Solder strip piece and battery assembly

Abstract

The utility model relates to the technical field of solar cells, and discloses a solder strip piece and a cell module. The welding strip piece is suitable for connecting adjacent battery pieces in series and comprises a first welding strip section, the first welding strip section comprises a first welding strip body and a plurality of first connecting structures formed on the first welding strip body, and the first connecting structures are arranged at intervals in the length direction of the first welding strip body; the first connecting structure comprises a first groove and a first conductive piece arranged in the first groove, the depth direction of the first groove is perpendicular to the extending direction of the first welding strip body, and the width size of the first connecting structure is larger than that of the first welding strip body on the plane perpendicular to the depth direction of the first groove. The contact area of the first groove and the grid line is larger, the bonding strength is enhanced, the first conductive piece and the end face of the first groove jointly make contact with the battery piece, the conductive connection performance of the welding strip piece and the battery piece is improved, low-temperature silver paste is saved, cost can be reduced, and the shielding of the welding strip piece on the battery piece is small.

Description

Technical Field

[0001] The utility model relates to the technical field of solar cells, and particularly relates to a solder ribbon component and a battery module. Background Art

[0002] In a main-gridless heterojunction solar cell, the connection between the solder ribbon and the cell includes two methods: welding and non-welding. Among them, in the welding method of connecting the solder ribbon and the cell, a large amount of low-temperature silver paste is required, and the material cost of the low-temperature silver paste is the main factor restricting the further development of photovoltaic modules. In the non-welding method, it can be achieved by dispensing glue, or by preparing a copper wire composite film with an embedded solder ribbon and then laminating it onto the cell. However, simply dispensing glue easily leads to insufficient bonding force, affecting the product stability, while adding a copper wire composite film easily causes shading to the cell, the structure is relatively complex and there is also a problem of cost increase.

[0003] In summary, among the various solder ribbon fixing methods for main-gridless heterojunction solar cells in the prior art, it is impossible to ensure the bonding force between the solder ribbon and the cell while streamlining the structure to avoid optical shading, and the cost is relatively high, and the product reliability is poor. Summary of the Utility Model

[0004] In view of this, the utility model provides a solder ribbon component and a battery module to solve the problems that the existing main-gridless heterojunction solar cell cannot ensure the bonding force between the solder ribbon and the cell while streamlining the structure to avoid optical shading, and the cost is relatively high, and the product reliability is poor.

[0005] In the first aspect, the utility model provides a solder ribbon component suitable for connecting adjacent cells in series, including a first solder ribbon section. The first solder ribbon section includes a first solder ribbon body and a plurality of first connection structures formed on the first solder ribbon body. The plurality of first connection structures are arranged at intervals along the length direction of the first solder ribbon body; any one of the first connection structures includes a first groove and a first conductive member disposed in the first groove. The depth direction of the first groove is perpendicular to the extension direction of the first solder ribbon body. In a plane perpendicular to the depth direction of the first groove, the width dimension of the first connection structure is greater than the width dimension of the first solder ribbon body.

[0006] In the present utility model, a plurality of first connection structures are arranged along the length direction of the first solder tape segment. The width dimension of the first groove of each connection structure is greater than the width dimension of the first solder tape body. Compared with the solder tape component directly contacting the grid line on the battery cell to achieve electrical connection, the contact area between the first groove and the grid line in this embodiment is larger, and the bonding strength is enhanced. Moreover, a first conductive component is arranged in the first groove, and the first conductive component and the end face of the first groove jointly contact the battery cell, further improving the electrical connection performance between the solder tape component and the battery cell. That is, the first connection structure directly serves as the connection point for fixing the solder tape component and the battery cell. There is no need to print the main grid on the surface of the battery cell, saving low-temperature silver paste, which helps to reduce costs and promote the development of main-grid-free solar cells. In addition, in this embodiment, the requirement for the width dimension of the solder tape component itself is relatively low, and the solder tape component can be set to a smaller width dimension, reducing the shielding of the battery cell by the solder tape component.

[0007] In an alternative embodiment, the first groove and the first solder tape body are of an integral structure.

[0008] In the present utility model, a plurality of first grooves are integrally formed on the first solder tape body, which helps to enhance the stability and reliability of the electrical connection between the first groove and the first conductive component and the battery cell.

[0009] In an alternative embodiment, one end of the first conductive component close to the notch of the first groove is flush with the notch end face of the first groove.

[0010] In the present utility model, one end of the first conductive component close to the notch of the first groove is flush with the notch end face of the first groove, which can maximize the contact area between the first conductive component and the battery cell and improve the bonding strength.

[0011] In an alternative embodiment, the first solder tape body is of a cylindrical structure; the first connection structure includes a cylindrical structure, or a prismatic structure, or a frustum-shaped structure, or a truncated pyramid-shaped structure; the axial direction of the first connection structure is perpendicular to the axial direction of the first solder tape body.

[0012] In the present utility model, the first solder tape body adopts a cylindrical structure, and a plurality of first connection structures are arranged at intervals along the axial direction of the first solder tape body, that is, the length direction. Each first connection structure has a connection plane for contacting the battery cell along the axial direction of the first solder tape body. The cross-sectional shape of the first connection structure in the depth direction can be various shapes such as circular, square, and triangular, and it is not limited that the cross-sectional sizes at different depths are the same. As long as the width of the contact surface between the first connection structure and the battery cell is a connection plane greater than the width of the first solder tape body, the contact area and connection strength between the solder tape component and the battery cell can be effectively increased.

[0013] In an alternative embodiment, in the axial direction of the first connection structure, the thickness dimension of the first connection structure is greater than or equal to the radial dimension of the first solder tape body.

[0014] In the present utility model, the thickness dimension of the first connection structure is greater than or equal to the radial dimension of the first solder tape body, which ensures sufficient contact between the end face of the first connection structure of the solder tape part and the solar cell, and also ensures the connection stability between the solder tape part and the solar cell.

[0015] In an alternative embodiment, the first solder tape segment includes a first base material, and a first coating layer and a first conductive layer that sequentially coat the first base material along the radial direction.

[0016] In the present utility model, a first conductive layer is provided outside the first coating layer in the first solder tape body, which can achieve conductive connection at a lower temperature, and can adapt to smaller silicon wafer sizes without high-temperature treatment, resulting in lower silicon wafer costs. In addition, it is also convenient to repair the first solder tape segment, improving the product yield.

[0017] In an alternative embodiment, it further includes a second solder tape segment. The second solder tape segment includes a second solder tape body and a plurality of second connection structures formed on the second solder tape body. The plurality of second connection structures are spaced apart along the length direction of the second solder tape body; any one of the second connection structures includes a second groove and a second conductive member disposed in the second groove. The notch direction of the second groove is opposite to the notch direction of the first groove, and the depth direction of the second groove is perpendicular to the extending direction of the second solder tape body. In a plane perpendicular to the depth direction of the second groove, the width dimension of the second connection structure is greater than the width dimension of the second solder tape body.

[0018] In the present utility model, the second solder tape segment and the first solder tape segment adopt the same material and structural settings, except that the orientation of the groove is opposite to that of the first solder tape segment to achieve the end-to-end connection of two adjacent solar cells.

[0019] In an alternative embodiment, a connecting portion connecting the first solder tape segment and the second solder tape segment; one end of the notch of the first groove of the first solder tape segment is adapted to contact the light-receiving surface of the solar cell, and one end of the notch of the second groove of the second solder tape segment is adapted to contact the backlight surface of the solar cell.

[0020] In the present utility model, a bent connecting portion is provided between the first solder tape segment and the second solder tape segment of the solder tape part to improve the contact stability between the first solder tape segment and the second solder tape segment and the side wall of the solar cell, avoid damage during the connection process between the solder tape part and the solar cell, and improve the service life.

[0021] The present utility model also provides a battery assembly, comprising: a plurality of battery cells and the above-mentioned solder strip member, and the solder strip member is connected in series with adjacent battery cells; for any adjacent first battery cell and second battery cell, one end of the slot opening of the first groove of the first solder strip segment is used to connect with the light-receiving surface of the first battery cell.

[0022] In the present utility model, between adjacent battery cells in the battery assembly, stable electrical connection is achieved with the battery cells through the first connection structure of the first solder strip segment, the contact area between the solder strip member and the battery cells is increased, and the bonding strength is increased; moreover, the width dimension of the solder strip member can be made smaller, which helps to reduce the shielding of the battery cells by the solder strip member, reduce the usage amount of low-temperature silver paste, and thus reduce the cost.

[0023] In an optional embodiment, the solder strip member comprises a second solder strip segment and a connecting portion connecting the first solder strip segment and the second solder strip segment; the second solder strip segment comprises a second solder strip main body and a plurality of second connection structures formed on the second solder strip main body, and the plurality of second connection structures are arranged at intervals along the length direction of the second solder strip main body; any one of the second connection structures comprises a second groove and a second conductive member arranged in the second groove, the slot opening direction of the second groove is opposite to the slot opening direction of the first groove, and one end of the slot opening of the second groove of the second solder strip segment is used to connect with the backlight surface of the second battery cell.

[0024] In the present utility model, one side of the slot opening of the first groove of the first solder strip segment in the solder strip member contacts the light-receiving surface of the first battery cell; one side of the slot opening of the second groove of the second solder strip segment of the solder strip member contacts the backlight surface of the second battery cell; the connecting portion of the solder strip member is bent and arranged, and both sides respectively abut against the sides of the first battery cell and the second battery cell, improving the connection stability between the solder strip member and the battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 is a schematic structural view of the first solder strip segment of the solder strip member in an embodiment of the present utility model;

[0027] Figure 2 is a front view schematic of the first solder strip segment of the solder strip member in an embodiment of the present utility model;

[0028] Figure 3 is a top view schematic of the first solder strip segment of the solder strip member in an embodiment of the present utility model;

[0029] Figure 4 It is a side view schematic diagram of the first solder tape segment of the solder tape part in the embodiment of the present utility model;

[0030] Figure 5 It is a structural schematic diagram of the battery module in the embodiment of the present utility model.

[0031] Description of the reference numerals:

[0032] 1. First solder tape segment; 11. First solder tape main body; 111. First base material; 112. First coating layer; 113. First conductive layer; 12. First connection structure; 121. First groove; 122. First conductive part; 2. Second solder tape segment; 3. Connection part;

[0033] 100. First battery cell; 200. Second battery cell. Detailed implementation manners

[0034] The present utility model will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. In addition, it should be noted that for the sake of description, only parts related to the present utility model are shown in the drawings rather than all structures. In the following description, the description of well-known structures and technologies is omitted to avoid unnecessarily confusing the concept of the present utility model. Structural schematic diagrams according to the embodiments of the present utility model are shown in the drawings. These figures are not drawn to scale, in which for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures and their relative sizes and positional relationships are only exemplary, and may actually deviate due to manufacturing tolerances or technical limitations. Those skilled in the art can design regions / layers with different shapes, sizes and relative positions according to actual needs. In the context of the present utility model, when a layer / component is referred to as being "on" another layer / component, the layer / component can be directly on the other layer / component, or there can be an intermediate layer / component between them. In addition, if a layer / component is "on" another layer / component in one orientation, then when the orientation is reversed, the layer / component can be "under" the other layer / component.

[0035] As Figures 1 to 5As shown in the figure, a solder strip component in this embodiment is suitable for connecting adjacent solar cells in series. It includes a first solder strip section 1, and the first solder strip section 1 includes a first solder strip body 11 and a plurality of first connection structures 12 formed on the first solder strip body 11. The plurality of first connection structures 12 are arranged at intervals along the length direction of the first solder strip body 11; any one of the first connection structures 12 includes a first groove 121 and a first conductive member 122 disposed in the first groove 121. The depth direction of the first groove 121 is perpendicular to the extension direction of the first solder strip body 11. In a plane perpendicular to the depth direction of the first groove 121, the width dimension of the first connection structure 12 is greater than the width dimension of the first solder strip body 11.

[0036] Specifically, in this embodiment, a plurality of first connection structures 12 are arranged along the length direction of the first solder strip section 1. The width dimension of the first groove 121 of each connection structure is greater than the width dimension of the first solder strip body. Compared with the solder strip component directly contacting the grid line on the solar cell to achieve conductive connection, the contact area between the first groove 121 and the grid line in this embodiment is larger, and the bonding strength is enhanced. Moreover, a first conductive member 122 is disposed in the first groove 121, and the first conductive member 122 and the end face of the first groove 121 jointly contact the solar cell, further improving the conductive connection performance between the solder strip component and the solar cell. That is, the first connection structure 12 directly serves as the connection point for fixing the solder strip component and the solar cell. There is no need to print the main grid on the surface of the solar cell, saving low-temperature silver paste, which helps to reduce costs and promote the development of main-grid-free solar cells; in addition, in this embodiment, the requirement for the width dimension of the solder strip component itself is relatively low, and the solder strip component can be set to a smaller width dimension, reducing the shielding of the solder strip component to the solar cell.

[0037] Furthermore, in this embodiment, the above-mentioned first groove 121 and the first solder strip body 11 are of an integral structure.

[0038] Specifically, laser drilling is performed at intervals along the length direction on the first solder strip body 11 to form a plurality of initial first grooves 121 with a depth along the radial direction of the first solder strip body 11. At this time, the width of the initial first groove 121 is equal to or slightly larger than the width dimension of the first solder strip body 11. Then, a conductive material is filled into the first groove 121. As the filling progresses step by step, the conductive material gradually expands the initial first groove 121 to form a first groove 121 with a width dimension significantly larger than that of the first solder strip body 11, and a first conductive member 122 filled in the first groove 121. Of course, the first groove 121 can also be directly formed while forming the first solder strip body 11. Integrally forming a plurality of first grooves 121 on the first solder strip body 11 helps to enhance the stability and reliability of the conductive connection between the first groove 121 and the first conductive member 122 and the solar cell.

[0039] The above-mentioned filled conductive material is a thermoplastic conductive adhesive or an ultraviolet conductive adhesive. Therefore, the first conductive member 122 includes a thermoplastic conductive adhesive layer or an ultraviolet conductive adhesive layer.

[0040] In one embodiment, as Figure 2 and Figure 4 shown, one end of the first conductive member 122 close to the notch of the first groove 121 is flush with the notch end face of the first groove 121. That is to say, the conductive material is filled until it is flush with the notch section of the first groove 121, maximizing the contact area between the first conductive member 122 and the battery cell and improving the bonding strength.

[0041] In one embodiment, the first solder strip body 11 is of a cylindrical structure; the first connecting structure 12 includes a cylindrical structure, or a prismatic structure, or a frustum structure, or a truncated pyramid structure; the axial direction of the first connecting structure 12 is perpendicular to the axial direction of the first solder strip body 11.

[0042] As Figures 1 to 4 shown, the first solder strip body 11 of this embodiment adopts a cylindrical structure, and a plurality of first connecting structures 12 are arranged at intervals along the axial direction of the first solder strip body 11, that is, the length direction. However, each first connecting structure 12 has a connecting plane for contacting the battery cell along the axial direction of the first solder strip body 11. The cross-sectional shape of the first connecting structure 12 in the depth direction can be various shapes such as circular, square, and triangular, and it is not limited that the cross-sectional sizes at different depths are the same. As long as the width of the contact surface between the first connecting structure 12 and the battery cell is a connecting plane larger than the width of the first solder strip body 11, the contact area and connection strength between the solder strip member and the battery cell can be effectively increased.

[0043] On the basis of the above solution, in the axial direction of the first connecting structure 12, the thickness dimension of the first connecting structure 12 is greater than or equal to the radial dimension of the first solder strip body 11.

[0044] In this embodiment, during the process of forming the initial first groove 121 by laser drilling and filling the conductive material into the initial first groove 121 to form the first groove 121 and the first conductive member 122, the bottom of the first groove 121 will protrude slightly beyond the outer periphery of the first solder strip body 11. In addition, the filling of the conductive material in the first groove 121 may also be slightly higher than the end face of the first groove 121. Therefore, the thickness dimension of the finally formed first connection structure 12 will be slightly larger than the radial dimension of the first solder strip body 11, ensuring sufficient contact between the end face of the first connection structure 12 of the solder strip member and the battery cell. In this embodiment, a fixture can be set outside the solder strip member during the processes of laser drilling and filling the conductive material to standardize and limit the thickness dimension and width dimension of each first connection structure 12, and finally form a first connection structure 12 with a thickness dimension equal to the radial dimension of the first solder strip body 11, ensuring both sufficient contact between the end face of the first connection structure 12 and the battery cell and the connection stability between the solder strip member and the battery cell.

[0045] As Figure 1 and Figure 4 shown, the first solder strip segment 1 includes a first base material 111 and a first coating layer 112 and a first conductive layer 113 that sequentially coat the first base material 111 along the radial direction of the first base material 111.

[0046] The above-mentioned first base material 111 is made of a copper base material, the first coating layer 112 is a tin-lead coating or a tin-lead-free coating or a tin-silver coating, and the first conductive layer 113 is a thermoplastic conductive material layer, which can specifically be a mixture of metal powder, glass powder, and synthetic resin. The metal powder includes powder materials of various metals such as gold, silver, copper, and aluminum. The surface of the first solder strip body 11 is treated with a thermoplastic conductive material, which can achieve conductive connection at a lower temperature, and can adapt to smaller silicon wafer sizes without high-temperature treatment, resulting in lower silicon wafer costs.

[0047] In one embodiment, as Figure 5 shown, the above-mentioned solder strip member further includes a second solder strip segment 2. The second solder strip segment 2 includes a second solder strip body and a plurality of second connection structures formed on the first solder strip body 11. The plurality of second connection structures are arranged at intervals along the length direction of the second solder strip body; any one of the second connection structures includes a second groove and a second conductive member disposed in the second groove. The notch direction of the second groove is opposite to the notch direction of the first groove 121, and the depth direction of the second groove is perpendicular to the extending direction of the second solder strip body. In a plane perpendicular to the depth direction of the second groove, the width dimension of the second connection structure is greater than the width dimension of the second solder strip body.

[0048] Specifically, the above-mentioned second solder strip segment 2 and the first solder strip segment 1 adopt the same material and structural settings, except that the notch direction of the groove is opposite to that of the first solder strip segment 1 to achieve the end-to-end connection of two adjacent battery cells.

[0049] Further, the above-mentioned solder strip member further includes: a connecting portion 3 connecting the first solder strip segment 1 and the second solder strip segment 2; one end of the notch of the first groove 121 of the first solder strip segment 1 is adapted to contact the light-receiving surface of the battery cell, and one end of the notch of the second groove of the second solder strip segment 2 is adapted to contact the backlight surface of the battery cell.

[0050] A bent connecting portion 3 is provided between the first solder strip segment 1 and the second solder strip segment 2 of the solder strip member to improve the contact stability between the first solder strip segment 1 and the second solder strip segment 2 and the side wall of the battery cell, avoid damage during the connection process between the solder strip member and the battery cell, and improve the service life.

[0051] As Figure 5 shown, this embodiment further provides a battery assembly, including: a plurality of battery cells and the above-mentioned solder strip member, and the solder strip member is connected in series with adjacent battery cells; for any adjacent first battery cell 100 and second battery cell 200, one end of the notch of the first groove 121 of the first solder strip segment 1 of the solder strip member is used to connect with the light-receiving surface of the first battery cell 100.

[0052] Specifically, between adjacent battery cells in the battery assembly, stable electrical connection is achieved with the battery cell through the first connection structure 12 of the first solder strip segment 1. The contact area between the solder strip member and the battery cell increases, and the bonding strength increases; moreover, the width dimension of the solder strip member can be made smaller, which helps to reduce the shielding of the battery cell by the solder strip member, reduce the usage amount of low-temperature silver paste, and thus reduce the cost.

[0053] Further, in the above-mentioned battery assembly, the solder strip member further includes a second solder strip segment 2 and a connecting portion 3 connecting the first solder strip segment 1 and the second solder strip segment 2; the second solder strip segment 2 includes a second solder strip main body and a plurality of second connection structures formed on the second solder strip main body, and the plurality of second connection structures are arranged at intervals along the length direction of the second solder strip main body; any one of the second connection structures includes a second groove and a second conductive member disposed in the second groove, the notch direction of the second groove is opposite to the notch direction of the first groove 121, and one end of the notch of the second groove of the second solder strip segment 2 is used to connect with the backlight surface of the second battery cell 200.

[0054] As Figure 5As shown, the lower surface of the first solder strip segment 1 of the solder strip part is the notch side of the first groove 121, the lower surface of the first solder strip segment 1 contacts the upper surface of the first solar cell 100, and the upper surface of the first solar cell 100 is the light-receiving surface; the upper surface of the second solder strip segment 2 of the solder strip part is the notch side of the second groove, the upper surface of the second solder strip segment 2 contacts the lower surface of the second solar cell 200, and the lower surface of the second solar cell 200 is the backlight surface; the connecting part 3 of the solder strip part is bent, and both sides respectively abut against the side surfaces of the first solar cell 100 and the second solar cell 200, improving the connection stability between the solder strip part and the solar cells. The further function descriptions of the above-mentioned respective modules are the same as those in the corresponding embodiments above, and will not be elaborated here.

[0055] Although the 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 welding strip, suitable for connecting adjacent battery cells in series, characterized in that: include: A first welding tape segment, wherein the first welding tape segment comprises a first welding tape body and a plurality of first connecting structures formed on the first welding tape body, wherein the plurality of first connecting structures are arranged at intervals along the length direction of the first welding tape body; any of the first connecting structures comprises a first groove and a first conductive member arranged in the first groove, wherein the depth direction of the first groove is perpendicular to the extension direction of the first welding tape body, and on a plane perpendicular to the depth direction of the first groove, the width dimension of the first connecting structure is greater than the width dimension of the first welding tape body.

2. The welding strip according to claim 1, characterized in that: The first groove and the first welding strip body are an integral structure.

3. The welding strip according to claim 1, characterized in that: One end of the first conductive member close to the notch of the first groove is flush with the end surface of the notch of the first groove.

4. The welding strip according to claim 1, characterized in that: The first welding strip body is a cylindrical structure; the first connecting structure includes a cylindrical structure, a prismatic structure, a truncated cone structure, or a prism structure; the axial direction of the first connecting structure is perpendicular to the axial direction of the first welding strip body.

5. The welding strip member according to claim 4, characterized in that: In the axial direction of the first connecting structure, the thickness dimension of the first connecting structure is greater than or equal to the radial dimension of the first welding strip body.

6. The welding strip member according to claim 1, characterized in that: The first welding strip segment includes a first substrate and a first coating layer and a first conductive layer radially sequentially covering the first substrate.

7. The welding strip according to any one of claims 1 to 6, characterized in that: Also includes: A second welding tape segment, wherein the second welding tape segment includes a second welding tape body and a plurality of second connecting structures formed on the second welding tape body, wherein the plurality of second connecting structures are arranged at intervals along the length direction of the second welding tape body; any second connecting structure includes a second groove and a second conductive member arranged in the second groove, wherein the notch direction of the second groove is opposite to the notch direction of the first groove, the depth direction of the second groove is perpendicular to the extension direction of the second welding tape body, and on a plane perpendicular to the depth direction of the second groove, the width dimension of the second connecting structure is greater than the width dimension of the second welding tape body.

8. The welding strip member according to claim 7, characterized in that: Also includes: A connecting portion connecting the first welding strip segment and the second welding strip segment; one end of the notch of the first groove of the first welding strip segment is suitable for contacting the light-receiving surface of the battery cell, and one end of the notch of the second groove of the second welding strip segment is suitable for contacting the backlight surface of the battery cell.

9. A battery assembly, characterized in that: include: Multiple battery cells; The welding strip member according to any one of claims 1 to 8, wherein the welding strip member connects adjacent battery cells in series; For any adjacent first battery cell and second battery cell, one end of the notch of the first groove of the first welding strip segment is used to be connected to the light-receiving surface of the first battery cell.

10. The battery assembly according to claim 9, characterized in that: The welding strip member includes a second welding strip segment and a connecting portion connecting the first welding strip segment and the second welding strip segment; The second welding tape segment includes a second welding tape body and a plurality of second connection structures formed on the second welding tape body, wherein the plurality of second connection structures are arranged at intervals along the length direction of the second welding tape body; any second connection structure includes a second groove and a second conductive member arranged in the second groove, wherein the notch direction of the second groove is opposite to the notch direction of the first groove, and a notch section of the second groove of the second welding tape segment is used to be connected to the backlight surface of the second battery cell.

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