Battery piece and photovoltaic module

Abstract

The utility model provides a battery piece and a photovoltaic assembly, and the battery piece comprises a battery body which is provided with a first edge extending along a first direction and a second edge extending along a second direction orthogonal to the first direction; the plurality of first electrodes are arranged on two opposite surfaces of the battery body, and the plurality of first electrodes extend along a first direction and are arranged at equal intervals along a second direction; a plurality of groups of first bonding pads, wherein the plurality of first bonding pads in the same group are arranged at equal intervals along the second direction; wherein the number of the first electrodes on at least one surface of the battery body is an odd number, so that a part of the first electrodes pass through the center lines of the first bonding pads on the same surface. The photovoltaic module comprises a battery piece layer which comprises a plurality of battery pieces which are arranged along rows and / or columns; and the sealing layer is laminated on the surface of the battery piece layer.

Description

Technical Field

[0001] At least one embodiment of the utility model relates to the field of photovoltaic technology, and in particular to a battery cell and a photovoltaic module. Background Art

[0002] The cells in photovoltaic modules mostly adopt a multi-busbar electrode pattern design, and a sub-grid is arranged between the main grids and arranged orthogonally to the main grids to collect the internal current of the battery body and then conduct the current collected on the main grids to the outside.

[0003] Configuring a cell with multiple busbars can effectively increase the current conduction efficiency, but configuring too many busbars will increase the shading area of ​​the busbars relative to the cell body, thereby affecting the effective area ratio of the cell and increasing the consumption of the slurry for printing the busbars.

[0004] In order to further increase the current conduction efficiency, a denser sub-grid is configured on the basis of maintaining the number of main grids to achieve a better current collection effect. In the electrode pattern design of heterojunction cells (i.e. HIT cells), since the number of sub-grids accounts for the largest proportion of the area of ​​the cell and the number is the largest, the impact on efficiency and slurry consumption is the greatest. On the basis of denser sub-grids, the width of the sub-grid is required to be narrower. In order to maintain the reliability requirements of the cell and the photovoltaic module formed by the cell, in the design of the electrode pattern for printing the main grid and / or sub-grid, it is necessary to take into account the better current collection effect, the contact characteristics of the slurry and the film layer used, and other design requirements.

[0005] At present, the number of secondary grids of mainstream heterojunction cells is mostly set to an even number. The electrode pattern design based on the even number of secondary grids often makes it impossible for a part of the secondary grid to connect to the center of the pad, which leads to a longer connection path and increased resistance loss. Therefore, how to provide a cell and photovoltaic module with both good current conduction efficiency and high reliability has become a technical problem that needs to be solved urgently. Utility Model Content

[0006] In order to solve at least one of the above and other technical problems in the prior art, the utility model provides a solar cell and a photovoltaic module with better current conduction efficiency and higher reliability.

[0007] An embodiment of the utility model provides a battery cell, comprising: a battery body, having a first side extending along a first direction and a second side extending along a second direction orthogonal to the first direction; a plurality of first electrodes, arranged on two opposite surfaces of the battery body, the plurality of first electrodes extending along the first direction and arranged at equal intervals along the second direction; a plurality of groups of first welding pads, the plurality of first welding pads in the same group being arranged at equal intervals along the second direction; wherein the first electrodes on at least one surface of the battery body are configured as an odd number so that a portion of the first electrodes pass through the center line of the first welding pads located on the same surface.

[0008] In an illustrative embodiment, the first pads in the same group are configured as an odd number; the first electrode disposed in the middle of the battery body passes through a center line of the first pad located near the middle of the battery body.

[0009] In an illustrative embodiment, the first pads in the same group are configured as an even number; the first electrode disposed in the middle of the battery body passes through the midpoint of a line formed by two adjacent first pads located near the middle of the battery body.

[0010] In an illustrative embodiment, the first soldering pad partially overlapping with the first electrode includes a soldering portion suitable for connecting to a soldering strip, and an extension portion protruding from an end of the soldering portion facing the first electrode, wherein the width of the extension portion is configured to be greater than the width of the first electrode; wherein the first electrode passes through the extension portions located on both sides of the soldering portion.

[0011] In an illustrative embodiment, the first electrode passes through a center line of the extension portion.

[0012] In an exemplary embodiment, a width of a first end of the extending portion away from the welding portion is smaller than a width of a second end of the extending portion close to the welding portion.

[0013] In an illustrative embodiment, the battery cell also includes a plurality of second electrodes, which are arranged on two opposite surfaces of the battery body, and the plurality of second electrodes extend along the second direction and are arranged at equal intervals along the first direction; wherein each of the second electrodes passes through the plurality of first pads in the same group.

[0014] In an illustrative embodiment, the battery cell further includes a second pad disposed at an end portion of the second electrode close to an edge of the battery body.

[0015] In an illustrative embodiment, in an orthographic projection along the thickness direction of the battery body, centers of the first welding pads located on two surfaces of the battery body overlap.

[0016] In an illustrative embodiment, in an orthographic projection along the thickness direction of the battery body, centers of at least a portion of the first welding pads located on two surfaces of the battery body are offset.

[0017] The embodiment of the utility model further provides a photovoltaic module, comprising: a cell layer, comprising a plurality of cells, wherein the plurality of cells are arranged along rows and / or columns; and a sealing layer laminated on the surface of the cell layer.

[0018] According to the cell and photovoltaic module provided by the utility model, the uniformly arranged first pads cooperate with the first electrodes configured as an odd number, so that a part of the first electrodes are arranged along the center line of the first pads and connected to the first pads, so that the current collected by the first electrodes can be evenly distributed to the first pads. Since the sizes of the first pads on both sides of the first electrode are roughly the same, the length of the connection path can also be minimized to shorten the resistance loss of the photocarriers on the first electrode 21, which is conducive to avoiding the occurrence of local electroluminescence darkening. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a battery cell according to an exemplary embodiment of the present utility model from a formal perspective;

[0020] Figure 2 yes Figure 1 A partial enlarged view of part A of the exemplary embodiment shown, showing the main grid and the auxiliary grid;

[0021] Figure 3 yes Figure 1 a partial enlarged view of portion B of the illustrated exemplary embodiment showing a first pad; and

[0022] Figure 4 yes Figure 1 The partially enlarged view of portion C of the exemplary embodiment shown shows the second pad.

[0023] In the drawings, the meanings of the reference numerals are as follows:

[0024] 1. The first pad;

[0025] 11. Welding part;

[0026] 12. Extension;

[0027] 2. Electrode;

[0028] 21. a first electrode;

[0029] 22. a second electrode;

[0030] 3. Battery body;

[0031] 4. a second pad; and

[0032] 5. Harpoon unit. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0034] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "include", "comprises", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0035] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0036] When using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, and C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc. When using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, or C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.

[0037] Figure 1 It is a schematic diagram of a battery cell according to an exemplary embodiment of the present utility model from a formal perspective. Figure 2 yes Figure 1 The partial enlarged view of part A of the exemplary embodiment shown shows the main grid and the auxiliary grid.

[0038] According to the battery cell provided by the utility model, Figure 1 and Figure 2As shown, it includes a battery body 3, a first electrode 21 and a plurality of groups of first pads 1. The battery body 3 has a first side extending along a first direction and a second side extending along a second direction orthogonal to the first direction. A plurality of first electrodes 21 are arranged on two opposite surfaces of the battery body 3. A plurality of first electrodes 21 extend along the first direction and are arranged at equal intervals along the second direction. A plurality of first pads 1 in the same group are arranged at equal intervals along the second direction. Among them, the first electrodes 21 on at least one surface of the battery body 3 are configured as an odd number so that a portion of the first electrodes 21 pass through the center line of the first pads 1 located on the same surface.

[0039] According to the embodiments of the present utility model, Figure 1 As shown, the battery cell also includes a plurality of second electrodes 22. The second electrodes 22 are arranged on two opposite surfaces of the battery body 3, and the plurality of second electrodes 22 extend along the second direction and are arranged at equal intervals along the first direction. Each second electrode 22 passes through a plurality of first pads 1 of the same group.

[0040] In an exemplary embodiment, the battery cell includes a battery body 3 and electrodes 2 formed on opposite surfaces of the battery body 3. In detail, the first electrode 21 (i.e., the secondary grid) in the electrode 2 is suitable for collecting the internal current of the battery body, and the second electrode 22 in the electrode 2 is suitable for conducting the collected current to the outside of the battery cell. In an exemplary embodiment, as Figure 1 As shown, the battery body 3 includes but is not limited to a heterojunction battery (i.e., a HIT battery) having a thickness direction (i.e., Figure 1 The first surface (as shown in the direction facing the paper) is away from Figure 1 In detail, the first surface and the second surface of the battery body 3 are both provided with electrodes 2. The electrodes 2 on the first surface and the second surface have the same number of main grids, and each second electrode 22 (i.e., main grid) is provided with the same number of first pads 1.

[0041] In such an embodiment, the uniformly arranged first pads 1 cooperate with the first electrodes 21 configured as an odd number, so that a portion of the first electrodes 21 are arranged along the center line of the first pads 1 and connected to the first pads 1, so that the current collected by the first electrodes 21 can be evenly distributed to the first pads 1. Since the sizes of the first pads 1 located on both sides of the first electrode 21 are substantially the same, the length of the connection path can also be minimized to shorten the resistance loss of the photocarriers on the first electrode 21, which is conducive to avoiding the occurrence of local electroluminescence darkening.

[0042] In an illustrative embodiment, Figure 1As shown, the battery body 3 includes but is not limited to being formed by two slices of a rectangular silicon wafer. In detail, the size of the battery body 3 is but is not limited to being configured to be 182.2 mm×95.8 mm, wherein the battery body 3 has a longer first side and a shorter second side. Further, a plurality of second electrodes 22 (i.e., main grids) are arranged along a first direction (e.g., Figure 1 In addition, each second electrode 22 (i.e., main grid) is arranged in an evenly spaced manner along the second direction of the battery body (i.e., Figure 1 A plurality of first pads 1 are arranged at equal intervals (in the left-right direction as shown), that is, the intervals between two adjacent first pads 1 are the same.

[0043] In an illustrative embodiment, 18 second electrodes 22 (i.e., main grids) are disposed on the front and back of the battery body 3. Further, the front of the battery body 3 includes but is not limited to 49 first electrodes 21 (i.e., auxiliary grids), and the back of the battery body 3 includes but is not limited to 105 first electrodes 21 (i.e., auxiliary grids). Furthermore, the spacing between two adjacent first electrodes 21 (i.e., auxiliary grids) located on the front of the battery body 3 includes but is not limited to being configured as 1.96 mm, and the spacing between two adjacent first electrodes 21 (i.e., auxiliary grids) located on the back of the battery body 3 includes but is not limited to being configured as 0.91 mm.

[0044] According to an embodiment of the present utility model, which is not shown in the figure, in the orthographic projection along the thickness direction of the battery body 3, the centers of the first welding pads 1 located on the two surfaces of the battery body 3 coincide with each other.

[0045] In an illustrative embodiment, Figure 2 As shown, the first pads 1 located on the first surface and the second surface are equally spaced along the second direction of the battery body 3 (such as Figure 2 Furthermore, in the orthographic projection along the thickness direction of the battery body 3, the first pads 1 on the first surface and the second surface at least partially overlap, wherein the first pads 1 of the same shape and size completely overlap, and the first pads 1 of different shapes / or sizes at least overlap in the center. Furthermore, the number of first electrodes 21 (i.e., auxiliary grids) disposed on the first surface may be different from the number of first electrodes 21 (i.e., auxiliary grids) disposed on the second surface, and adjacent first electrodes 21 (i.e., auxiliary grids) have different spacings.

[0046] For example, the number of first electrodes 21 (i.e., auxiliary grids) arranged on the first surface (e.g., the front surface) of the battery body 3 is less than the number of first electrodes 21 (i.e., auxiliary grids) arranged on the second surface (e.g., the back surface) of the battery body 3, wherein the center spacing between adjacent first electrodes 21 (i.e., auxiliary grids) arranged on the first surface includes but is not limited to being configured as 1mm to 2.5mm; the center spacing between adjacent first electrodes 21 (i.e., auxiliary grids) arranged on the second surface includes but is not limited to being configured as 0.7mm to 1.8mm.

[0047] In such an embodiment, the first pads 1 located on the first surface and the second surface of the battery body 3 are evenly distributed, which can better distribute the internal stress of the battery body 3. In addition, they overlap in the thickness direction of the battery body 3, which is beneficial to compact the welding when welding the first pads 1 to the welding strip, and reduce the occurrence of desoldering.

[0048] According to another embodiment of the present invention, which is not shown in the figure, in the orthographic projection along the thickness direction of the battery body 3, the centers of at least a portion of the first pads 1 located on two surfaces of the battery body 3 are misaligned.

[0049] In an illustrative embodiment, the first pads 1 on the first surface and the second surface are arranged at equal intervals along the second direction of the battery body 3. Further, in the orthographic projection along the thickness direction of the battery body 3, the first pads 1 on the first surface and the second surface are staggered along the extension direction of the second electrode 22 (i.e., the main grid).

[0050] For example, the edges of the first pads 1 on the first surface and the second surface overlap.

[0051] For another example, the first pads 1 on the first surface and the second surface are completely misaligned.

[0052] In another exemplary embodiment, the first pads 11 on the first surface are arranged at equal intervals along the second direction of the battery body 3. Furthermore, the first pads 11 on the second surface are arranged at variable intervals along the second direction of the battery body 3.

[0053] For example, the first pads 1 located near the middle of the first and second surfaces at least partially overlap, and the first pads 1 located near the edges of the first and second surfaces are staggered along the extension direction of the second electrode 22 (ie, the main grid).

[0054] In such an embodiment, the first pad 1 is suitable for connecting the second electrode 22 (i.e., the main grid) to the welding strip to conduct the current collected by the first electrode 21 (i.e., the auxiliary grid). The first pads 1 located on the first surface and the second surface that overlap each other may cause tin accumulation during welding. The molten tin with a large area and a thick thickness may be crushed or form hidden cracks (especially at the edge of the battery body 3) due to the squeezing force during the subsequent lamination process.

[0055] To this end, the first pads 1 on only one surface of the battery body 3 may be arranged equidistantly, and the first electrodes 21 (i.e., the auxiliary grids) may be arranged in odd numbers according to the positions of the first pads 1 to better collect current; while the first pads 1 on the other surface of the battery body 1 may be arranged non-equidistantly, so that the first pads 1 on the two surfaces are staggered in the orthographic projection in the thickness direction of the battery body 3 to further disperse the stress on the edge of the battery body 3.

[0056] According to the embodiments of the present utility model, Figure 1 and Figure 2 As shown, the first pads 1 in the same group are configured in odd numbers. The first electrode 21 disposed in the middle of the battery body 3 passes through the center line of the first pad 1 located near the middle of the battery body 3 .

[0057] In an exemplary implementation, Figure 1 As shown, the first electrode 2 disposed in the middle of the battery body 3 is located on the center line of the battery body 3. The center line of the battery body 3 is defined as being parallel to the long side of the battery body 3 and dividing the battery body 3 into two equal parts.

[0058] In an illustrative embodiment, Figure 1 and Figure 2 As shown, a first electrode 21 (i.e., auxiliary grid) disposed in the middle of the battery body 3 can be configured to coincide with the center line of the second side of the battery body 3. Further, one of the odd number of first pads 1 on the second electrode 22 (i.e., main grid) is located on the first electrode 21 (i.e., auxiliary grid), and the other first pads 1 are symmetrically disposed on both sides of the first electrode 21 (i.e., auxiliary grid).

[0059] According to an embodiment of the present invention, not shown in the figure, the first pads 1 in the same group are configured as an even number. The first electrode 21 disposed in the middle of the battery body 3 passes through the midpoint of the line formed by two adjacent first pads 1 located near the middle of the battery body 3.

[0060] In an exemplary implementation, Figure 1As shown, the midpoint of the line connecting the two first electrodes 2 disposed in the middle of the battery body 3 is located on the center line of the battery body 3. The center line of the battery body 3 is defined as being parallel to the long side of the battery body 3 and dividing the battery body 3 into two equal parts.

[0061] In an illustrative embodiment, Figure 1 and Figure 2 As shown, a first electrode 21 (i.e., auxiliary grid) disposed in the middle of the battery body 3 can be configured to coincide with the center line of the second side of the battery body 3. Further, an even number of first pads 1 on the second electrode 22 (i.e., main grid) are symmetrically disposed on both sides of the first electrode 21 (i.e., auxiliary grid). It should be understood that the embodiments of the present disclosure are not limited thereto.

[0062] For example, the first electrode 21 (i.e., the auxiliary grid) disposed in the middle of the battery body 3 may only be close to the center line of the second side of the battery body 3, but not coincide with the center line of the second side. The first pad 1 is symmetrically disposed on the battery body 3 with the first electrode 21 (i.e., the auxiliary grid) as the center line.

[0063] In such an embodiment, the first pad 1 symmetrically designed with the first electrode 21 (i.e., the auxiliary grid) located in the middle of the battery body 3 as the center line can adjust the position distribution of the first pad 1 when the number of pads and / or the pad size are fixed, so that there is a larger design window in the electrode pattern design of the second electrode 22 (i.e., the main grid) and the first pad 1 and / or the first electrode 21 (i.e., the auxiliary grid). This can improve the efficiency of the design and is conducive to improving the yield rate of the battery cell and the photovoltaic module during the printing process.

[0064] Figure 3 yes Figure 1 The illustrated partial enlarged view of portion B of the exemplary embodiment shows the first pad.

[0065] According to the embodiments of the present utility model, Figure 3 As shown, the first pad 1 partially overlapped with the first electrode 21 includes a welding portion 11 suitable for connecting with the welding strip, and an extension portion 12 protruding from the end of the welding portion 11 facing the first electrode 21, and the width of the extension portion 12 is configured to be greater than the width of the first electrode 21. The first electrode 21 passes through the extension portions 12 located on both sides of the welding portion 11.

[0066] According to the embodiments of the present utility model, Figure 3 As shown, the first electrode 21 (ie, the auxiliary grid) passes through the center line of the extension portion 12 .

[0067] According to the embodiments of the present utility model, Figure 3As shown, the width of the first end of the extending portion 12 away from the welding portion 11 is smaller than the width of the second end of the extending portion 12 close to the welding portion 11 .

[0068] In an illustrative embodiment, Figure 3 As shown, the welding portion 11 of the first pad 1 includes but is not limited to being configured in any one of a rectangular, chamfered rectangular, circular, elliptical, and racetrack shapes. In detail, the two ends (such as Figure 3 The left and right ends of the extension 12 are symmetrically provided. Further, the width of the narrowest position of the extension 12 (as shown in FIG. Figure 3 The spacing between the upper side and the lower side as shown includes but is not limited to being configured to be two to three times the width of the first electrode 21 (ie, the auxiliary grid).

[0069] In an illustrative embodiment, Figure 3 As shown, the extension portion 12 includes but is not limited to being configured in a trapezoidal shape. In detail, the second end of the extension portion 12 is integrally connected to the welding portion 11, and the first end of the extension portion 12 protrudes outward in a direction parallel to the first electrode 21 (i.e., the secondary grid). Among them, the first pad 1 (including the welding portion 11 and the extension portion 12) and the second electrode 22 (i.e., the main grid) include but are not limited to being integrally printed on the battery body 3.

[0070] When the first pad 1 only equipped with the welding portion 11 is welded to the welding strip, the molten solder will fuse with the slurry of the printed first electrode 21 (i.e., the auxiliary grid), causing the first electrode 21 (i.e., the auxiliary grid) with a relatively thin width to be melted, thereby forming a welding broken grid. In such an embodiment, the width of the overlapping position of the first pad 1 and the first electrode 21 (i.e., the auxiliary grid) can be increased by configuring the extension portion 12 on both sides of the welding portion 11, which is beneficial to prevent the molten solder from fusing with the first electrode 21 (i.e., the auxiliary grid) and preventing the first electrode 21 (i.e., the auxiliary grid) from being melted. Therefore, the formation of welding broken grids can be effectively reduced.

[0071] Figure 4 yes Figure 1 The partially enlarged view of portion C of the exemplary embodiment shown shows the second pad.

[0072] According to the embodiments of the present utility model, Figure 4 As shown, the battery cell also includes a plurality of second electrodes 22 disposed on two opposite surfaces of the battery body 3, the plurality of second electrodes 22 extending along the second direction and being arranged at equal intervals along the first direction. Each second electrode 22 passes through a plurality of first pads 1 of the same group.

[0073] According to the embodiments of the present utility model, Figure 4As shown, the battery cell further includes a second pad 4 disposed at an end of the second electrode 22 close to an edge of the battery body 3 .

[0074] In an illustrative embodiment, the spacing between the second pad 4 and the adjacent first pad 1 is configured to be different from (e.g., greater than or less than) the spacing between two adjacent first pads 1. Further, the spacing between the second pad 4 and the edge of the battery body 3 is configured to be different from the spacing between two adjacent first pads 1. It should be understood that the embodiments of the present utility model are not limited thereto.

[0075] For example, the distance between the second pad 4 and the adjacent first pad 1 is configured to be the same as the distance between two adjacent first pads 1 .

[0076] For another example, the spacing between the second pad 4 and the edge of the battery body 3 is constructed to be the same as the spacing between two adjacent first pads 1, specifically to meet the overall design of the battery cell and / or the weldability requirements of the first pad 1 and the second pad 4.

[0077] In an illustrative embodiment, Figure 4 As shown, the size of the second pad 4 includes but is not limited to being configured to be larger than the first pad 1. In detail, three first pads 1 are configured between two second pads 4 of the same second electrode 22 (ie, main grid).

[0078] Furthermore, the second pad 4 is also connected to the harpoon portion 5. The harpoon portion 5 includes but is not limited to being configured as a rectangular structure with an opening at one side.

[0079] In such an embodiment, the harpoon portion 5 configured by the second pad 4 is suitable for collecting the edge current of the battery body 3, and when welding with the welding strip through the second pad 4, cold welding is not likely to occur.

[0080] Based on the same inventive concept as the cell, the utility model also provides a photovoltaic module, comprising: a plurality of cells arranged in rows and / or columns; a laminate laminated on the front and back of the cell; and a frame arranged at the edge of the laminate extending from the cell.

[0081] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only for reference to the drawings and are not intended to limit the scope of protection of the present invention. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted when they may cause confusion in the understanding of the present invention.

[0082] The embodiments of the present invention are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present invention is defined by the attached claims and their equivalents. Without departing from the scope of the present invention, a person skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A battery cell, characterized in that: include: A battery body (3) having a first side extending along a first direction and a second side extending along a second direction orthogonal to the first direction; A plurality of first electrodes (21) are arranged on two opposite surfaces of the battery body (3), the plurality of first electrodes (21) extending along the first direction and being arranged at equal intervals along the second direction; A plurality of groups of first solder pads (1), wherein a plurality of the first solder pads (1) in the same group are arranged at equal intervals along the second direction; The first electrodes (21) on at least one surface of the battery body (3) are configured as an odd number so that a portion of the first electrodes (21) pass through the center line of the first pad (1) located on the same surface.

2. The battery cell according to claim 1, characterized in that: The first pads (1) in the same group are configured as an odd number; The first electrode (21) disposed in the middle of the battery body (3) passes through the center line of the first welding pad (1) located near the middle of the battery body (3).

3. The battery cell according to claim 1, characterized in that: The first pads (1) in the same group are configured as an even number; The first electrode (21) disposed in the middle of the battery body (3) passes through the midpoint of a line formed by two adjacent first welding pads (1) located near the middle of the battery body (3).

4. The battery cell according to any one of claims 1 to 3, characterized in that: The first pad (1) partially overlapped with the first electrode (21) comprises a welding portion (11) suitable for connecting to a welding strip, and an extension portion (12) protruding from an end of the welding portion (11) facing the first electrode (21), wherein the width of the extension portion (12) is configured to be greater than the width of the first electrode (21); Wherein, the first electrode (21) passes through the extension portion (12) located on both sides of the welding portion (11).

5. The battery cell according to claim 4, characterized in that: The first electrode (21) passes through the center line of the extension portion (12).

6. The battery cell according to claim 4, characterized in that: The width of a first end of the extending portion (12) away from the welding portion (11) is smaller than the width of a second end of the extending portion (12) close to the welding portion (11).

7. The battery cell according to any one of claims 1 to 3, characterized in that: It also includes a plurality of second electrodes (22) disposed on two surfaces of the battery body (3) that are opposite to each other, wherein the plurality of second electrodes (22) extend along the second direction and are arranged at equal intervals along the first direction; Each of the second electrodes (22) passes through a plurality of the first pads (1) in the same group.

8. The battery cell according to claim 7, characterized in that: It also includes a second welding pad (4) which is arranged at the end of the second electrode (22) close to the edge of the battery body (3).

9. The battery cell according to any one of claims 1 to 3, characterized in that: In an orthographic projection along the thickness direction of the battery body (3), the centers of the first welding pads (1) located on two surfaces of the battery body (3) coincide with each other.

10. The battery cell according to any one of claims 1 to 3, characterized in that: In an orthographic projection along the thickness direction of the battery body (3), the centers of at least a portion of the first welding pads (1) located on two surfaces of the battery body (3) are offset.

11. A photovoltaic module, characterized in that: include: A battery cell layer, comprising a plurality of battery cells as claimed in any one of claims 1 to 9, wherein the plurality of battery cells are arranged in rows and / or columns; as well as The sealing layer is laminated on the surface of the battery sheet layer.

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