Battery cell, battery and electric device

Abstract

The application belongs to the technical field of power batteries, and particularly relates to a battery monomer, a battery and a power utilization device. The battery monomer comprises an electrode lead-out piece and an electrode assembly; the electrode assembly comprises an electrode main body and an electrode lug, the electrode lug is arranged on at least one side of the electrode main body along a second direction, the electrode lug is welded and fixed with the electrode lead-out piece, and a welding mark is formed on the electrode lug, the welding mark comprises at least two first welding marks arranged along a first direction, a second welding mark is arranged between the two adjacent first welding marks, the second welding mark is in a strip shape, and extends from one of the two adjacent first welding marks to the other, and the first direction intersects with the second direction. The second welding mark is arranged between the two adjacent first welding marks, the second welding mark is used for physical bridging, the edge of the electrode lug along the first direction is shaped to release stress, the problem of deformation, warping and even cracking of the short side of the electrode lug can be effectively improved, and the overcurrent capacity of the battery monomer during charging and discharging can be improved.

Description

Technical Field

[0001] This invention relates to the field of power battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Technology

[0002] Lithium-ion batteries mainly consist of a cathode, anode, electrolyte, and separator. The rapid development of lithium-ion battery technology has placed higher demands on manufacturing processes. In the assembly of lithium battery cells, ultrasonic welding is used to weld the tabs and electrode leads together. An ultrasonic welding machine mainly consists of a transducer, amplitude transformer, and welding head. The transducer converts electrical energy into high-frequency mechanical vibration, and the welding head converts this high-frequency mechanical vibration energy into frictional heat between the metal foils of the tabs, connecting the tabs to the electrode leads.

[0003] With the increasing requirements for lithium battery capacity and continuous improvement in safety performance, the number of tab layers and the size of the tabs have also increased accordingly. In order to ensure the welding effect after the increase in the number of tab layers, it is necessary to improve the welding parameters and welding effect. At the same time, in order to ensure the charging overcurrent capacity, two solder marks are often welded on a single tab. The double solder marks cause huge deformation of the tab, which can easily cause problems such as tab lifting or even cracking. Summary of the Invention

[0004] The purpose of this invention is to provide a battery cell, a battery, and an electrical device to solve the problem of increased soldering causing the tabs to warp or even crack.

[0005] To achieve this objective, firstly, the present invention adopts the following technical solution: A single battery cell, comprising: Electrode leads; An electrode assembly includes an electrode body and a tab. The tab is disposed on at least one side of the electrode body along a second direction. The tab is welded and fixed to the electrode lead-out member, and a solder mark is formed on the tab. The solder mark includes at least two first solder marks arranged along a first direction. A second solder mark is disposed between two adjacent first solder marks. The second solder mark is elongated and extends from one of the two adjacent first solder marks to the other. The first direction intersects the second direction.

[0006] As an alternative to the above-mentioned battery cell, a plurality of second solder marks are provided between two adjacent first solder marks, and the plurality of second solder marks are arranged in parallel, or at least some of the second solder marks are arranged in an intersecting manner.

[0007] As an alternative to the aforementioned battery cell, the second solder mark extends in a straight line; Alternatively, the second solder mark extends in a curve; Alternatively, some of the second solder marks extend in a straight line, while some of the second solder marks extend in a curve.

[0008] As an alternative to the aforementioned battery cell, the second solder mark extends in a straight line along the first direction.

[0009] As an optional solution for the aforementioned battery cell, the distance D2 between two adjacent second solder marks is 0.3mm-1.3mm; And / or, multiple second solder marks are evenly spaced.

[0010] As an alternative to the aforementioned battery cell, the second solder marks all extend in a straight line, and adjacent second solder marks are connected end to end in sequence. Alternatively, the second solder mark includes at least two solder mark groups, each solder mark group including intersecting straight solder marks and curved solder marks, all of the straight solder marks are arranged in parallel, all of the curved solder marks are arranged in parallel, and in two adjacent solder mark groups, the straight solder marks and the curved solder marks are connected end to end.

[0011] As an alternative to the above-mentioned battery cell, the number N of the second solder marks and the thickness H of the tab satisfy: 0.6 ≤ / N ≤ 1.2, where the unit of H is millimeters; And / or, the number of the second solder marks is 5-10.

[0012] As an alternative to the aforementioned battery cell, the second solder mark is spaced apart from the first solder mark along the first direction; Alternatively, the second solder mark may overlap with the first solder mark at both ends along the first direction.

[0013] As an alternative to the above-mentioned battery cell, the distance L4 between the second solder mark and the first solder mark along the first direction is less than or equal to 1.5 mm; Alternatively, the overlap length L5 between the second solder mark and the first solder mark at both ends along the first direction is less than or equal to 3 mm.

[0014] As an alternative to the above-mentioned battery cell, the dimension L1 of the first solder mark along the first direction and the dimension L2 of the first solder mark along the second direction satisfy: L1 > L2. And / or, the dimension L1 of the first solder mark along the first direction and the distance D1 between two adjacent first solder marks satisfy: L1 > D1; And / or, the length L3 of the second solder mark and the distance D1 between two adjacent first solder marks satisfy: L3 = D1 + 2mm; And / or, the length L3 of the second solder mark and the dimension L of the electrode tab along the first direction satisfy: 10% ≤ L3 / L ≤ 30%; And / or, the distance D1 between two adjacent first solder marks is 5mm-15mm; And / or, the dimension L1 of the first solder mark along the first direction is 10mm-20mm; And / or, the dimension L2 of the first solder mark along the second direction is 3-9 mm, where the second direction is the width direction of the electrode tab; And / or, the tab includes a first edge and a second edge disposed along a second direction, the first edge being connected to the electrode body, the second direction being the width direction of the tab, and a plurality of recesses being disposed within the first solder mark, the minimum distance D3 between the recess and the first edge along the second direction being 4mm-10mm, and the minimum distance D5 between the recess and the second edge along the second direction being 1mm-5mm; And / or, the electrode tab includes two third edges disposed along the first direction, and the first solder mark is provided with a plurality of recesses, wherein the minimum distance D4 between the recesses and the third edges along the first direction is 2mm-8mm; And / or, the second solder mark is a groove, the cross-sectional shape of which is an arc.

[0015] As an optional embodiment of the above-mentioned battery cell, the radius R1 of the groove and the depth H1 of the groove satisfy: 0.15mm≤R1-H1≤0.25mm; And / or, the radius R1 of the groove is 0.15mm-0.35mm, and the depth of the groove is 0.05mm-0.15mm.

[0016] To achieve this objective, secondly, the present invention adopts the following technical solution: A battery comprising the aforementioned battery cell.

[0017] To achieve this objective, in a third aspect, the present invention adopts the following technical solution: An electrical device comprising the aforementioned battery.

[0018] The beneficial effects of this invention are: In the battery cell provided by the present invention, a second solder mark is provided between two adjacent first solder marks. The second solder mark is used to physically bridge the connection and shape the edge of the tab along the first direction to release stress. This can effectively improve the problem of tab deformation, warping, or even cracking. At the same time, the second solder mark increases the current path and can improve the current carrying capacity of the battery cell during charging and discharging.

[0019] The battery and power device provided by the present invention use the above-mentioned battery cells, which can solve the problem of increased soldering causing the tabs to lift or even crack. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a battery cell provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the solder mark structure in a battery cell provided in Embodiment 1 of the present invention; Figure 3 This is a cross-sectional view of the electrode tab provided in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the solder mark structure in a battery cell provided in Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the structure of a battery cell provided in Embodiment 3 of the present invention; Figure 6 This is a schematic diagram of the structure of a battery cell provided in Embodiment 4 of the present invention; Figure 7 This is a schematic diagram of the structure of a battery cell provided in Embodiment 5 of the present invention.

[0021] In the picture: 11. Electrode tab; 111. First edge; 112. Second edge; 113. Third edge; 12. Electrode body; 13. Solder mark; 131. First solder mark; 1311. Recess; 132. Second solder mark; 132a. Straight solder mark; 132b. Curved solder mark. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1 This invention provides an electrical device, including a main body and a battery disposed on the main body, the battery providing electrical energy to the main body. The electrical device can take many forms, such as mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys, power tools, or various household appliances. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0027] In this embodiment, the electrical device is described using a vehicle as an example. A battery is installed inside the vehicle, located at the bottom, front, or rear. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle, such as a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle. The battery not only serves as the vehicle's operating power source but also as its driving power source, replacing or partially replacing gasoline or natural gas to provide propulsion.

[0028] The present invention provides a battery, which refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0029] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery.

[0030] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells housed within the housing.

[0031] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0032] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0033] In this embodiment, the battery cell includes an electrode assembly and an electrode lead-out member. The electrode assembly includes an electrode body 12 and a tab 11 connected to the electrode body 12. The tab 11 is located on at least one side of the electrode body 12 along a second direction. The tab 11 is welded and fixed to the electrode lead-out member so that the current collected by the tab 11 can be output outward through the electrode lead-out member. The second direction is the Y direction in the figure.

[0034] In some embodiments, the electrode lead-out component includes an adapter plate and a terminal post. The battery cell also includes a housing and a cover plate. The electrode assembly and the adapter plate are disposed inside the housing, and the terminal post is disposed on the cover plate. The adapter plate electrically connects the tab 11 and the terminal post to efficiently and safely conduct the current collected by the tab 11 to the terminal post, ultimately enabling the battery cell to supply power to the outside.

[0035] In some other embodiments, the electrode lead can be a post, which is directly electrically connected to the tab 11 to achieve direct output of the current collected by the tab.

[0036] To meet the increased requirements for battery capacity and safety performance, tab 11 includes multiple tab layers to reduce internal resistance, widen the current channel, ensure the release of battery capacity, and significantly improve the specific capacity under high current; it also helps to reduce heat generation, thereby reducing the risk of thermal runaway.

[0037] To ensure the welding effect after increasing the number of tab layers, such as Figure 1 As shown, the solder mark 13 formed by welding the tab 11 to the electrode lead includes two first solder marks 131 arranged along a first direction, wherein the first direction is the length direction of the tab 11, specifically... Figure 1 In the X direction. By setting two first solder marks 131, the welding area can be increased, and the welding and fixing effect of the multi-layer tab layer and the electrode lead-out can be improved.

[0038] In some other embodiments, the number of first solder marks 131 formed on the tab 11 can be adjusted according to actual needs, for example, three, four or more.

[0039] In some embodiments, the first solder mark 131 is generally rectangular, and the dimension L1 of the first solder mark 131 along the first direction is greater than the dimension L2 of the first solder mark 131 along the second direction, thereby increasing the fixing area of ​​the tab 11 and the electrode lead along its length direction, which is beneficial to improving the fixing effect of the tab 11 and the electrode lead.

[0040] In some other embodiments, the dimension L1 of the first solder mark 131 along the first direction may be equal to or slightly smaller than the dimension L2 of the first solder mark 131 along the second direction.

[0041] In some other embodiments, the shape and size of the first solder mark 131 can be set according to actual needs.

[0042] In this embodiment, the tab 11 is roughly trapezoidal, with the lower base of the trapezoid connected to the electrode body 12. The extension directions of the upper and lower bases of the trapezoid are the length directions of the tab 11, i.e., the first direction; the height direction of the trapezoid is the width direction of the tab 11, i.e., the second direction, which is the Y direction in the figure.

[0043] Since at least two first solder marks 131 are arranged at intervals along the first direction, the tab 11 is prone to deformation, warping, or even cracking on the short side (i.e. the edge extending along the Y direction) of the first solder mark 131, which affects the quality and performance of the battery cell.

[0044] To address the aforementioned issues, in this embodiment, a second solder mark 132 is provided between two adjacent first solder marks 131. The second solder mark 132 is elongated and extends from one of the two adjacent first solder marks 131 to the other. By providing the second solder mark 132 between two adjacent first solder marks 131, a physical bridging is achieved, shaping the edge of the tab 11 along the first direction to release stress. This effectively improves the problem of deformation, warping, and even cracking of the tab 11. Simultaneously, the second solder mark 132 increases the current flow path, enhancing the current flow capacity of the battery cell during charging and discharging.

[0045] To ensure the effective fixation of the tab 11 to the electrode lead, the dimension L1 of the first solder mark 131 along the first direction and the distance D1 between two adjacent first solder marks 131 satisfy: L1 > D1. This setting can control the distance between two adjacent first solder marks 131, avoiding an excessively large distance between them, which would reduce the area of ​​the first solder mark 131 and affect the fixation effect between the tab 11 and the electrode lead; at the same time, it can also prevent the second solder mark 132 from being too long and affecting the shaping effect of the tab 11.

[0046] like Figure 1 and Figure 2As shown, multiple second solder marks 132 are provided between two adjacent first solder marks 131, and the multiple second solder marks 132 are arranged in parallel. On the one hand, by increasing the number of second solder marks 132, the force release effect is improved, which is beneficial to ensuring the shaping effect of the second solder marks 132 on the tab 11; on the other hand, the second solder marks 132 are evenly distributed, and the tab 11 at the location of the second solder mark 132 is subjected to uniform force.

[0047] The second weld mark 132 extends in a straight line. Specifically, the welding head that forms the second weld mark 132 has multiple parallel straight raised ridges, and correspondingly, the second weld mark 132 is a straight groove. By making the second weld mark 132 straight, the forming of the second weld mark 132 is convenient, which helps to simplify the structure of the welding head; moreover, there is no intersection between the second weld marks 132, which reduces stress concentration caused by weld mark intersection; at the same time, the straight second weld mark 132 has a neat and beautiful appearance.

[0048] In this embodiment, the second weld mark 132 is a groove with a circular arc cross-sectional shape, i.e., a straight groove is replaced by a circular arc groove. This reduces the sharp edges of the groove, which helps to reduce stress concentration.

[0049] Optionally, the inner wall of the groove transitions smoothly with the surface of the tab 11 to reduce stress concentration at the connection between the groove and the plane.

[0050] like Figure 3 As shown, the radius R1 of the groove and the depth H1 of the groove satisfy the condition: 0.15mm≤R1-H1≤0.25mm. This setting makes the groove depth H1 smaller than the groove radius, which helps to reduce the groove depth and reduce the impact of the second solder mark 132 on the strength of the electrode 11. At the same time, it helps to ensure the shaping effect of the electrode 11.

[0051] Optionally, the radius R1 of the groove is 0.15mm-0.35mm. For example, typical non-limiting values ​​of R1 can be 0.15mm, 0.17mm, 0.19mm, 0.2mm, 0.22mm, 0.24mm, 0.25mm, 0.27mm, 0.3mm, 0.32mm, 0.34mm, and 0.35mm.

[0052] Optionally, the depth H1 of the groove is 0.05mm-0.15mm. Exemplarily, typical non-limiting values ​​of H1 can be 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.14mm, or 0.15mm.

[0053] In other embodiments, the depth H1 of the groove, the radius R1 of the groove, and the relationship between H1 and R1 can be set according to actual needs, and are not limited here.

[0054] In some other embodiments, the cross-sectional shape of the groove may also be other shapes, such as triangles, rectangles, or other polygons, or other irregular shapes.

[0055] In this embodiment, the second solder mark 132 extends along the first direction and is arranged in the same direction as the two adjacent first solder marks 131, which helps to release stress and improve the shaping effect of the tab 11.

[0056] In some other embodiments, the extension direction of the second solder mark 132 can be adjusted according to actual needs, and is not limited here. For example, the second solder mark 132 can be set at an angle to the first direction, such as the extension direction of the second solder mark 132 being perpendicular to the first direction, that is, the second solder mark 132 extends along the Y direction.

[0057] like Figure 1 As shown, the multiple second solder marks 132 are evenly spaced, which helps to improve the uniformity of the distribution of the second solder marks 132, thereby uniformly distributing the force on the tab 11.

[0058] Optionally, the distance D2 between two adjacent second solder marks 132 is 0.3mm-1.3mm. Within the above range, D2 facilitates forming and improves the shaping effect of the tab 11.

[0059] For example, typical non-limiting values ​​for D2 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, or 1.2mm.

[0060] In some other embodiments, the spacing between the second solder marks 132 may be non-uniformly distributed, and the specific spacing may be adjusted according to actual needs.

[0061] In this embodiment, the quantity N of the second solder marks 132 and the dimension H of the tab 11 along the second direction satisfy the following relationship: 0.6 ≤ (H-10) / N ≤ 1.2, where H is in millimeters. It should be noted that the above relationship is only between the values ​​of N and H. Limiting H to millimeters is only to limit the range of H values ​​so that H-10 is a positive number.

[0062] By limiting the relationship between the number N of the second solder marks 132 and the dimension H of the tab 11 along the second direction, the number of the second solder marks 132 can be reasonably designed to ensure the distance between adjacent second solder marks 132 and the dimension range of the second solder marks 132 along the second direction, so as to facilitate processing and improve the shaping effect of the tab 11.

[0063] For example, the number N of the second solder marks 132 can be 5-10 to ensure the shaping effect of the tabs 11 and improve the overcurrent capacity of the battery cells during charging and discharging.

[0064] In this embodiment, as Figure 2 As shown, the second solder mark 132 overlaps with the first solder mark 131 at both ends along the first direction. That is, both ends of the second solder mark 132 extend into the first solder mark 131. By setting the second solder mark 132 to overlap with the first solder mark 131, the bridging effect of the second solder mark 132 is improved, thereby increasing the current path and improving the current carrying capacity of the battery cell during charging and discharging.

[0065] Because the depth of the second solder mark 132 is relatively small, the deformation of the overlapping area between the second solder mark 132 and the first solder mark 131 will not be significantly aggravated. However, the overlap length between the second solder mark 132 and the first solder mark 131 should not be too long, as the overlap length process does not significantly increase the current carrying capacity and will lead to an increase in the instability of the second solder mark 132. Therefore, the overlap length L5 between the two ends of the second solder mark 132 and the first solder mark 131 along the first direction is less than or equal to 3 mm to ensure the stability of the second solder mark 132.

[0066] To ensure the shaping effect of the tab 11, the length L3 of the second solder mark 132 and the dimension L of the tab 11 along the first direction must satisfy: 10% ≤ L3 / L ≤ 30%. When the above ratio is too small, the shaping effect of the second solder mark 132 on the tab 11 is poor, and it may even aggravate the cracking of the tab 11. At the same time, if the length of the second solder mark 132 is too small, it will affect the welding strength, and if the solder mark area is small, it will affect the current carrying capacity of the battery cell. On the other hand, if the ratio is too large, it will affect the normal welding and make it difficult to guarantee the welding quality.

[0067] Optionally, the length L3 of the second solder mark 132 and the distance D1 between the two adjacent first solder marks 131 satisfy: L3=D1+2mm, so as to ensure the length of the second solder mark 132, thereby achieving a bridging effect between the two adjacent first solder marks 131.

[0068] Optionally, the distance D1 between two adjacent first weld marks 131 is 5mm-15mm. Within the above range, D1 can avoid stress concentration caused by the two first weld marks 131 being too close, ensure the stability of weld penetration and strength, reduce the deformation of the tab 11, and avoid the risk of burn-through due to heat accumulation.

[0069] To ensure the welding and fixing effect between the tab 11 and the electrode lead, the dimension L1 of the first solder mark 131 along the first direction can be 10mm-20mm, and the dimension L2 of the first solder mark 131 along the second direction can be 3-9mm, so as to ensure the area of ​​the first solder mark 131, thereby ensuring the fixing effect between the tab 11 and the electrode lead.

[0070] In some other embodiments, the dimensions of the first solder mark 131 along the first and second directions can be set according to actual needs, and are not limited here.

[0071] like Figure 1 As shown, the tab 11 includes a first edge 111 and a second edge 112 arranged along a second direction. The first edge 111 is connected to the electrode body 12. A plurality of recesses 1311 are provided in the first solder mark 131. The minimum distance D3 between the recesses 1311 and the first edge 111 along the second direction is 4mm-10mm, and the minimum distance D5 between the recesses 1311 and the second edge 112 along the second direction is 1mm-5mm. Through the above arrangement, the first solder mark 131 is at a certain distance from both the first edge 111 and the second edge 112, avoiding the recesses 1311 from being too close to the first edge 111 or the second edge 112, which would cause severe deformation of the tab 11, thereby helping to ensure the flatness of the tab 11.

[0072] Specifically, the multiple recesses 1311 are arranged in a matrix to simplify the arrangement and improve the uniformity of the distribution of the recesses 1311. The minimum distance between a recess 1311 along the second direction and the first edge 111 refers to a distance D3 between a recess 1311 and the first edge 111 in a row of recesses 1311 closest to the first edge 111; the minimum distance between a recess 1311 along the second direction and the second edge 112 refers to a distance D5 between a recess 1311 and the second edge 112 in a row of recesses 1311 closest to the second edge 112.

[0073] In some other embodiments, the arrangement of the plurality of recesses 1311 can be set according to specific needs. For example, the plurality of recesses 1311 can be arranged in a circular array, and there is no specific limitation.

[0074] Similarly, the tab 11 includes two third edges 113 arranged along the first direction. The minimum distance D4 between the recess 1311 and the third edge 113 along the first direction is 2mm-8mm. This avoids the recess 1311 being too close to the third edge 113, which could cause severe deformation of the tab 11 and thus help ensure the flatness of the tab 11. Specifically, the tab 11 is trapezoidal in shape. The length of the second edge 112 is less than the length of the first edge 111. Among the multiple recesses 1311 arranged in a matrix, the distance between the two recesses 1311 located at both ends of the first direction and the third edge 113 in the row of recesses 1311 closest to the second edge 112 is the minimum distance D4.

[0075] When welding the tab 11 to the electrode lead, a conventional ultrasonic welding head is first used to weld to form a first weld mark 131, which initially connects the tab 11 to the electrode lead. Then, a welding head with strip teeth is used to perform bridging welding to form a second weld mark 132, one end of which partially overlaps with the first weld mark 131. Finally, a conventional ultrasonic welding head is used to weld to form another first weld mark 131, the other end of which partially overlaps with the second weld mark 132.

[0076] Example 2 This embodiment provides an electrical device, which has a structure largely the same as that of Embodiment 1, except that, as Figure 4 As shown, the second solder mark 132 is spaced apart from the first solder mark 131 along the first direction. This arrangement can prevent the first solder mark 131 and the second solder mark 132 from overlapping, thereby avoiding stress concentration in the overlapping area and large deformation.

[0077] It is understandable that the smaller the distance between the second solder mark 132 and the first solder mark 131, the better the bridging capability for current flow and the better the shaping effect on the tab 11. Therefore, in this embodiment, the distance L4 between the second solder mark 132 and the first solder mark 131 along the first direction is less than or equal to 1.5 mm, so as to ensure the shaping effect on the tab 11 and the improvement of current flow capability.

[0078] Example 3 This embodiment provides an electrical device, which has a structure largely the same as that of Embodiments 1 and 2, except that, as shown in the example... Figure 5 As shown, at least some of the second solder marks 132 are arranged in an intersecting pattern.

[0079] Specifically, the second solder marks 132 all extend in a straight line, and multiple second solder marks 132 are arranged along the second direction, with adjacent second solder marks 132 connected end to end. This arrangement not only allows the second solder marks 132 to bridge between the two first solder marks 131 and increase the current path, but also makes adjacent second solder marks 132 intersect, which can reduce the number of solder mark endpoints and reduce the deformation of the electrode tab 11.

[0080] Optionally, the plurality of second solder marks 132 are divided into two groups, with the second solder marks 132 in each group arranged in parallel and evenly spaced. One group of second solder marks 132 extends along the first direction, while the other group of second solder marks 132 is arranged at an angle relative to the first direction and connects the ends of the second solder marks 132 on both sides.

[0081] In some other embodiments, the extension direction and tilt angle of the second solder mark 132 can be adjusted according to actual needs, and no limitation is made here.

[0082] In some other embodiments, any two intersecting second solder marks 132 may not intersect, that is, the extending directions of the second solder marks 132 are not parallel, but they do not have an intersection point.

[0083] Example 4 This embodiment provides an electrical device, which has a structure largely the same as that of Embodiments 1 and 2, except that, as shown in the example... Figure 6 As shown, the second solder mark 132 extends in a curve, and multiple second solder marks 132 are arranged in parallel and evenly spaced, which can also increase the current carrying capacity and shape the tab 11.

[0084] Optionally, the second solder mark 132 may extend in a wavy shape. In some other embodiments, the specific extension shape of the second solder mark 132 can be set according to actual needs.

[0085] Example 5 This embodiment provides an electrical device, which has a structure largely the same as that of Embodiments 1 and 2, except that, as shown in the example... Figure 7 As shown, part of the second solder mark 132 extends in a straight line, while the remaining part of the second solder mark 132 extends in a curve.

[0086] Specifically, the second solder mark 132 includes at least two solder mark groups, each solder mark group including intersecting straight solder marks 132a and curved solder marks 132b. All straight solder marks 132a are arranged in parallel, and all curved solder marks 132b are arranged in parallel. In two adjacent solder mark groups, the straight solder marks 132a and curved solder marks 132b are connected end to end. Specifically, the first end of a straight solder mark 132a in one solder mark group extends to the first solder mark 131, and the second end connects to the second end of a curved solder mark 132b in the adjacent solder mark group. Correspondingly, the second end of a curved solder mark 132a extends to the first solder mark 131, and the first end connects to the first end of a straight solder mark 132a in the adjacent solder mark group.

[0087] Optionally, the extension direction of the straight solder mark 132a can be set at an acute angle to the first direction, and the curved solder mark 132b can extend in a wavy shape. In the same solder mark group, the middle parts of the straight solder mark 132a and the curved solder mark 132b intersect.

[0088] In some other embodiments, the extension direction of the straight solder mark 132a can be adjusted according to actual needs. For example, the straight solder mark 132a can extend along a first direction.

[0089] In some other embodiments, the specific extension shape of the curved solder mark 132b can be set according to actual needs; for example, the curved solder mark 132b can be extended in an arc.

[0090] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery cell, characterized in that, include: Electrode leads; An electrode assembly includes an electrode body (12) and a tab (11). The tab (11) is disposed on at least one side of the electrode body (12) along a second direction. The tab (11) is welded and fixed to the electrode lead-out member, and a solder mark (13) is formed on the tab (11). The solder mark (13) includes at least two first solder marks (131) arranged along a first direction. A second solder mark (132) is disposed between two adjacent first solder marks (131). The second solder mark (132) is elongated and extends from one of the two adjacent first solder marks (131) to the other. The first direction intersects the second direction.

2. The battery cell according to claim 1, characterized in that, A plurality of second solder marks (132) are provided between two adjacent first solder marks (131), the plurality of second solder marks (132) are arranged in parallel, or at least some of the second solder marks (132) are arranged in an intersecting manner.

3. The battery cell according to claim 2, characterized in that, The second solder mark (132) extends in a straight line; Alternatively, the second solder mark (132) extends in a curve; Alternatively, some of the second solder marks (132) extend in a straight line, while some of the second solder marks (132) extend in a curve.

4. The battery cell according to claim 2, characterized in that, The second solder mark (132) extends in a straight line along the first direction.

5. The battery cell according to claim 4, characterized in that, The distance D2 between two adjacent second solder marks (132) is 0.3mm-1.3mm; And / or, multiple second solder marks (132) are evenly spaced.

6. The battery cell according to claim 2, characterized in that, The second solder mark (132) extends in a straight line, and adjacent second solder marks (132) are connected end to end in sequence; Alternatively, the second solder mark (132) includes at least two solder mark groups, each solder mark group including intersecting straight solder marks (132a) and curved solder marks (132b), all the straight solder marks (132a) are arranged in parallel, all the curved solder marks (132b) are arranged in parallel, and in two adjacent solder mark groups, the straight solder marks (132a) and the curved solder marks (132b) are connected end to end.

7. The battery cell according to claim 2, characterized in that, The number N of the second solder mark (132) and the dimension H of the tab (11) along the second direction satisfy: 0.6≤(H-10) / N≤1.2, where the unit of H is millimeters; And / or, the number of the second solder mark (132) is 5-10.

8. The battery cell according to any one of claims 1-7, characterized in that, The second solder mark (132) is spaced apart from the first solder mark (131) along the first direction; Alternatively, the second solder mark (132) may overlap with the first solder mark (131) at both ends along the first direction.

9. The battery cell according to claim 8, characterized in that, The distance L4 between the second solder mark (132) and the first solder mark (131) along the first direction is less than or equal to 1.5 mm; Alternatively, the overlap length L5 between the two ends of the second solder mark (132) and the first solder mark (131) along the first direction is less than or equal to 3 mm.

10. The battery cell according to any one of claims 1-7, characterized in that, The dimension L1 of the first solder mark (131) along the first direction and the dimension L2 of the first solder mark (131) along the second direction satisfy: L1 > L2; And / or, the dimension L1 of the first solder mark (131) along the first direction and the distance D1 between two adjacent first solder marks (131) satisfy: L1 > D1; And / or, the length L3 of the second solder mark (132) and the distance D1 between two adjacent first solder marks (131) satisfy: L3 = D1 + 2mm; And / or, the length L3 of the second solder mark (132) and the dimension L of the tab (11) along the first direction satisfy: 10%≤L3 / L≤30%; And / or, the distance D1 between two adjacent first solder marks (131) is 5mm-15mm; And / or, the dimension L1 of the first solder mark (131) along the first direction is 10mm-20mm; And / or, the dimension L2 of the first solder mark (131) along the second direction is 3-9 mm, the second direction being the width direction of the tab (11); And / or, the tab (11) includes a first edge (111) and a second edge (112) disposed along a second direction, the first edge (111) being connected to the electrode body (12), the second direction being the width direction of the tab (11), and a plurality of recesses (1311) being disposed in the first solder mark (131), the minimum distance D3 between the recess (1311) and the first edge (111) along the second direction being 4mm-10mm, and the minimum distance D5 between the recess (1311) and the second edge (112) along the second direction being 1mm-5mm; And / or, the tab (11) includes two third edges (113) arranged along the first direction, and a plurality of recesses (1311) are provided in the first solder mark (131), wherein the minimum distance D4 between the recesses (1311) and the third edges (113) along the first direction is 2mm-8mm; And / or, the second solder mark (132) is a groove, the cross-sectional shape of which is an arc.

11. The battery cell according to claim 10, characterized in that, The radius R1 of the groove and the depth H1 of the groove satisfy the following condition: 0.15mm ≤ R1 - H1 ≤ 0.25mm; And / or, the radius R1 of the groove is 0.15mm-0.35mm, and the depth of the groove is 0.05mm-0.15mm.

12. A battery, characterized in that, Includes the battery cell as described in any one of claims 1-11.

13. An electrical appliance, characterized in that, Includes the battery as described in claim 12.

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