Battery case, battery

Abstract

The application discloses a battery shell and a battery, and belongs to the technical field of batteries.The battery shell comprises a shell body, the shell body comprising a first side wall and a second side wall arranged at an included angle, the first side wall and the second side wall being connected to each other and forming a corner structure between the first side wall and the second side wall; an insulating coating, the insulating coating comprising a first insulating coating arranged on the surface of the first side wall, a second insulating coating arranged on the surface of the second side wall, and a corner coating connecting the first insulating coating and the second insulating coating; the thickness of the first insulating coating is t0, the maximum thickness of the second insulating coating is t1, and 0 < t1-t0 <= 2.5 mm is satisfied.The application not only ensures that the corner coating is smooth and has moderate thickness when the insulating paste coated on the surface of the second side wall and the corner structure is solidified, but also makes the internal stress generated when the insulating paste coated on the second side wall is solidified small, thereby improving the insulating performance and the adhesion of the insulating coating on the surface of the shell body.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery casing and a battery. Background Technology

[0002] To improve battery safety, an insulating layer is usually placed on the surface of the battery body. The two most common insulating layers are PET heat shrink tubing or PET tape. PET heat shrink tubing shrinks and wraps around the surface of the battery casing after being heated, while PET tape adheres to the surface of the battery casing through its own adhesive layer. The adhesion between the insulating layer and the battery body of these two structures is low. The insulating layer is easy to fall off after it is damaged, which leads to the failure of the insulation performance of the battery body. This can easily cause external short circuits, fires, and other phenomena, thus reducing the battery's safety performance.

[0003] To address the aforementioned issues, related technologies involve applying an insulating coating to the surface of the battery body to improve the adhesion between the insulating coating and the battery body. However, during the slurry application process, when the thickness of the slurry applied to the upper and lower surfaces of the battery casing is relatively thin, the resulting coating exhibits poor insulation performance. Conversely, when the thickness of the applied slurry is relatively thick, the resulting insulating coating exhibits lower adhesion to the casing. Utility Model Content

[0004] The embodiments of this application provide a battery casing and a battery, which can improve the technical problems of poor insulation performance of the battery casing and easy peeling of the insulating coating.

[0005] In a first aspect, embodiments of this application provide a battery casing, comprising: The shell body includes at least a first sidewall and a second sidewall arranged at an angle, the first sidewall and the second sidewall are connected to each other, and a corner structure is formed between the first sidewall and the second sidewall; The insulating coating includes a first insulating coating disposed on the surface of a first sidewall, a second insulating coating disposed on the surface of a second sidewall, and a corner coating connecting the first insulating coating and the second insulating coating; The thickness of the first insulating coating is t0, and the maximum thickness of the second insulating coating is t1, satisfying the condition: 0 < t1 - t0 ≤ 2.5 mm.

[0006] This application sets the maximum thickness t1 of the second insulating coating to be greater than the thickness t0 of the first insulating coating. This not only ensures that the thickness of the second insulating coating is moderate, but also ensures that the corner coating formed on the corner structure surface is smooth and of moderate thickness during the curing and leveling process of the insulating slurry applied to the second sidewall and corner structure surface. This improves the insulation performance and the adhesion of the insulating coating to the surface of the shell body. At the same time, by setting the maximum thickness t1 of the second insulating coating to be less than 2.5 mm, the volume shrinkage of the insulating slurry applied to the second sidewall is small during the curing and leveling process, the difference in curing speed between the slurry surface and the interior is small, and the generated internal stress is small, thereby improving the adhesion of the insulating coating to the surface of the shell body.

[0007] Optionally, the corner coating has an arc-shaped structure, and the minimum thickness of the corner coating is t2. The minimum thickness t2 of the corner coating and the thickness t0 of the first insulating coating satisfy: t0×30%≤t2≤t0×100%.

[0008] By reasonably setting the minimum thickness t2 of the corner coating, this application not only ensures the superior insulation performance of the corner coating and prevents the risk of the shell body being exposed when the corner coating is too thin, but also ensures that the internal stress generated by the insulating slurry during the curing process is small, thereby improving the adhesion of the corner coating to the surface of the shell body.

[0009] Optionally, the second insulating coating includes an arc-shaped portion located at the end of the second insulating coating away from the corner coating; the radius of the arc-shaped portion is r1, and the radius of the corner coating is r2, satisfying: r1≥r2.

[0010] This application ensures that the internal stress generated in the arc-shaped part during the curing process of the insulating slurry is less than that generated in the corner coating by controlling the radius r1 of the arc-shaped part to be no less than the radius r2 of the corner coating. This prevents the slurry from flowing from the corner coating to the arc-shaped part, so that the thickness of the corner coating can meet the insulation performance requirements.

[0011] Optionally, the angle between the tangent at the intersection of the arc-shaped portion and the second sidewall and the second sidewall is θ, satisfying: 100°≤θ<180°.

[0012] This application optimizes the internal stress generated before the arc-shaped part is cured by setting the angle θ between the tangent at the intersection of the arc-shaped part and the second sidewall and the second sidewall. This reduces cracking during the curing process of the slurry and prevents the slurry from flowing from the corner coating to the arc-shaped part, thus ensuring that the arc-shaped part is at a suitable thickness and improving the adhesion of the arc-shaped part to the surface of the shell body.

[0013] Optionally, the thickness of the first sidewall is t3, and the thickness of the first insulating coating t0 and the thickness of the first sidewall t3 satisfy: t3×5%≤t0≤t3×95%.

[0014] This application achieves better mechanical strength and insulation performance by reasonably setting the thickness t0 of the first insulating coating. At the same time, it reduces the internal stress generated during the curing process of the first insulating coating, thereby improving the adhesion of the first insulating coating to the surface of the shell body.

[0015] Optionally, the second sidewall includes a first sub-sidewall and a second sub-sidewall extending along a second direction. The first sub-sidewall and the second sub-sidewall are disposed at opposite ends of the first sidewall in a first direction, and at least one of the first sub-sidewall or the second sub-sidewall is provided with at least one pole post through hole.

[0016] This application provides conditions for setting the terminals by setting through holes, thereby enabling the battery to connect with the external circuit, ensuring stable power output, achieving low impedance current conduction, and reducing power loss.

[0017] Optionally, at least one pole post through hole is provided on the first sub-side wall.

[0018] This application provides a battery with a more stable connection to an external circuit by providing at least one terminal through-hole on the first sub-sidewall.

[0019] Optionally, at least a portion of the first sub-sidewall is covered with a second insulating coating, the width of the second insulating coating on the first sub-sidewall along the second direction being x1, satisfying: 1.5mm≤x1≤10mm, and the first and second directions intersecting each other.

[0020] This application ensures a larger creepage distance and electrical clearance between adjacent batteries in the battery pack by setting the width x1 of the second insulating coating on the first sub-sidewall along the second direction to 1.5mm~10mm, thereby improving battery safety. Simultaneously, it ensures that the busbar welding area is within 15mm². 2 The above measures ensure high current transmission, guarantee the strength of the connection structure, and maintain the stability of the conductive path.

[0021] Optionally, a sealing structure is provided at the connection between the second sub-sidewall and the first sidewall. The sealing structure is used to seal the connection between the second sub-sidewall and the first sidewall, and the sealing structure is wrapped in an insulating coating.

[0022] This application improves the corrosion resistance and insulation performance of the casing body by wrapping the edge sealing structure in the insulating coating, thereby increasing the battery's service life.

[0023] Optionally, the second insulating coating further includes an extension disposed between the arcuate portion and the corner coating.

[0024] This application, by providing an extension, makes the transition between the arc-shaped portion and the corner coating smoother, increases the contact area and bonding strength between the second insulating coating and the corner coating, and allows the arc-shaped portion, corner coating and extension to better form an integrated structure, thereby improving the strength of the insulating coating and improving the insulation performance of the battery casing.

[0025] Optionally, the roughness Rz of the surface of the first sidewall near the first insulating coating and the surface of the second sidewall near the second insulating coating is ≤50μm.

[0026] The surface roughness Rz of the first and second sidewalls of this application does not exceed 50 μm. The low roughness indicates that the surface of the housing body does not need to be roughened, thus avoiding the metal dust generated during the roughening process from affecting the insulation performance of the insulating coating and reducing the adverse effects of metal dust on product quality and safety.

[0027] Optionally, the insulating coating includes one of a polyurethane coating and a polyacrylate coating; and / or, the housing body includes one of a stainless steel housing, a nickel-plated steel strip housing, an aluminum alloy housing, and a titanium alloy housing.

[0028] This application sets the insulating coating as either a polyurethane coating or a polyacrylate coating. The polyurethane coating or the polyacrylate coating can bond tightly to the surface of the casing body, improving the adhesion of the insulating coating to the surface of the casing body without roughening. By reasonably setting the type of casing body, the strength, corrosion resistance and stability of the casing body are ensured, thereby improving the battery life.

[0029] Secondly, embodiments of this application provide a battery, comprising: The battery housing provided in the first aspect of this application has a cavity inside the battery housing; The battery cell is located inside the cavity of the battery casing.

[0030] This application provides a battery casing on the surface of the battery cell, which enables the battery to have better insulation performance and the insulation performance to be stable and durable, thereby improving the battery's service life.

[0031] Optionally, the battery further includes at least one terminal post, which is disposed in a terminal post through hole. The area of ​​the plane containing the terminal post is s0, and the coverage area of ​​the insulating coating on the plane containing the terminal post is s1, satisfying: 0.12≤s1 / s0≤0.95.

[0032] This application improves battery safety by rationally setting the ratio of the area s0 of the plane where the terminal post is located to the coverage area s1 of the insulating coating on the plane where the terminal post is located. This results in a larger creepage distance and electrical clearance between adjacent batteries in the battery pack, better battery insulation performance, and improved battery safety. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of a first-type battery casing provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a second type of battery casing provided in an embodiment of this application; Figure 3 yes Figure 1 Enlarged view of A in the middle; Figure 4 yes Figure 1 Enlarged view of B in the middle; Figure 5 yes Figure 2 Enlarged view of C in the middle; Figure 6 This is a schematic diagram of the structure of a third type of battery casing provided in an embodiment of this application; Figure 7 yes Figure 6 Enlarged view of D; Figure 8 This is a schematic diagram of the structure of the fourth type of battery casing provided in the embodiments of this application; Figure 9 This is a schematic diagram of the structure of a first-type battery provided in an embodiment of this application; Figure 10 yes Figure 9 Top view; Figure 11 This is a schematic diagram of the structure of a second type of battery provided in an embodiment of this application; Figure 12 yes Figure 11 Top view.

[0035] Explanation of reference numerals in the attached figures: 100. Battery casing; 10. Casing body; 11. First sidewall; 12. Second sidewall; 13. Sealing structure; 121. First sub-sidewall; 122. Second sub-sidewall; 123. Terminal through hole; 20. Insulating coating; 21. First insulating coating; 22. Second insulating coating; 23. Corner coating; 221. Arc-shaped portion; 222. Extension portion; 200. Battery; 101. Battery cell; 102. Terminal; 103. Explosion-proof valve. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "inner" and "outer" refer to the outline of the device.

[0037] In the description of this application, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, "at least one" means one or more, and "multiple" means two or more, unless otherwise explicitly specified. In this application, unless otherwise stated, directional terms such as "inner" and "outer" refer to the outline of the device.

[0038] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Additionally, in the description of this application, the term "comprising" means "including but not limited to".

[0039] The technical solution of this application is as follows: Firstly, this application provides a battery casing 100, please refer to... Figures 1 to 8 , Figure 1 , Figure 2 , Figure 6 and Figure 8This is a schematic diagram of the structure of the battery casing 100 provided in the embodiment of this application. The battery casing 100 includes a casing body 10 and an insulating coating 20. The casing body 10 includes at least a first sidewall 11 and a second sidewall 12 arranged at an angle, the first sidewall 11 and the second sidewall 12 are connected to each other, and a corner structure is formed between the first sidewall 11 and the second sidewall 12. The insulating coating 20 includes a first insulating coating 21 disposed on the surface of the first sidewall 11, a second insulating coating 22 disposed on the surface of the second sidewall 12, and a corner coating 23 connecting the first insulating coating 21 and the second insulating coating 22. The thickness of the first insulating coating 21 is t0, and the maximum thickness of the second insulating coating 22 is t1, satisfying: 0 < t1 - t0 ≤ 2.5 mm, for example, it can be 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, or 2.5 mm.

[0040] In this application, by first setting the maximum thickness t1 of the second insulating coating 22 to be greater than the thickness t0 of the first insulating coating 21, it is ensured that the thickness of the second insulating coating 22 is moderate, thereby resulting in better insulation performance on the surface of the second sidewall 12. Furthermore, it ensures that during the curing and leveling process of the insulating slurry applied to the second sidewall 12 and the corner structure surface, the corner coating 23 formed on the corner structure surface is smooth and of moderate thickness. This not only ensures better insulation performance at the corner structure and prevents the problem of easy exposure of the shell body 10 due to a thin corner coating 23, but also… This design allows the first insulating coating 21, the second insulating coating 2, and the corner coating 23 to form an integrated structure, improving the adhesion of the insulating coating 20 to the surface of the housing body 10. Secondly, by setting the maximum thickness t1 of the second insulating coating 22 to less than 2.5 mm, the insulating slurry coated on the second sidewall 12 experiences less volume shrinkage during curing and leveling, resulting in a smaller difference in curing speed between the slurry surface and the interior, and thus less internal stress. This reduces the "peel force" between the insulating coating 20 and the housing body 10, thereby improving the adhesion of the insulating coating 20 to the surface of the housing body 10. In other words, by reasonably controlling the maximum thickness t1 of the second insulating coating 22, this application ensures that the insulating coating 20 formed on the surface of the housing body 10 has a complete and uninterrupted structure. This not only improves the insulation performance of the insulating coating 20 but also enhances its adhesion to the surface of the housing body 10, resulting in a battery housing 100 with excellent and stable insulation performance.

[0041] In some embodiments, please refer to Figure 3 and Figure 5 The corner coating 23 has an arc-shaped structure and a minimum thickness of t2. The minimum thickness t2 of the corner coating 23 and the thickness t0 of the first insulating coating 21 satisfy the following condition: t0×30%≤t2≤t0×100%. For example, t0 can be 30% t1, 50% t1, 70% t1, 90% t1, 100% t1, etc.

[0042] This application sets the corner coating 23 into an arc-shaped structure, so that the first insulating coating 21 and the second insulating coating 22 can be smoothly transitioned. Compared with the right-angle structure of the corner coating 23, the corner coating 23 has a lower risk of being bumped, which improves the adhesion of the entire insulating coating 20 to the surface of the housing body 10, thereby improving the insulation stability of the battery housing 100.

[0043] Understandably, by setting the minimum thickness t2 of the corner coating 23 to be greater than or equal to 30% of the thickness t0 of the first insulating coating 21, not only is the superior insulation performance of the corner coating 23 ensured, so that the insulation performance meets the requirements of 3000V withstand voltage and insulation resistance exceeding 1GΩ, but the risk of the shell body 10 being exposed when the corner coating 23 is too thin is also prevented. At the same time, by setting the minimum thickness t2 of the corner coating 23 to be less than the thickness t0 of the first insulating coating 21, the appropriate thickness makes the internal stress generated by the insulating slurry during the curing process smaller, thereby improving the adhesion of the corner coating 23 to the surface of the shell body 10.

[0044] In some embodiments, please refer to Figure 3 and Figure 5 The second insulating coating 22 includes an arc-shaped portion 221, which is located at the end of the second insulating coating 22 away from the corner coating 23. The radius of the arc-shaped portion 221 is r1, and the radius of the corner coating 23 is r2, satisfying that r1 ≥ r2. It can be understood that the radius r1 of the arc-shaped portion 221 refers to the radius of the circle containing the outer edge arc of the arc-shaped portion 221; the radius r2 of the corner coating 23 refers to the radius of the circle containing the outer edge arc of the corner coating 23.

[0045] This application improves the adhesion of the second insulating coating 22 to the surface of the housing body 10 by setting the second insulating coating 22 to include an arc-shaped portion 221. The arc-shaped structure enables the stress generated by the coated insulating slurry during the curing process to be evenly distributed along the arc direction, thereby avoiding problems such as the second insulating coating 22 falling off and cracking, and improving the insulation stability of the housing body 10.

[0046] It is understandable that by controlling the radius r1 of the arc-shaped part 221 to be no less than the radius r2 of the corner coating 23, the internal stress generated by the arc-shaped part 221 during the curing process of the insulating slurry is ensured to be less than the internal stress generated by the corner coating 23, thus preventing the slurry from flowing from the corner coating 23 to the arc-shaped part 221, and ensuring that the thickness of the corner coating 23 meets the requirements of insulation performance.

[0047] In some embodiments, please refer to Figure 3The angle between the tangent at the intersection of the arc-shaped part 221 and the second side wall 12 and the second side wall 12 is θ, which satisfies: 100°≤θ<180°, for example, it can be 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, 175°, etc.

[0048] This application sets the angle θ between the tangent at the intersection of the arc-shaped portion 221 and the second sidewall 12 and the second sidewall 12 to 100°≤θ<180°. This reduces the internal stress generated in the arc-shaped portion 221 before curing, minimizing cracking during the curing process and preventing the slurry from flowing from the corner coating 23 to the arc-shaped portion 221. This ensures the arc-shaped portion 221 has a suitable thickness, improving its adhesion to the surface of the housing body 10. Furthermore, it provides uniformity in the thickness of the insulating coating 20, allowing multiple batteries to adhere better and form a high-performance battery pack.

[0049] In some embodiments, please refer to Figure 3 and Figure 5 The thickness of the first sidewall 11 is t3. The thickness t0 of the first insulating coating 21 and the thickness t3 of the first sidewall 11 satisfy: t3×5%≤t0≤t3×95%. For example, it can be 5%t3, 10%t3, 20%t3, 30%t3, 40%t3, 50%t3, 60%t3, 70%t3, 80%t3, 90%t3, 95%t3, etc.

[0050] This application sets the thickness t0 of the first insulating coating 21 to be greater than 5% of the thickness t3 of the first sidewall 11, thereby giving the first insulating coating 21 better mechanical strength and insulation performance. At the same time, setting the thickness t0 of the first insulating coating 21 to be less than 95% of the thickness t3 of the first sidewall 11 avoids the first insulating coating 21 being too thick, thereby reducing the internal stress generated during the curing process of the first insulating coating 21, improving the adhesion of the first insulating coating 21 to the surface of the housing body 10, reducing the cost of the insulating coating 20, and increasing the energy density of the battery.

[0051] In some embodiments, please refer to Figure 1 and Figure 2 The second sidewall 12 includes a first sub-sidewall 121 and a second sub-sidewall 122 extending along a second direction. The first sub-sidewall 121 and the second sub-sidewall 122 are disposed at opposite ends of the first sidewall 11 in a first direction. At least one of the first sub-sidewall 121 or the second sub-sidewall 122 is provided with at least one pole post through hole 123.

[0052] This application provides conditions for setting the terminal 102 by setting the terminal through hole 123, thereby enabling the battery 200 to be connected to the external circuit, ensuring stable power output, achieving low impedance current conduction, and reducing power loss.

[0053] In some embodiments, at least one pole post through hole 123 is provided on the first sub-side wall 121.

[0054] This application provides at least one electrode through-hole 123 on the first sub-sidewall 121, thereby enabling the electrode 102 to exist on the first sub-sidewall 121, thus allowing the battery 200 to be connected to the external circuit more stably.

[0055] In some embodiments, at least a portion of the first sub-sidewall 121 is covered with a second insulating coating 22. The width of the second insulating coating 22 on the first sub-sidewall 121 along the second direction is x1, satisfying: 1.5mm ≤ x1 ≤ 10mm, for example, it can be 1.5mm, 3.5mm, 5.5mm, 7.5mm, 9.5mm, 10mm, etc., and the first direction and the second direction intersect each other. The first direction is... Figure 1 and Figure 2 The direction of the X-axis, the second direction is Figure 1 and Figure 2 The Y-axis is located in the direction of the X-axis, which is perpendicular to the Y-axis.

[0056] This application improves the insulation performance of the battery casing 100 by setting the width x1 of the second insulating coating 22 on the first sub-sidewall 121 along the second direction to be greater than or equal to 1.5 mm, ensuring a larger creepage distance and electrical clearance between adjacent batteries in the battery pack, thereby improving battery safety. Simultaneously, by setting the width x1 of the second insulating coating 22 on the first sub-sidewall 121 along the second direction to be less than or equal to 10 mm, it ensures that the busbar welding area is within 15 mm². 2 The above measures ensure high current transmission, guarantee the strength of the connection structure, and maintain the stability of the conductive path.

[0057] For example, the battery casing 100 is a cylinder.

[0058] In some embodiments, please refer to Figure 1 and Figure 4 A sealing structure 13 is provided at the connection between the second sub-side wall 122 and the first side wall 11. The sealing structure 13 is used to seal the connection between the second sub-side wall 122 and the first side wall. The sealing structure 13 is wrapped in the insulating coating 20.

[0059] This application improves the corrosion resistance and insulation performance of the casing body 10 by wrapping the edge sealing structure 13 in the insulating coating 20, so that the insulating coating 20 covers the cross-section of the casing body 10, thereby improving the battery's service life.

[0060] Please see Figure 4 It is understandable that the edge width of the sealing structure 13 is x3, and the width of the insulating coating 20 at the sealing structure 13 along the second direction is x2 (x2 is the sum of the width of the second insulating coating 22 at the sealing structure 13 and the thickness of the corner coating 23 in the second direction), satisfying: x3 < x2.

[0061] Please see Figure 8 It is understandable that the connection between the second sub-side wall 122 and the first side wall 11 is not provided with an edge sealing structure 13.

[0062] In some embodiments, please refer to Figure 5 The second insulating coating 22 also includes an extension 222, which is disposed between the arcuate portion 221 and the corner coating 23.

[0063] This application provides an extension 222 between the arc-shaped portion 221 and the corner coating 23. The extension 222 makes the transition between the arc-shaped portion 221 and the corner coating 23 smoother, increases the contact area and bonding strength between the second insulating coating 22 and the corner coating 23, and makes the arc-shaped portion 221, the corner coating 23 and the extension 222 better form an integrated structure, improves the strength of the insulating coating 20 and improves the insulation performance of the battery casing 100.

[0064] In some embodiments, the roughness Rz of the surface of the first sidewall 11 near the first insulating coating 21 and the surface of the second sidewall 12 near the second insulating coating 22 is ≤50μm, for example, it can be 10μm, 20μm, 30μm, 35μm, 40μm, 50μm, etc., where surface refers to the surface of the first sidewall 11 and the second sidewall 12 that is in contact with the insulating coating 20.

[0065] The surface roughness Rz of the first sidewall 11 near the first insulating coating 21 and the second sidewall 12 near the second insulating coating 22 does not exceed 50 μm. The low roughness means that the surface of the housing body 10 (referring to the surface of the housing body 10 in the area covered by the insulating coating 20) does not need to be roughened. This avoids the metal dust generated during the roughening process from affecting the insulating performance of the insulating coating 20, reduces the adverse effects of metal dust on product quality and safety, and improves the safety of the processing process, thus avoiding the problem of metal dust explosion.

[0066] In some embodiments, the insulating coating 20 includes a polyurethane coating or a polyacrylate coating; and / or, the housing body 10 includes a stainless steel housing, a nickel-plated steel strip housing, an aluminum alloy housing, or a titanium alloy housing.

[0067] This application uses an insulating coating 20, either a polyurethane coating or a polyacrylate coating, to achieve a tight bond with the surface of the casing 10. Simultaneously, the insulating coating 20 is anchored to the micro-recessed structure on the surface of the casing 10, improving the adhesion of the insulating coating 20 to the casing 10 surface without roughening. This solves the problem of low adhesion between the unroughened casing 10 and the insulating coating 20, thus improving battery safety. Furthermore, both polyurethane and polyacrylate coatings exhibit good thermal stability, with a thermal weight loss ratio ≤10% at 200℃, ensuring good insulation performance of the battery casing 100 under thermal runaway temperatures of 160~180℃. Moreover, the thermal conductivity of both polyurethane and polyacrylate coatings is ≥0.30 W / (m·K), which is superior to the 0.2 W / (m·K) of existing products.

[0068] It is understandable that by setting the housing body 10 to one of stainless steel housing, nickel-plated steel strip housing, aluminum alloy housing, or titanium alloy housing, the strength, corrosion resistance, and stability of the housing body 10 are ensured, thereby improving the battery life.

[0069] In some embodiments, when the roughness Rz of the surface of the first sidewall 11 near the first insulating coating 21 and the surface of the second sidewall 12 near the second insulating coating 22 is 35≤Rz≤50μm, the insulating coating 20 is a single layer; when the roughness Rz of the surfaces of the first sidewall 11 and the second sidewall 12 is <35μm, the insulating coating 20 is an N-layer, where N≥2.

[0070] Please see Figure 6 and Figure 7 It is understood that when the insulating coating 20 has N layers (N≥2), the coating provided on the surface of the second sidewall 12 in each layer may include an extension 222 or may not include an extension 222.

[0071] This application sets different numbers of insulating coatings 20 according to the different surface roughness Rz of the first sidewall 11 and the second sidewall 12, and sets the corresponding insulating coatings 20 according to the actual situation, thereby improving the adhesion of the insulating coatings 20 to the surface of the housing body 10.

[0072] It is understandable that when the surface roughness Rz of the first sidewall 11 and the second sidewall 12 satisfies 35≤Rz≤50μm, the relatively large roughness Rz allows a single layer to achieve a relatively large adhesion of the insulating coating 20 to the surface of the housing body 10. When the surface roughness Rz of the first sidewall 11 and the second sidewall 12 is <35μm, the roughness Rz is relatively small, and the insulating coating 20 consists of N layers (N≥2). The innermost layer is used to improve the adhesion of the coating to the surface of the housing body 10, prevent the outer coating from falling off, and improve the safety performance of the battery. The outermost layer is used to improve the insulation performance (voltage withstand and insulation resistance) of the battery housing 100. The composition of different coatings is different (when the insulating coating 20 is a single layer, the adhesion of the single-layer insulating coating 20 to the surface of the housing body 10 is slightly less than the adhesion of the innermost layer of the multi-layer insulating coating 20 to the surface of the housing body 10).

[0073] It is understandable that the total thickness of the insulating coating 20 is approximately the same whether it is a single layer or N layers (N≥2). For example, the total thickness of the insulating coating 20 is 50~250μm. When the insulating coating 20 is a single layer, the thickness of the single layer is 50~250μm. When the insulating coating 20 is N layers (N≥2), the thickness of the innermost coating layer is 10~125μm, and the thickness of the outermost coating layer is 40~125μm.

[0074] For example, a first transition layer is provided between the first sidewall 11 and the first insulating coating 21. The first transition layer can serve as a connecting medium to connect the first sidewall 11 and the first insulating coating 21, ensuring the adhesion between the first insulating coating 21 and the first sidewall 11. A second transition layer is provided between the second sidewall 12 and the second insulating coating 22. The second transition layer can serve as a connecting medium to connect the second sidewall 12 and the second insulating coating 22, ensuring the adhesion between the second insulating coating 22 and the first sidewall 11.

[0075] Exemplarily, the manufacturing process of the battery casing 100 includes: When the insulating coating 20 is a single layer, an insulating slurry is prepared and sprayed onto the surface of the housing body 10. After curing, an insulating coating 20 is formed on the surface of the housing body 10, resulting in a battery housing 100.

[0076] When the insulating coating 20 has N layers (N≥2), a first insulating slurry is prepared and sprayed onto the surface of the housing body 10. After curing, a first cured layer is formed on the surface of the housing body 10. A second insulating slurry is prepared and sprayed onto the surface of the housing body 10. After curing, a second cured layer is formed on the surface of the housing body 10. The above steps are repeated until the Nth cured layer is formed. It is understood that different cured layers can be made of the same material or different materials. The insulating grout is a solvent-free coating, and the curing method used is a light-curing process.

[0077] For example, before the first spraying, a local area of ​​the housing body 10 is pretreated with adhesive. The adhesive curing method can be one of solvent evaporation curing, heat curing and light curing.

[0078] Secondly, this application provides a battery 200, please refer to... Figures 9 to 12 , Figure 9 and Figure 11 The present invention provides a schematic diagram of the structure of a battery 200, which includes a battery housing 100 and a battery cell 101 provided in the first aspect of the present invention. The battery housing 100 has a cavity, and the battery cell 101 is disposed in the cavity of the battery housing 100.

[0079] In this application, by providing the aforementioned battery casing 100 on the surface of the cell 101, the battery 200 has better insulation performance, and the insulation performance is durable and stable, thereby improving the service life of the battery 200.

[0080] In some embodiments, please refer to Figure 8 and Figure 10 The battery 200 also includes at least one terminal post 102, which passes through the terminal post through hole 123; the area of ​​the plane containing the terminal post 102 is s0 (see [reference]). Figure 10 and Figure 12 s0 includes the sum of the areas of the plane where the pole post 102 is located and the circular or square ring formed by the first insulating coating 21), and the coverage area of ​​the insulating coating 20 on the plane where the pole post 102 is located is s1 (s1 includes the sum of the areas of the circular or square ring formed by the second insulating coating 22 and the circular or square ring formed by the first insulating coating 21), which satisfies: 0.12≤s1 / s0≤0.95, for example, s1 / s0 can be 0.12, 0.3, 0.5, 0.7, 0.8, 0.9, 0.95, etc.

[0081] In this application, by reasonably setting the ratio of the area s0 of the plane where the terminal post 102 is located to the coverage area s1 of the insulating coating 20 on the plane where the terminal post 102 is located, the creepage distance and electrical clearance between adjacent batteries 200 in the battery pack are made larger, the insulation performance of the battery 200 is better, and the safety of the battery 200 is improved.

[0082] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A battery casing (100), characterized in that, include: The housing body (10) includes at least a first sidewall (11) and a second sidewall (12) arranged at an angle, the first sidewall (11) and the second sidewall (12) being connected to each other and forming a corner structure between the first sidewall (11) and the second sidewall (12); The insulating coating (20) includes a first insulating coating (21) disposed on the surface of the first sidewall (11), a second insulating coating (22) disposed on the surface of the second sidewall (12), and a corner coating (23) connecting the first insulating coating (21) and the second insulating coating (22). The thickness of the first insulating coating (21) is t0, and the maximum thickness of the second insulating coating (22) is t1, satisfying: 0 < t1 - t0 ≤ 2.5 mm.

2. The battery casing (100) according to claim 1, characterized in that, The corner coating (23) has an arc-shaped structure. The minimum thickness of the corner coating (23) is t2. The minimum thickness t2 of the corner coating (23) and the thickness t0 of the first insulating coating (21) satisfy: t0×30%≤t2≤t0×100%.

3. The battery casing (100) according to claim 2, characterized in that, The second insulating coating (22) includes an arcuate portion (221) located at one end of the second insulating coating (22) away from the corner coating (23); The radius of the arc-shaped part (221) is r1, and the radius of the corner coating (23) is r2, satisfying: r1≥r2.

4. The battery casing (100) according to claim 3, characterized in that, The angle between the tangent at the intersection of the arc-shaped part (221) and the second sidewall (12) and the second sidewall (12) is θ, which satisfies: 100°≤θ<180°.

5. The battery casing (100) according to claim 1, characterized in that, The thickness of the first sidewall (11) is t3, and the thickness t0 of the first insulating coating (21) and the thickness t3 of the first sidewall (11) satisfy: t3×5%≤t0≤t3×95%.

6. The battery casing (100) according to claim 1, characterized in that, The second sidewall (12) includes a first sub-sidewall (121) and a second sub-sidewall (122) extending along a second direction. The first sub-sidewall (121) and the second sub-sidewall (122) are disposed at opposite ends of the first sidewall (11) in a first direction. At least one of the first sub-sidewall (121) or the second sub-sidewall (122) is provided with at least one pole post through hole (123).

7. The battery casing (100) according to claim 6, characterized in that, The first sub-sidewall (121) is provided with at least one pole post through hole (123).

8. The battery casing (100) according to claim 7, characterized in that, At least a portion of the first sub-sidewall (121) is covered with the second insulating coating (22), and the width of the second insulating coating (22) on the first sub-sidewall (121) along the second direction is x1, satisfying: 1.5mm≤x1≤10mm, and the first direction and the second direction intersect each other.

9. The battery casing (100) according to claim 7, characterized in that, The second sub-sidewall (122) is provided with a sealing structure (13) at the connection between the first sidewall (11). The sealing structure (13) is used to seal the connection between the second sub-sidewall (122) and the first sidewall. The sealing structure (13) is wrapped in the insulating coating (20).

10. The battery casing (100) according to claim 3 or 4, characterized in that, The second insulating coating (22) further includes an extension (222) disposed between the arcuate portion (221) and the corner coating (23).

11. The battery casing (100) according to any one of claims 1-9, characterized in that, The surface roughness Rz of the first sidewall (11) near the first insulating coating (21) and the second sidewall (12) near the second insulating coating (22) is ≤50μm.

12. The battery casing (100) according to any one of claims 1-9, characterized in that, The insulating coating (20) includes one of a polyurethane coating and a polyacrylate coating; and / or, The housing body (10) includes one of the following: stainless steel housing, nickel-plated steel strip housing, aluminum alloy housing, and titanium alloy housing.

13. A battery (200), characterized in that, include: The battery housing (100) as described in any one of claims 1-12, wherein the battery housing (100) has a cavity inside; A battery cell (101) is disposed in the cavity of the battery casing (100).

14. The battery (200) according to claim 13, characterized in that, The battery (200) further includes at least one terminal (102) which passes through a terminal through-hole (123). The area of ​​the plane where the pole post (102) is located is s0, and the coverage area of ​​the insulating coating (20) on the plane where the pole post (102) is located is s1, satisfying: 0.12≤s1 / s0≤0.95.

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