Battery and electric device

Abstract

A battery and an electric device. The battery comprises a battery cell (1) and a current collecting disc (2). The battery cell (1) is provided with a tab (11); the current collecting disc (2) is welded to the tab (11); the current collecting disc (2) is provided with at least one welding area (21); and the at least one welding area (21) is provided with at least two weld spots (211) of different sizes and / or shapes. By providing weld spots (211) of different sizes or different shapes, and reasonably arranging the positions of the weld spots (211) of different sizes and shapes, the arrangement of the weld spots (211) is optimized, thereby increasing the density of the weld spots (211) provided on the current collecting disc (2), improving the welding strength and reliability, and achieving high-strength welding under the premise of using low-power welding. In addition, the optimized distribution of the weld spots (211) improves the overall performance of the battery, such as current conduction capability and thermal management performance.

Description

Battery and electric device TECHNICAL FIELD

[0001] The utility model relates to a battery technical field, specifically, relate to a battery and electric device. BACKGROUND

[0002] With the development of battery technology, batteries are increasingly used in mobile phones, computers, tablets, Bluetooth headsets, power tools, cars, energy storage, and other fields. People have higher requirements for battery charging time. In order to achieve high-rate charging and discharging of cylindrical lithium batteries / sodium batteries / manganese iron phosphate batteries, the commonly used method to improve the rate of the battery in design is to change the current flow path in the current collector and increase the tab current-carrying area. One of the solutions is the full tab design. The full tab design does not require die cutting of the uncoated current collector. Instead, the full tab structure of the battery cell is flattened, and the current collector disc is then welded to the end face of the flattened battery cell using laser welding. This method has a shorter and more uniform current flow path for the tabs, resulting in a significant reduction in internal resistance. This means that the battery can more effectively transmit current during high-power discharge, thereby improving the performance and efficiency of the battery.

[0003] However, the existing technology has the following problems: the current collector disc of the existing full tab cylindrical battery is laser welded to the tabs of the winding core. The welding surface of the current collector disc is in flat contact with the battery cell. The tab area is thin, and the welding interface is close to the separator. The welding energy can easily be conducted to the separator, causing the separator to shrink and even burn, resulting in poor welding and battery short circuits, high welding scrap rate, and potential safety hazards. Reducing the welding power will affect the welding strength of the current collector disc and the tabs. The current collector disc welding area and the battery cell end face may not be properly bonded.

[0004] Therefore, there is an urgent need for a battery.

[0005] Utility model content

[0006] One of the purposes of the utility model is to address the deficiencies of the prior art and provide a battery that can achieve high-strength welding at a lower power while reducing thermal damage to the battery. The welding points have a high density and good conductivity.

[0007] To solve the above technical problems, the application adopts the following technical solutions:

[0008] A battery is provided, comprising a battery cell and a current collector disc. The battery cell has tabs, and the current collector disc is welded to the tabs. The current collector disc has at least one welding area, and at least two welding points with different sizes and / or shapes are provided in the at least one welding area.

[0009] Specifically, at least one smaller welding point is arranged between two adjacent same welding points; and / or, at least one welding point with different shape is arranged between two adjacent same welding points.

[0010] Specifically, the welding areas are annular and arranged around the axis of the current collecting plate, and when the number of the welding areas is two or more, each welding area is in a surrounding and surrounded structure with another welding area.

[0011] All the welding points in the same welding area are arranged along the circumferential direction of the corresponding welding area.

[0012] Specifically, the center line of each welding area is collinear with the center line of the current collecting plate.

[0013] Specifically, the current collecting plate has a welding surface in the thickness direction of the current collecting plate, the welding points are located on the welding surface, the total area of the welding points is A1, the area of the welding surface is A2, and the relationship A1>0.5A2 is satisfied.

[0014] Specifically, two adjacent welding points at least partially overlap.

[0015] Specifically, all the welding points are circular, and in two welding points with the closest diameters, the diameter difference of the two welding points is greater than 0.2mm.

[0016] Specifically, the diameter of the welding point is less than 3mm.

[0017] Specifically, the battery cell has a hollow structure with an opening, and the current collecting plate is provided with a center hole corresponding to the position of the opening.

[0018] The battery cell has the advantages that: by setting welding points with different sizes or shapes and reasonably distributing the positions of the welding points with different sizes and shapes, the arrangement of the welding points is optimized, the density of the welding points arranged in the current collecting plate is improved, the strength and reliability of welding are improved, smaller welding points are used under the same welding strength, the energy required by the welding points is low, and the welding energy is not easy to conduct to the diaphragm, high strength welding is realized under the premise of low-power welding, and the overall performance of the battery is also improved, including the improvement of current conduction capacity and thermal management performance.

[0019] The second purpose of the utility model is to provide an electric device comprising the battery. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the present application and together with the description serve to explain the present application. In the drawings:

[0021] Fig. 1 is a schematic diagram of welding of different size welding points in the present application;

[0022] Fig. 2 is a schematic diagram of a battery in the present application;

[0023] Fig. 3 is a schematic diagram of welding of different shape welding points in the present application;

[0024] Fig. 4 is a schematic diagram of welding of overlapping welding points in the present application;

[0025] Wherein: 1 - battery cell; 11 - tab; 2 - current collector plate; 21 - welding area; 211 - welding point; 2111 - first welding point; 2112 - second welding point; 2113 - third welding point; 2114 - fourth welding point; 212 - center hole. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application. 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 the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments of the present application, and are not intended to limit the present application.

[0027] In the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium; it can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the claims, and any person skilled in the art can make several possible changes and modifications without departing from the concept of the present application, therefore the protection scope of the present application should be limited by the scope defined by the claims of the present application.

[0029] A battery generally includes a tab, a cell, a current collector and a shell, wherein the current collector is used to connect the tab of the battery and the external circuit, help the current flow out of the cell, and provide physical support, and as the energy density of the battery improves and people's requirements for the charging and discharging time of the battery improve, the importance of optimizing the current flow path of the current collector and the stability of the battery in high-power applications continues to improve.

[0030] The existing connection method generally uses a series of welding spots of the same size to connect the current collector and the tab, which can ensure uniform distribution of current and improve the stability of mechanical connection. However, when a larger welding spot is set, the welding energy required is large, which is easy to conduct to the separator, causing the separator to shrink and even burn, and the large welding spot has a low coverage density on the current collector, and the size and shape of the welding spot may not fully adapt to the actual needs of the current, increasing the local resistance and affecting the overall current transmission efficiency. When a small welding spot is welded, reducing the welding power will affect the welding strength of the current collector and the tab, and the ideal welding scheme needs to find a balance between the size of the welding spot, the welding energy and strength, and the influence of the welding spot on the current transmission efficiency of the tab. However, it is difficult to consider these aspects simultaneously in actual production, which affects the performance of the battery.

[0031] As shown in FIG. 1, the present application optimizes the arrangement of the welding spots 211 by combining welding spots 211 of different shapes and sizes and reasonably allocating the positions of the welding spots 211 of different sizes and shapes, thereby improving the density of the welding spots 211 in the current collector, improving the strength and reliability of the welding, and because the control method of the welding quality in the prior art is changed, the welding parameters can be more conveniently adjusted in the production process to adapt to different production requirements and standards, thereby improving the production efficiency and product consistency.

[0032] Embodiment 1

[0033] As shown in FIGS. 1 and 2, a battery includes a cell 1 and a current collector 2, the cell 1 has a tab 11, the current collector 2 is welded with the tab 11, the current collector 2 has at least one welding area 21, the welding area 21 is an area on the current collector 2 for welding connection with the tab 11 of the cell 1, and the at least one welding area 21 has at least two welding spots 211 of different sizes and / or shapes, wherein the sizes are different in that the sizes of the areas occupied by the welding spots 211 after welding are different, and the shapes are different in that the shapes of the welding spots 211 formed in the thickness direction of the current collector 2 are different.

[0034] For example, as shown in FIG. 1, the first soldering points 2111 and the second soldering points 2112 can be arranged in the current collecting plate 2 at the same time. Since the first soldering points 2111 are arranged to be larger, more power is needed to heat and melt the larger area during soldering, so as to form a firm soldering connection. The higher power can provide more heat, so that the solder is fully melted, thereby ensuring the firmness of the first soldering points 2111. However, since the first soldering points 2111 have a large energy, it is necessary to ensure that the distance between the first soldering points 2111 is far enough to avoid the heat concentration affecting the diaphragm. The second soldering points 2112 are smaller, and the energy for soldering is low, and the second soldering points 2112 occupy a small area of the current collecting plate 2, so the position of the second soldering points 2112 is more flexible. However, since the energy for soldering is small, it is easy to cause a false soldering. By arranging the first soldering points 2111 and the second soldering points 2112 at the same time, the advantages can be complementary. There are more gaps between the first soldering points 2111. By reasonably distributing the second soldering points 2112 between the first soldering points 2111, the density of the soldering points 211 can be improved, and the distribution of the current can be more accurately controlled, the local resistance is reduced, and the overall current transmission efficiency is improved. When the first soldering points 2111 are arranged, the current collecting plate 2 and the tab 11 are already stably combined together to provide a preliminary mechanical fixation. On this basis, when the second soldering points 2112 are soldered, the position is stable, so the false soldering can be reduced. In addition, the arrangement of the second soldering points 2112 also improves the overall soldering strength. Under the same soldering strength, the size of the first soldering points 2111 can be reduced, so as to prevent the energy of the first soldering points 2111 from being too large to cause the diaphragm to burn out when the energy is transmitted to the diaphragm. The safety performance of the battery is improved.

[0035] As shown in FIG. 3, for example, the first soldering points 2111 and the third soldering points 2113 can be arranged in the current collecting plate 2. The first soldering points 2111 are arranged in a circular shape. Since the energy is concentrated when the first soldering points 2111 are arranged in a circular shape, the energy is transmitted to the diaphragm to burn out the diaphragm. Therefore, the third soldering points 2113 can be arranged in a long strip shape. Under the same size of the soldering points 211, the third soldering points 2113 arranged in a long strip shape can disperse the soldering energy, and the third soldering points 2113 arranged between the first soldering points 2111 will not cause the heat concentration to burn out the diaphragm. By arranging the third soldering points 2113 between the first soldering points 2111, the density of the soldering points 211 can be improved, so as to improve the flow path of the current in the tab 11 to the current collecting plate 2, and improve the soldering quality.

[0036] Preferably, at least one smaller welding spot 211 is arranged between two adjacent same welding spots 211; and / or, at least one welding spot 211 with different shape is arranged between two adjacent same welding spots 211. Smaller welding spots 211 arranged between welding spots 211 with same size and same shape can fill the gap between them, thereby improving the density of the overall welding area 21. Such design helps to improve the uniformity of the welding connection and reduce the risk of false welding and poor contact. Arranging welding spots 211 with different shapes (such as circular, rectangular, hexagonal, etc.) between adjacent same welding spots 211 can help better adapt to the actual shape of the welding area 21 and improve the density and overall strength of the welding area 21. Such strategy helps to provide better coverage at different welding positions.

[0037] In some embodiments, a series of welding spots 211 with increasing sizes can be arranged in the current collector plate 2, and these welding spots 211 can be arranged reasonably, such as arranging the second largest welding spot 211 in the gap of the largest welding spot 211, and so on. By arranging a series of welding spots 211 with increasing sizes in the current collector plate 2, the coverage of the welding spots 211 on the current collector plate 2 can be improved, thereby providing more paths for the electrical connection between the tab 11 and the current collector plate 2, optimizing the conduction efficiency, and also having better welding strength.

[0038] Preferably, the welding area 21 is annular and arranged around the axis of the current collector plate 2. When the number of welding areas 21 is two or more, the welding areas 21 are in a surrounding and surrounded structure. In the same welding area 21, all welding spots 211 are arranged along the circumferential direction of the corresponding welding area 21. Such layout can ensure that the welding areas 21 are evenly distributed around the current collector plate 2, thereby improving the stability and uniformity of welding. Arranging the welding area 21 around the axis of the current collector plate 2 helps to balance the stress distribution during welding and reduce the problem of uneven mechanical stress caused by axis asymmetry.

[0039] For cylindrical full-tab battery, it is a better choice to arrange the welding area 21 as annular. The annular welding area 21 is consistent with the winding form of the tab of the battery cell 1, so that the welding area 21 can better adapt to the overall structure of the battery, enhance the stability and conduction performance of the battery, and the annular design of the welding area 21 also matches the annular design of the tab 11 of the full-tab battery, ensuring the alignment of the welding position and the tab 11, improving the welding quality and current transmission efficiency.

[0040] Preferably, the center line of each welding area 21 is collinear with the center line of the current collector plate 2. The collinear design ensures that each welding area 21 is aligned with the central axis of the current collector plate 2, ensuring the consistency of the welding spots 211 in each area, thereby improving the overall welding quality and stability.

[0041] Preferably, the current collector plate 2 has a welding surface in the thickness direction of the current collector plate 2, the welding points 211 are located on the welding surface, the total area of the welding points 211 is A1, and the area of the welding surface is A2, and the relationship A1>0.5A2 is satisfied. In order to ensure sufficient current conduction channels, reduce the current density, prevent heat generation in the welding area 21 during high-rate charging and discharging, and ensure the welding strength in the welding area 21, the area of the welding points 211 is set in the above range.

[0042] Embodiment 2

[0043] As shown in FIG. 4, preferably, two adjacent welding points 211 at least partially overlap. By overlapping the welding points 211 of the current collector plate 2, the preheating function is provided for the next welding point, i.e., the first welding point 2111, after the fourth welding point 2114 is welded, so that the tab 11 is welded in a higher temperature environment, reducing the welding energy required for welding. When the first welding point 2111 is welded, the tab 11 is connected to the current collector plate 2 as a whole after the fourth welding point 2114 is welded, so that the heat can be quickly transferred to the fourth welding point 2114 when the first welding point 2111 is welded, reducing the heat-affected depth of welding and avoiding the safety problem of large single-point penetration in the discrete spot welding mode. Among them, the fourth welding point 2114 is larger than the first welding point 2111.

[0044] In some embodiments, by first welding a small welding point 211 and then welding a large welding point 211 at the position of the small welding point 211, since the tab 11 is connected to the current collector plate 2 after the small welding point 211 is welded, the use of smaller welding power will not cause false welding when welding again, because the small welding point 211 first forms a preliminary connection to ensure good basic contact between the tab 11 and the current collector plate 2, and the heat generated during subsequent welding is smoothly transferred, which can reduce the heat-affected depth caused by one-time large welding point 211 welding, thereby reducing the risk of welding defects.

[0045] Preferably, all the welding points 211 are circular in shape, and in the two welding points 211 with the closest diameters, the diameter difference between the two welding points 211 is greater than 0.2 mm. The diameter difference between different welding points 211 is greater than 0.2 mm, which has a lower requirement for the welding process, making the production process more stable and easy to control.

[0046] Preferably, the diameter of the welding point 211 is less than 3 mm, and the smaller diameter of the welding point 211 produces a smaller heat-affected zone during welding, which helps to control the distribution of heat and reduce the impact on the surrounding material.

[0047] Preferably, the battery cell 1 is in a hollow structure with an opening, and the center hole 212 of the current collector 2 is arranged at the position corresponding to the opening, the hollow structure is arranged in the battery cell 1 to facilitate the injection of electrolyte, and the electrolyte can infiltrate the battery along the hollow structure, and the center hole 212 of the current collector 2 is arranged to provide an inlet for the injection of electrolyte.

[0048] The welding spot 211 can be welded in various ways, such as spot welding, laser welding, and ultrasonic welding.

[0049] Preferably, the welding spot 211 is welded by laser welding, which allows very precise control of the welding position and depth, and helps to flexibly arrange the welding spot 211.

[0050] Embodiment 3

[0051] The battery of the present application is suitable for various electrical equipment, such as consumer electronics: mobile phones, notebook computers, tablet computers, etc.; household appliances: wireless vacuum cleaners, smart home devices, etc.; electric vehicles: electric bicycles, electric scooters, electric cars, etc.; portable devices: handheld tools, outdoor equipment, etc.; medical devices: portable medical instruments, health monitoring devices, etc.

[0052] The above description shows and describes several preferred embodiments of the present application, but as mentioned before, the present application is not limited to the forms disclosed herein, and should not be considered as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the present application, by the above teachings or related technical or knowledge. Any modification and change made by those skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the appended claims of the present application.

Claims

1. A battery, characterized by: The battery comprises a cell (1) having a tab (11) and a current collector plate (2) welded with the tab (11), the current collector plate (2) has at least one welding area (21) with at least two welding spots (211) of different sizes and / or shapes in the welding area (21).

2. The battery according to claim 1, wherein: There is at least one smaller welding spot (211) between two adjacent welding spots (211) of the same size; And / or, there is at least one welding spot (211) of different shape between two adjacent welding spots (211) of the same size.

3. The battery of claim 2, wherein: The welding area (21) is annular and arranged around the axis of the current collector plate (2), when the number of welding areas (21) is two or more, each welding area (21) is in a surrounding and surrounded structure with another welding area (21). All the welding spots (211) in the same welding area (21) are arranged along the circumferential direction of the corresponding welding area (21).

4. The battery of claim 3, wherein: The center line of each welding area (21) is collinear with the center line of the current collector plate (2).

5. The battery of claim 1, wherein: The current collector plate (2) has a welding surface in the thickness direction of itself, the welding spots (211) are located on the welding surface, the total area of the welding spots (211) is A1, the area of the welding surface is A2, and the relationship A1>0.5A2 is satisfied.

6. The battery of claim 1, wherein: Two adjacent welding spots (211) at least partially overlap.

7. The battery of claim 1, wherein: All the welding spots (211) are circular in shape, and in the two welding spots (211) with the closest diameters, the diameter difference of the two welding spots (211) is greater than 0.2mm.

8. The battery of claim 6, wherein: The diameter of the welding spot (211) is less than 3mm.

9. The battery of claim 1, wherein: The cell (1) is in a hollow structure with an opening, and the current collector plate (2) is provided with a center hole (212) corresponding to the position of the opening.

10. An electrical device, characterized by: The battery comprises the battery according to any one of claims 1 to 9.

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