Shell insulation structure of power battery and power battery

Abstract

The utility model provides a shell insulation structure of a power battery and the power battery, and belongs to the technical field of power batteries, and the shell insulation structure of the power battery comprises a top cover and a shell; the shell is composed of a first base body layer, a first inner insulating layer located on the inner wall surface of the first base body layer and a first outer insulating layer located on the outer wall surface of the first base body layer. The top cover comprises a cover plate, and a positive pole and a negative pole which are arranged on the cover plate, and the cover plate comprises a second base body layer and a second outer insulating layer located on the surface of the outer wall of the second base body layer; the top cover covers the opening of the cavity structure to form a containing cavity, the naked battery cell is located in the containing cavity, and the positive pole and the negative pole are correspondingly and electrically connected with the positive pole piece and the negative pole piece on the naked battery cell respectively. After a naked battery cell is placed in the shell, the top cover is covered on the opening of the cavity structure to form sealing, so that the shell insulation structure of the battery has a good insulation effect and is simple in structure, and the manufacturing efficiency of the battery cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and in particular to a shell insulation structure of a power battery and a power battery. Background Art

[0002] As a core component of new energy vehicles, power batteries have always been a focus of industry attention for their technological advancement and market development. The insulation structure of a power battery's casing is crucial for ensuring its safe operation. It not only protects the battery from external environmental influences, such as water, dust, and impact, but also isolates the high-voltage components within the battery from the outside world to prevent leakage and short circuits. The insulation structure of a power battery's casing also prevents safety hazards such as battery cell fire, explosion, and secondary damage.

[0003] However, the current power battery casing insulation structure is complex and the manufacturing process is cumbersome. Existing technologies achieve battery insulation by installing plastic parts on the end caps, insulating sheets on the outside of the internal cells, bottom support plates, and insulating films and top sheets wrapped around the outer casing to ensure battery safety. However, the numerous and complex components used in the battery casing insulation structure hinder improvements in battery manufacturing efficiency. Utility Model Content

[0004] The present application provides a power battery shell insulation structure and a power battery to solve the problems of complex power battery shell insulation structure and low manufacturing efficiency.

[0005] In the first aspect, the present application provides an outer shell insulation structure of a power battery, which is used to wrap a bare battery cell, including: a top cover and a shell; the shell is a cavity structure with an opening at the top, and the shell is composed of a first base layer and a first inner insulating layer respectively located on the inner wall surface of the first base layer and a first outer insulating layer respectively located on the outer wall surface of the first base layer; the top cover includes a cover plate, and a positive electrode post and a negative electrode post arranged on the cover plate, and the cover plate includes a second base layer and a second outer insulating layer located on the outer wall surface of the second base layer; the top cover is covered at the opening of the cavity structure to form a accommodating cavity, the bare battery cell is located in the accommodating cavity, and the positive electrode post and the negative electrode post are respectively electrically connected to the positive electrode sheet and the negative electrode sheet on the bare battery cell.

[0006] Through the above scheme, since the outer shell insulation structure for the power battery is a cavity structure composed of a shell and a top cover, and the shell is composed of a first base layer and a first inner insulation layer located on the inner wall surface of the first base layer and a first outer insulation layer located on the outer wall surface of the first base layer, the shell has a good insulation effect, and the cover is composed of a second base layer and a second outer insulation layer located on the outer wall surface of the second base layer, so that the cover has a good insulation effect. Therefore, after the bare battery cell is placed in the shell, the top cover is closed on the opening of the cavity structure to form a seal, that is, a battery with a good insulation effect is formed. In this way, the outer shell insulation structure of the battery can have a good insulation effect and a simple structure. During the manufacturing process, there is no need to repeatedly wrap the bare battery cell and the outer part of the battery with an insulating film, and many unnecessary structures are reduced, thereby improving the manufacturing efficiency of the battery cell.

[0007] In a possible design, the top cover is connected to the shell by welding, and the outer surface of the welding connection position forms a first protective layer, which is insulating powder or paint.

[0008] Through the above solution, since the top cover and the shell are directly welded together, the accommodating cavity formed by the cover and the shell can be made more secure, and the insulating powder or coating can provide an additional electrical insulation layer to prevent current leakage and improve the safety of the battery. Insulating powder or coating is applied to the outer surface of the weld connection location, and the edge coverage performance provided by the insulating powder spraying technology is utilized to ensure that every part of the battery is effectively insulated and protected. At the same time, the insulating powder spraying technology can realize automated production, improve the spraying yield rate, and meet the needs of car manufacturers and battery manufacturers. Insulating powder or coating has a cost advantage over some traditional insulating materials, which helps to reduce the overall material cost of the battery.

[0009] In a possible design, the cover plate further includes a second inner insulating layer on the inner wall surface of the second base layer.

[0010] The cover plate is further provided with a second inner insulating layer on the inner wall surface of the second base layer, so that the insulation performance of the cover plate is better, the insulation performance of the top cover is improved, and the insulation effect of the outer shell insulation structure of the power battery is further improved.

[0011] In a possible design, the thickness of the first outer insulating layer and the second outer insulating layer is 0.03 mm to 0.15 mm.

[0012] Through the above solution, if the thickness of the first outer insulating layer and the second outer insulating layer is less than 0.03mm, an effective insulation effect cannot be achieved, resulting in an inability to guarantee insulation performance. If the thickness of the first outer insulating layer and the second outer insulating layer is too thick, for example, greater than 0.15mm, it may increase the amount of material used, thereby increasing costs. In mass production, the thickness range of the insulating layer needs to be controlled within 0.03mm to 0.15mm to achieve sufficient safety while ensuring performance. Strict control of the thickness of the first outer insulating layer and the second outer insulating layer is crucial to the safety performance of the battery.

[0013] In one possible design, the shell is composed of a bottom of a cavity structure and a side surrounding the bottom of the cavity structure, the thickness of the first inner insulation layer at the bottom is 0.3mm-0.6mm, and the thickness of the first inner insulation layer at the side is 0.03~0.15mm.

[0014] With the above solution, the bottom of the battery casing, serving as the support base for the entire battery, must withstand greater mechanical pressure. Furthermore, the angle between the bottom of the cavity structure and the side portions surrounding it creates an angle. This angle requires a sufficiently thick insulating layer to ensure adequate insulation. Therefore, the thickness of the first inner insulating layer at the bottom is 0.3mm-0.6mm. When the thickness of the first inner insulating layer at the bottom is less than 0.3mm, the casing cannot effectively insulate, resulting in a loss of battery insulation performance. A thickness greater than 0.6mm at the bottom may increase material usage, thereby increasing costs. The thickness of the first inner insulating layer at the side is 0.03-0.15mm. When the thickness of the first inner insulating layer at the side is less than 0.03mm, it cannot effectively insulate, resulting in a loss of insulation performance. Excessive thickness of the first inner insulating layer at the side, for example, greater than 0.15mm, may increase material usage, thereby increasing costs. In mass production, the thickness of the first inner insulating layer at the side position needs to be controlled within the range of 0.03 mm to 0.15 mm to achieve sufficient safety while ensuring performance.

[0015] In a possible design, the first inner insulating layer, the first outer insulating layer, and the second outer insulating layer are formed by flow coating, dipping, or printing.

[0016] Through the above-mentioned scheme, the coverage provided by flow coating, dip coating, or printing techniques enables the coating of both the inner and outer surfaces of the power battery housing with an effective insulating layer. This ensures that the battery housing material used has sufficient insulating properties, thereby improving battery manufacturing efficiency. Flow coating is a method in which a liquid coating is evenly applied to the surface of the battery housing or cover plate using a curtain or rain application. This method can achieve a thick, uniform coating with strong adhesion in one application. Flow coating is suitable for applications with high coating thickness requirements and can provide excellent insulating properties. Dip coating involves immersing the battery housing or cover plate in an insulating coating and then lifting it up. During the lifting process, the coating is evenly applied to the surface, forming a layer. Dip coating achieves uniform coating distribution and is suitable for battery housings or cover plates with complex shapes. By controlling the lifting speed and coating viscosity, the coating thickness can be precisely controlled. Printing technology, particularly inkjet printing, is a high-precision coating method that sprays insulating material directly onto the battery cell surface, forming a uniform, continuous coating. Inkjet printing technology enables precise control of insulation layer thickness to meet the needs of different battery models and application scenarios. Furthermore, inkjet printing offers advantages such as wide material adaptability, excellent coating uniformity, energy conservation and environmental protection, high automation, and strong customization capabilities. The insulation layer of the battery casing can be more effectively formed through flow coating, dip coating, or printing. Each method offers unique advantages and can meet different production efficiency, cost control, environmental protection requirements, and performance standards.

[0017] In one possible design, an upper plastic is provided above the periphery of the positive electrode column and the negative electrode column, and the upper plastic is electrically connected to the positive electrode column and insulated from the negative electrode column; a lower plastic is provided below the periphery of the positive electrode column and the negative electrode column, and the lower plastic is insulated from the positive electrode column and the negative electrode column.

[0018] The above solution, by placing an upper plastic over the terminals and ensuring electrical connection to the positive terminal and insulated connection to the negative terminal, prevents accidental short circuits during battery use, thereby improving battery safety. The lower plastic is insulated from both terminals, which helps to properly distribute and manage heat within the battery, preventing local overheating and reducing the risk of thermal runaway. The use of plastic strengthens the connection between the terminals and the top cover, improving the structural stability of the entire battery top cover.

[0019] In a possible design, a sealing ring is provided between the upper plastic and the lower plastic.

[0020] Through the above solution, a sealing ring is provided between the upper plastic and the lower plastic, which can effectively prevent the material exchange between the inside of the accommodating cavity where the bare battery cell is located and the external environment, prevent moisture, dust, etc. from invading the interior of the battery, and improve the protection level of the battery.

[0021] In a possible design, the cover plate is further provided with an explosion-proof valve and a liquid injection hole, and the liquid injection hole is provided with a sealing member.

[0022] Through the above solution, the explosion-proof valve is an important component of battery safety design. When abnormal conditions cause internal pressure to rise in the battery, the explosion-proof valve can open promptly to release the internal pressure, preventing the battery from exploding, thereby protecting the safety of the battery and the surrounding environment. The injection hole is the channel used to inject electrolyte during the battery manufacturing process. After injection, the injection hole must be sealed to prevent electrolyte leakage and the intrusion of external contaminants. The seal design of the injection hole prevents the generation of metal particles and burrs, which may fall into the battery and cause a short circuit. The use of the seal ensures the cleanliness of the battery interior, improving the reliability and safety of the battery.

[0023] In a second aspect, a power battery is provided, comprising a bare cell and the outer shell insulation structure of any of the above-mentioned power batteries, wherein the bare cell comprises a positive electrode sheet, a negative electrode sheet and the bare cell, the bare cell being located in a receiving cavity, and the positive electrode column and the negative electrode column being electrically connected to the positive electrode sheet and the negative electrode sheet on the bare cell respectively.

[0024] The beneficial effects of the power battery provided in various possible designs of the above-mentioned second aspect can be referred to the beneficial effects brought about by the above-mentioned first aspect and various possible implementation methods of the first aspect, and will not be repeated here.

[0025] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to more clearly understand the technical means of the embodiments of the present application, they can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0027] Figure 1 This is a schematic diagram of the insulation structure of the power battery shell provided in one embodiment of the present application.

[0028] Figure 2 for Figure 1 A cross-sectional view along the A-A1 direction of the shell insulation structure of the power battery provided.

[0029] Figure 3 for Figure 2A partial magnified view of the D area in the middle.

[0030] Figure 4 This is a schematic structural diagram of a top cover provided in one embodiment of the present application.

[0031] Figure 5 for Figure 4 Front view of the provided top cover.

[0032] Figure 6 for Figure 4 Rear view of the supplied top cover.

[0033] Figure 7 for Figure 5 A cross-sectional view of the top cover along the B-B1 direction is provided.

[0034] Figure 8 for Figure 7 Enlarged view of the local E area in the middle.

[0035] Figure 9 This is a schematic structural diagram of a housing provided in one embodiment of the present application.

[0036] Figure 10 for Figure 9 A front view of the housing is provided.

[0037] Figure 11 for Figure 9 A cross-sectional view of the shell along the C-C1 direction is provided.

[0038] Figure 12 for Figure 11 Enlarged view of area F in the middle.

[0039] Explanation of the reference numerals: 100, shell; 102, first base layer; 101, first outer insulating layer; 103, first inner insulating layer; 200, top cover; 202, second base layer; 201, second outer insulating layer; 210, lower plastic; 205, sealing ring; 411, upper plastic; 410, positive electrode; 420, negative electrode; 430, explosion-proof valve; 440, liquid injection hole; h1, the height of the first assembly area is; h2, the height of the second assembly area is; D, area D; E, area E; F, area F. DETAILED DESCRIPTION

[0040] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover non-exclusive inclusions.

[0042] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiment" in various places in the specification does not necessarily refer to the same embodiment, nor does it necessarily refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0043] The term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists, A and B exist, and B exists. Additionally, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0044] The directional words appearing in the following description are all directions shown in the drawings and do not limit the specific structure of this application. For example, in the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., which indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting this application.

[0045] In addition, the terms "first", "second", etc. in the description and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order, and may explicitly or implicitly include one or more such features.

[0046] In the description of this application, unless otherwise specified, "plurality" means more than two (including two), and similarly, "multiple groups" means more than two (including two).

[0047] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, the "connection" or "connection" of a mechanical structure may refer to a physical connection. For example, the physical connection may be a fixed connection, such as a fixed connection through a barrier, such as a fixed connection through screws, bolts, or other barrier; the physical connection may also be a detachable connection, such as a mutual snap connection or snap connection; the physical connection may also be an integral connection, such as a connection formed by welding, bonding, or integral molding. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0048] As the core component of new energy vehicles, the insulation structure of the power battery shell is a key part to ensure the safe operation of the power battery.

[0049] In the related art, the outer shell insulation structure of current power batteries is complex and the manufacturing process is relatively cumbersome. In the existing technology, the battery insulation effect is achieved by installing plastic parts on the end caps, insulating sheets on the outside of the internal battery cells, bottom support plates, and insulating films and top sheets wrapped around the outer shell to ensure battery safety. However, the battery outer shell insulation structure uses a large number of structural components and is complex, which hinders the improvement of battery manufacturing efficiency.

[0050] In view of this, an embodiment of the present application provides a shell insulation structure of a power battery and a power battery, wherein the shell insulation structure of the power battery is configured as a composition of a top cover and a shell, and the top cover is configured to have a second outer insulation layer on the outer surface, and the shell is configured as a cavity structure capable of accommodating bare battery cells, and is composed of a first base layer and a first inner insulation layer respectively located on the inner wall surface of the first base layer and a first outer insulation layer on the outer wall surface of the first base layer, which makes the shell have a good insulation effect. Therefore, the bare battery cell is directly placed in the accommodating cavity formed by the top cover and the shell, which can complete the production of the battery, which makes the shell insulation structure of this power battery simple and effectively improves the manufacturing efficiency of the battery.

[0051] Figure 1 This is a schematic diagram of the insulation structure of the power battery shell provided in one embodiment of the present application. Figure 2 for Figure 1 A cross-sectional view along the A-A1 direction of the shell insulation structure of the power battery provided. Figure 3 for Figure 2 A partial enlarged view of the D area in the middle. Please refer to Figures 1 to 3 The outer shell insulation structure of the power battery in this embodiment is used to wrap the bare battery cell. The outer shell insulation structure of the power battery includes a top cover 200 and a shell 100.

[0052] Figure 9 Schematic diagram of the structure of the housing 100 provided in one embodiment of the present application. Figure 10 for Figure 9 A front view of the housing 100 is provided. Figure 9 and Figure 10 The shell 100 is a cavity structure with an opening at the top. The shell 100 is composed of a first base layer 102, a first inner insulating layer 103 located on the inner wall surface of the first base layer 102, and a first outer insulating layer 101 located on the outer wall surface of the first base layer 102.

[0053] It can be understood that the material of the first base layer 102 in this embodiment is the material of the battery shell 100 in the prior art, for example, it can be a metal material or an aluminum alloy material, but the shell 100 material in this embodiment is a metal material or an aluminum alloy material. The inner surface and the outer surface are respectively provided with a first inner insulating layer 103 and a first outer insulating layer 101, so that the shell 100 structure in this embodiment itself has insulating properties, so that the process of manufacturing the battery can be simpler, and there is no need to wind and wrap the bare battery cell with an insulating film multiple times during the manufacturing process.

[0054] In this embodiment, the outer shell of the power battery is used to accommodate bare cells, so the outer shell is set to an open cavity structure. In order to ensure the hardness of the power battery shell, the material of the first base layer 102 is metal or alloy, and the first base layer 102 in the shell serves as a support. In this application, a first inner insulating layer 103 and a first outer insulating layer 101 are formed on the inner wall surface and the outer wall surface of the first base layer 102 respectively to make the shell 100 have sufficient hardness while also having good insulation performance. However, due to the different material toughness of the first base layer 102, the first inner insulating layer 103 and the first outer insulating layer 101, it is impossible to directly stamp the synthetic material with the first inner insulating layer 103 and the first outer insulating layer 101 on the first base layer 102 to obtain an open cavity structure. Therefore, in this application, the first base layer 102 is first formed into an open cavity structure, and then the first inner insulating layer 103 or the first outer insulating layer 101 is formed, thereby providing a shell insulation structure with an insulating effect, overcoming the technical difficulty that the shell insulation structure with an insulating effect cannot be stamped out at present.

[0055] Figure 11 for Figure 9 The cross-sectional view of the housing 100 along the C-C1 direction is provided. Figure 9 and Figure 11 The housing 100 is composed of a bottom portion of a cavity structure and a side portion surrounding the bottom portion of the cavity structure. The thickness of the first inner insulating layer 103 at the bottom portion is 0.3 mm to 0.6 mm, and the thickness of the first inner insulating layer 103 at the side portion is 0.03 to 0.15 mm.

[0056] Through the above solution, the bottom of the battery shell 100 serves as the supporting base of the entire battery and needs to withstand greater mechanical pressure. In addition, there will be an angle at the connection position between the bottom of the cavity structure and the side surrounding the bottom of the cavity structure. The angle needs to be filled with an insulating layer of sufficient thickness to ensure that the battery has sufficient insulation effect. Therefore, strictly controlling the thickness of the first inner insulating layer 103 is crucial to the safety performance of the battery. The thickness of the first inner insulating layer 103 at the bottom position is 0.3mm-0.6mm. When the thickness of the first inner insulating layer 103 at the bottom position is less than 0.3mm, the shell 100 cannot achieve an effective insulation effect, resulting in the inability to guarantee the insulation performance of the battery. When the thickness of the first inner insulating layer 103 at the bottom position is greater than 0.6mm, the amount of material used may increase, thereby increasing costs.

[0057] The thickness of the first inner insulating layer 103 at the side is 0.03 to 0.15 mm. If the thickness of the first inner insulating layer 103 at the side is less than 0.03 mm, effective insulation cannot be achieved, resulting in an inability to guarantee insulation performance. If the thickness of the first inner insulating layer 103 at the side is too thick, for example, greater than 0.15 mm, it may increase the amount of material used, thereby increasing costs. In mass production, the thickness of the first inner insulating layer 103 at the side needs to be controlled within the range of 0.03 mm to 0.15 mm to achieve sufficient safety while ensuring performance.

[0058] Figure 4 Schematic diagram of the structure of the top cover 200 provided in one embodiment of the present application. Figure 5 for Figure 4 A front view of the top cover 200 is provided. Figure 6 for Figure 4 A rear view of the top cover 200 is provided. Please refer to Figures 4 to 6 The top cover 200 includes a cover plate and a positive electrode post 410 and a negative electrode post 420 disposed on the cover plate. The cover plate is composed of a second base layer 202 and a second outer insulating layer 201 located on the outer wall surface of the second base layer 202. The top cover 200 covers the opening of the cavity structure to form a receiving cavity. The bare cell is located in the receiving cavity. The positive electrode post 410 and the negative electrode post 420 are electrically connected to the positive and negative electrode sheets on the bare cell, respectively.

[0059] In this embodiment, the outer shell insulation structure of the power battery is set as a cavity structure composed of a shell 100 and a top cover 200, and the shell 100 is composed of a first base layer 102, a first inner insulation layer 103 located on the inner wall surface of the first base layer 102, and a first outer insulation layer 101 located on the outer wall surface of the first base layer 102, so that the shell 100 has a good insulation effect. Therefore, the outer shell insulation structure of the battery can have a good insulation effect and a simple structure. After the bare battery cell is placed in the shell 100, the top cover 200 is closed on the opening of the cavity structure to form a seal, that is, a battery with good insulation effect is formed. During the manufacturing process, there is no need to repeatedly wrap the bare battery cell and the outer part of the battery after forming the insulating film, and many unnecessary structures are reduced, which improves the manufacturing efficiency of the battery cell.

[0060] Figure 7 for Figure 4 A cross-sectional view of the top cover 200 along the B-B1 direction is provided. Figure 8 for Figure 7 A partial enlarged view of the E area in the middle. Please refer to Figure 7 and Figure 8 An upper plastic 411 is provided above the periphery of the positive electrode post 410 and the negative electrode post 420. The upper plastic 411 is electrically connected to the positive electrode post 410 and insulated from the negative electrode post 420. A lower plastic 210 is provided below the periphery of the positive electrode post 410 and the negative electrode post 420. The lower plastic 210 is insulated from the positive electrode post 410 and the negative electrode post 420.

[0061] Through the above solution, by setting the upper plastic 411 above the pole and ensuring that it is electrically connected to the positive pole 410 and insulated from the negative pole 420, it is possible to prevent accidental short circuits during battery use, thereby improving the safety of the battery. The lower plastic 210 is insulated from both poles, which helps to reasonably distribute and manage heat inside the battery, prevent local overheating, and reduce the risk of thermal runaway of the battery. Plastic has friction, and the lower plastic 210 is located between the cover and the bare cell to prevent displacement between the pole and the positive and negative poles of the bare cell, which can enhance the connection strength between the pole and the top cover 200 and improve the structural stability of the entire battery top cover 200.

[0062] It is understandable that the ends of the lower plastic 210 exceed the length of the ends of the cover. When the top cover 200 is covered on the opening of the cavity structure, the edge of the lower plastic 210 is folded 90 degrees and can be inserted vertically downward along the opening of the cavity structure.

[0063] Through the above solution, when the top cover 200 is covered on the opening of the cavity structure, the edge portion of the lower plastic 210 is inserted along the opening of the cavity structure to form a seal for the cavity structure, which can prevent the influence of environmental factors such as moisture and dust, thereby improving the protection level of the battery. In addition, the lower plastic 210, as an electrical insulating material, generally has good chemical corrosion resistance, can effectively prevent current leakage, and can protect the battery from the influence of chemical corrosion, thereby improving the safety of the battery and extending the service life of the battery.

[0064] Please continue to refer to Figure 7 and Figure 8 A sealing ring 205 is provided between the upper plastic 411 and the lower plastic 210 .

[0065] Through the above solution, the sealing ring 205 is provided between the upper plastic 411 and the lower plastic 210, which can effectively prevent the material exchange between the inside of the accommodating cavity where the bare battery cell is located and the external environment, prevent moisture, dust, etc. from invading the interior of the battery, and improve the protection level of the battery.

[0066] In this embodiment, the top cover 200 is connected to the housing 100 by welding, and a first protective layer is formed on the outer surface of the welding connection position. The first protective layer is insulating powder or coating.

[0067] Through the above solution, since the top cover 200 and the shell 100 are directly welded together, the accommodating cavity formed by the cover body and the shell 100 can be made more solid, and the insulating powder or paint can provide an additional electrical insulation layer to prevent current leakage and improve the safety of the battery. Insulating powder or paint is provided on the outer surface of the welding connection position, and the edge coverage performance provided by the insulating powder spraying technology is utilized to ensure that every part of the battery is effectively insulated and protected. At the same time, the insulating powder spraying technology can realize automated production, improve the spraying yield rate, and meet the needs of car manufacturers and battery manufacturers. Insulating powder or paint has a cost advantage over some traditional insulating materials, which helps to reduce the overall material cost of the battery.

[0068] In a possible design, the cover plate is further provided with an explosion-proof valve 430 and a liquid injection hole 440 , and the liquid injection hole 440 is provided with a sealing member.

[0069] Through the above solution, the explosion-proof valve 430 is an important part of the battery safety design. When the pressure inside the battery increases due to abnormal conditions, the explosion-proof valve 430 can be opened in time to release the internal pressure and prevent the battery from exploding, thereby protecting the safety of the battery and the surrounding environment. The injection hole 440 is a channel for injecting electrolyte during the battery manufacturing process. After the injection is completed, it is necessary to ensure the sealing of the injection hole 440 to prevent electrolyte leakage and the intrusion of external contaminants. The seal design of the injection hole 440 can prevent the generation of metal particles and burrs, which may fall into the interior of the battery and cause a short circuit. The use of seals can ensure the cleanliness of the interior of the battery and improve the reliability and safety of the battery.

[0070] In this embodiment, the thickness of the first outer insulating layer 101 and the second outer insulating layer 201 is 0.03 mm to 0.15 mm.

[0071] Through the above solution, if the thickness of the first outer insulating layer 101 and the second outer insulating layer 201 is less than 0.03mm, an effective insulation effect cannot be achieved, resulting in an inability to guarantee insulation performance. If the thickness of the first outer insulating layer 101 and the second outer insulating layer 201 is too thick, for example, greater than 0.15mm, it may increase the amount of material used, thereby increasing costs. In mass production, the thickness range of the insulating layer needs to be controlled within 0.03mm to 0.15mm to achieve sufficient safety while ensuring performance. Strictly controlling the thickness of the first outer insulating layer 101 and the second outer insulating layer 201 is crucial to the safety performance of the battery.

[0072] Figure 12 for Figure 11 Enlarged view of the F area in the middle. Please refer to Figure 12 During the manufacturing process of the housing 100, a certain range of assembly areas need to be reserved on the inner and outer sides of the top edge of the cavity structure. For example, a first assembly area is reserved on the outer side of the top edge of the cavity structure, where the first outer insulating layer 101 is not formed. A second assembly area is reserved on the inner side of the top edge of the cavity structure, where the first inner insulating layer 103 is not formed.

[0073] The reason why the first outer insulating layer 101 is not formed in the first assembly area is that during the manufacturing process of the battery, the bare battery cell needs to be placed in the shell 100 first, and then the top cover 200 is covered on the shell 100. Finally, the contact position of the top cover 200 and the shell 100 is further fixed and connected. Generally, this fixed connection method is welding. Therefore, the first assembly area needs to be reserved to ensure smooth welding.

[0074] The reason why the first inner insulating layer 103 is not formed in the second assembly area is: during the manufacturing process of the battery, the top cover 200 includes a lower plastic 210 with an insulating effect, and the structure of the lower plastic 210 will exceed the edge of the cover plate. The size of the cover plate is completely corresponding to the opening size of the cavity structure. When the top cover 200 is changed to the shell 100, the cover plate is aligned with the opening of the cavity structure. Therefore, the lower plastic 210 at the edge of the cover plate will be inserted downward along the inside of the opening of the cavity structure, so that the inside of the edge of the opening of the cavity structure has an insulating effect, so that the first inner insulating layer 103 does not need to be formed in the second assembly area; and the fact that the first inner insulating layer 103 is not formed in the second assembly area can also ensure that the lower plastic 210 can be smoothly inserted into the inside of the opening of the cavity structure, so that the top cover 200 can be more smoothly assembled on the shell 100.

[0075] In this embodiment, the height of the first assembly area is the distance between the upper edge of the first outer insulating layer 101 and the upper edge of the first base layer 102. In this embodiment, the height of the first assembly area is h1, and the range of h1 is 0 mm to 1.0 mm.

[0076] In this embodiment, the height of the second assembly area is the distance between the upper edge of the first inner insulating layer 103 and the upper edge of the first base layer 102. In this embodiment, the height of the second assembly area is h2, and the range of h2 is 2.0 mm to 5.0 mm.

[0077] In some embodiments, the cover plate further includes a second base layer 202 and a second inner insulating layer may be provided on the inner wall surface. The second inner insulating layer provided on the inner wall surface of the second base layer 202 of the cover plate improves the insulation performance of the cover plate, further improving the insulation performance of the top cover 200, and thereby improving the insulation effect of the outer shell insulation structure of the power battery.

[0078] The first inner insulating layer 103 , the first outer insulating layer 101 , the second inner insulating layer and the second outer insulating layer 201 may be formed by flow coating, dipping or printing.

[0079] Curtain coating is a method of evenly applying a liquid coating to the surface of the battery casing 100 or cover plate using a curtain or shower. This method can achieve a thicker coating in one application, resulting in uniform and strong adhesion. Curtain coating is suitable for applications requiring high coating thickness and can provide excellent insulation performance.

[0080] Dip coating involves immersing the battery case 100 or cover plate in an insulating coating and then lifting it. During the lifting process, the coating is evenly applied to the surface, forming a coating. Dip coating achieves uniform coating distribution and is suitable for battery cases 100 or cover plates with complex shapes. By controlling the lifting speed and the viscosity of the coating, the coating thickness can be precisely controlled.

[0081] Printing technology, such as inkjet printing technology, is a high-precision coating formation method that can spray insulating materials directly onto the surface of battery cells to form a uniform, continuous coating. Inkjet printing technology can achieve precise control of the thickness of the insulation layer to meet the needs of different battery models and application scenarios. In addition, inkjet printing technology has the advantages of wide material adaptability, good coating uniformity, energy saving and environmental protection, high degree of automation and strong customization capabilities. The insulation layer of the battery shell can be more effectively formed by shower coating, dip coating or printing. They each have unique advantages and can meet different production efficiency, cost control, environmental protection requirements and performance standards.

[0082] Through the above scheme, the covering performance provided by the flow coating, dip coating or printing technology can make it possible to cover the inner wall surface and the outer wall surface of the power battery shell with an insulating layer having an effective insulating protection effect, so that the shell material of the battery used has sufficient insulating performance, thereby improving the efficiency of battery manufacturing.

[0083] Based on the shell insulation structure of the power battery mentioned above, this embodiment also provides a power battery, including a bare cell and the shell insulation structure of any of the above power batteries, the bare cell has a positive electrode sheet and a negative electrode sheet, the bare cell is located in the accommodating cavity, and the positive electrode column and the negative electrode column are respectively electrically connected to the positive electrode sheet and the negative electrode sheet on the bare cell. The manufacturing process of the power battery in this application includes: first, the bare cell with the top cover fixedly connected is loaded into the shell; then, the top cover and the shell are welded and sealed, and an insulating layer is sprayed on the shell cover weld and the exposed area of ​​the first substrate layer or the second substrate layer around it; finally, a seal is welded on the injection hole that has been completed. Since the shell insulation structure of the power battery and its beneficial effects have been described in detail in the previous embodiments, this application will not repeat them here.

[0084] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A shell insulation structure of a power battery, used to wrap a bare battery cell, characterized in that: include: Top cover and housing; The shell is a cavity structure with an upper opening, and is composed of a first base layer, a first inner insulating layer located on the inner wall surface of the first base layer, and a first outer insulating layer located on the outer wall surface of the first base layer; The top cover includes a cover plate, and a positive electrode column and a negative electrode column arranged on the cover plate, and the cover plate includes a second base layer and a second outer insulating layer located on the outer wall surface of the second base layer; The top cover is covered at the opening of the cavity structure to form a accommodating cavity, and the bare battery cell is located in the accommodating cavity. The positive electrode post and the negative electrode post are electrically connected to the positive electrode sheet and the negative electrode sheet on the bare battery cell respectively.

2. The shell insulation structure of the power battery according to claim 1, characterized in that: The top cover is connected to the shell by welding, and the outer surface of the welding connection position forms a first protective layer, which is insulating powder or paint.

3. The shell insulation structure of the power battery according to claim 1, characterized in that: The cover plate further includes a second inner insulating layer on the inner wall surface of the second base layer.

4. The shell insulation structure of the power battery according to claim 1, characterized in that: The thickness of the first outer insulating layer and the second outer insulating layer is 0.03-0.15 mm.

5. The shell insulation structure of the power battery according to claim 1 or 4, characterized in that: The shell is composed of a bottom of a cavity structure and a side surrounding the bottom of the cavity structure. The thickness of the first inner insulating layer at the bottom is 0.3mm-0.6mm, and the thickness of the first inner insulating layer at the side is 0.03-0.15mm.

6. The shell insulation structure of the power battery according to claim 1, characterized in that: The first inner insulating layer, the first outer insulating layer and the second outer insulating layer are formed by flow coating, dipping or printing.

7. The shell insulation structure of the power battery according to claim 1, characterized in that: An upper plastic is provided above the outer periphery of the positive electrode column and the negative electrode column, and the upper plastic is electrically connected to the positive electrode column and insulated from the negative electrode column; a lower plastic is provided below the outer periphery of the positive electrode column and the negative electrode column, and the lower plastic is insulated from the positive electrode column and the negative electrode column.

8. The shell insulation structure of the power battery according to claim 7, characterized in that: A sealing ring is provided between the upper plastic and the lower plastic.

9. The shell insulation structure of the power battery according to claim 7, characterized in that: The cover plate is also provided with an explosion-proof valve and a liquid injection hole, and the liquid injection hole is provided with a sealing member.

10. A power battery, characterized in that: The invention comprises a bare battery cell and a shell insulation structure of a power battery according to any one of claims 1 to 9, wherein the bare battery cell has a positive electrode sheet, a negative electrode sheet and a bare battery cell, the bare battery cell is located in the accommodating cavity, and the positive electrode column and the negative electrode column are electrically connected to the positive electrode sheet and the negative electrode sheet respectively.

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