, the insulating ring includes a first insulating portion, a portion of which is exposed on the outer side of the housing body and the end cap opposite to the receiving cavity, wherein the insulating coating at least covers the seam area between the first insulating portion and the housing body, and / or the insulating coating at least covers the seam area between the first insulating portion and the end cap.

[0008] In some embodiments, the shell body is cylindrical and includes a bottom wall and a side wall. The side wall is connected to the bottom wall and extends circumferentially along the bottom wall in an annular shape. The end of the side wall facing away from the bottom wall is bent toward the side where the receiving cavity is located to form a flange. The flange is annular and defines the opening on its inner side. The first insulating portion is disposed between the flange and the end cap, and in the radial direction of the opening, the radial inner end of the first insulating portion extends beyond the inner edge of the flange.

[0009] In some embodiments, the insulating coating covers at least a portion of the outer surface of the flange facing away from the receiving cavity, and the insulating coating covering the flange is spaced apart from the first insulating portion; or, in the radial direction of the insulating ring, the insulating coating extends inward from the outer surface of the flange to the exposed surface of the first insulating portion; or, in the radial direction of the insulating ring, the insulating coating extends outward from the outer surface of the end cap facing away from the receiving cavity to the exposed surface of the first insulating portion; or, in the radial direction of the insulating ring, the insulating coating extends from the outer surface of the flange to the outer surface of the end cap, and completely covers the exposed surface of the insulating ring.

[0010] In some embodiments, the shell sidewall is formed with a raised rib protruding toward the receiving cavity, the raised rib cooperating with the flange to define a fixing groove, and the insulating ring is fixed in the fixing groove and wraps around the periphery of the end cap.

[0011] In some embodiments, the insulating coating includes a coating body region and a coating edge region, the coating edge region being connected to the periphery of the coating body region and extending in a ring shape along the circumference of the coating body region, the thickness of the coating body region being greater than the thickness of the coating edge region.

[0012] In some embodiments, the thickness of the coating body region is 90 μm-110 μm, and / or, the thickness of the coating edge region gradually decreases in the direction from the coating body region toward the coating edge region.

[0013] In some embodiments, the protective layer is an acrylic coating, an epoxy coating, or a polyurethane coating; and / or, the adhesion layer is an acrylic coating, an epoxy coating, or a polyurethane coating.

[0014] In some embodiments, the thickness of the adhesion layer is 15μm-25μm, and / or the thickness of the protective layer is 75μm-85μm.

[0015] In some embodiments, the adhesion layer is an insulating layer and / or a thermally conductive layer; and / or, the protective layer is an insulating layer, a thermally conductive layer, a wear-resistant layer, a flame-retardant layer, and / or an anti-aging layer.

[0016] A battery cell according to a second aspect of the present invention includes: a battery casing according to a first aspect of the present invention; and an electrode assembly disposed within the battery casing.

[0017] According to the battery cell of the present invention, by providing the battery casing described in the first aspect, the overall performance of the battery cell is improved.

[0018] A battery device according to a third aspect of the present invention includes a housing and a battery cell according to a second aspect of the present invention, the battery cell being disposed within the housing.

[0019] According to the battery device of the present invention, by providing the battery cells described in the first aspect, the overall performance of the battery device is improved.

[0020] Additional aspects and advantages of the invention 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 the invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present invention; Figure 2 yes Figure 1 A partial enlarged view of the battery cell shown; Figure 3 This is a cross-sectional view of a battery cell according to an embodiment of the present invention; Figure 4 yes Figure 3 A partial enlarged view of the battery cell shown; Figure 5 yes Figure 4 A partial enlarged view of the battery cell shown; Figure 6 This is a partial cross-sectional view of the battery casing according to an embodiment of the present invention.

[0022] Figure label: 1. Battery cell; 100. Battery casing; 10. Shell; 101. Receiving cavity; 11. Shell body; 111. Shell bottom wall; 112. Shell side wall; 1121. Rib; 113. Flanged edge; 12. End cap; 13. Insulating ring; 131. First insulating part; 20. Insulating coating; 21. Adhesion layer; 22. Protective layer; 23. Main coating area; 24. Coating edge area; 200, positive electrode post; 300, negative electrode post; 400, electrode assembly. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated 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 the present invention, and should not be construed as limiting the present invention.

[0024] The following is for reference. Figures 1-6 A battery casing 100 according to an embodiment of the first aspect of the present invention is described.

[0025] like Figure 1 , Figure 4 and Figure 6 As shown, a battery casing 100 according to a first aspect embodiment of the present invention includes: a casing 10 and an insulating coating 20.

[0026] Specifically, the inner side of the housing 10 defines a receiving cavity 101; the housing 10 includes: a housing body 11, an end cap 12, and an insulating ring 13, the housing body 11 being in a first direction (e.g. Figure 3 and Figure 4 One side of the vertical direction shown (e.g.) Figure 3 An opening is formed on the upper side of the shell body 11 shown; the end cap 12 is connected to the shell body 11 and seals the opening; the insulating ring 13 extends in a ring shape along the circumference of the end cap 12 and is disposed between the end cap 12 and the shell 10 to insulate the end cap 12 from the shell 10; the insulating coating 20 is disposed on the outer surfaces of at least two of the shell body 11, the end cap 12 and the insulating ring 13.

[0027] In this embodiment, one of the housing body 11 and the end cap 12 is connected to the positive terminal 200 of the battery cell 1, and the other is connected to the negative terminal 300 of the battery cell 1. By including the housing body 11 and the end cap 12 in this embodiment, the electrode assembly 400 can be easily installed into the receiving cavity 101 of the housing 10. By providing an insulating ring 13 between the housing body 11 and the end cap 12, the insulation performance between the housing body 11 and the end cap 12 can be guaranteed, and short circuit between the positive and negative terminals of the battery cell 1 can be avoided.

[0028] The insulating coating 20 can be applied only to the outer surfaces of the housing body 11 and the insulating ring 13, or only to the outer surfaces of the end cap 12 and the insulating ring 13, or it can be applied to both the housing body 11 and the end cap 12. Alternatively, the insulating coating 20 can be applied to the housing body 11, the end cap 12, and the insulating ring 13 simultaneously. Therefore, the insulating coating 20 can be applied at appropriate locations on the housing 10 as needed to fully enhance the insulation and protective performance of the battery casing 100.

[0029] This embodiment increases the coverage area of ​​the insulating coating 20 on the housing 10 by covering at least two of the outer surfaces of the housing body 11, end cap 12, and insulating ring 13 with the insulating coating 20, thus ensuring the insulation performance of the battery housing 100 and reducing the risk of the battery housing 100 being scratched. Furthermore, simultaneously covering two of the housing body 11, end cap 12, and insulating ring 13 with the insulating coating 20 facilitates coverage of the connection points between adjacent components, thereby improving the sealing and corrosion resistance of the connection points. It also further strengthens the insulation performance between the end cap 12 and the housing body 11, reducing the risk of discharge in the edge areas of the housing body 11 or end cap 12.

[0030] According to an embodiment of the present invention, by providing an insulating coating 20 on the outer surfaces of at least two of the shell body 11, end cap 12 and insulating ring 13, the coverage area of ​​the insulating coating 20 on the outer surface of the battery shell 100 can be increased, thereby improving the overall insulation and protection performance of the battery shell 100.

[0031] In some embodiments of the present invention, reference is made to... Figure 5 The insulating ring 13 includes a first insulating portion 131, a portion of which is exposed on the outside of the housing body 11 and the end cap 12 away from the receiving cavity 101. Thus, the first insulating portion 131 can increase the electrical distance between the housing body 11 and the end cap 12, reducing the risk of discharge in the edge region of the housing body 11 or the end cap 12.

[0032] In some embodiments of the present invention, reference is made to... Figure 5 As shown, the insulating coating 20 at least covers the seam area between the first insulating part 131 and the shell body 11. It should be noted that during the charging and discharging process of a single battery cell, electric field distortion and charge concentration may occur in the edge area of ​​the metal shell body. If the edge of the shell body is close to the end cap or surrounding components with high voltage potential, it may lead to electrical clearance breakdown.

[0033] Since the dielectric constant of the insulating coating 20 differs from that of air, this embodiment, by completely covering the joint area between the first insulating part 131 and the shell body 11 with the insulating coating 20, can improve the uniformity of the electric field at the edge of the shell body 11, making the electric field distribution smooth and reducing the risk of discharge at the sharp corners of the shell body 11's edge, thus further enhancing electrical safety performance. In addition, the insulating coating 20 can also isolate external corrosive media such as water vapor, salt spray, and chemicals, effectively preventing corrosion on the inner surface of the shell body 11's edge area and extending the service life of the shell body 11.

[0034] In some embodiments of the present invention, reference is made to... Figure 5The insulating coating 20 at least covers the joint area between the first insulating part 131 and the end cap 12. Since the insulating coating 20 itself has good chemical corrosion resistance, this embodiment, by covering the joint area between the first insulating part 131 and the end cap 12 with the insulating coating 20, forms a physical isolation barrier at the connection point between the end cap 12 and the first insulating part 131, isolating external corrosive media such as water vapor, salt spray, and chemicals. This effectively prevents corrosion on the extended surface of the end cap 12 in contact with the insulating ring 13, which helps extend the service life of the housing 10 material in the area where the insulating ring 13 is located, and can further improve the sealing performance of the insulating ring 13.

[0035] In some embodiments of the present invention, such as Figures 1-3 As shown, the shell body 11 is a circular column.

[0036] In some embodiments of the present invention, such as Figure 3 and Figure 4 As shown, the shell body 11 includes a bottom wall 111 and a side wall 112. The side wall 112 is connected to the bottom wall 111 and extends in a ring shape along the circumference of the bottom wall 111. The end of the side wall 112 facing away from the bottom wall 111 (e.g.) Figure 3 The upper end of the shell sidewall 112 shown is bent toward the side where the receiving cavity 101 is located to form a flange 113, which is annular and has an opening defined on the inner side.

[0037] The portion of the insulating ring 13 located on the side of the end cap 12 facing away from the fixing groove in the first direction is the first insulating part 131. The first insulating part 131 is disposed between the flange 113 and the end cap 12. In the radial direction from the outside to the inside of the opening, the radial inner end of the first insulating part 131 extends beyond the inner periphery of the flange 113. Thus, the first insulating part 131 can effectively isolate the end cap 12 from the flange 113, further increasing the electrical distance between the housing body 11 and the end cap 12, and avoiding the risk of short circuit or discharge due to direct contact between the end cap 12 and the flange 113.

[0038] In some embodiments of the present invention, such as Figure 3 and Figure 4 As shown, the insulating coating 20 completely covers the outer surface of the shell sidewall 112, partially covers the outer surface of the shell bottom wall 111, and covers at least part of the outer surface of the flange 113. Because the insulating coating 20 has good chemical corrosion resistance, this embodiment, by having the insulating coating 20 simultaneously cover the outer surfaces of the shell bottom wall 111, shell sidewall 112, and flange 113, can improve the insulation protection performance of the shell body 11, reduce the risk of pitting corrosion and oxidation of the shell body 11, extend the service life of the shell body 11, enhance the wear resistance of the shell body 11, and protect the shell body 11 from external environmental corrosion.

[0039] In some embodiments of the present invention, such as Figure 5 As shown, the insulating coating 20 covers at least a portion of the outer surface of the flange 113 facing away from the receiving cavity 101, and the insulating coating 20 covering the flange 113 is spaced apart from the first insulating portion 131. For example Figure 5 As shown, the insulating coating 20 on the upper surface of the flange 113 does not completely cover the upper surface of the flange 113. Furthermore, the insulating coating 20 on the upper surface of the flange 113 is spaced apart from the inner circumference of the flange 113. In this way, the insulating coating 20 on the flange 113 and the insulating ring 13 are spaced apart and do not contact each other. In this embodiment, the insulating ring 13 may not have an insulating coating 20, or the insulating coating 20 on the flange 113 and the insulating coating 20 on the insulating ring 13 may be spaced apart and not in contact.

[0040] In some embodiments of the present invention, reference is made to... Figure 5 As shown, in the radial direction of the insulating ring 13, the insulating coating 20 extends from the outer surface of the flange 113 (e.g., Figure 5 The upper surface of the flange 113 shown extends to the exposed surface of the first insulating portion 131 (e.g., the upper surface of the flange 113 shown). Figure 5 (as shown on the upper surface of the first insulating part 131), at this time, the insulating coating 20 can completely cover the joint area between the first insulating part 131 and the flange 113.

[0041] In this embodiment, by extending the insulating coating 20 from the upper surface of the flange 113 to the upper surface of the first insulating part 131, the insulating coating 20 can completely cover the edge area of ​​the flange 113, improve the uniformity of the electric field, make the electric field smoothly distributed, reduce the risk of discharge at the sharp corner of the edge of the flange 113, further improve electrical safety performance, and can also isolate external water vapor, salt spray, chemicals and other corrosive media, effectively prevent corrosion of the inner surface of the flange 113 of the shell body 11, and extend the service life of the shell body 11.

[0042] In some embodiments of the present invention, reference is made to... Figure 5 As shown, in the radial direction of the insulating ring 13, the insulating coating 20 extends from the outer surface of the end cap 12 away from the receiving cavity 101 (e.g., Figure 5 The upper surface of the end cap 12 shown extends outward to the exposed surface of the first insulating portion 131 (e.g., the upper surface of the end cap 12 shown). Figure 5As shown in the diagram, the upper surface of the first insulating part 131 and / or the radially inner circumferential surface of the first insulating part 131 are covered. At this point, the insulating coating 20 can completely cover the joint area between the first insulating part 131 and the end cap 12. This forms a physical barrier at the connection point between the end cap 12 and the first insulating part 131, isolating it from external corrosive media such as moisture, salt spray, and chemicals. This effectively prevents corrosion on the extended surface of the end cap 12 in contact with the insulating ring 13, extending the service life of the housing 10 material in the area where the insulating ring 13 is located, and further improving the sealing performance of the insulating ring 13.

[0043] In some embodiments of the present invention, reference is made to... Figure 5 As shown, in the radial direction of the insulating ring 13, the insulating coating 20 extends from the outer surface of the flange 113 (e.g., Figure 5 The upper surface of the flange 113 shown extends inward to the outer surface of the end cap 12 opposite to the receiving cavity 101 (e.g., Figure 5 The upper surface of the end cap 12 shown), and the insulating coating located between the end cap and the flange completely covers the exposed surface of the first insulating portion 131 (e.g., the upper surface of the end cap 12), and the insulating coating between the end cap and the flange completely covers the exposed surface of the first insulating portion 131 (e.g., the upper surface of the end cap 12). Figure 5 The upper surface of the first insulating portion 131 and the radially inner peripheral surface of the first insulating portion 131 are shown. This improves the electrical insulation, sealing, and corrosion resistance of the connection points between the end cap 12, the insulating ring 13, and the housing body 11, thereby extending the service life of the battery casing 100.

[0044] In some embodiments of the present invention, such as Figure 5 As shown, the shell sidewall 112 has a raised rib 1121 protruding into the receiving cavity 101. The raised rib 1121 cooperates with the flange 113 to define a fixing groove. The insulating ring 13 is fixed in the fixing groove and wraps around the periphery of the end cap 12. This improves the installation efficiency between the end cap 12, the insulating ring 13 and the shell body 11, and enhances the connection reliability between the end cap 12, the insulating ring 13 and the shell body 11.

[0045] In some examples, such as Figure 5 As shown, the rib 1121 is formed by protruding from a portion of the shell sidewall 112 toward the center of the receiving cavity 101. For example, the rib 1121 is formed by bending a portion of the shell sidewall 112. This simplifies the structure of the shell body 11 and facilitates processing.

[0046] In some embodiments of the present invention, such as Figure 6 As shown, the insulating coating 20 includes an adhesion layer 21 and a protective layer 22 stacked in the thickness direction. The adhesion layer 21 is disposed on the outer surface of the housing 10 away from the receiving cavity 101, and the protective layer 22 is disposed on the side surface of the adhesion layer 21 away from the housing 10.

[0047] The housing 10 defines a receiving cavity 101 for accommodating the electrode assembly 400 and the electrolyte. The battery housing 100 may also have terminals electrically connected to the electrode assembly 400. At least a portion of the housing 10 may be metallic; for example, the housing 10 may include a housing body 11 and an end cap 12, wherein either the housing body 11 or the end cap 12 may be made of stainless steel, aluminum, or an aluminum alloy. In some examples, the housing 10 may be cuboid in shape, or it may be cylindrical.

[0048] The side of the housing 10 facing away from the receiving cavity 101 is the outer surface of the housing 10. The insulating coating 20 is a coating with insulating properties and is disposed on the outer surface of the housing 10. For example, the insulating coating 20 can be applied to the outer surface of the housing 10 by spraying or coating, or it can be formed on the outer surface of the housing 10 by impregnation, or it can be formed on the outer surface of the housing 10 by printing or vapor deposition. By providing the insulating coating 20 on the outer surface of the housing 10, the insulating coating 20 can protect and insulate the housing 10, improving the protective and insulating performance of the battery cell 1. At the same time, compared with the method of setting insulating parts on the outside of the housing 10 by means of film or heat shrink tubing, the insulating coating 20 in this embodiment has a high degree of adhesion to the housing 10, the connection is more reliable, and the risk of deformation and peeling of the insulating coating 20 can be reduced.

[0049] The insulating coating 20 of this embodiment includes an adhesion layer 21 and a protective layer 22. The adhesion layer 21 is configured to adhere to the outer surface of the housing 10. Furthermore, the adhesion layer 21 is configured to adhere to the outer surface of the housing 10 without surface pretreatment. That is, the outer surface of the housing 10 does not need to undergo surface pretreatment, and the adhesion layer 21 can still effectively and reliably adhere to the outer surface of the housing 10. Thus, during the processing of the battery housing 100, there is no need to perform surface pretreatment on the outer surface of the housing 10, thereby reducing processing steps, improving the processing and assembly efficiency of the battery housing 100, and reducing processing costs.

[0050] It should be noted that in this embodiment, the adhesion layer 21 is directly attached to the outer surface of the housing 10 without surface pretreatment. The adhesion force (interfacial bonding strength or interfacial shear strength) between the adhesion layer 21 and the outer surface of the housing 10 can reach the preset adhesion force between the housing 10 and the insulating coating 20, thus meeting the connection strength requirements between the insulating coating 20 and the housing 10. For example, the adhesion force between the adhesion layer 21 and the outer surface of the housing 10 reaches level 0 (tested using the ISO2409 cross-cut test).

[0051] The insulating coating 20 also includes a protective layer 22, which is disposed on the side of the attachment layer 21 facing away from the outer surface of the housing 10. That is, the protective layer 22 is attached to the side of the attachment layer 21 facing away from the outer surface of the housing 10. In this embodiment, by setting the attachment layer 21 to attach the protective layer 22 to the outer surface of the housing 10, the connection strength between the insulating coating 20 and the outer surface of the housing 10 can be improved, reducing the risk of deformation and detachment of the insulating coating 20, and ensuring the insulation performance of the battery casing 100. It should be noted that the protective layer 22 is an insulating coating. The protective layer 22 can isolate the outer surface of the housing 10 from the external environment, reducing the risk of the housing 10 being scratched or worn through, and extending the service life of the battery casing 100.

[0052] During the processing of the insulating coating 20, an adhesion layer 21 can be sprayed onto the outer surface of the housing 10 first. After the adhesion layer 21 has initially cured or cured to its final shape, a protective layer 22 can be sprayed onto the surface of the adhesion layer 21. The protective layer 22 can be a single layer or multiple layers. The curing method for the adhesion layer 21 and the protective layer 22 can be UV curing.

[0053] In this embodiment, the insulating coating 20 includes an attachment layer 21 and a protective layer 22, and the protective layer 22 is attached to the outer surface of the housing 10 through the attachment layer 21. Thus, the insulating coating 20 can protect the housing 10 and reduce the risk of the housing 10 being scratched. The attachment layer 21 can improve the connection strength between the insulating coating 20 and the housing 10, reduce the risk of deformation and detachment of the insulating coating 20, ensure the insulation performance of the battery casing 100, and improve the service life of the battery cell 1.

[0054] In some embodiments of the present invention, the outer surface of the housing 10 is configured not to undergo physical surface pretreatment and / or chemical surface pretreatment. This reduces processing steps, lowers processing costs, and improves processing efficiency.

[0055] In some embodiments of the present invention, at least a portion of the housing 10 is made of metal (e.g., the housing body 11 and end cap 12 described below), wherein the metal material of the housing 10 includes a metal substrate body and an anti-corrosion layer formed on the surface of the metal substrate body, wherein the anti-corrosion layer can be a plating layer, for example, a nickel plating layer or a chromium plating layer. This improves the corrosion resistance of the metal material of the housing 10.

[0056] In some embodiments of the present invention, the interfacial bonding strength between the adhesion layer 21 and the outer surface of the housing 10 is greater than the interfacial bonding strength between the protective layer 22 and the outer surface of the housing 10. This improves the connection strength between the insulating coating 20 and the outer surface of the housing 10, reduces the risk of the insulating coating 20 detaching, and ensures the insulating protective effect of the insulating coating 20 on the housing 10.

[0057] In some embodiments of the present invention, the protective layer 22 is an acrylic coating, an epoxy coating, or a polyurethane coating; and / or, the adhesion layer 21 is an acrylic coating, an epoxy coating, or a polyurethane coating.

[0058] Acrylic coatings are polymer coating systems formed by free radical polymerization or silane and epoxy modification with acrylate or methacrylate as the core monomers. The core of the coating consists of an insulating resin matrix, functional fillers (such as boron nitride and alumina) and adhesion promoters (phosphate esters and silane coupling agents).

[0059] The acrylic coating system exhibits high volume resistivity and a breakdown voltage greater than or equal to 20kV / mm, effectively blocking current conduction and ensuring the insulation performance of the insulating coating 20. Furthermore, the acrylic coating system achieves grade 0 adhesion to metal substrates using the cross-cut adhesion test and a tensile strength ≥3MPa, ensuring a strong bond between the insulating coating 20 and the shell 10, preventing peeling. Simultaneously, the acrylic coating system demonstrates excellent resistance to chemical corrosion and damp heat aging, withstanding environmental temperatures ranging from -40℃ to 120℃, resulting in high reliability.

[0060] Epoxy coating is a polymer coating with epoxy resin as the base material, which undergoes a cross-linking reaction with amine and acid anhydride curing agents to form a three-dimensional network structure. Insulating fillers such as alumina and silica can be added as needed. Epoxy coating has a high volume resistivity and a breakdown voltage greater than or equal to 30kV / mm, effectively blocking current conduction and ensuring the insulation performance of the insulating coating 20. The epoxy coating is tightly bonded to the metal substrate through chemical bonds, achieving a cross-cut adhesion grade of 0 and a pull-out strength ≥4MPa, ensuring a strong bond between the insulating coating 20 and the shell 10 that is not easily peeled off. Simultaneously, the epoxy coating exhibits good resistance to chemical corrosion and damp heat aging, and can withstand environmental temperatures ranging from -40℃ to 150℃, demonstrating high reliability.

[0061] The polyurethane coating is a material system that uses polyurethane resin as the core base material (generated by the reaction of isocyanate and polyol), combined with curing agents and functional fillers (such as insulating and wear-resistant fillers). Through the cross-linking reaction of isocyanate and active hydrogen, a dense polymer coating is formed. The polyurethane coating forms urea bonds with the metal substrate, achieving a cross-cut adhesion grade of 0 and a tensile strength ≥3MPa. This improves the adhesion between the insulating coating 20 and the shell 10, ensuring a strong bond between them. The polyurethane coating has a high volume resistivity and a breakdown voltage ≥15kV / mm, effectively guaranteeing the insulation performance of the insulating coating 20. Simultaneously, the polyurethane coating exhibits good flexibility, enhancing its impact and vibration resistance and reducing the risk of cracking. Furthermore, the polyurethane coating demonstrates excellent weather resistance and chemical corrosion resistance, withstanding environmental temperatures ranging from -40℃ to 120℃, exhibiting high durability and reliability.

[0062] It should be noted that when the adhesion layer 21 and the protective layer 22 are the aforementioned acrylic coating, epoxy coating, or polyurethane coating, the insulation performance, adhesion performance, mechanical strength, color, and photocuring performance of the adhesion layer 21 and the protective layer 22 can be adjusted by adding different components. Specifically, by adding different components, the materials of the adhesion layer 21 and the protective layer 22 are different, and their functions and effects are also different.

[0063] In some embodiments of the present invention, reference is made to... Figure 6 The thickness of the adhesion layer 21 can be 15μm-25μm, and / or the thickness of the protective layer 22 can be 75μm-85μm. For example, the thickness of the adhesion layer 21 can be 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm or 25μm, and the thickness of the protective layer 22 can be 75μm, 76μm, 77μm, 78μm, 79μm, 80μm, 81μm, 82μm, 83μm, 84μm or 85μm.

[0064] In this embodiment, by making the thickness of the adhesion layer 21 greater than or equal to 15 μm and less than or equal to 20 μm, the adhesion layer 21 can form an effective and dense insulating film layer, ensuring the insulation performance of the adhesion layer 21, ensuring a reliable and effective connection with the outer surface of the housing 10, and also ensuring the heat dissipation effect of the adhesion layer 21, reducing the risk of vibration cracking of the adhesion layer 21. By making the thickness of the protective layer 22 greater than or equal to 75 μm and less than or equal to 85 μm, the protective effect on the housing 10 can be improved, and the risk of vibration cracking caused by excessive thickness of the protective layer 22 can also be avoided.

[0065] In some embodiments of the present invention, the adhesion layer 21 is an insulating layer and / or a thermally conductive layer; that is, the adhesion layer 21 may be only an insulating layer, or it may be only a thermally conductive layer, or it may be an insulating and thermally conductive layer. Thus, the adhesion layer 21 can enhance the bonding strength between the housing 10 and the insulating coating 20, while also providing insulating and / or thermally conductive functions, thereby improving the insulating effect of the insulating coating 20 and ensuring the heat dissipation performance of the battery casing 100.

[0066] In some embodiments of the present invention, the protective layer 22 is an insulating layer, a thermally conductive layer, a wear-resistant layer, a flame-retardant layer, and / or an anti-aging layer. That is, the protective layer 22 can be a single layer, possessing at least one of the properties of insulation, thermal conductivity, wear resistance, flame retardancy, and anti-aging. Alternatively, the protective layer 22 can be multiple layers, each possessing at least one of the properties of insulation, thermal conductivity, wear resistance, flame retardancy, and anti-aging. When the protective layer 22 is multiple layers, each layer has a different protective performance. Thus, the insulating coating 20 can possess the functions of insulation, thermal conductivity, wear resistance, flame retardancy, and anti-aging, improving the service life of the battery casing 100 and ensuring the operational safety of the battery cell 1.

[0067] In some embodiments of the present invention, reference is made to... Figure 4 and Figure 5 The insulating coating 20 includes a coating body area 23 and a coating edge area 24. The coating edge area 24 is connected to the periphery of the coating body area 23 and extends in a ring shape along the circumference of the coating body area 23. The thickness of the coating body area 23 is greater than the thickness of the coating edge area 24.

[0068] It should be noted that when the periphery of the edge of the insulating coating is perpendicular to the surface of the metal substrate, the edge of the insulating coating will form a huge stress concentration point. When the battery device is subjected to vibration and thermal cycling for a long time, stress will accumulate at this point due to the difference in thermal expansion coefficients between the insulating coating and the metal substrate. This can easily cause the insulating coating to crack, peel up, or peel off over a large area starting from the edge.

[0069] In this embodiment, by setting a coating edge region 24 around the periphery of the coating body region 23 and making the thickness of the coating edge region 24 less than the thickness of the coating body region 23, the height difference between the edge position of the insulating coating 20 and the surface of the housing 10 can be reduced, the concentrated stress between the edge position of the insulating coating 20 and the housing 10 can be reduced, the risk of cracking and peeling of the insulating coating 20 can be reduced, and the risk of the insulating coating 20 scratching adjacent battery cells 1 due to the sharp boundary at the boundary can also be reduced.

[0070] In some embodiments of the present invention, reference is made to... Figure 4 and Figure 5The thickness of the coating body region 23 is 90μm-110μm. For example, the thickness of the coating body region 23 can be 90μm, 92μm, 94μm, 96μm, 98μm, 100μm, 102μm, 104μm, 106μm, 108μm, or 110μm. In this embodiment, by making the thickness of the coating body region 23 greater than or equal to 90μm and less than or equal to 110μm, an effective and dense insulating film layer can be formed, ensuring the insulation performance of the coating body region 23. It also avoids curing shrinkage stress caused by excessive thickness, ensuring the connection strength between the insulating coating 20 and the shell 10, and reducing the risk of the insulating coating 20 peeling off. In addition, it also ensures the heat dissipation performance of the battery shell 100.

[0071] In some embodiments of the present invention, reference is made to... Figure 4 and Figure 5 In the direction from the coating body region 23 toward the coating edge region 24, the thickness of the coating edge region 24 gradually decreases. In this embodiment, by making the thickness of the coating edge region 24 gradually decrease in the direction away from the coating body region 23, a gentle slope can be formed in the coating edge region 24. This can effectively disperse and release stress, improve the adhesion and long-term reliability of the insulating coating 20 in the coating edge region 24, and ensure the integrity of the insulating barrier of the battery casing 100.

[0072] According to a second aspect of the present invention, a battery cell 1 includes a battery casing 100 and an electrode assembly 400, wherein the electrode assembly 400 is disposed within the battery casing 100.

[0073] The electrode assembly 400 may include a positive electrode, a negative electrode, and an insulating separator, with the insulating separator disposed between the positive and negative electrode. The electrode assembly 400 includes a positive electrode tab and a negative electrode tab. The battery casing 100 may have a positive electrode post 200 and a negative electrode post 300, with the positive electrode tab connected to the positive electrode post 200 and the negative electrode tab connected to the negative electrode post 300.

[0074] According to the battery cell 1 of the present invention, by providing the battery casing 100 of the first aspect embodiment, the connection strength between the insulating coating 20 and the casing 10 can be improved, the risk of deformation and peeling of the insulating coating 20 can be reduced, the insulation performance of the battery casing 100 can be guaranteed, and the service life of the battery cell 1 can be improved.

[0075] According to a second aspect of the present invention, a battery device includes a housing and a battery cell 1 according to the second aspect of the present invention. The battery cell 1 is disposed in the housing, and there may be multiple battery cells 1.

[0076] According to the battery device of the present invention, by providing the battery cell 1 of the second aspect embodiment described above, the connection strength between the insulating coating 20 and the housing 10 is improved, the risk of deformation and peeling of the insulating coating 20 is reduced, the insulation performance of the battery housing 100 is guaranteed, the service life of the battery cell 1 is improved, thereby improving the overall performance of the battery device.

[0077] In the description of this invention, 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," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0078] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0079] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0080] 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 the present invention. 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.

[0081] Although embodiments of the invention 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 the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery casing (100), characterized in that, include: A housing (10) having an inner cavity (101) defined therein and comprising: a housing body (11), an end cap (12), and an insulating ring (13). The housing body (11) has an opening on one side in a first direction. The end cap (12) is connected to the housing body (11) and covers the opening. The insulating ring (13) extends in a ring shape along the circumference of the end cap (12). The insulating ring (13) is disposed between the end cap (12) and the housing (10) to insulate the end cap (12) from the housing (10). An insulating coating (20) is provided on the outer surfaces of at least two of the shell body (11), the end cap (12), and the insulating ring (13).

2. The battery casing (100) according to claim 1, characterized in that, The insulating ring (13) includes a first insulating portion (131), a portion of which protrudes from the outer side of the housing body (11) and the end cap (12) opposite to the receiving cavity (101). Wherein, the insulating coating (20) at least covers the seam area between the first insulating part (131) and the shell body (11), and / or, the insulating coating (20) at least covers the seam area between the first insulating part (131) and the end cap (12).

3. The battery casing (100) according to claim 2, characterized in that, The shell body (11) is cylindrical and includes a bottom wall (111) and a side wall (112). The side wall (112) is connected to the bottom wall (111) and extends in a ring along the circumference of the bottom wall (111). The end of the side wall (112) facing away from the bottom wall (111) is bent towards the side where the receiving cavity (101) is located to form a flange (113). The flange (113) is ring-shaped and defines the opening on its inner side. The first insulating part (131) is disposed between the flange (113) and the end cap (12), and in the radial direction of the opening, the radial inner end of the first insulating part (131) extends beyond the inner edge of the flange (113).

4. The battery casing (100) according to claim 3, characterized in that, The insulating coating (20) covers at least a portion of the flange (113) away from the outer surface of the receiving cavity (101), and the insulating coating (20) covering the flange (113) is spaced apart from the first insulating portion (131); or, In the radial direction of the insulating ring (13), the insulating coating (20) extends inward from the outer surface of the flange (113) to the exposed surface of the first insulating portion (131); or, In the radial direction of the insulating ring (13), the insulating coating (20) extends outward from the outer surface of the end cap (12) opposite to the receiving cavity (101) to the exposed surface of the first insulating portion (131); or, In the radial direction of the insulating ring (13), the insulating coating (20) extends from the outer surface of the flange (113) to the outer surface of the end cap (12) and completely covers the exposed surface of the insulating ring (13).

5. The battery casing (100) according to claim 3, characterized in that, The shell sidewall (112) is formed with a raised rib (1121) protruding toward the receiving cavity (101). The raised rib (1121) cooperates with the flange (113) to define a fixing groove. The insulating ring (13) is fixed in the fixing groove and wraps around the periphery of the end cap (12).

6. The battery casing (100) according to any one of claims 1-5, characterized in that, The insulating coating (20) includes a coating body area (23) and a coating edge area (24). The coating edge area (24) is connected to the periphery of the coating body area (23) and extends in a ring shape along the circumference of the coating body area (23). The thickness of the coating body area (23) is greater than the thickness of the coating edge area (24).

7. The battery casing (100) according to claim 6, characterized in that, The thickness of the coating body region (23) is 90μm-110μm, and / or the thickness of the coating edge region (24) gradually decreases in the direction from the coating body region (23) toward the coating edge region (24).

8. The battery casing (100) according to any one of claims 1-5, characterized in that, The insulating coating (20) includes an attachment layer (21) and a protective layer (22) stacked in the thickness direction. The attachment layer (21) is disposed on the outer surface of the housing (10) away from the receiving cavity (101), and the protective layer (22) is disposed on the side surface of the attachment layer (21) away from the housing (10).

9. The battery casing (100) according to claim 8, characterized in that, The protective layer (22) is an acrylic coating, an epoxy coating, or a polyurethane coating; and / or, the adhesion layer (21) is an acrylic coating, an epoxy coating, or a polyurethane coating.

10. The battery casing (100) according to claim 8, characterized in that, The thickness of the adhesion layer (21) is 15μm-25μm, and / or the thickness of the protective layer (22) is 75μm-85μm.

11. The battery casing (100) according to claim 8, characterized in that, The adhesion layer (21) is an insulating layer and / or a thermally conductive layer; and / or, the protective layer (22) is an insulating layer, a thermally conductive layer, a wear-resistant layer, a flame-retardant layer and / or an anti-aging layer.

12. A battery cell (1), characterized in that, include: Battery casing (100) according to any one of claims 1-11; An electrode assembly (400) is disposed within the battery casing (100).

13. A battery device, characterized in that, It includes a housing and a battery cell (1) according to claim 12, wherein the battery cell (1) is disposed in the housing.

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