Battery pack and battery device

Abstract

The utility model relates to battery technology field, concretely relates to a battery pack and battery device, the battery pack includes: a plurality of single battery, along first direction sequentially arrange, electrically conductive spare is used for connecting the pole of adjacent two batteries, pole assembly is welded with electrically conductive spare and forms the welding mark, the welding mark has long side and short side, the extension direction of long side is perpendicular to first direction, in the extension direction of long side, the length of welding mark is L1mm, the width of welding mark is L2mm, the ratio L1 / L2 satisfies: 2 <= (L1 / L2) <= 5. The long side of welding mark is perpendicular to the battery arrangement direction in the application, can maximize the welding mark length, thereby make full use of the space of pole assembly perpendicular to the arrangement direction, directly increase the cross section of overcurrent, and, the length-width ratio of welding mark is limited in a certain range in the application, can improve the overcurrent area simultaneously, can also guarantee the welding quality.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a battery pack and battery device. Background Technology

[0002] Currently, multiple batteries in a battery pack are connected via busbars. Traditional batteries have circular terminals, so the solder joints between the terminals and the busbars are also circular. During charging and discharging, current is transferred through these solder joints.

[0003] However, with the increase in battery charging and discharging speeds, under conditions of high-rate charging or high-current discharging, this circular solder mark, due to its small cross-section, cannot meet the demand for efficient current transmission, resulting in limited overcurrent capacity and affecting the battery's fast charging performance and overall performance. Utility Model Content

[0004] In view of this, the present invention provides a battery pack and battery device to solve the problem that the small cross-sectional area of ​​the circular solder mark cannot meet the requirements of efficient current transmission.

[0005] In a first aspect, this utility model provides a battery pack, which includes: Multiple individual battery cells are arranged sequentially along a first direction; each individual battery cell is provided with an electrode assembly. Conductive components are used to connect two adjacent individual cells to the terminal assembly; the conductive components are welded to the terminal assembly to form a solder mark; The solder mark has a long side and a short side, and the extension direction of the long side is perpendicular to the first direction; In the direction of the long side extension, the length of the solder mark is L1mm and the width of the solder mark is L2mm. The ratio of the length of the solder mark to the width of the solder mark, L1 / L2, satisfies: 2≤(L1 / L2)≤5.

[0006] Beneficial effects: The above technical solution aligns the long side of the solder mark perpendicular to the arrangement direction of the individual cells. This maximizes the solder mark length without increasing the width of the battery pack, i.e., without increasing the dimension in the first direction. This fully utilizes the space perpendicular to the arrangement direction of the electrode assembly, directly increasing the current-carrying cross-section. Furthermore, this embodiment limits the aspect ratio of the solder mark to a certain range, which can improve the current-carrying area while ensuring welding quality. If the ratio is too small, the solder mark will be nearly circular, resulting in insufficient current-carrying area. If the ratio is too large, the solder mark will be too long, easily leading to uneven heat distribution and poor welding quality.

[0007] Secondly, this utility model also provides a battery device, which includes: The housing has a receiving cavity; At least one battery pack, as described in any of the above embodiments, is disposed in a housing. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this utility model, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the structure of a single battery cell and a conductive component in an embodiment of this utility model; Figure 2 This is an enlarged schematic diagram showing the mating position of the single battery cell and the conductive component in an embodiment of this utility model; Figure 3 This is a schematic diagram of the solder mark and electrode post in an embodiment of this utility model; Figure 4 This is a schematic diagram of some parameters of the solder mark and pole in the top view of an embodiment of this utility model; Figure 5 This is a schematic diagram of another part of the parameters of the solder mark and pole in the top view of the embodiment of this utility model.

[0010] Explanation of reference numerals in the attached figures: 1. Single cell battery; 2. Conductive components; 3. Solder mark; 31. Long side; 32. Short side; 33. First straight edge; 34. First arc; 4. Pole post assembly; 41. Cover plate; 42. Pole post; 421. Second straight edge; 422. Second arc-shaped part. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0012] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0013] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0014] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0015] Currently, multiple batteries in a battery pack are connected via busbars. Traditional batteries have circular terminals 42, and therefore the solder joint 3 between the terminals 42 and the busbar is also circular. During charging and discharging, current is transferred through this solder joint 3. However, with the increasing charging and discharging speeds of batteries, under conditions of high-rate charging or high-current discharging, this circular solder joint 3, due to its small cross-sectional area, cannot meet the demands for efficient current transfer, resulting in limited current carrying capacity and affecting the battery's fast-charging performance and overall performance.

[0016] In view of this, the present invention provides a battery pack and battery device to solve the problem that the small cross-sectional area of ​​the circular solder mark 3 cannot meet the requirements of efficient current transmission.

[0017] The following is combined Figures 1 to 5 The following describes embodiments of the present invention.

[0018] According to an embodiment of the present invention, a battery pack is provided, which includes a single cell 1, a conductive element 2, and an electrode assembly 4.

[0019] Specifically, in this embodiment, multiple individual battery cells 1 are arranged sequentially and stacked along a first direction. The arrangement direction, i.e., the stacking direction, can be along the thickness direction of the individual battery cells 1 or along the height direction of the individual battery cells 1. Of course, this embodiment is merely an example of the stacking direction of the individual battery cells 1, and is not intended to limit it. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0020] Furthermore, in this embodiment, each individual battery cell 1 is provided with an electrode post assembly 4, and the conductive element 2 is used to connect the electrode post assemblies 4 of two adjacent individual battery cells 1, thereby connecting the two individual battery cells 1 in series or in parallel. The connection method between the conductive element 2 and the electrode post assembly 4 can be welding, riveting, or bonding. In this embodiment, the connection method between the conductive element 2 and the electrode post assembly 4 by welding is used as an example.

[0021] Furthermore, in this embodiment, the electrode assembly 4 is welded to the conductive component 2 to form a solder mark 3, which has a long side 31 and a short side 32. The shape of the solder mark 3 can be rectangular, elliptical, or quasi-elliptical. Of course, this embodiment is merely an example of the shape of the solder mark 3, and is not intended to limit it. Those skilled in the art can modify it according to actual circumstances, as long as the solder mark 3 has a long side 31 and a short side 32.

[0022] Furthermore, in this embodiment, the extension direction of the long side 31 is perpendicular to the first direction. When the individual cells 1 are stacked along the thickness direction, the extension direction of the long side 31 can be either the length direction of the individual cell 1 or the height direction of the individual cell 1.

[0023] Specifically, in the extension direction of the long side 31, the length of the solder mark 3 is L1mm, the width of the solder mark 3 is L2mm, and the ratio between the length of the solder mark 3 and the width of the solder mark 3 is L1 / L2. The ratio L1 / L2 satisfies: 2≤(L1 / L2)≤5.

[0024] For example, the ratio L1 / L2 can be 2, 2.5, 3, 3.5, 4, 4.5, 5, etc. Of course, this embodiment is merely an example illustrating the specific value of the ratio L1 / L2, but it is not intended to limit the scope. Those skilled in the art can modify it according to the actual situation, as long as the same technical effect is achieved.

[0025] With this configuration, the long side 31 of the solder mark 3 is perpendicular to the arrangement direction of the individual battery cells 1. This maximizes the length of the solder mark 3 without increasing the width of the battery pack, i.e., without increasing the dimension in the first direction. This fully utilizes the space of the electrode assembly 4 perpendicular to the arrangement direction, directly increasing the current-carrying cross-section. Furthermore, this embodiment limits the aspect ratio of the solder mark 3 within a certain range, which can increase the current-carrying area while ensuring welding quality. If the ratio is too small, the solder mark 3 will be nearly circular, resulting in insufficient current-carrying area. If the ratio is too large, the solder mark 3 will be too long, easily causing poor soldering.

[0026] Furthermore, in an optional embodiment, the length L1mm of the solder mark 3 satisfies: 15mm≤L1mm≤30mm.

[0027] For example, L1mm can be 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, etc. Of course, this embodiment is merely an example of the length of the solder mark 3, and is not intended to limit it. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0028] By limiting L1 within a certain range, the above technical solution ensures sufficient current-carrying area and better adapts to the structural dimensions of the electrode post 42 and the conductive component 2, thus avoiding welding defects. If L1 is too small, the current-carrying area will be insufficient, failing to meet the requirements for high current transmission. If L1 is too large, it may easily exceed the size range of the electrode post 42 or the conductive component 2, causing the solder mark 3 to overflow the edge of the electrode post 42, resulting in a cold solder joint.

[0029] Furthermore, in an optional implementation, L2 satisfies: 6mm ≤ L2 mm ≤ 15mm.

[0030] For example, L2mm can be 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, etc. Of course, this embodiment is merely an example of a specific value for L2mm, but it is not intended to limit the scope. Those skilled in the art can modify it according to the actual situation, as long as the same technical effect is achieved.

[0031] By limiting L2 within a certain range, the above technical solution can shorten the current path and reasonably reduce the lateral distance of current transmission, thereby reducing resistance and heat generation. It also prevents the solder mark 3 from overflowing from the terminal 42, thus avoiding short circuits with surrounding components inside the single cell 1. If L2 is too small, the current transmission path within the solder mark 3 will widen, increasing the lateral distance from the terminal 42 to the conductive component 2, leading to increased resistance and heat generation. If L2 is too large, it may exceed the thickness dimension of the terminal 42, causing the solder mark 3 to overflow along the thickness direction, potentially short-circuiting with other components.

[0032] Furthermore, in an alternative embodiment, the solder mark 3 has a rectangular structure.

[0033] With this configuration, the above technical solution sets the solder mark 3 as a rectangular structure, which maximizes the utilization of the rectangular area on the surface of the pole 42. Compared with a circle, a rectangle has a larger area for the same perimeter, thus resulting in stronger current carrying capacity. At the same time, during the welding process, the welding path is straight, so there is no need for bends during laser welding, resulting in more uniform heat distribution.

[0034] Furthermore, in an optional embodiment, the solder mark 3 has a first straight edge 33 and a first arc portion 34. Along the length direction of the first straight edge 33, the first arc portion 34 is located on both sides of the first straight edge 33. The short side 32 of the first straight edge 33 is aligned with the straight section of the first arc portion 34, so that the first straight edge 33 and the first arc portion 34 surround each other to form a racetrack shape.

[0035] With this setup, the laser spends a relatively long time at the right angle of the rectangular weld mark 3 during laser welding, which can easily lead to heat accumulation and potentially cause localized overmelting. Therefore, in the above technical solution, a rounded portion is used instead of a right angle. This allows for a smooth transition of the welding path during laser welding, resulting in more uniform heat distribution. At the same time, the racetrack-shaped weld mark 3 still has a long side 31, thus ensuring a larger flow area and optimizing welding quality.

[0036] Furthermore, in an optional embodiment, in the length direction of the first straight edge 33, the length of the first straight edge 33 is L3mm, the length of the first arc portion 34 is L4mm, and the ratio L3 / L4 between the length of the first straight edge 33 and the length of the first arc portion 34 satisfies: 2.5≤(L3 / L4)≤3.5.

[0037] For example, the ratio L3 / L4 can be 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, etc. Of course, the above technical solutions are merely illustrative examples of specific values ​​for the ratio L3 / L4, but are not intended to limit the application. Those skilled in the art can modify them according to actual circumstances, as long as the same technical effect is achieved.

[0038] Furthermore, in this embodiment, L3mm satisfies: 15mm≤L3mm≤25mm, and L4mm satisfies: 3mm≤L4mm≤8mm.

[0039] For example, L3mm can be 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, etc. Of course, this embodiment is merely an example of a specific value for L3mm, but it is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0040] For example, L4mm can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, etc. Of course, this embodiment is merely an example of a specific value for L4mm, but it is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0041] By setting it this way, the technical solution limits the ratio between the length of the first straight edge 33 and the length of the first arc portion 34 to a certain range. This ensures that the first straight edge 33 provides sufficient flow area while the arc portion fully optimizes the welding path, resulting in uniform heat distribution during welding. If the ratio is too small, the arc portion will be too large and the first straight edge 33 will be too short, leading to a reduction in flow area. If the ratio is too large, the first straight edge 33 will be too large and the arc portion will be too short, causing the corners of the weld mark 3 to be close to right angles, which can easily lead to heat concentration during laser welding.

[0042] Furthermore, in an optional embodiment, the radius of curvature of the first arc portion 34 is Rmm, and satisfies 6mm≤Rmm≤10mm.

[0043] For example, Rmm can be 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc. Of course, this embodiment is merely an example of a specific value for Rmm, but it is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0044] With this configuration, the above technical solution limits the radius of curvature of the first arc portion 34 to a certain range, which optimizes the laser welding path. During the welding process, a better curvature allows the laser to pass through the arc portion at a uniform speed, resulting in a more even heat distribution. Simultaneously, a better curvature ensures uniform stress distribution at the edge of the weld mark 3, improving fatigue resistance. If the radius of curvature is too small, the arc will be too steep or close to a right angle, leading to heat concentration and significant stress concentration when the laser bends. If the radius of curvature is too large, the arc will be too gentle, causing the arc portion to occupy too much directional space, thus compressing the length of the first straight edge 33 and reducing the flow area.

[0045] Furthermore, in an optional embodiment, the terminal assembly 4 includes a cover plate 41 and a terminal 42. The terminal 42 is disposed on the cover plate 41 and is welded to the conductive component 2 to form a solder mark 3. The terminal 42 and the cover plate 41 can be connected by welding, bonding, or riveting. In actual installation, mounting holes can be provided on the cover plate 41, and the terminal 42 can be directly disposed in the mounting holes. The tab of the single battery 1 passes through the mounting holes and connects to the terminal 42.

[0046] Of course, the above technical solution is only an example of the installation method of pole post 42 and cover plate 41, but it does not limit the method. Those skilled in the art can make changes according to the actual situation, as long as the same technical effect can be achieved.

[0047] Furthermore, in the above technical solution, the pole post 42 has a near-elliptical structure, and the longest extension direction of the pole post 42 is the same as the longest extension direction of the solder mark 3, so that the overall structural shape of the pole post 42 corresponds to that of the solder mark 3. That is to say, the pole post 42 can be the same racetrack-shaped structure as the solder mark 3. And along the vertical direction, the projected area of ​​the pole post 42 is not less than the projected area of ​​the solder mark 3, that is, the area occupied by the pole post 42 needs to be larger than the area of ​​the solder mark 3, to ensure that the solder mark 3 can be completely formed on the pole post 42 and will not exceed the edge of the pole post 42.

[0048] With this configuration, the longest direction of the electrode post 42 aligns with the long side 31 of the solder mark 3, ensuring a shape match between the electrode post 42 and the solder mark 3. This guarantees that the long side 31 of the solder mark 3 falls entirely on the electrode post 42, preventing the solder mark 3 from overflowing the electrode post 42 and causing incomplete soldering. Simultaneously, the current transmission path from the electrode post 42 to the solder mark 3 is shorter and more uniform, reducing contact resistance to some extent. Furthermore, the above technical solution ensures that the projected area of ​​the electrode post 42 is not less than the projected area of ​​the solder mark 3, providing sufficient support for the solder mark 3 and preventing it from extending beyond the edge of the electrode post 42, thereby improving welding quality.

[0049] Furthermore, in an optional embodiment, the length direction of the cover plate 41 is the longest extension direction of the electrode post 42. That is, the cover plate 41, the electrode post 42, and the solder mark 3 all extend along the length direction of the single cell 1.

[0050] With this configuration, the length direction of the cover plate 41 is aligned with the longest extension direction of the pole post 42, maximizing the length of the long side 31 of the pole post 42 within a limited space. This indirectly increases the area of ​​the solder joint 3 and enhances the current-carrying capacity of the pole post 42. Furthermore, since the pole post 42 is installed along the length direction of the cover plate 41, the force direction of the pole post 42 is consistent with the support direction of the cover plate 41, resulting in a stronger connection between the pole post 42 and the cover plate 41 and improved structural stability.

[0051] Furthermore, in an optional embodiment, the ratio of the projected area of ​​the solder mark 3 on the pole post 42 to the total area of ​​the pole post 42 along the direction perpendicular to the pole post 42 is between 0.6 and 0.85.

[0052] For example, the area ratio can be 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, etc. Of course, the above technical solutions are merely illustrative examples of specific area ratio values, but are not intended to limit the possibilities. Those skilled in the art can modify them according to actual circumstances, as long as the same technical effect is achieved.

[0053] Furthermore, in this embodiment, the solder area can be 290 mm². 2 Up to 500mm 2 Between these, the pole area can be 350mm². 2 Up to 600mm 2 between.

[0054] For example, the solder area can be 290mm². 2 300mm 2 350mm 2 400mm 2 450mm 2 500mm 2 And so on. Of course, the above technical solutions are merely illustrative examples of specific values ​​for the solder area, but are not intended to limit the scope. Those skilled in the art can modify them according to actual circumstances, as long as the same technical effect is achieved.

[0055] Furthermore, the pole area can be 350 mm². 2 400mm 2 450mm 2 500mm 2 550mm 2 600mm 2And so on. Of course, the above technical solutions are merely illustrative examples of specific values ​​for the pole area, but are not intended to limit the scope. Those skilled in the art can modify them according to actual circumstances, as long as the same technical effect is achieved. Furthermore, in an optional embodiment, along the longest extending direction of the pole post 42, the length of the pole post 42 is L5mm, the width of the pole post 42 is L6mm, and the ratio L5 / L6 between the length and the width of the pole post 42 is between 2.5 and 3.3.

[0056] For example, the ratio L5 / L6 can be 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, etc. Of course, the above technical solutions are merely illustrative examples of specific values ​​for the ratio L5 / L6, but are not intended to limit the application. Those skilled in the art can modify them according to actual circumstances, as long as the same technical effect is achieved.

[0057] This configuration limits the ratio of the length to the width of the electrode post 42 within a certain range. This ensures that the length of the electrode post 42 is sufficient to cover the width of the solder mark 3, guaranteeing welding reliability and preventing solder mark overflow that could lead to a cold solder joint. Simultaneously, it prevents the electrode post 42 from being too long and occupying excessive space, controlling the volume of the individual battery cell 1, reducing space waste, and improving space utilization. If the ratio is too small, the electrode post 42 will be too short, and the width of the solder mark 3 may exceed the length of the electrode post 42 during actual welding, leading to solder mark overflow and a risk of a cold solder joint. If the ratio is too large, the electrode post 42 will be too long, and the portion exceeding the width of the solder mark 3 will have no practical function, thus wasting the overall space occupied by the individual battery cell 1 and increasing its volume.

[0058] Furthermore, in an optional implementation, L5 satisfies: 32 mm ≤ L5 mm ≤ 40 mm; L6 satisfies: 12 mm ≤ L6 mm ≤ 18 mm.

[0059] For example, L5mm can be 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, etc. Of course, this embodiment is merely an example of a specific value for L5mm, but it is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0060] For example, L6mm can be 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, etc. Of course, this embodiment is merely an example of a specific value for L6mm, but it is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0061] Furthermore, in an optional embodiment, the pole post 42 has a second straight edge portion 421 and a second arc portion 422. Along the length direction of the second straight edge portion 421, the second arc portion 422 is located on both sides of the second straight edge portion 421, so that the second straight edge portion 421 and the second arc portion 422 surround each other to form a racetrack shape.

[0062] With this configuration, the above technical solution constructs the electrode post 42 into a racetrack-shaped structure, which allows the shape of the electrode post 42 to match that of the solder mark 3, further optimizing the current transmission path. Furthermore, it also optimizes the current distribution; in practical applications, the rounded portion can prevent current concentration at the corners of the electrode post 42, reducing localized heating.

[0063] Furthermore, in an optional embodiment, the extension direction of the second straight edge 421 in the longitudinal direction is perpendicular to the first direction, that is, the pole post 42 is arranged in the same direction as the solder mark 3. In the horizontal direction, the distance between the long side 31 of the solder mark 3 and the edge of the second straight edge 421 is L7mm, and L7mm ranges from 3 mm to 5 mm.

[0064] For example, L7mm can be 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5.0mm, etc. Of course, this embodiment is merely an example of a specific value for L7mm, and does not impose any limitations. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0065] With this configuration, the above technical solution limits the horizontal distance between the long side 31 of the solder mark 3 and the edge of the second straight edge 421 of the terminal post 42 within a certain range, allowing for sufficient positioning tolerance and preventing the solder mark 3 from overflowing the terminal post 42. Furthermore, it efficiently utilizes the space of the terminal post 42, maximizing the area of ​​the solder mark 3 and improving the current carrying capacity of the single cell 1. Moreover, maintaining a distance between the solder mark 3 and the edge of the terminal post 42, and using the central structure of the terminal post 42 for stable support, enhances the support strength.

[0066] Furthermore, in an optional embodiment, the distance between the second arc portion 422 and the short side 32 of the solder mark 3 in the horizontal direction is L8mm, and L8mm ranges from 3 mm to 5 mm.

[0067] For example, L8mm can be 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5.0mm, etc. Of course, this embodiment is merely an example of a specific value for L8mm, and does not impose any limitations. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0068] This configuration limits the horizontal distance between the second arc portion 422 and the short side 32 within a certain range, improving the smoothness of the welding process and preventing overlap between the short side 32 and the second arc portion 422, thereby reducing welding defects. Simultaneously, it reduces the path of current from the second arc portion 422 to the weld bead 3, thus reducing power transmission loss. Furthermore, it allows for structural matching of the transition position between the short side 32 and the second arc portion 422, reducing stress concentration between them.

[0069] Furthermore, in an optional embodiment, in the length direction of the second straight edge portion 421, the length of the second straight edge portion 421 is L9mm, the length of the second arc portion 422 is L10mm, and the ratio L9 / L10 is between 1.2 and 2.2.

[0070] For example, the ratio L9 / L10 can be 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, etc. Of course, this embodiment is merely an example illustrating the specific values ​​of the ratio L9 / L10, and is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0071] Furthermore, in this embodiment, L9 mm ranges from 25 mm to 33 mm, and L10 mm ranges from 15 mm to 22 mm.

[0072] For example, L9mm can be 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, etc. Of course, this embodiment is merely an example of a specific value for L9mm, but it is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0073] For example, L10mm can be 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, etc. Of course, this embodiment is merely an example of a specific value for L10mm, but it is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0074] By setting it this way, the above technical solution limits the ratio L9 / L10 within a certain range, ensuring that the pole 42 provides sufficient current-carrying area while also possessing good structural adaptability. If the ratio is too small, it means that the proportion of the second arc portion 422 is too large, resulting in the second straight edge portion 421 being too short, leading to a reduction in the effective current-carrying area of ​​the pole 42 and a weaker current transmission capacity. If the ratio is too large, it will cause the proportion of the second straight edge portion 421 to be too large, while the second arc portion 422 will be too short, approaching a right angle, which can easily lead to current and heat concentration at the corner position.

[0075] Secondly, this utility model also provides a battery device, which includes: The housing has a receiving cavity; At least one battery pack, as described in any of the above embodiments, is disposed in a housing.

[0076] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery pack, characterized in that, include: Multiple individual battery cells (1) are arranged sequentially along a first direction; each individual battery cell (1) is provided with a terminal assembly (4). A conductive element (2) is used to connect the terminal assembly (4) of two adjacent single cells (1); the conductive element (2) is welded to the terminal assembly (4) to form a solder mark (3); The solder mark (3) has a long side (31) and a short side (32), and the extension direction of the long side (31) is perpendicular to the first direction; In the extension direction of the long side (31), the length of the solder mark (3) is L1mm, the width of the solder mark (3) is L2mm, and the ratio L1 / L2 satisfies: 2≤(L1 / L2)≤5.

2. The battery pack according to claim 1, characterized in that, The length L1mm of the solder mark (3) satisfies: 15 mm ≤ L1 mm ≤ 30 mm.

3. The battery pack according to claim 1, characterized in that, The width L2mm of the solder mark (3) satisfies: 6 mm≤L2mm≤15 mm.

4. The battery pack according to any one of claims 1 to 3, characterized in that, The solder mark (3) has a rectangular structure.

5. The battery pack according to any one of claims 1 to 3, characterized in that, The solder mark (3) has a first straight edge (33) and a first arc (34). Along the length direction of the first straight edge (33), the first arc (34) is located on both sides of the first straight edge (33), so that the first straight edge (33) and the first arc (34) surround each other to form a racetrack shape.

6. The battery pack according to claim 5, characterized in that, In the length direction of the first straight edge (33), the length of the first straight edge (33) is L3mm, and the length of the first arc part (34) is L4mm. The ratio L3 / L4 satisfies: 2.5≤(L3 / L4)≤3.

5.

7. The battery pack according to claim 6, characterized in that, The radius of curvature of the first arc portion (34) is R mm, and satisfies 6 mm ≤ R mm ≤ 10 mm.

8. The battery pack according to any one of claims 1 to 3, characterized in that, The pole assembly (4) includes: Cover plate (41). A pole post (42) is disposed on the cover plate (41); the pole post (42) is welded to the conductive element (2) to form the solder mark (3); The pole post (42) has an elliptical structure. The longest extension direction of the pole post (42) is the same as the longest extension direction of the solder mark (3) and is in the vertical direction. The projected area of ​​the pole post (42) is not less than the projected area of ​​the solder mark (3).

9. The battery pack according to claim 8, characterized in that, The length direction of the cover plate (41) is the longest extension direction of the pole post (42).

10. The battery pack according to claim 8, characterized in that, Along the direction perpendicular to the pole post (42), the ratio of the projected area of ​​the solder mark (3) on the pole post (42) to the total area of ​​the pole post (42) is between 0.6 and 0.

85.

11. The battery pack according to claim 9, characterized in that, Along the longest extension direction of the pole (42), the length of the pole (42) is L5mm and the width of the pole (42) is L6mm, and the ratio L5 / L6 is between 2.5 and 3.

3.

12. The battery pack according to claim 11, characterized in that, L5 satisfies: 32 mm ≤ L5 mm ≤ 40 mm.

13. The battery pack according to claim 11, characterized in that, L6 satisfies: 12 mm ≤ L6 mm ≤ 18 mm.

14. The battery pack according to any one of claims 9 to 13, characterized in that, The pole post (42) has a second straight edge (421) and a second arcuate part (422). Along the length direction of the second straight edge (421), the second arcuate part (422) is located on both sides of the second straight edge (421), so that the second straight edge (421) and the second arcuate part (422) surround each other to form a runway shape.

15. The battery pack according to claim 14, characterized in that, The extension direction of the second straight edge (421) is perpendicular to the first direction; along the horizontal direction, the distance between the long side (31) and the edge of the second straight edge (421) is L7mm, where L7mm satisfies: 3 mm-5 mm.

16. The battery pack according to claim 15, characterized in that, Along the horizontal direction, the distance between the second arc portion (422) and the short side (32) is L8mm, where L8mm satisfies: 3 mm-5 mm.

17. The battery pack according to claim 16, characterized in that, In the length direction of the second straight edge (421), the length of the second straight edge (421) is L9mm, the length of the second arc part (422) is L10mm, and the ratio L9 / L10 is between 1.2 and 2.

2.

18. A battery device, characterized in that, include: The housing has a receiving cavity; At least one battery pack as claimed in any one of claims 1 to 17 is disposed in the housing.

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