Battery pack and electric device

Abstract

The utility model discloses a battery pack and a power utilization device, relates to the technical field related to batteries, and is used for solving the problem of low assembly efficiency of an existing battery pack. The battery pack provided by the utility model has a first direction, the battery pack comprises a single battery, a busbar and an acquisition terminal, the single battery comprises a shell, a cover plate, a battery cell and a pole, the shell is provided with an accommodating cavity and an opening communicated with the accommodating cavity, the cover plate covers the opening, the battery cell is arranged in the accommodating cavity, the battery cell and the cover plate are distributed along the first direction, and the pole penetrates through the cover plate; the busbar is arranged on one side, deviating from the battery cell, of the pole in the first direction; the collection terminal is clamped between the pole and the busbar in the first direction and connected with the pole and the busbar, the collection terminal is provided with a limiting part which extends in the first direction and is connected with the pole, and the limiting part can limit the collection terminal and the pole in the direction perpendicular to the first direction. The battery pack assembling device is used for improving the battery pack assembling efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular to a battery pack and an electrical device. Background Art

[0002] The battery pack contains CCS components (battery pack collection integrated components). Among them, CCS components mainly include busbars, FPCs, collection terminals and other components. As the core part of the battery safety monitoring center, CCS components play a vital role in the safety performance of the battery pack.

[0003] In the prior art, the busbar is electrically connected to the collection terminal, and the collection terminal is electrically connected to the pole of the single battery in the battery pack. Therefore, during the assembly process, two processes are required to respectively realize the above two electrical connections, resulting in low battery assembly efficiency. Utility Model Content

[0004] The present application provides a battery pack and an electrical device, which can solve the problem of low assembly efficiency of existing battery packs.

[0005] To achieve the above-mentioned purpose, the battery pack provided in the present application has a first direction, and the battery pack includes:

[0006] A single battery comprises a shell, a cover plate, a battery cell and a pole, wherein the shell has a receiving cavity and an opening communicating with the receiving cavity, the cover plate is arranged on the opening, the battery cell is arranged in the receiving cavity, the battery cell and the cover plate are distributed along the first direction, and the pole is passed through the cover plate;

[0007] A bus bar, arranged on a side of the pole away from the battery cell in the first direction;

[0008] a collection terminal, sandwiched between the pole and the busbar in the first direction and connected to both the pole and the busbar, the collection terminal being used to collect temperature information and / or voltage information of the battery cell;

[0009] Wherein, a limiting portion is provided on the collection terminal, the limiting portion extends along a first direction and is connected to the pole, and the limiting portion can limit the collection terminal and the pole in a direction perpendicular to the first direction.

[0010] In this technical solution, the present application sandwiches the collection terminal between the pole and the busbar in the first direction, and the collection terminal is connected to both the pole and the busbar. It can also be understood that the collection terminal and the busbar are stacked above the pole, and along the first direction, the collection terminal, the busbar and the pole are at least partially overlapped. Therefore, during the specific installation, the limiting portion provided on the collection terminal can be used to pre-position the collection terminal and the pole in a direction perpendicular to the first direction, which is convenient for pre-positioning between the two and is conducive to ensuring assembly accuracy. Subsequently, the three can be connected simultaneously through the overlapping parts of the three to improve the assembly efficiency of the battery pack. Since the three are connected together at one time, the reliability of the connection can also be effectively improved, reducing the problems of poor electrical contact caused by poor connection reliability during the use of the battery pack.

[0011] In some embodiments of the present application, the collecting terminal is welded to the pole, the busbar is welded to the collecting terminal, and a welding mark is formed on the wall of the busbar facing away from the collecting terminal.

[0012] In some embodiments of the present application, the orthographic projection of the weld on the cover is located within the orthographic projection of the pole on the cover, and the orthographic projection of the pole on the cover is located within the orthographic projection of the collection terminal on the cover.

[0013] In some embodiments of the present application, a groove is provided on the side of the busbar facing away from the collecting terminal, the groove is recessed toward the collecting terminal, the weld mark is located at the bottom of the groove, and in the first direction, a size H1mm of a portion of the weld mark protruding relative to the bottom of the groove is less than or equal to a depth H2mm of the groove.

[0014] In some embodiments of the present application, a window groove is provided on the pole, and the weld has a first edge and a second edge on the positive projection of the pole, the second edge is farther away from the window groove than the first edge, a first gap L1mm is formed between the first edge and the window groove, a second gap L2mm is formed between the second edge and the outer peripheral side of the pole, and the dimension between the first edge and the second edge is L3mm, wherein 20≥L1≥1, 20≥L2≥1, 5≥L3≥1.

[0015] In some embodiments of the present application, a window groove is provided on the pole, a first observation hole penetrating along the first direction is provided on the busbar, and a second observation hole penetrating along the first direction is provided on the collection terminal. In the first direction, the first observation hole, the second observation hole and the window groove at least partially overlap.

[0016] In some embodiments of the present application, a positioning portion is provided on the cover plate, an adapting portion is provided on the collection terminal, and the positioning portion is connected to the limiting portion.

[0017] In some embodiments of the present application, the positioning portion is a positioning column, the limiting portion is a limiting hole that passes through the acquisition terminal along the first direction, and the positioning column is installed in the limiting hole.

[0018] In some embodiments of the present application, the limiting portion includes two limiting bending portions arranged on the collecting terminal, and the collecting terminal is provided with two limiting bending portions, the two limiting bending portions are arranged opposite to each other at intervals, and both are bent toward the cover plate, and the pole is positioned in the interval between the two limiting bending portions.

[0019] In some embodiments of the present application, the limiting portion is a limiting groove provided on the collecting terminal, the limiting groove is recessed along a first direction toward a direction away from the pole, and the notch of the limiting groove faces the pole, and the portion of the pole close to the collecting terminal is embedded in the limiting groove.

[0020] On the other hand, the present application also provides an electrical device, which includes the battery pack described in any of the above technical solutions.

[0021] Since the electrical device provided in the present application includes the battery pack recorded in any of the above technical solutions, the two can solve the same technical problems and achieve the same technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 is an exploded view of the battery pack in Example 1 of the present application;

[0024] Figure 2 is a top view of the battery pack in the first embodiment of the present application;

[0025] Figure 3 yes Figure 2 Sectional view of section AA;

[0026] Figure 4 yes Figure 3 A magnified view of part B in FIG.

[0027] Figure 5 is an exploded view of the battery pack in the second embodiment of the present application;

[0028] Figure 6 is a three-dimensional diagram of the collection terminal in the battery pack in the second embodiment of the present application;

[0029] Figure 7 It is a three-dimensional diagram of the collection terminal in the battery pack in the third embodiment of the present application.

[0030] The main reference numerals in the drawings of this application specification are described as follows:

[0031] 1-single battery; 11-housing; 111-accommodating chamber; 112-opening; 12-cover plate; 121-positioning portion; 1211-positioning column; 13-battery cell; 14-pole column; 141-window slot; 1411-first slot section; 1412-second slot section;

[0032] 2-bus; 21-first observation hole; 22-groove; 23-first connecting portion; 24-second connecting portion; 25-main body;

[0033] 3-collection terminal; 31-second observation hole; 32-limiting portion; 321-limiting bending portion; 322-limiting groove; 323-limiting hole;

[0034] 4-weld mark; 41-first edge; 42-second edge. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0036] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0037] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0038] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0039] The present application provides a battery pack and an electrical device, which are described in detail below. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments of the present application. In the following embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0040] Reference Figure 1 to Figure 3 The battery pack provided in the present application has a first direction Z, and the battery pack includes a single battery 1, a busbar 2 and a collection terminal 3. The single battery 1 includes a shell 11, a cover plate 12, a battery cell 13 and a pole 14. The shell 11 has a receiving cavity 111 and an opening 112 connected to the receiving cavity 111. The cover plate 12 is covered on the opening 112. The battery cell 13 is arranged in the receiving cavity 111. The battery cell 13 and the cover plate 12 are distributed along the first direction Z, and the pole 14 is penetrated by the cover plate 12. The busbar 2 is arranged on the side of the pole 14 away from the battery cell 13 in the first direction Z. The collection terminal 3 is sandwiched between the pole 14 and the busbar 2 in the first direction Z, and is connected to both the pole 14 and the busbar 2. The collection terminal 3 is used to collect temperature information and / or voltage information of the battery cell 13. The collecting terminal 3 is provided with a limiting portion 32 , which extends along the first direction Z and is connected to the pole 14 . The limiting portion 32 can limit the collecting terminal 3 and the pole 14 in a direction perpendicular to the first direction Z.

[0041] In this technical solution, the present application sandwiches the collection terminal 3 between the pole 14 and the bus bar 2 in the first direction Z, and the collection terminal 3 is connected to both the pole 14 and the bus bar 2. It can also be understood that the collection terminal 3 and the bus bar 2 are stacked above the pole 14, and along the first direction Z, the collection terminal 3, the bus bar 2 and the pole 14 at least partially overlap. Therefore, during the specific installation, the limiting portion 32 provided on the collection terminal 3 is used to pre-position the collection terminal 3 and the pole 14 in a direction perpendicular to the first direction Z, which is convenient for pre-positioning between the two and is conducive to ensuring assembly accuracy. Subsequently, the three can be connected simultaneously through the overlapping parts of the three, thereby improving the assembly efficiency of the battery pack. In addition, since the three are connected together at one time, the reliability of the connection can be effectively improved, and the problems of poor electrical contact caused by poor connection reliability during the use of the battery pack can be reduced.

[0042] The busbar 2 may be a copper busbar, an aluminum busbar, a copper sheet, an aluminum sheet or the like, and is used to realize the series connection or parallel connection between adjacent single cells 1 .

[0043] It should be noted that the acquisition terminal 3 is mainly used in the signal acquisition harness, and is responsible for collecting the temperature information and / or voltage information of the battery cell in the single cell 1. The temperature information and / or voltage information is transmitted to the control unit through the acquisition terminal 3. The control unit determines the state of the single cell 1 based on these signals, such as whether the temperature is too high or too low, and whether the voltage value of the single cell 1 is too low or too high. Based on this information, the control unit can control the cooling system, PTC (Positive Temperature Coefficient, positive temperature coefficient thermistor) heating device, main relay and other components accordingly to cool or heat the single cell 1, and cut off the output of the single cell 1 to the outside, thereby ensuring the safe operation of the entire battery pack.

[0044] In some embodiments, the battery pack further includes a connecting screw, which is passed through the busbar 2 and the collecting terminal 3 and connected to the pole 14 to press the busbar 2 and the collecting terminal 3 onto the pole along the first direction Z, thereby achieving electrical connection between the pole 14, the busbar 2 and the collecting terminal 3, and ensuring that the connection between the three is stable and reliable.

[0045] In some embodiments of the present application, the collection terminal 3 is welded to the pole 14, the busbar 2 is welded to the collection terminal 3, and a weld mark 4 is formed on the wall of the busbar 2 facing away from the collection terminal 3. The present application facilitates simplifying the welding of the collection terminal 3 to the pole 14, the connection of the busbar 2 to the collection terminal 3 by welding, and ensures that the contact between the three is stable and reliable. At the same time, the busbar 2, the collection terminal 3 and the pole 14 can be fixed by welding at one time through the same process.

[0046] In the specific processing process, the specific implementation plan is to divide the CCS into equal-sized parts, cover the CCS on the battery cell, place the cross-connection position collection terminal 3 between the pole 14 and the bus 2 to form a sandwich structure, and apply pressure from the copper nozzle during welding to completely fit the collection terminal 3 with the bus 2 and the pole 14. The welding parameters during welding are power: 3200W (inside), 1200W (outside); speed: 80mm / s. In this way, the poor welding caused by the accumulation of CCS tolerances can be reduced, and the cost of components and production costs can be reduced. In addition, the technology is simple to implement, and can also reduce components such as bolts and protective bases, reduce the investment in welding equipment, reduce the labor hours for bolt installation, and avoid poor contact caused by the gap between the bolts and the base.

[0047] For example, the pole 14 is provided with a window groove 141, and the orthographic projection of the weld mark 4 on the pole 14 can be a closed annular structure, and surrounds the outer periphery of the window groove 141. Alternatively, the pole 14 is provided with a window groove 141, and the orthographic projection of the weld mark 4 on the pole 14 can be a multi-segment structure, and the weld mark of the multi-segment structure surrounds the outer periphery of the window groove 141 and encloses to form an annular structure.

[0048] In some embodiments of the present application, the orthographic projection of the weld mark 4 on the cover plate 12 is located within the orthographic projection of the pole 14 on the cover plate 12, and the orthographic projection of the pole 14 on the cover plate 12 is located within the orthographic projection of the collection terminal 3 on the cover plate 12, thereby ensuring that the collection terminal 3 can completely cover the pole 14, and the three must overlap at the position where the weld mark 4 is located, which is conducive to increasing the welding tension.

[0049] Reference Figure 3 and Figure 4 A groove 22 is provided on the side of the busbar 2 facing away from the collection terminal 3, and the groove 22 is recessed toward the collection terminal 3. The weld mark 4 is located at the bottom of the groove 22. In the first direction Z, the size H1mm of the protruding portion of the weld mark 4 relative to the bottom of the groove 22 is less than or equal to the groove depth H2mm of the groove 22, thereby preventing the weld mark 4 from protruding from the upper surface of the busbar 2 and ensuring the neatness of the appearance of the battery pack. At the same time, it can also prevent the burrs of the weld mark from contacting the outer shell of the battery pack and damaging the outer shell of the battery pack.

[0050] Based on any of the above embodiments, a window groove 141 is provided on the pole 14, and the positive projection of the weld mark 4 on the pole 14 has a first edge 41 and a second edge 42, the second edge 42 is relatively far from the window groove 141 relative to the first edge 41, a first gap L1mm is formed between the first edge 41 and the window groove 141, a second gap L2mm is formed between the second edge 42 and the outer peripheral side of the pole 14, and the dimension between the first edge 41 and the second edge 42 is L3mm, wherein 20≥L1≥1, 20≥L2≥1, and 5≥L3≥1. Therefore, 20≥L1≥1 is conducive to preventing the welding track from exceeding the edge of the pole, resulting in a poor welding track and insufficient welding strength. At the same time, 20≥L2≥1 can prevent the insulation under the pole from being damaged due to welding and forming a poor explosion hole, and 5≥L3≥1 can ensure the welding strength between the three.

[0051] It should be noted that the welding strength of the embodiment of the present application can be tested by pulling one of the pole 14, the collection terminal 3 and the bus bar 2 in a horizontal direction perpendicular to the stacking direction of the pole 14, the collection terminal 3 and the bus bar 2, and testing the tensile force and shear force to determine when the pole 14, the collection terminal 3 and the bus bar 2 welded together will break or separate. The greater the tensile force that the pole 14, the collection terminal 3 and the bus bar 2 welded together can withstand, the better the welding strength, that is, the better the strength of the battery pack.

[0052] The performance of the technical solution provided in the embodiments of the present application is evaluated in conjunction with specific embodiments.

[0053] Embodiments 1 to 24 are provided. Embodiments 1 to 5 satisfy 20≥L1≥1, L2=10, L3=2.25. Embodiments 6 to 10 satisfy L1=10, 20≥L2≥1, L3=2.25. Embodiments 11 to 16 satisfy L1=10, L2=10, 5≥L3≥1. Embodiments 17 and 18 do not satisfy 20≥L1≥1, and satisfy L2=10, L3=2.25. Embodiments 19 and 20 do not satisfy 20≥L2≥1, and satisfy L2=10, L3=2.25. Embodiments 21 and 22 do not satisfy 20≥L2≥1, 20≥L2≥1, and satisfy 5≥L3≥1. Embodiments 23 and 24 do not satisfy 5≥L3≥1, and satisfy 20≥L2≥1, 20≥L2≥1. Specific parameters and test results are detailed in Table 1.

[0054] Table 1

[0055]

[0056]

[0057] It can be seen that the strength of the battery pack in the above-mentioned embodiments 1 to 16 is relatively high. In embodiments 17 to 22, the dimension between the first edge 41 and the second edge 42 is L3mm, that is, the weld width L3mm satisfies 5≥L3≥1, indicating that the welding strength is mainly related to the weld width. In these embodiments, the battery pack also has good strength. In embodiment 23, the dimension between the first edge 41 and the second edge 42 is L3mm less than 1, at this time the weld is narrow and the welding strength is low. In embodiment 24, it can be known through experiments that in embodiments 14 to 16, as the dimension L3mm between the first edge 41 and the second edge 42 increases, the welding strength does not increase proportionally. Continuing to increase the size of L3 will lead to increased welding energy consumption and increased mold cost required for welding, and the mold is difficult to adapt to the pole space. Therefore, there is no need to set the dimension L3mm between the first edge 41 and the second edge 42 to be larger.

[0058] In some embodiments of the present application, a window groove 141 is provided on the pole 14, a first observation hole 21 penetrating along the first direction Z is provided on the bus 2, and a second observation hole 31 penetrating along the first direction Z is provided on the collecting terminal 3. In the first direction Z, the first observation hole 21, the second observation hole 31 at least partially overlap with the window groove 141. When welding the bus 2 and the collecting terminal 3, the operator can observe the pole 14 through the first observation hole 21 and the second observation hole 31, which facilitates welding.

[0059] Furthermore, the first observation hole 21 and the second observation hole 31 overlap with the center line of the window groove 141. The first observation hole 21 and the second observation hole 31 completely overlap along the first direction Z. The window groove 141 includes a first groove section 1411 and a second groove section 1412. The second groove section 1412 is away from the collection terminal 3 relative to the first groove section 1411. The diameter of the second groove section 1412 is smaller than the diameter of the first groove section 1411, that is, a step is formed between the first groove section 1411 and the second groove section 1412 to improve the structural strength of the pole 14. In addition, the diameter of the first observation hole 21 and the diameter of the second observation hole 31 are both larger than the diameter of the second groove section 1412, which is more conducive to observing the pole 14 and facilitates welding.

[0060] In order to realize the installation and positioning of the acquisition terminal 3, there are multiple embodiments for the installation and positioning of the acquisition terminal 3, which are described below respectively.

[0061] Embodiment 1

[0062] A positioning portion 121 is provided on the cover plate 12, and a limiting portion 32 is provided on the collection terminal 3. The positioning portion 121 and the limiting portion 32 are connected, and the cover plate 12 and the collection terminal 3 can be directly positioned in a direction perpendicular to the first direction Z. In addition, since the pole 14 is fixed on the cover plate 12, the positioning portion 121 and the limiting portion 32 are connected, and the pole 14 and the collection terminal 3 can also be indirectly positioned in a direction perpendicular to the first direction Z.

[0063] like Figure 1 As shown, the positioning portion 121 is a positioning column 1211, the limiting portion 32 is a limiting hole 323 that passes through the collection terminal 3 along the first direction Z, and the positioning column 1211 is penetrated in the limiting hole 323, thereby indirectly positioning the pole 14 and the collection terminal 3 in a direction perpendicular to the first direction Z. The positioning structure is simple and easy to implement.

[0064] Of course, the positioning portion 121 may also be a positioning hole, and the limiting portion 32 may be a limiting column.

[0065] Embodiment 2

[0066] like Figure 5 and Figure 6 As shown, the battery pack includes a first direction Z, a second direction X and a third direction Y that intersect each other. The limiting portion 32 includes two limiting bending portions 321 provided on the collection terminal 3, the two limiting bending portions 321 are provided opposite to each other along the second direction X, and are both bent toward the cover plate 12, and the pole 14 is positioned in the interval between the two limiting bending portions 321, so that the collection terminal 3 only needs to be designed into a desired structure as required, and the outer peripheral side of the pole 14 is positioned and matched with the limiting bending portion 321 of the collection terminal 3.

[0067] Alternatively, the collection terminal 3 is provided with two limiting bending portions 321 , which are arranged opposite to each other along the third direction Y with an interval, and the pole 14 is positioned in the interval between the two limiting bending portions 321 , which is not shown in the figure.

[0068] Embodiment 3

[0069] like Figure 7 As shown, the limiting portion 32 is a limiting groove 322 provided on the collection terminal 3, the limiting groove 322 is recessed along the first direction Z in the direction away from the pole 14, and the notch of the limiting groove 322 faces the pole 14, and the part of the pole 14 close to the collection terminal 3 is embedded in the limiting groove 322, ensuring that the pole 14 can be limited in the limiting groove 322 in both the second direction X and the third direction Y, which is beneficial to improve the positioning accuracy between the two.

[0070] On the other hand, the present application also provides an electrical device, which includes the battery pack described in any of the above technical solutions.

[0071] Since the electrical device provided in the present application includes the battery pack recorded in any of the above technical solutions, the two can solve the same technical problems and achieve the same technical effects.

[0072] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims. In addition, the specification uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. The content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery pack, characterized in that: Having a first direction (Z), the battery pack comprises: A single cell battery (1) comprises a shell (11), a cover plate (12), a battery cell (13) and a pole (14); the shell (11) has a receiving cavity (111) and an opening (112) communicating with the receiving cavity (111); the cover plate (12) covers the opening (112); the battery cell (13) is arranged in the receiving cavity (111); the battery cell (13) and the cover plate (12) are distributed along the first direction (Z); and the pole (14) passes through the cover plate (12); A busbar (2) is arranged on a side of the pole (14) facing away from the battery core (13) in the first direction (Z); a collection terminal (3), which is sandwiched between the pole (14) and the busbar (2) in the first direction (Z), and is connected to both the pole (14) and the busbar (2), and the collection terminal (3) is used to collect temperature information and / or voltage information of the battery cell (13); The collecting terminal (3) is provided with a limiting portion (32), the limiting portion (32) extends along a first direction (Z) and is connected to the pole (14), and the limiting portion (32) can limit the collecting terminal (3) and the pole (14) in a direction perpendicular to the first direction (Z).

2. The battery pack according to claim 1, characterized in that: The collecting terminal (3) is welded to the pole (14), the busbar (2) is welded to the collecting terminal (3), and a welding mark (4) is formed on the wall surface of the busbar (2) facing away from the collecting terminal (3).

3. The battery pack according to claim 2, characterized in that: The orthographic projection of the weld mark (4) on the cover plate (12) is located within the orthographic projection of the pole (14) on the cover plate (12), and the orthographic projection of the pole (14) on the cover plate (12) is located within the orthographic projection of the collection terminal (3) on the cover plate (12).

4. The battery pack according to claim 2 or 3, characterized in that: A groove (22) is provided on a side of the busbar (2) facing away from the collecting terminal (3), the groove (22) is recessed toward the collecting terminal (3), the weld mark (4) is located at the bottom of the groove (22), and in the first direction (Z), a size H1 mm of a portion of the weld mark (4) protruding relative to the bottom of the groove (22) is less than or equal to a groove depth H2 mm of the groove (22).

5. The battery pack according to claim 2, characterized in that: The pole (14) is provided with a window groove (141); the weld mark (4) has a first edge (41) and a second edge (42) in the positive projection of the pole (14); the second edge (42) is farther away from the window groove (141) than the first edge (41); a first gap L1 mm is formed between the first edge (41) and the window groove (141); a second gap L2 mm is formed between the second edge (42) and the outer peripheral side of the pole (14); the dimension between the first edge (41) and the second edge (42) is L3 mm, wherein 20≥L1≥1, 20≥L2≥1, and 5≥L3≥1.

6. The battery pack according to claim 1, characterized in that: The pole (14) is provided with a window groove (141), the busbar (2) is provided with a first observation hole (21) extending along the first direction (Z), and the collection terminal (3) is provided with a second observation hole (31) extending along the first direction (Z); in the first direction (Z), the first observation hole (21), the second observation hole (31) and the window groove (141) at least partially overlap.

7. The battery pack according to claim 1, characterized in that: The cover plate (12) is provided with a positioning portion (121), and the positioning portion (121) is connected to the limiting portion (32).

8. The battery pack according to claim 7, characterized in that: The positioning portion (121) is a positioning column (1211), the limiting portion (32) is a limiting hole (323) that passes through the collection terminal (3) along the first direction (Z), and the positioning column (1211) is installed in the limiting hole (323).

9. The battery pack according to claim 1, characterized in that: The limiting portion (32) comprises two limiting bending portions (321) provided on the collecting terminal (3); the two limiting bending portions (321) are arranged opposite to each other at a distance and are both bent toward the cover plate (12); and the pole (14) is positioned in the interval between the two limiting bending portions (321).

10. The battery pack according to claim 1, characterized in that: The limiting portion (32) is a limiting groove (322) provided on the collecting terminal (3); the limiting groove (322) is recessed along the first direction (Z) in a direction away from the pole (14); the notch of the limiting groove (322) faces the pole (14); and a portion of the pole (14) close to the collecting terminal (3) is embedded in the limiting groove (322).

11. An electrical device, characterized in that: A battery pack comprising the battery pack as claimed in any one of claims 1 to 10.

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