Battery monomer, battery and electric device

Abstract

The utility model relates to a battery monomer which comprises a shell and a top cover, a surface treatment area is formed on the inner wall of one end, close to an opening, of the shell, and the surface treatment area can weaken the reflection phenomenon of light rays. When the top cover and the shell are subjected to laser welding operation, laser entering the shell through the gap between the top cover and the shell irradiates the surface treatment area of the inner wall of the shell firstly, is reflected by the surface treatment area and then is further diffused into the shell. The surface treatment area can weaken the reflection phenomenon of light, so that the energy density of the laser after being reflected by the surface treatment area can be obviously reduced, and a battery cell, a plastic part of a top cover and the like are not easy to burn. Therefore, even if the phenomenon of light leakage exists in the laser welding process of the top cover and the shell, the battery cell and the top cover are not easy to be bad. Therefore, the yield of the battery monomer can be obviously improved. In addition, the utility model also provides a battery and an electric device.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] The assembly of battery cells typically involves multiple welding steps. For example, after the battery cells are installed in the casing, a top cover must be welded to the edge of the casing opening to seal the casing. Laser welding is currently used in most welding processes due to its advantages such as high efficiency and high precision. However, during laser welding, the laser can enter the casing through the gap between the top cover and the casing, causing problems such as burns to the battery cells and the plastic underneath the top cover. Utility Model Content

[0003] Based on this, it is necessary to provide a battery cell, a battery and an electrical device that can improve the yield in order to address the above problems.

[0004] A battery cell includes a shell and a top cover. The shell has an opening at at least one end. The top cover is welded to the shell and covers the opening. A surface treatment area is formed on the inner wall of the shell near the end of the opening. The orthographic projection of the side of the top cover facing the inner wall of the shell on the inner wall of the shell at least partially overlaps with the surface treatment area, and the surface treatment area can reduce the reflection of light.

[0005] In one embodiment, the shell is square, having two oppositely disposed long sides and two oppositely disposed short sides, and the surface treatment area is distributed on the inner walls where the two short sides are located and extends along the short sides.

[0006] In one embodiment, the inner wall where the long side is located and the inner wall where the short side is located are transitionally connected by a rounded structure, and the distance between the two ends of the surface treatment area in the extension direction and the edge of the rounded structure is more than 3 mm.

[0007] In one embodiment, a distance between an upper edge of the surface treatment area and an edge of the opening is greater than 0.2 mm.

[0008] In one embodiment, the top cover includes a cover plate and a plastic component. The plastic component is installed on the inner side of the cover plate, and the side of the plastic component facing the inner wall of the shell is covered with a heat-resistant layer.

[0009] In one embodiment, the surface of the surface-treated area forms a diffuse reflection surface.

[0010] In one embodiment, an embossed structure is formed on the surface of the surface-treated area, and the diffuse reflection surface is formed in the area where the embossed structure is located; or, the surface of the surface-treated area is roughened to form the diffuse reflection surface.

[0011] In one embodiment, the surface of the surface-treated area is covered with a light-absorbing layer.

[0012] In one embodiment, the light absorbing layer is configured as a dark film layer.

[0013] In one embodiment, the surface of the surface-treated area forms a diffuse reflection surface, and the surface of the surface-treated area is covered with a light-absorbing layer.

[0014] When laser welding the top cover and the housing of a battery cell, the laser light entering the housing through the gap between the two will first strike the surface-treated area on the inner wall of the housing. After reflection from the surface-treated area, the laser light will diffuse further into the housing. Because the surface-treated area reduces light reflection, the energy density of the laser light after reflection from the surface-treated area is significantly reduced, making it less likely to burn the battery cell, the plastic components of the top cover, and so on. Therefore, even if light leakage occurs during the laser welding of the top cover and the housing, it is unlikely to cause defects in the battery cell or the top cover. Consequently, the yield rate of the battery cell can be significantly improved.

[0015] A battery comprises a battery cell as described in any one of the above preferred embodiments.

[0016] An electrical device comprises the battery cell described in any one of the above preferred embodiments or the battery described in any one of the above preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only 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.

[0018] Figure 1 This is a schematic structural diagram of a battery cell in one embodiment of the present invention;

[0019] Figure 2 for Figure 1 A schematic diagram of the structure of the shell in the battery cell shown;

[0020] Figure 3 for Figure 2 An enlarged schematic diagram of a part A in the shell shown;

[0021] Figure 4 This is a structural schematic diagram of a housing in another embodiment of the present utility model;

[0022] Figure 5 for Figure 4 An enlarged schematic diagram of a part B in the shell shown;

[0023] Figure 6 for Figure 1 End view of the top cover in the battery cell shown. DETAILED DESCRIPTION

[0024] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this utility model, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0027] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0028] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0029] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0030] The utility model discloses an electric device, a battery and a battery cell. The electric device includes the battery or the battery cell, and can be provided with electric energy by the battery or the battery cell. The electric device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, an energy storage device, an amusement ride, an elevator and a lifting device, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys or electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc. Energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc. Amusement rides can be carousels, bungee jumping machines, etc.

[0031] The vehicle may be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle. A new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle. For new energy vehicles, the battery may serve as a driving power source, thereby replacing fossil fuels in providing driving power. This application does not impose any specific restrictions on the electrical device.

[0032] The above-mentioned battery can be a battery pack or a battery module. When the above-mentioned battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and a plurality of the above-mentioned battery cells. The plurality of battery cells can be electrically connected in series, in parallel, or in a mixture of series and parallel, and communicated with the battery management system to form a battery pack. The above-mentioned battery management system controls and monitors the working status of each battery cell. In addition, the plurality of battery cells can also be connected in series and / or in parallel first, and form a battery module with the module management system, and then the plurality of battery modules are electrically connected in series, in parallel, or in a mixture of series and parallel, and together with the battery management system form a battery pack.

[0033] The multiple battery cells in the battery pack or battery module can be mounted on a supporting structure such as a housing, frame, or bracket. Electrical connections can be established between the individual battery cells and between the battery cells and the battery management system via a busbar assembly. The battery cells can be lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, and their external shapes can be cylindrical, flat, rectangular, or other, but are not limited to these. Specifically, in this embodiment, the battery cells are lithium-ion prismatic batteries.

[0034] See also Figures 1 to 6 In one embodiment of the present invention, a battery cell 10 includes a housing 100 and a top cover 200 .

[0035] The housing 100 can be formed from materials such as aluminum and stainless steel. It has an internal space for accommodating battery cells (not shown), electrolyte, and other components. Furthermore, at least one end of the housing 100 is provided with an opening 101 through which the battery cells can be loaded. The top cover 200 is welded to the housing 100 and covers the opening 101, thereby sealing the opening 101 and creating a relatively closed environment within the housing 100.

[0036] The top cover 200 includes a cover plate 210 and a plastic component 220. The plastic component 220 can be attached to the underside of the cover plate 210 (i.e., the side facing the interior of the housing 100) by bonding, snapping, or other means. The cover plate 210 is typically formed of metal, and the plastic component 220 is typically formed of rubber. When the top cover 200 is welded to the housing 100, a weld mark is formed between the side of the cover plate 210 and the inner wall of the housing 100. This weld mark is typically annular and extends around the circumference of the opening 101, thereby forming a good seal between the top cover 200 and the housing 100.

[0037] The outer contour of the housing 100 determines the outer contour of the battery cell 10. Since the battery cell 10 in this embodiment is a prismatic battery, the housing 100 is square, with two opposing long sides and two opposing short sides. Furthermore, the opening 101 of the housing 100 and the cover 210 are also rectangular.

[0038] Please refer again Figure 3 and Figure 5 The inner wall of the housing 100, where the long side is located, and the inner wall of the short side are connected by a rounded structure. The inner wall of the housing 100, where the two short sides are located, is formed with steps 110 for supporting the top cover 200. The steps 110 can position and limit the top cover 200, thereby ensuring that the top cover 200 remains stable during the welding process.

[0039] Furthermore, a surface treatment area 102 is formed on the inner wall of the housing 100 near one end of the opening 101, and the orthographic projection of the side surface of the top cover 200 facing the inner wall of the housing 100 on the inner wall of the housing 100 at least partially overlaps with the surface treatment area 102. Moreover, the surface treatment area 102 can reduce the reflection of light.

[0040] The side of the top cover 200 facing the inner wall of the shell 100 refers to the side arranged around the top cover 200. The surface treatment area 102 can reduce the reflection of light by diffusely reflecting the light, absorbing the light, or combining diffuse reflection and light absorption. When the top cover 200 and the shell 100 are laser welded, the laser that enters the interior of the shell 100 through the gap between the top cover 200 and the shell 100 will first irradiate the surface treatment area 102 on the inner wall of the shell 100, and then further diffuse into the interior of the shell 100 after being reflected by the surface treatment area 102. Since the surface treatment area 102 can reduce the reflection of light, the energy density of the laser after being reflected by the surface treatment area 102 will be significantly reduced, so that it is not easy to burn the battery cell, the plastic part 220 of the top cover 200, etc.

[0041] Please refer again Figure 6 In this embodiment, the side of the plastic part 220 facing the inner wall of the housing 100 is covered with a heat-resistant layer 221. The heat-resistant layer 221 can be a heat-resistant coating or heat-resistant tape, such as polyimide (PI) tape, adhered to the side of the plastic part 220. Due to its material properties, the plastic part 220 is easily burned. Even after the laser is weakened by the surface treatment area 102, the possibility of burning the plastic part 220 still exists. By providing the heat-resistant layer 221, the plastic part 220 can be effectively isolated from the laser, thereby further protecting the top cover 200.

[0042] Specifically, in this embodiment, the surface treatment area 102 is distributed along the inner wall of the two short sides and extends along the short sides. Through testing and analysis, the inventors found that during the laser welding process, light leakage between the long sides of the shell 100 and the top cover 200 was not obvious, and light leakage mainly occurred between the short sides of the shell 100 and the top cover 200. Therefore, by forming the surface treatment area 102 only on the inner wall of the two short sides of the shell 100, the process can be simplified without reducing the yield of the battery cells 10. Optionally, the orthographic projection of the side surfaces of the top cover 200 corresponding to the short sides of the shell 100 on the inner wall of the shell 100 falls completely within the range of the surface treatment area 102.

[0043] Of course, in other embodiments, if the process allows, an annular surface treatment area 102 may be formed on the inner wall of the housing 100 along the circumference of the opening 101 .

[0044] Specifically, in this embodiment, the distance between the upper edge of the surface treatment area 102 and the edge of the opening 101 is greater than 0.2 mm, thereby reducing the possibility of explosion points occurring during the laser welding process of the housing 100 and the top cover 200.

[0045] See also Figure 2 and Figure 3 In one embodiment, the surface of the surface treated area 102 forms a diffuse reflection surface. That is, the surface treated area 102 diffusely reflects the laser irradiated on the surface treated area 102, thereby achieving the purpose of reducing the laser reflection phenomenon.

[0046] The surface of the surface-treated area 102 can be embossed to form an embossed structure 120, thereby forming a diffuse reflective surface in the area where the embossed structure 120 is located. The embossed structure 120 can increase the roughness of the surface of the surface-treated area 102, thereby forming a diffuse reflective surface. Specifically, the embossed structure 120 includes a plurality of recessed teeth, which can be regular or irregular in shape. The depth of the teeth is generally 0.05 mm to 0.1 mm, the spacing between the teeth is 0.5 mm to 1.0 mm, and the size of the teeth is 0.2 mm to 0.5 mm.

[0047] In order to facilitate processing, the arrangement of the embossed structure 120 needs to consider avoiding the step 120 and the rounded corner structure. More specifically, the distance between the two ends of the embossed structure 120 in the extending direction and the edge of the rounded corner structure is more than 3 mm.

[0048] Alternatively, the surface of the surface-treated region 102 may be roughened to form a diffusely reflective surface. Roughening methods include pickling, sandblasting, and the like, which can increase the roughness of the surface-treated region 102, thereby forming a diffusely reflective surface. Optionally, the surface roughness of the surface-treated region 102 is not less than Ra 0.5.

[0049] See also Figure 4 and Figure 5 In another embodiment, the surface of the surface treated area 102 is covered with a light absorbing layer 130. That is, the surface treated area 102 absorbs the laser irradiated on the surface treated area 102, thereby reducing the laser reflection phenomenon.

[0050] More specifically, the light-absorbing layer 130 is configured as a dark film layer. The dark film layer can be a dark color, such as a coating or plating formed of a black or brown high-temperature resistant material, or a dark film bonded to the surface treatment area 102. The dark film layer can be made of nylon, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyimide (PI), etc. The configuration of the light-absorbing layer 130 does not require consideration of avoiding the step 110 and the rounded corner structure. Therefore, the light-absorbing layer 130 can extend to the step 110 and the rounded corner structure, thereby obtaining a larger surface treatment area 102.

[0051] It should be noted that in other embodiments, the embossed structure 120 and the light-absorbing layer 130 can be used in combination. That is, the surface-treated region 102 comprises both a diffusely reflective surface and a light-absorbing layer 130. In this manner, the surface-treated region 102 can simultaneously diffusely reflect and absorb light, thereby significantly reducing light reflection.

[0052] When the top cover 200 and the shell 100 are laser-welded together, the laser beam entering the interior of the shell 100 through the gap between the top cover 200 and the shell 100 will first irradiate the surface-treated area 102 on the inner wall of the shell 100, and then, after being reflected by the surface-treated area 102, further diffuse into the interior of the shell 100. Because the surface-treated area 102 can reduce the reflection of light, the energy density of the laser beam after reflection from the surface-treated area 102 is significantly reduced, making it less likely to burn the battery cell, the plastic part 220 of the top cover 200, etc. As can be seen, even if light leakage occurs during the laser welding process between the top cover 200 and the shell 100, it is unlikely to cause defects in the battery cell and the top cover 200. Therefore, the yield rate of the battery cell 10 can be significantly improved.

[0053] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A battery cell, characterized in that: The invention comprises a shell and a top cover, wherein at least one end of the shell is provided with an opening, the top cover is welded to the shell and covers the opening, a surface treatment area is formed on the inner wall of the shell near one end of the opening, the orthographic projection of the side of the top cover facing the inner wall of the shell on the inner wall of the shell at least partially overlaps with the surface treatment area, and the surface treatment area can reduce the reflection of light.

2. The battery cell according to claim 1, wherein: The shell is square in shape, and has two oppositely disposed long sides and two oppositely disposed short sides. The surface treatment area is distributed on the inner walls where the two short sides are located and extends along the short sides.

3. The battery cell according to claim 2, characterized in that: The inner wall where the long side is located and the inner wall where the short side is located are transitionally connected by a rounded structure, and the distance between the two ends of the surface treatment area in the extension direction and the edge of the rounded structure is more than 3 mm.

4. The battery cell according to claim 1, wherein: A distance between an upper edge of the surface treatment area and an edge of the opening is greater than 0.2 mm.

5. The battery cell according to claim 1, characterized in that The top cover includes a cover plate and a plastic component. The plastic component is installed on the inner side of the cover plate, and the side of the plastic component facing the inner wall of the shell is covered with a heat-resistant layer.

6. The battery cell according to any one of claims 1 to 5, characterized in that: The surface of the surface-treated area forms a diffuse reflection surface.

7. The battery cell according to claim 6, characterized in that An embossed structure is formed on the surface of the surface-treated area, and the diffuse reflection surface is formed in the area where the embossed structure is located; or the surface of the surface-treated area is roughened to form the diffuse reflection surface.

8. The battery cell according to any one of claims 1 to 5, characterized in that: The surface of the surface-treated area is covered with a light-absorbing layer.

9. The battery cell according to claim 8, characterized in that The light absorbing layer is configured as a dark film layer.

10. The battery cell according to any one of claims 1 to 5, characterized in that: The surface of the surface-treated area forms a diffuse reflection surface, and the surface of the surface-treated area is covered with a light-absorbing layer.

11. A battery, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 10.

12. An electrical device, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 10 or the battery according to claim 11.

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