Battery and battery device

Abstract

The battery comprises a shell and a sealing nail, the shell is provided with a first step structure sunken towards the interior of the shell, the first step structure comprises a first side wall and a first bottom plate which are connected with each other, and the first bottom plate is provided with a liquid injection hole; the sealing nail is arranged in the first step structure, the outer wall of the shell is covered with an insulating coating, and the insulating coating covers the first step structure and the sealing nail. The sealing nail is connected with the first side wall in a welding fixing mode, and the gap between the sealing nail and the first side wall is eliminated. And the shell is flat, so that the insulating material can be uniformly sprayed, and a relatively complete and flat coating is formed, so that the insulating effect of the battery is relatively good.

Description

Technical Field

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

[0002] Lithium-ion batteries have advantages such as high energy density and power density, light weight, and small size, and are widely used in energy storage devices and power supplies for new energy vehicles. A lithium-ion battery mainly consists of electrode plates, a separator, and an electrolyte. During the manufacturing process, through holes are usually machined in the battery casing as injection holes to inject electrolyte into the battery casing, immersing the electrode plates in the electrolyte.

[0003] After the battery is filled with electrolyte, sealing pins are typically used to seal the filling hole to ensure its airtightness. However, due to installation process limitations, gaps may remain between the sealing pins and the filling hole, resulting in an uneven surface at that location. This leads to uneven application of insulating material, poor insulation, and potential safety hazards to the battery. Utility Model Content

[0004] This application provides a battery and a battery device that allows the insulating coating to be sprayed evenly, forming a more complete and smooth coating, resulting in better battery insulation.

[0005] This application provides a battery comprising a casing and a sealing pin. The casing has a first stepped structure recessed into the casing. The first stepped structure includes a first sidewall and a first bottom plate connected to each other. The first bottom plate has a liquid injection hole. The sealing pin is disposed in the first stepped structure, and the sidewall of the sealing pin is welded and fixed to the first sidewall. The outer wall of the casing is covered with an insulating coating, which covers the first stepped structure and the sealing pin.

[0006] The aforementioned sealing nails are connected to the first sidewall by welding, eliminating the gap between the sealing nails and the first sidewall. This allows the insulating coating to be sprayed more evenly, forming a more complete and smooth coating, resulting in better insulation performance. Attached Figure Description

[0007] Figure 1 A schematic diagram of a battery provided for an embodiment of this application;

[0008] Figure 2 A schematic diagram of another battery provided for an embodiment of this application;

[0009] Figure 3 A top view of a battery provided for an embodiment of this application;

[0010] Figure 4 A top view of another battery provided for an embodiment of this application;

[0011] Figure 5 A schematic diagram of another battery provided for an embodiment of this application;

[0012] Figure 6 A schematic diagram of another battery provided for an embodiment of this application;

[0013] Figure 7 A schematic diagram of a battery device provided for an embodiment of this application;

[0014] Figure 8 A schematic diagram of another battery device provided for an embodiment of this application.

[0015] Figure label:

[0016] 1-Shell; 2-Sealing nail; 3-First step structure; 31-First base plate; 32-First side wall; 4-Injection hole; 5-Insulating coating; 23-Protrusion; 6-Second step structure; 61-Second base plate; 62-Second side wall; 11-Base plate; 100-Battery; 101-Box body; 1011-Base plate of the box body; 102-Cold plate. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description of the application is provided in conjunction with the accompanying drawings and embodiments.

[0018] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more” unless the context clearly indicates otherwise.

[0019] References to “an embodiment” or “a specific embodiment” as used in this specification mean that one or more embodiments of this application include a particular feature, structure, or characteristic described in connection with that embodiment. The terms “comprising,” “including,” “having,” and variations thereof mean “including, but not limited to,” unless otherwise specifically emphasized.

[0020] A battery consists of a casing and cells housed within it. Each cell comprises electrode plates and a separator. An electrolyte filling machine injects electrolyte into the cavity of the battery casing. Part of the electrolyte permeates the cell, while the remainder occupies unfilled space within the casing. The more electrolyte permeates the cell, the better the wetting effect. Uniformly wetting the electrode plates ensures optimal electrochemical performance; incomplete wetting will negatively impact the battery's performance consistency. After electrolyte filling, the battery casing is sealed, and an insulating coating is applied to the exterior to achieve insulation.

[0021] In some related technologies, sealing pins are used to seal the electrolyte filling hole. Typically, the sealing pin is welded to the filling hole to block it. After the filling hole and sealing pin are welded using a through-welding process, gaps may exist at the weld joint due to process variations, and the surface may be uneven. When spraying paint on the battery casing after welding, the coating effect at the welded area of ​​the sealing pin and filling hole is poor. The coating cannot cover the gaps, resulting in inadequate insulation in those areas.

[0022] To address the aforementioned issues, embodiments of this application provide a battery and battery device with improved insulation and enhanced safety.

[0023] Figure 1 A schematic diagram of a battery provided for an embodiment of this application, such as... Figure 1 As shown, the battery provided in this application includes a casing 1 and a sealing pin 2. The casing 1 has a first stepped structure 3 recessed into the interior of the casing 1. The first stepped structure 3 includes a first bottom plate 31 with an injection hole 4 and a first sidewall 32 connected to the first bottom plate 31. The sealing pin 2 is disposed in the first stepped structure 3 to block the injection hole 4 and prevent electrolyte from flowing out of the casing 1. Furthermore, the sidewall of the sealing pin 2 is welded and fixed to the first sidewall 32 of the first stepped structure 3. The outer wall of the casing 1 is coated with an insulating coating 5, which covers the first stepped structure 3 and the sealing pin 2.

[0024] The sealing nail 2 is connected to the first side wall 32 by welding, which eliminates the gap between the sealing nail 2 and the first side wall 32, allowing the insulating coating 5 to be sprayed more evenly, thus forming a more complete and flat coating, resulting in better insulation of the battery.

[0025] The insulating coating 5 of the battery casing 1 enhances the battery's insulation capabilities, preventing short circuits and leakage. The casing 1 is typically made of metal, such as aluminum, steel, or nickel-plated iron. Therefore, the casing 1 has a certain degree of conductivity. Since the positive and negative electrodes are connected via the electrolyte, and the electrolyte is in contact with the casing 1, a pressure difference exists between the positive and negative electrodes and the casing 1, causing the casing 1 to become charged. The insulating coating 5 effectively isolates the electrode plates inside the battery casing 1 from the external environment, preventing current from flowing directly through the casing 1 to the outside, thus improving battery safety. The insulating coating 5 also protects the battery from environmental factors such as moisture and dust, extending its lifespan. Some insulating materials have good thermal conductivity, which helps dissipate heat from the battery module after assembling individual cells, preventing overheating of the battery module. In this application, the battery refers to an individual cell. The insulating coating 5 is typically selected from organic materials with good insulating properties. The insulating coating 5 can be formed on the outer surface of the battery casing 1 by processes such as spraying, coating, and electrophoresis. In this exemplary embodiment, the insulating coating 5 can be a polyethylene (PE) coating, a polyurethane (PU) coating, an epoxy (EP) coating, a potassium silicate coating, a siloxane coating, etc.

[0026] When welding the sealing nail 2 to the first sidewall 32, a butt welding process can be used. Butt welding refers to aligning the end faces of the two weldments and heating them at the contact point. The alignment and continuity of the weld seam help to form a more uniform and smooth weld surface. Compared with through welding or other welding methods, butt welding of the sealing nail 2 to the first sidewall 32 provides a better sealing effect and a smoother joint.

[0027] When the sidewall of the sealing nail 2 is welded to the first sidewall 32, the solder or molten metal at the weld solidifies to form a bulge 23, which slightly protrudes from the first step structure 3. This results in an uneven surface on the housing 1, leading to poor insulation after the insulating material is sprayed. To solve this problem, the housing 1 is also provided with a second step structure 6. Figure 2 A schematic diagram of another battery provided for embodiments of this application, such as... Figure 2As shown, in one embodiment, the housing 1 can be a circular housing 1, and the first step structure 3 is annular. The housing 1 also has a second step structure 6 recessed into the interior of the housing 1. The second step structure 6 is located on the outer periphery of the first step structure 3 and connects the housing 1 and the first step structure 3. The second step structure 6 is also annular. The housing 1 includes a base plate 11, and the aforementioned first step structure 3 and second step structure 6 are both located on the base plate 11. Along a direction perpendicular to the first base plate 31, the height of the base plate 11, the second step structure 6, and the first step structure 3 gradually decreases, and their diameters gradually shrink. That is, the first step structure 3 is closer to the interior of the housing 1 than the second step structure 6. It is worth noting that the housing 1 may also include a top plate (not shown in the figure) disposed opposite to the base plate 11, and the aforementioned first step structure 3 and second step structure 6 may also be disposed on the top plate. The sealing nail 2 is located in the first step structure 3. On the one hand, the volume of the sealing nail 2 can be made smaller, resulting in a smaller weld line filling area and a smaller weld size. Because the welding area is uneven, reducing the welding size allows for a more uniform overall insulating coating 5. Furthermore, the excess material after welding is contained within the second-step structure, resulting in a smoother surface for the casing 1 and better insulation performance of the insulating coating 5. This also prevents excess material from protruding from the battery casing 1 and contacting other external structures, reducing the risk of short circuits.

[0028] It is worth noting that the top and bottom plates mentioned above are determined based on the battery's installation orientation. For example, [the following text is incomplete and likely refers to a different battery configuration]. Figure 1 When the battery is flipped over, the bottom plate is considered the top plate.

[0029] In one embodiment, the second step structure 6 includes a second base plate 61 connected to the first sidewall 32 of the first step structure 3. The area a of the first base plate 31 and the area b of the second base plate 61 satisfy: 1.2 ≤ a:b ≤ 2. The ratio of the area a of the first base plate 31 to the area b of the second base plate 61 cannot be too small. If it is too small, the diameter of the first step structure 3 will be small, the size of the sealing nail 2 will be limited, the welding area will be insufficient, and the risk of sealing failure will increase. The ratio a to b cannot be too large either. If it is too large, the diameter of the first step structure 3 will be large, the size of the sealing nail 2 will be large, and the flatness of the sprayed insulating coating 5 will be poor. Along the height direction N of the battery, the height c of the first step structure 3 and the height d of the second step structure 6 satisfy: 0.8 ≤ c:d ≤ 1.5. If the ratio of the height c of the first step structure 3 to the height d of the second step structure 6 is too small, the sealing nail 2 will easily protrude from the first step structure 3, and a gap will easily remain between the sidewalls of the sealing nail 2 and the second step structure 6, resulting in poor spraying effect. If the ratio of c to d is too large, the height of the second step structure 6 will be too large, requiring an increase in the height recessed into the shell, occupying internal space. In summary, by satisfying the above proportional relationship between the first step structure 3 and the second step structure 6, the volume of the sealing nail 2 can be made smaller, while ensuring sufficient welding area with the sealing nail 2, thus improving the sealing and spraying effects. The battery height direction N mentioned above refers to the axial direction of the injection hole 4.

[0030] In some specific embodiments, the ratio of the area a of the first base plate 31 to the area b of the second base plate 61, a:b, can be 1.2, 1.4, 1.6, 1.8, or 2.0. The ratio of the height c of the first step structure 3 to the height d of the second step structure 6, c:d, can be 0.8, 1, 1.2, 1.4, or 1.5.

[0031] In one embodiment, the surface of the sealing pin 2 that is away from the first base plate 31 does not exceed the base plate 11 of the housing 1. That is, the sealing pin is located entirely in the recessed area of ​​the battery housing, so that when the battery is installed on an external carrier, the mounting surface is flat and the installation is firm and reliable.

[0032] Please continue to refer to Figure 2In a further embodiment, the second step structure 6 includes a second base plate 61 and a second sidewall 62 connected to each other, and the surface of the sealing nail 2 away from the first base plate 31 is flush with the second base plate 61. The welded protrusion 23 is located in the second step structure 6 and will not overflow to the outside of the plane where the base plate 11 of the housing 1 is located. Both the sealing nail 2 and the protrusion are located in the concave area of ​​the housing, which allows the battery housing 1 to maintain good flatness. After assembling multiple batteries, the overall flatness of the assembled batteries is good. When a heat dissipation device such as a cold plate is added to the battery module, the large contact area with the cold plate can improve the heat transfer effect. In addition, the sealing nail 2 is embedded in the first step structure 3, and from the appearance of the battery, the exterior of the battery housing 1 is flat, which allows the insulating material to be sprayed evenly, forming a more complete and flat coating, thereby improving the insulation effect of the battery.

[0033] In other embodiments, the height of the sealing pin 2 may be less than the height of the first step structure 3 along the height direction of the battery.

[0034] Figure 3 A top view of a battery provided for an embodiment of this application, such as... Figure 3 As shown, in one embodiment, the first step structure 3 and the injection hole 4 are coaxially arranged. The coaxial machining of the first step structure 3 and the injection hole 4 ensures a high degree of fit when installing the sealing pin 2, reducing the possibility of the sealing pin 2 failing to install due to eccentricity between the injection hole 4 and the first step structure 3. Furthermore, the housing 1, the first step structure 3, the injection hole 4, and the second step structure 6 can all be coaxially arranged. In the specific fabrication of the housing 1, the first step structure 3 and the second step structure 6 can be formed on the surface of the housing 1 by stamping. The coaxial arrangement of the housing 1, the first step structure 3, and the second step structure 6 facilitates processing.

[0035] The casing 1 can be a cylinder or a square prism. In some of the embodiments described above, the battery is a cylindrical battery. Figure 4 Another top view of a battery provided for an embodiment of this application, such as Figure 4 As shown, in other embodiments, the battery is also suitable for a prismatic battery. Specifically, the housing 1 can be a prismatic housing, and the first step structure 3 and the second step structure 6 are both prismatic annular. The housing 1, the second step structure 6, the first step structure 3, and the injection hole 4 can be coaxially arranged.

[0036] If the length of the injection hole 4 is equal to the thickness of the first base plate 31, the electrolyte may flow along the wall of the first base plate 31 facing the inside of the shell during injection, resulting in low injection efficiency. Figure 5 A schematic diagram of another battery provided for embodiments of this application, such as... Figure 5As shown, in one embodiment, the wall of the injection hole 4 extends into the interior of the housing 1, resembling a tube. Specifically, along a direction perpendicular to the first base plate 31, the length of the wall of the injection hole 4 is greater than the thickness of the first base plate 31. Therefore, when the injection machine injects electrolyte, the electrolyte can flow directly into the bottom of the housing 1 along the hole wall, improving the injection efficiency.

[0037] In one embodiment, the edge of the injection hole 4 facing the interior of the housing 1 can be rounded during processing. The rounded corner design facilitates the smooth flow of electrolyte and improves injection efficiency.

[0038] Figure 6 A schematic diagram of another battery provided for embodiments of this application, such as... Figure 6 As shown, in one embodiment, the first base plate 31, the second base plate 61, and the base plate 11 of the housing 1 are parallel to each other. The second sidewall 62 is connected to the base plate 11, and the second sidewall 62 and the base plate 11 form an obtuse angle. Correspondingly, the second sidewall 62 and the second base plate 61 also form an obtuse angle. Thus, the second stepped structure 6 and the base plate 11 form a gentle slope. When spraying the insulating layer, this gentle slope is less likely to create dead angles that prevent spraying at the angles, thus avoiding the problem of discontinuous insulating coating 5.

[0039] Embodiments of this application also provide a battery device, which includes a housing 101 and a plurality of batteries 100 disposed within the housing. Based on the excellent insulation properties of the batteries, this battery device also possesses excellent insulation properties, resulting in high battery safety.

[0040] Figure 7 A schematic diagram of a battery device provided for an embodiment of this application, such as... Figure 7 As shown, in one embodiment, the plurality of batteries 100 can be arranged along a first direction M, which is parallel to the bottom plate 1011 of the housing, with the battery's electrolyte filling hole 4 facing the bottom plate of the housing. Since the sealing pin 2 and redundant solder are hidden in the first step structure 3 and the second step structure 6, the contact surface between the battery 100 and the bottom plate 1011 of the housing is relatively flat, making the connection between the battery 100 and the housing 101 firm and reliable.

[0041] Figure 8 A schematic diagram of another battery device provided for embodiments of this application, as shown below. Figure 8As shown, in another embodiment, the battery device may further include a cold plate 102, which is disposed between two batteries 100, with the electrolyte injection hole 4 of the battery 100 facing the cold plate 102. The housing 1 may be cylindrical, and the axial direction of the housing 1 is parallel to the bottom plate 1011 of the casing. Since the sealing nail 2 and redundant solder are hidden in the first step structure 3 and the second step structure 6, the contact surface between the battery 100 and the cold plate 102 is relatively flat, improving the heat transfer effect between the battery 100 and the cold plate 102. This allows the battery 100 to dissipate heat well, improving the safety of the battery device. The battery 100 is bonded and fixed to the cold plate 102, and part of the adhesive may also be contained in the concave area of ​​the battery (first step structure 3 or second step structure 6) to increase the bonding area and increase the bonding strength between the battery 100 and the cold plate 102.

[0042] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A battery, characterized in that, The device includes a housing and a sealing pin. The housing has a first step structure that is recessed into the interior of the housing. The first step structure includes a first sidewall and a first bottom plate that are connected to each other. The first bottom plate has an injection hole. The sealing pin is disposed in the first step structure, and the sidewall of the sealing pin is welded and fixed to the first sidewall. The outer wall of the housing is covered with an insulating coating that covers the first stepped structure and the sealing pin.

2. The battery according to claim 1, characterized in that, The housing also has a second step structure recessed into the housing. The second step structure is located on the outer periphery of the first step structure and connects the housing and the first step structure. The first step structure is closer to the interior of the housing than the second step structure.

3. The battery according to claim 2, characterized in that, The second step structure includes a second base plate, which is connected to the first side wall. The area a of the first base plate and the area b of the second base plate satisfy: 1.2≤a:b≤2.

4. The battery according to claim 2, characterized in that, Along the height direction of the battery, the height c of the first step structure and the height d of the second step structure satisfy 0.8≤c:d≤1.

5.

5. The battery according to claim 2, characterized in that, The second step structure also includes a second sidewall, which is connected to the bottom plate of the housing and has an obtuse angle with the bottom plate.

6. The battery according to claim 2, characterized in that, Along the height direction of the battery, the surface of the sealing pin away from the first base plate does not exceed the base plate of the housing.

7. The battery according to claim 6, characterized in that, The second step structure includes a second base plate, which is connected to the first side wall, and the surface of the sealing nail away from the first base plate along the height direction of the battery is flush with the second base plate.

8. The battery according to any one of claims 1 to 7, characterized in that, The shell is a cylinder or a square prism.

9. A battery device, characterized in that, It includes a housing and a plurality of batteries as described in any one of claims 1 to 8, wherein the plurality of batteries are disposed within the housing.

10. The battery device according to claim 9, characterized in that, The injection hole faces the bottom plate of the box.

11. The battery device according to claim 9, characterized in that, It also includes a cold plate, which is disposed between the two batteries, with the liquid injection hole facing the cold plate; the housing is cylindrical, and the axial direction of the housing is parallel to the bottom plate of the box.

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