Solar Cells and Photovoltaic Modules

Abstract

In the field of photovoltaics, the company provides solar cells and photovoltaic modules. [Solution] The solar cell comprises a base, a plurality of thin grids arranged at intervals along a first direction, a plurality of groups of spot welds arranged along a second direction, and a plurality of main grids arranged along the second direction, the base includes a central region and peripheral regions located on both sides of the central region, the plurality of thin grids extend along the second direction, the spot weld groups include a plurality of spot welds, the plurality of spot welds are arranged along the first direction, the number of spot welds located in the central region of one spot weld group is equal to the number of thin grids located in the central region, the spot welds located in the central region are connected one-to-one to the thin grids, the main grids are connected to the spot weld groups, and at least one spot weld group is arranged at an interval between two adjacent main grids.

Description

[Technical Field]

[0001] TECHNICAL FIELD Embodiments of the present disclosure relate to the field of photovoltaics, and more particularly to solar cells and photovoltaic modules. [Background technology]

[0002] While fossil energy pollutes the atmosphere and has limited reserves, solar energy has the advantages of being clean, pollution-free, and abundant in resources, so solar energy is replacing fossil energy as the core clean energy. Solar cells, with their good photoelectric conversion efficiency, have become the most important part of clean energy utilization.

[0003] Solar cell modules are one of the key components of solar power generation devices. Sunlight irradiates the battery cells from the front side. Each battery cell includes a battery cell substrate and main and sub-grid lines on the front side of the battery cell substrate. The main and sub-grid lines cover part of the front side of the battery cell substrate. To save slurry, solar cells without a main grid were developed. Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present disclosure provide solar cells and photovoltaic modules that can at least conserve slurry and facilitate testing of the solar cells. [Means for solving the problem]

[0005] According to some embodiments of the present disclosure, in one aspect of the embodiments of the present disclosure, a solar cell is disclosed, the solar cell comprising: a base; a plurality of thin grids arranged at intervals along a first direction; a plurality of groups of spot welds arranged along a second direction; and a plurality of main grids arranged along the second direction, wherein the base includes a central region and peripheral regions located on both sides of the central region, the plurality of thin grids extend along the second direction, the group of spot welds includes a plurality of spot welds, the plurality of spot welds are arranged along the first direction, the number of spot welds located in the central region of one group of spot welds is equal to the number of thin grids located in the central region, and the spot welds located in the central region are connected in a one-to-one correspondence with the thin grids, the main grid is connected to the group of spot welds, and at least one group of spot welds is arranged at a distance between two adjacent main grids.

[0006] In some embodiments, there is at least one spot weld group spaced between any two adjacent main grids.

[0007] In some embodiments, one spot weld group is spaced between some two adjacent main grids, and multiple spot weld groups are spaced between some two adjacent main grids.

[0008] In some embodiments, the main grid includes a first main grid and a second main grid, wherein one of the first main grids is connected to all of the spot welds in one of the group of spot welds, and one of the second main grids is connected to some of the spot welds in one of the group of spot welds.

[0009] In some embodiments, at least one of the spot welds is spaced apart between adjacent first and second main grids.

[0010] In some embodiments, the width of the first main grid in the second direction is greater than the width of the second main grid in the second direction.

[0011] In some embodiments, the base includes opposing front and back surfaces, the thin grid, the spot weld group, and the main grid are respectively provided on the front and back surfaces, and the front projection of the main grid located at least partially on the front surface on the front surface intersects with the front projection of the main grid located on the back surface on the front surface.

[0012] In some embodiments, the base includes opposing front and back surfaces, the thin grid, the spot weld group, and the main grid are provided on the front surface, and the thin grid and the spot weld group are provided on the back surface.

[0013] In some embodiments, the number of the spot weld group is N, and the number of the main grid is n, where N / 4 ≦ n < N, and both n and N are positive integers.

[0014] In some embodiments, the number of the spot weld group is 15 to 22.

[0015] In some embodiments, the number of the main grid is 4 to 11.

[0016] In some embodiments, in the direction from the peripheral region to the central region, the area of the front projection of the spot weld closest to the peripheral region of the central region on the base is larger than the area of the front projection of the spot weld farthest from the peripheral region of the central region on the base.

[0017] In some embodiments, the base includes a front surface and a back surface, and the plurality of thin grids may further include a plurality of first thin grids arranged at intervals along a first direction and a plurality of second thin grids arranged at intervals along the first direction, the plurality of first thin grids extending along a second direction, the first thin grids being located on the front surface, and the number of the first thin grids being 70 to 150, the plurality of second thin grids extending along the second direction Y being located on the back surface, and the number of the second thin grids being 80 to 400, the plurality of spot weld groups including a plurality of first spot weld groups arranged along the second direction, the first spot weld groups being located on the front surface, each first spot weld group including a plurality of first spot welds, the plurality of first spot welds being arranged along the first direction, and one first spot weld connected to one first thin grid.

[0018] In some embodiments, the width of the first thin grid is between 10 and 30 μm and / or the width of the second thin grid is between 15 and 50 μm.

[0019] In some embodiments, the height of the first thin grid is between 6 and 30 μm and / or the height of the second thin grid is between 4 and 25 μm.

[0020] In some embodiments, the number of the first group of spot welds is between 12 and 26.

[0021] In some embodiments, the laser device further includes a plurality of first main grids arranged along a second direction, the first main grids being located on the front surface, the first main grids being connected to the first group of spot welds, and at least one of the first group of spot welds being spaced apart between two adjacent first main grids.

[0022] In some embodiments, the substrate further includes a plurality of second spot weld groups arranged along the second direction and a plurality of second main grids arranged along the second direction, wherein the second spot weld groups are located on the back surface, each of the second spot weld groups includes a plurality of second spot welds, the plurality of second spot welds are arranged along the first direction, one second spot weld is connected to one of the second thin grids, and an orthogonal projection of the first spot weld group on the front surface is offset from an orthogonal projection of the second spot weld group on the front surface, and the second main grid is located on the back surface, the second main grid is connected to the second spot weld group, and an orthogonal projection of the first main grid on the front surface is offset from an orthogonal projection of the second main grid on the front surface.

[0023] According to some embodiments of the present disclosure, in another aspect of the embodiments of the present disclosure, a photovoltaic module is provided, the photovoltaic module including a cell string, and the cell string includes solar cells connected in series, the solar cells including a base, a plurality of thin grids arranged at intervals along a first direction, a plurality of groups of spot welds arranged along a second direction, a plurality of main grids arranged along the second direction, and a PV relay, wherein the base includes a central region and peripheral regions located on both sides of the central region, the plurality of thin grids extend along the second direction, and the groups of spot welds include a plurality of spot welds. the spot welds are arranged along the first direction, the number of spot welds located in the central region of one of the spot weld groups is equal to the number of thin grids located in the central region, and the spot welds located in the central region are connected to the thin grids in a one-to-one correspondence, the main grid is connected to the spot weld groups, and at least one spot weld group is disposed at an interval between two adjacent main grids, the PV re-horns connect two adjacent solar cells, and each PV re-horn is connected to a corresponding one of the spot weld groups of the solar cell.

[0024] In some embodiments, the solar cells in the cell string are arranged along the first direction, and the main grids of two adjacent solar cells in the cell string are arranged intersecting in the second direction. [Effects of the Invention]

[0025] The technical solutions provided in the embodiments of the present disclosure have at least the following advantages:

[0026] By providing multiple spot weld groups, each of which includes multiple spot welds, the main grid and the fine grid can be connected by the spot welds when connecting them, thereby improving the reliability of the connection between the main grid and the fine grid. Furthermore, by arranging the number of spot welds located in the central region of the spot weld group equal to the number of fine grids located in the central region and connecting the spot welds located in the central region one-to-one with the fine grids, the reliability of the connection between the main grid and each fine grid can be improved when each fine grid is connected to the main grid. Meanwhile, compared to the conventional technical solution in which at least one spot weld group is spaced between two main grids, i.e., none of the spot weld groups are connected to the main grid, at least one spot weld group is not connected to the main grid, and each spot weld group is connected to the main grid, this technical solution can reduce the number of main grids. Compared to batteries with main grids, when performing IV (power-voltage) testing on batteries without main grids, the test probe can only contact the fine grids, resulting in lower test accuracy. Compared to technical solutions without main grids, this technical solution partially installs main grids, allowing the test probes to contact the main grids, improving the testing accuracy of battery cells. Furthermore, the main grids allow the entire solar cell to be connected, improving the photoelectric conversion efficiency of the solar cell and increasing battery efficiency by 0.01% to 0.015%. [Brief explanation of the drawings]

[0027] One or more embodiments are illustratively described in the accompanying drawings, but these illustrative descriptions are not intended to limit the embodiments, and parts denoted by the same reference numerals in the accompanying drawings are similar parts, and unless otherwise specified, the figures in the accompanying drawings are not limited to scale. In order to more clearly explain the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without any creative effort. [Figure 1] FIG. 1 is a diagram showing the front structure of a solar cell provided in one embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram showing the back surface structure of a solar cell provided in one embodiment of the present disclosure. [Figure 3] FIG. 3 is a diagram showing another rear structure of a solar cell provided in one embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram showing the structure of a spot weld of a solar cell provided in one embodiment of the present disclosure. [Figure 5] FIG. 5 is a diagram illustrating the structure of a solar cell provided in one embodiment of the present disclosure. [Figure 6] FIG. 6 is a diagram illustrating another structure of a solar cell provided in one embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram illustrating another structure of a solar cell provided in one embodiment of the present disclosure. [Figure 8] FIG. 8 is a diagram illustrating another structure of a solar cell provided in one embodiment of the present disclosure. [Figure 9] FIG. 9 is a diagram illustrating the structure of a photovoltaic module provided in one embodiment of the present disclosure. [Figure 10] FIG. 10 is a diagram illustrating the structure of a solar cell in a photovoltaic module provided in one embodiment of the present disclosure. [Figure 11] FIG. 11 is a cross-sectional view of a photovoltaic module provided in one embodiment of the present disclosure. [Figure 12] FIG. 12 is a diagram showing the front structure of a solar cell provided in one embodiment of the present disclosure. [Figure 13] FIG. 13 is a diagram showing the back surface structure of a solar cell provided in one embodiment of the present disclosure. [Figure 14] FIG. 14 is a diagram showing another front structure of a solar cell provided in one embodiment of the present disclosure. [Figure 15] FIG. 15 is a diagram showing another front structure of a solar cell provided in one embodiment of the present disclosure. [Figure 16] FIG. 16 is a diagram showing another rear structure of a solar cell provided in one embodiment of the present disclosure. [Figure 17] FIG. 17 is a diagram showing another rear structure of a solar cell provided in one embodiment of the present disclosure. [Figure 18] FIG. 18 is a diagram illustrating the structure of a photovoltaic module provided in one embodiment of the present disclosure. [Figure 19] FIG. 19 is a cross-sectional view of a photovoltaic module provided in one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0028] As can be seen from the background art, current solar cells are generally divided into two types. One is a battery cell with a main grid. In such a battery cell, the main grid covers part of the front surface of the solar cell substrate, blocking part of the sunlight. The sunlight shining on the main grid cannot be converted into electrical energy, thereby reducing the performance of the solar cell. The other is a battery cell without a main grid. In such a battery cell, there is no main grid, only a thin grid portion, and all main grids and spot welds have been removed. This battery cell improves the photoelectric conversion efficiency of the solar cell, but it affects the efficiency testing of the battery cell. Because all main grids and spot welds have been removed, the test probe can only contact the thin grid, which is relatively small, so the test probe's test accuracy is very high and the test results obtained from the test do not accurately represent the true level of the solar cell.

[0029] In the embodiment of the present disclosure, multiple spot weld groups are provided, and each spot weld group is arranged to include multiple spot welds. This allows the main grid and the thin grid to be connected by the spot welds when they are connected to each other, thereby improving the reliability of the connection between the main grid and the thin grid. Furthermore, the number of spot welds located in the central region of the spot weld group is equal to the number of thin grids located in the central region, and the spot welds located in the central region are arranged so that they are connected one-to-one to the thin grids. This improves the reliability of the connection between the main grid and each thin grid when each thin grid is connected to the main grid. Meanwhile, compared to the conventional technical solution in which at least one spot weld group is spaced between two main grids, i.e., none of the spot weld groups are connected to the main grid, at least one spot weld group is not connected to the main grid, and each spot weld group is connected to the main grid, this technical solution can reduce the number of main grids. Compared to a battery with main grids, when performing an IV (power-voltage) test on a battery without main grids, the test probe can only contact the thin grids, resulting in lower test accuracy. Compared to technical solutions without main grids, this technical solution partially installs main grids, allowing the test probes to contact the main grids, improving the testing accuracy of battery cells. Furthermore, the main grids allow the entire solar cell to be connected, improving the photoelectric conversion efficiency of the solar cell and increasing battery efficiency by 0.01% to 0.015%.

[0030] Hereinafter, each embodiment of the present disclosure will be described in detail in conjunction with the drawings. However, as will be understood by those skilled in the art, although many technical details are proposed in the embodiments of the present disclosure to help readers better understand the present disclosure, the technical solutions claimed for protection in the embodiments of the present disclosure can be realized without these technical details and various changes and modifications based on the following embodiments.

[0031] As shown in FIG. 1, FIG. 1 is a diagram illustrating the front structure of a solar cell provided in one embodiment of the present disclosure.

[0032] In some embodiments, the solar cell provided in the embodiments of the present disclosure may include a base 100, which includes a central region 110 and peripheral regions 120 located on opposite sides of the central region 110 in a first direction X.

[0033] The solar cell provided in the embodiments of the present disclosure may further include a plurality of thin grids 101 arranged at intervals along a first direction X, and the plurality of thin grids 101 extend along a second direction Y.

[0034] The solar cell provided in the embodiments of the present disclosure may further include a plurality of spot weld groups 102 arranged along the second direction Y, each of which includes a plurality of spot welds 112, the plurality of spot welds 112 being arranged along the first direction X, the number of spot welds 112 located in the central region 110 of one spot weld group 102 being equal to the number of thin grids 101 located in the central region 110, and the spot welds 112 located in the central region 110 being connected to the thin grids 101 in a one-to-one correspondence.

[0035] The solar cell provided in the embodiments of the present disclosure may further include a plurality of main grids 103 arranged along the second direction Y, the main grids 103 being connected to the spot weld groups 102, and at least one spot weld group 102 being spaced apart between two adjacent main grids 103.

[0036] In the embodiment of the present disclosure, a plurality of spot weld groups 102 are provided, and each spot weld group 102 includes a plurality of spot welds 112, so that when connecting the main grid 103 and the thin grids 101, the main grid 103 and the thin grids 101 can be connected by the spot welds 112. This improves the reliability of the connection between the main grid 103 and the thin grids 101, and also improves the reliability of the connection between the main grid 103 and each thin grid 101 when each thin grid 101 is connected to the main grid 103, because the number of spot welds 112 located in the central region 110 of the spot weld group 102 is equal to the number of thin grids 101 located in the central region 110 and the spot welds 112 located in the central region 110 are connected to the thin grids 101 in a one-to-one correspondence. Meanwhile, compared to the conventional technical solution in which at least one spot weld group 102 is spaced apart between two main grids 103, i.e., not all spot weld groups 102 are connected to the main grids 103, but rather at least one spot weld group 102 is not connected to the main grids 103 and all spot weld groups are connected to the main grids, this technical solution can reduce the number of main grids 103. Compared to batteries with main grids, when performing IV (power-voltage) testing on batteries without main grids, the test probe can only contact a thin grid, resulting in lower test accuracy. Compared to the technical solution without main grids, this technical solution partially installs the main grids 103, allowing the test probe to contact the main grids 103, improving battery cell test accuracy. Furthermore, the main grids allow communication between the entire solar cell, thereby increasing the photoelectric conversion efficiency of the solar cell and improving battery efficiency by 0.01% to 0.015%.

[0037] In some embodiments, the base 100 may include opposing front and back surfaces 130 and 140. In some embodiments, the solar cell is a single-sided cell, with the front surface 130 of the base 100 serving as a light-receiving surface to receive incident light, and the back surface 140 serving as a backlight surface. In some embodiments, the solar cell is a double-sided cell, with both the front surface 130 and the back surface 140 of the base 100 serving as light-receiving surfaces to receive incident light. As can be appreciated, the backlight surface in the embodiments of the present disclosure can also receive incident light, but is defined as a backlight surface because the light-receiving level of the incident light is weaker than the light-receiving level of the light-receiving surface.

[0038] As shown in FIG. 1 and FIG. 2, FIG. 2 is a diagram illustrating the rear structure of a solar cell provided in one embodiment of the present disclosure.

[0039] In some embodiments, the thin grid 101, spot welds 102, and main grid 103 are provided on the front surface 130, and the thin grid 101 and spot welds 102 are provided on the back surface 140. The thin grid 101 and spot welds 102 are provided on the front surface 130 and back surface 140, and the thin grid 101 provided on the front surface 130 and back surface 140 can collect carriers in the solar cell base 100 and easily concentrate and output these collected carriers. The spot welds 102 on the front surface facilitate connection between the spot welds 102 on the front surface 130 and the main grid 103, and the spot welds 102 on the back surface 140 facilitate connection between the spot welds 102 and the PV relay later during the photovoltaic module manufacturing process.

[0040] In some embodiments, the backside of the solar cell does not have a main grid.

[0041] As shown in FIGS. 1 and 3, FIG. 3 is a diagram illustrating another rear structure of a solar cell provided in one embodiment of the present disclosure.

[0042] In some embodiments, the fine grid 101, the spot welds 102, and the main grid 103 are disposed on the front surface 130 and the back surface 140, respectively, such that the orthogonal projection of the main grid 103 disposed on the front surface 130 on the front surface 130 intersects with the orthogonal projection of the main grid 103 disposed on the back surface 140 on the front surface 130. As can be understood, if the main grid 103 on the front surface 130 and the main grid 103 on the back surface 140 completely overlap, the test probes will always test the same locations on the front surface 130 and the back surface 140 during testing, which would result in inaccurate testing. However, by arranging the orthogonal projection of the main grid 103 disposed on the front surface 130 on the front surface 130 and the orthogonal projection of the main grid 103 disposed on the back surface 140 on the front surface 130 intersect, different locations can be tested during testing, thereby improving test accuracy.

[0043] Note that the term "intersecting" here refers to the fact that the orthogonal projection of the main grid 103 located on the front surface 130 on the front surface 130 and the orthogonal projection of the main grid 103 located on the back surface 140 on the front surface 130 are arranged in a shifted or spaced apart arrangement.

[0044] In some embodiments, the orthogonal projections of some of the main grids 103 located on the front surface 130 on the front surface 130 intersect with the orthogonal projections of the main grids 103 located on the back surface 140 on the front surface 130, and in some embodiments, the orthogonal projections of all of the main grids 103 located on the front surface 130 on the front surface 130 on the back surface 14 ... front surface 130 on the back surface 140 on the front surface 130 on the front surface 130 on the front surface 130 on the front surface 130 on the back surface 140 on the front surface 130 on the front surface 130 on the front surface 13

[0045] In some embodiments, spot welds 102 may be located only on the front surface 130 of base 100. If main grid 103 is located only on the front surface 130 of base 100, spot welds 102 may be aligned with main grid 103 and located only on the front surface 130 of base 100.

[0046] 1 , in some embodiments, the number of thin grids 101 located on the front surface 130 of the base 100 may be 70 to 125, such as 75, 80, 85, 90, 95, or 100. As can be appreciated, the greater the number of thin grids 101, the greater the carrier collection capability of the solar cell; similarly, the greater the number of thin grids 101, the greater the light-blocking area of the front surface 130 of the base 100. Therefore, by setting the number of thin grids 101 located on the front surface 130 of the base 100 to 70 to 125, it is possible to achieve both the carrier collection capability and the light-blocking area of the solar cell, thereby improving the performance of the solar cell.

[0047] In some embodiments, the number of thin grids 101 located on the back surface 140 of the base 100 may be 88 to 400, such as 100, 130, 170, 200, 240, 280, or 300. As can be appreciated, the greater the number of thin grids 101 on the back surface of the base 100, the greater the carrier collection capability of the solar cell; similarly, the greater the number of thin grids 101, the greater the amount of material consumed by the thin grids 101. Therefore, by setting the number of thin grids 101 located on the back surface 140 of the base 100 to 88 to 400, it is possible to achieve both the carrier collection capability of the solar cell and the manufacturing cost of the solar cell.

[0048] In some embodiments, the number of thin grids 101 located on the front surface 130 of the base 100 may be equal to or less than the number of thin grids 101 located on the back surface 140 of the base 100. As can be appreciated, since the back surface 140 is typically a backlight surface compared to the front surface 130, having a larger number of thin grids on the back surface 140 can enhance the carrier collection capability of the solar cell without affecting the light absorption of the front surface.

[0049] In some embodiments, the number of thin grids 101 located on the front surface 130 of the base 100 may be greater than the number of thin grids 101 located on the back surface 140 of the base 100, and can be adjusted according to actual circumstances.

[0050] In some embodiments, the width of the thin grid 101 located on the front surface 130 of the base 100 may be 11 μm to 15 μm, such as 12 μm, 13 μm, 14 μm, or 15 μm. As can be appreciated, the wider the thin grid 101, the higher the carrier collection capability of the solar cell. Similarly, the wider the thin grid 101, the larger the light-blocking area of the front surface 130 of the base 100. Therefore, by setting the width of the thin grid 101 located on the front surface 130 of the base 100 to 11 μm to 15 μm, the carrier collection capability of the solar cell and the light-blocking area can both be achieved, thereby improving the performance of the solar cell.

[0051] In some embodiments, the width of the thin grid 101 located on the back surface 140 of the base 100 may be 13 μm to 17 μm, such as 14 μm, 15 μm, or 16 μm. As can be appreciated, the wider the thin grid 101 is on the back surface of the base 100, the higher the carrier collection capability of the solar cell. Similarly, the wider the thin grid 101 is, the more material is consumed by the thin grid 101. Therefore, by setting the width of the thin grid 101 located on the back surface 140 of the base 100 to 13 μm to 17 μm, it is possible to achieve both the carrier collection capability of the solar cell and the manufacturing cost of the solar cell.

[0052] In some embodiments, the width of the thin grid 101 located on the front surface 130 of the base 100 may be equal to or less than the width of the thin grid 101 located on the back surface 140 of the base 100. As can be appreciated, since the back surface 140 is typically a backlight surface compared to the front surface 130, a larger width of the thin grid on the back surface 140 can enhance the carrier collection capability of the solar cell without affecting the light absorption of the front surface of the solar cell.

[0053] In some embodiments, the height of the thin grid 101 located on the front surface 130 of the base 100 may be 18 μm to 22 μm, such as 19 μm, 20 μm, or 21 μm. As can be appreciated, the higher the height of the thin grid 101, the easier it is to weld the thin grid 101 to the main grid 103, and the higher the thin grid 101, the more material is consumed by the thin grid. Therefore, by setting the height of the thin grid 101 located on the front surface 130 of the base 100 to 18 μm to 22 μm, the cost of the solar cell is also taken into consideration, while taking into account the difficulty of the solar cell manufacturing process. Meanwhile, when a solar cell receives sunlight, the incident angle of the sunlight received daily may not be perpendicular. If the incident light is not perpendicular, it will inevitably be affected by the height of the thin grid 101 and some of the light will be blocked, and the higher the height of the thin grid 101, the more sunlight will likely be blocked. Therefore, by setting the height of the thin grid 101 located on the front surface 130 of the base 100 to 18 μm to 22 μm, the light-blocking area of the front surface 130 of the base 100 can be reduced.

[0054] In some embodiments, the height of the thin grid 101 located on the back surface 140 of the base 100 may be 14 μm to 17 μm, such as 15 μm or 16 μm. The higher the height of the thin grid 101 on the back surface 140, the easier it is to weld the thin grid 101 to the PV wafer, and the higher the thin grid 101, the more material is consumed by the thin grid. Therefore, by setting the height of the thin grid 101 located on the back surface 140 of the base 100 to 14 μm to 17 μm, it is possible to take into consideration the difficulty of the solar cell manufacturing process and the cost of the solar cell.

[0055] In some embodiments, the number of spot weld groups 102 may be 15 to 22, such as 16, 17, 18, 19, or 20. For the front surface, a larger number of spot weld groups 102 facilitates connection between the main grid 103 and the thin grid 101. For the back surface, if the main grid 103 is not included, a larger number of spot weld groups 102 facilitates connection to the PV relay. For the back surface, if the main grid 103 is included, a larger number of spot weld groups 102 facilitates connection between the main grid 103 and the thin grid 101. However, a larger number of spot weld groups 102 may affect the light absorption of the front surface 130 and consume more material. Setting the number of spot weld groups 102 to 15 to 22 facilitates the manufacturing process of the solar cell and reduces the cost required for manufacturing the solar cell.

[0056] In some embodiments, the number of spot welds 102 may refer to the number of spot welds 102 located on the front surface 130 of the base 100 .

[0057] In some embodiments, the number of spot welds 102 located on the back surface 140 of the base 100 may be the same as the number of spot welds 102 located on the front surface 130 of the base 100. This facilitates forming spot welds 102 on both the front surface 130 and the back surface 140 of the base 100. The spot welds 102 can be formed using the same template, reducing the complexity of the solar cell manufacturing process.

[0058] In some embodiments, the number of main grids 103 located on the front surface 130 of the base 100 may be less than the number of spot welds 102. This reduces the number of main grids 103 and reduces the amount of slurry used, while still leaving the main grids 103 to facilitate testing the electrical performance of the solar cells with test probes.

[0059] As shown in FIG. 4, FIG. 4 is a diagram illustrating the structure of a spot weld provided in one embodiment of the present disclosure.

[0060] In some embodiments, the spot weld 112 may include two end portions 122 facing each other along the second direction Y and a main body portion 132 connecting the two end portions 122, wherein the lengths of the two end portions 122 in the first direction X are greater than the length of the main body portion 132 in the first direction X, and the widths of the two end portions 122 in the second direction Y are smaller than the width of the main body portion 132 in the second direction Y.

[0061] As can be seen, contact between the thin grid 101 and the spot welds 112 is necessary during the printing process, and misalignment may occur during the printing process. In this case, by configuring the spot welds 112 to include two ends 122 and making the two ends 122 longer, contact between the spot welds 112 and the thin grid 101 is possible even if misalignment occurs during printing, thereby increasing the reliability of the contact between the thin grid 101 and the spot welds 112. In the case of the main body 132, the main body 132 needs to be welded to the main grid 103 or the PV reflex. Similarly, if misalignment between the main grid 103 and the PV reflex may occur during welding alignment, configuring the main body 132 to be wider in the second direction Y can facilitate welding of the spot welds 112.

[0062] In some embodiments, the number of main grids 103 may be 4 to 11, for example, 5, 6, 7, 8, 9, or 10. As can be appreciated, when testing solar cells, the more main grids 103 there are, the more accurate the test will be, but the more main grids 103 there are, the more light will be blocked from the solar cells. Therefore, by setting the number of main grids 103 to 4 to 11, the accuracy of testing the solar cells can be improved while also improving the performance of the solar cells.

[0063] In some embodiments, the numbers on the main grid 103 mentioned above may refer to the numbers located on the front surface 130 of the base 100 .

[0064] In some embodiments, the main grid 103 may be located only on the front surface 130 of the base 100. Providing the main grid 103 only on the front surface 130 of the base 100 facilitates testing of the solar cells and prevents the main grid 103 from affecting the light absorption of the back surface of the solar cells, improving the performance of the solar cells and facilitating testing of the solar cells.

[0065] In some embodiments, at least one spot weld group 102 is spaced between any two adjacent main grids 103. For a given solar cell size, spaced apart by at least one spot weld group 102 between any two adjacent main grids 103 can limit the number of main grids 103, improve solar cell testing accuracy, and enhance solar cell performance.

[0066] In some embodiments, one spot weld group 102 is spaced apart between some two adjacent main grids 103, and multiple spot weld groups 102 are spaced apart between some two adjacent main grids 103. For example, one spot weld group 102 is spaced apart between some two adjacent main grids 103, and two spot weld groups 102 are spaced apart between some two adjacent main grids 103. Similarly, for a given solar cell size, the number of main grids 103 can be limited, thereby improving solar cell testing accuracy and enhancing solar cell performance.

[0067] In some embodiments, the number of spaced apart spot welds 102 between any two adjacent main grids 103 may be equal, for example, two or three spot welds 102 between any two adjacent main grids 103. In some embodiments, the number of spaced apart spot welds 102 between two main grids 103 may be different, for example, two spot welds 102 between some two main grids 103 and three spot welds 102 between some two main grids 103.

[0068] In some embodiments, the main grids 103 arranged along the second direction Y are uniformly arranged on the surface of the base 100. That is, the main grids 103 are not only located on one side of the surface of the base 100 in the second direction Y, but also on both sides, so that the test probe can be used to test the performance of both sides of the solar cell arranged along the second direction Y, thereby further improving the reliability of the test.

[0069] As shown in FIG. 5, FIG. 5 is a diagram illustrating the structure of a solar cell provided in one embodiment of the present disclosure.

[0070] In some embodiments, the main grid 103 may include a first main grid 113 and a second main grid 123, where one first main grid 113 is connected to all of the spot welds 112 in one spot weld group 102, and one second main grid 123 is connected to some of the spot welds 112 in one spot weld group 102. In other words, the lengths of the main grids 103 in the first direction X are different, and providing the first main grid 113 allows all of the thin grids 101 to be connected, while providing the second main grid 123 reduces shading of the main grid 103 and improves the reliability of the solar cell.

[0071] In some embodiments, different second main grids 123 may be installed with offset positions. For example, let the number of thin grids 101 be n, where n is a positive integer, and the n thin grids 101 are divided into a first thin grid through an n-th thin grid along the first direction X; let the number of second main grids 123 be N, where N is a positive integer, and the N second main grids 123 are divided into a first main grid through an N-th main grid along the second direction Y, and the first main grid is connected to the first thin grid through the n / N-th thin grid, and the second main grid is connected to the (n / N)+1-th thin grid through the 2n / N-th thin grid. Others can be inferred from this.

[0072] In some embodiments, different second main grids 123 may be offset and not connected to the same thin grid 101. Similar to the above example, different second main grids 123 are sequentially connected to different thin grids 101.

[0073] In some embodiments, different second main grids 123 may be installed offset, and different second main grids 123 are not connected to the same thin grid 101, and the connections between the second main grids 123 arranged along the second direction Y and different thin grids 101 are not arranged sequentially along the first direction X. For example, let the number of thin grids 101 be n, and the n thin grids 101 are divided into a first thin grid to an nth thin grid along the first direction X; let the number of second main grids 123 be N, and the N second main grids 123 be divided into a first main grid to an Nth main grid along the second direction Y; the first main grid is connected to the first thin grid to the n / Nth thin grid; the second main grid is connected to the (3n / N)+1th thin grid to the 4n / Nth thin grid; and the third main grid is connected to the (8n / N)+1th thin grid to the 9n / Nth thin grid; and there is no arrangement rule between different second main grids 123.

[0074] As can be seen, compared to an arrangement of the second main grid 123 not having a regular arrangement, the second main grid 123 having a certain regular arrangement makes it easier to manufacture the screen plate, which makes it easier to manufacture the solar cell and improves the appearance of the solar cell.

[0075] Regarding the relationship between n and N above, n may be an integer multiple of N. If there is no integer multiple relationship between n and N, n / N can be converted to an integer when setting the connection relationship between the second main grid 123 and the thin grid 101. Converting to an integer here refers to rounding down the remainder when performing division to obtain an integer. For example, converting 8 / 3 to an integer results in 2.

[0076] As shown in FIG. 6, FIG. 6 is a diagram illustrating another structure of a solar cell provided in one embodiment of the present disclosure.

[0077] In some embodiments, the same thin grids 101 are connected between different second main grids 123. For example, the number of thin grids 101 is eight, and the thin grids 101 arranged along the first direction X are divided into a first thin grid to an eighth thin grid, and the number of second main grids 123 is three, and the second main grids 123 arranged along the second direction Y are divided into a first main grid to a third main grid, and the first main grid can be connected to the first thin grid to the fifth thin grid, the second main grid can be connected to the third thin grid to the seventh thin grid, and the third main grid can be connected to the fourth thin grid to the eighth thin grid.

[0078] As can be understood, the same thin grids 101 are also connected between different second main grids 123, so that for different second main grids 123, the multiple second main grids 123 are electrically connected to all of the thin grids 101. In this way, by testing the second main grids 123, the performance of the solar cell can be well reflected.

[0079] The above exemplary explanation is a schematic explanation for easy understanding, and does not limit the number and connection method of the fine grids 101 and the second main grids 123.

[0080] In some embodiments, the lengths of the different second main grids 123 may be the same, and in some embodiments, the lengths of the different second main grids 123 may be different. Compared to second main grids 123 of different lengths, setting all second main grids 123 to the same length makes it easier to fabricate a screen plate for the solar cell, which in turn makes it easier to manufacture the solar cell and improves the appearance of the solar cell.

[0081] In some embodiments, at least one spot weld group 102 is spaced apart between adjacent first main grids 113 and second main grids 123. As can be appreciated, the more spot weld groups 102 spaced apart between adjacent first main grids 113 and second main grids 123, the fewer first main grids 113 and second main grids 123 are required for a given size solar cell due to area limitations. This reduces the amount of light that the main grids 103 block from the solar cell, and the first main grids 113 and second main grids 123 also facilitate testing of the solar cell.

[0082] In some embodiments, the width of the first main grid 113 in the second direction Y is larger than the width of the second main grid 123 in the second direction Y. This allows the first main grid 113 to be the main grid that the test probe primarily contacts, and by installing the first main grid 113 so that it connects to all of the spot welds 112 in the spot weld group 102, the accuracy of testing the solar cell can be further improved. On the other hand, setting the width of the first main grid 113 larger in the second direction Y makes it easier for the test probe to contact the first main grid 113, which contributes to the progress of the test.

[0083] In some embodiments, each main grid 103 is electrically connected to all of the spot welds 112 in the group of spot welds 102, or each main grid 103 is electrically connected to only a portion of the spot welds 112 in the group of spot welds 102. In other words, all of the main grids 103 are connected to all of the spot welds 112 in the group of spot welds 102, or only a portion of the spot welds 112 in the group of spot welds 102.

[0084] When the main grid 103 includes only main grids 103 connected to some of the spot welds 112 in the group of spot welds 102, the main grids 103 connected to only some of the spot welds 112 make testing easier and the test results more accurate than when using a technical solution without a main grid. When the main grid 103 includes only main grids 103 that are electrically connected to all of the spot welds 112 in the group of spot welds 102, the accuracy of the test results can be further improved.

[0085] As shown in FIG. 7, FIG. 7 is a diagram showing another structure of the solar cell provided in the embodiment of the present disclosure, which may be the front or back side of the solar cell.

[0086] In some embodiments, the main grids 103 include only main grids 103 that are connected to some of the spot welds 112 in the spot weld group 102, and the same thin grids 101 are connected to different main grids 103. This allows all the thin grids 101 to be electrically connected by multiple main grids 103, which can accurately reflect the performance of the solar cell during testing and minimize the amount of slurry, thereby further improving the performance of the solar cell.

[0087] As shown in FIG. 1, in some embodiments, the number of the spot welding portion groups 102 is N, and the number of the main grids 103 is n, where N / 4≦n<N, both n and N are positive integers. By setting the relationship between the number of the main grids 103 and the number of the spot welding portion groups as N / 4≦n<N, that is, by setting the number of the main grids 103 to be smaller than the number of the spot welding portion groups 102, at least one spot welding portion group 102 is arranged at an interval between two adjacent main grids 103. By setting the number of the main grids 103 to be not less than 1 / 4 of the number of the spot welding portion groups 102, it is possible to prevent the number of the main grids 103 from being too small to make the test accurate, and improve the reliability of the test results.

[0088] In some embodiments, the area of the orthographic projection of the base 100 of the spot welding portion 112 closest to the peripheral region 120 of the central region 110 is larger than the area of the orthographic projection of the base 100 of the spot welding portion 112 farthest from the peripheral region 120 of the central region 110. As can be understood, the closer the portion is to the edge of the solar cell, the lower the connection reliability between the spot welding portion 112 and the main grid 103. Thereby, by setting the area of the orthographic projection of the base 100 of the spot welding portion 112 closest to the peripheral region 120 of the central region 110 to be larger than the area of the orthographic projection of the base 100 of the spot welding portion 112 farthest from the peripheral region 120 of the central region 110, the connection reliability between the spot welding portion 112 and the main grid 103 can be improved.

[0089] In some embodiments, in the direction from the peripheral region 120 to the central region 110, the area of the orthographic projection of the base 100 of the spot welding portion 112 may decrease sequentially. By increasing the area of the orthographic projection of the base 100 of the spot welding portion 112 located at the edge, the connection reliability between the spot welding portion group 102 and the main grid 103 can be improved. On the other hand, by relatively reducing the area of the spot welding portion 112 located at the center, the amount of material used can be reduced, and the cost of the solar cell can be reduced.

[0090] In some embodiments, the solar cell further includes an electrode 104, the electrode 104 being located in the peripheral region 120, the electrode 104 being connected to the plurality of thin grids 101, and the electrode 104 being Y-shaped. As can be appreciated, during the process of manufacturing the solar cell, the thin grid 101 and the spot welds 112 may not be printed in the peripheral region 120 because the peripheral region 120 may be shielded. Setting the electrode 104 in a Y-shape for contact between the electrode and the thin grid 101 and the main grid 103 facilitates the manufacturing process of the solar cell.

[0091] As shown in FIG. 8, FIG. 8 is a diagram illustrating another structure of a solar cell provided in one embodiment of the present disclosure.

[0092] In some embodiments, the solar cell includes two bifurcated cells, and the main grids 103 of the two bifurcated cells are arranged in a cross-like manner in the second direction Y. By arranging the main grids 103 of the two bifurcated cells in a cross-like manner along the second direction Y, the test probe can contact the main grids 103 at different positions during testing, thereby improving the reliability of the test results.

[0093] In an embodiment of the present disclosure, multiple spot weld groups 102 are provided, and each spot weld group 102 is arranged to have multiple spot welds 112. By doing so, when the main grid 103 is connected to the thin grid 101, the main grid 103 and the thin grid 101 can be connected by the spot welds 112, thereby improving the connection reliability between the main grid 103 and the thin grid 101. Furthermore, by setting the number of spot welds 112 located in the central region 110 of the spot weld group 102 to be equal to the number of thin grids 101 located in the central region 110, and by arranging the spot welds 112 located in the central region 110 so that they are connected in a one-to-one correspondence with the thin grids 101, the connection reliability between the main grid 103 and each thin grid 101 can be improved when each thin grid 101 is connected to the main grid 103. Meanwhile, compared to the conventional technical solution in which at least one spot weld group 102 is spaced apart between two main grids 103 (i.e., none of the spot weld groups 102 are connected to a main grid 103, at least one spot weld group 102 is not connected to a main grid 103, and each spot weld group is connected to a main grid), this technical solution can reduce the number of main grids 103. However, compared to batteries with main grids, when performing IV (power-voltage) testing on a battery without main grids, the test probe can only contact a thin grid, resulting in lower test accuracy. Compared to technical solutions without main grids, this technical solution partially installs the main grids 103, allowing the test probe to contact the main grids 103, improving battery cell test accuracy. Furthermore, the main grids 103 allow communication throughout the solar cell, improving the photoelectric conversion efficiency of the solar cell and increasing battery efficiency by 0.01% to 0.015%.

[0094] Another embodiment of the present disclosure further provides a photovoltaic module, which includes some or all of the embodiments of the solar cell described above. Hereinafter, the photovoltaic module provided in another embodiment of the present disclosure will be described with reference to the drawings. For parts that are the same as or corresponding to the above embodiments, please refer to the corresponding descriptions of the above embodiments. Hereinafter, the description will not be repeated.

[0095] As shown in Figures 9 to 11, Figure 9 is a diagram showing the structure of a photovoltaic module provided in an embodiment of the present disclosure, Figure 10 is a diagram showing the structure of a solar cell provided in one embodiment of the present disclosure, and Figure 11 is a cross-sectional view along the M1M2 direction of Figure 9 provided in one embodiment of the present disclosure.

[0096] In some embodiments, a photovoltaic module may include a cell string, the cell string comprising solar cells 205 connected in series, the solar cells 205 including a base 200, a plurality of thin grids 201 arranged at intervals along a first direction X, a plurality of groups of spot welds 202 arranged along a second direction Y, a plurality of main grids 203 arranged along the second direction Y, and a PV ribbon 206, wherein the base 200 includes a central region 210 and peripheral regions 220 located on opposite sides of the central region 210 in the first direction, the plurality of thin grids 201 extending along the second direction Y, and the groups of spot welds 202 including a plurality of spot welds 21 2, wherein a plurality of spot welds 212 are arranged along the first direction X, the number of spot welds 212 located in the central region 210 of one spot weld group 202 is equal to the number of thin grids 201 located in the central region 210, and the spot welds 212 located in the central region 210 are connected to the thin grids 201 in a one-to-one correspondence, a main grid 203 is connected to the spot weld groups 202, and at least one spot weld group 202 is disposed at an interval between two adjacent main grids 203, and PV re-horns 206 connect two adjacent solar cells 205, and each PV re-horn 206 is connected to a corresponding spot weld group 202 of each solar cell 205.

[0097] The photovoltaic module may further include an encapsulation layer 207 for covering the surface of the cell string.

[0098] The photovoltaic module may further include a cover plate 208 for covering the surface of the encapsulation layer 207 remote from the cell string.

[0099] In an embodiment of the present disclosure, a battery cell in a photovoltaic module includes a plurality of spot weld groups 202, and each spot weld group 202 is arranged to have a plurality of spot welds 212. By doing so, when the main grid 203 is connected to the thin grid 201, the main grid 203 and the thin grid 201 can be connected by the spot welds 212, thereby improving the connection reliability between the main grid 203 and the thin grid 201. In addition, by setting the number of spot welds 212 located in the central region 210 of the spot weld group 202 to be equal to the number of thin grids 201 located in the central region 210, and by arranging the spot welds 212 located in the central region 210 so that they are connected in a one-to-one correspondence with the thin grids 201, the connection reliability between the main grid 203 and each thin grid 201 can be improved when each thin grid 201 is connected to the main grid 203. Meanwhile, compared to the conventional technical solution in which at least one spot weld group 202 is spaced apart between two main grids 203, i.e., none of the spot weld groups 202 are connected to a main grid 203, and at least one spot weld group 202 is not connected to a main grid 203, and each spot weld group is connected to a main grid, this technical solution can reduce the number of main grids 203, and when performing an IV (power-voltage) test on a battery without main grids, the test probe can only contact the thin grid 201, resulting in lower test accuracy compared to a battery with no main grid. Compared to a technical solution without main grids, this technical solution partially installs the main grids 203, allowing the test probe to contact the main grids 203, improving battery cell test accuracy, and the main grids 203 allow communication throughout the solar cell, thereby improving the photoelectric conversion efficiency of the solar cell.

[0100] In some embodiments, the solar cell includes, but is not limited to, any one of a PERC cell (Passivated Emitter Rear Cell), a TOPCon cell (Tunnel Oxide Passivated Contact), a HIT / HJT cell (Hetero Junction Technology), a perovskite solar cell, and a stacked cell, including, but not limited to, a stacked cell of a perovskite cell and a crystalline silicon cell, a stacked cell of a perovskite cell and a perovskite cell, and a stacked cell of a perovskite solar cell and a thin film cell.

[0101] The solar cell may be a monocrystalline silicon solar cell, a polysilicon solar cell, an amorphous silicon solar cell, or a multi-component solar cell, and the multi-component solar cell may specifically be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell. In some embodiments, the solar cell may be a whole cell or a slice cell, and a slice cell is a cell formed by cutting a whole cell.

[0102] In some embodiments, the encapsulation layer 207 includes a first encapsulation layer (not shown) and a second encapsulation layer (not shown), where the first encapsulation layer covers one of the front surface and the back surface of the battery cell, and the second encapsulation layer covers the other of the front surface and the back surface of the battery cell. Specifically, at least one of the first encapsulation layer and the second encapsulation layer may be an organic encapsulation layer such as a polyvinyl butyral (PVB) adhesive film, an ethylene-vinyl acetate copolymer (EVA) adhesive film, a polyethylene-octene copolymer (polyolefin thermoplastic elastomer (POE)) adhesive film, or a polyethylene glycol terephthalate (PET) adhesive film.

[0103] As can be seen, there is a boundary between the first sealing layer and the second sealing layer before the lamination process is performed, and after the lamination process is performed, the concepts of the first sealing layer and the second sealing layer disappear in the molded photovoltaic module, and the first sealing layer and the second sealing layer are integrated to form sealing layer 207.

[0104] In some embodiments, the cover plate 208 may be a cover plate with a light-transmitting function, such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 208 facing the sealing layer 207 may be an uneven surface, thereby improving the utilization efficiency of incident light. The cover plate 208 includes a first cover plate and a second cover plate, where the first cover plate faces the first sealing layer and the second cover plate faces the second sealing layer.

[0105] In some embodiments, the solar cells 205 in the cell string are arranged along a first direction X, and the main grids of two adjacent solar cells 205 in the cell string are arranged crosswise in a second direction Y. For the photovoltaic module, the main grids of two adjacent solar cells 205 in the cell string are arranged crosswise in the second direction Y, so that different potentials of the photovoltaic module can be tested and the reliability of the test results can be improved.

[0106] In addition, the embodiments of the present disclosure provide a solar cell that can improve the performance of the solar cell and reduce the cost of the solar cell. In the solar cell provided in the embodiments of the present disclosure, a base is provided, which collects light and generates photo-generated carriers. A first thin grid is provided on the front surface, and the number of first thin grids is set to 70 to 150. The greater the number of first thin grids, the higher the carrier collection capability, but the stronger the light-blocking effect on the front surface of the solar cell, reducing the luminous flux irradiated onto the surface of the base and reducing the number of photo-generated carriers generated in the base. Thus, by setting the number of first thin grids to 70 to 150, the solar cell has a certain carrier collection capability and can reduce the light-blocking effect of the first thin grids on the surface of the base. A second thin grid is provided on the back surface, and the number of second thin grids is set to 80 to 400. The greater the number of second thin grids, the higher the carrier collection capability, but the more materials are consumed and the higher the cost. By setting the number of second thin grids to 80 to 400, the solar cell has a certain carrier collection capability and the cost of the solar cell can be reduced. By providing a first spot weld group located on the front surface and configuring the first spot weld group to include a plurality of first spot welds, the connection between the first spot welds and the first thin grid can be controlled, and the connection between the first thin grid and the main grid or PV relay can be easily made.

[0107] As shown in Figures 12 and 13, Figure 12 is a diagram showing the front structure of a solar cell provided in an embodiment of the present disclosure, and Figure 13 is a diagram showing the back structure of a solar cell provided in an embodiment of the present disclosure.

[0108] In some embodiments, the solar cell may include a base 300 with a front surface 310 and a back surface 320 .

[0109] The solar cell may further include a plurality of first thin grids 301 arranged at intervals along the first direction X, the plurality of first thin grids 301 extending along the second direction Y, the first thin grids 301 located on the front surface 310, and the number of the first thin grids 301 being 70 to 150.

[0110] The solar cell may further include a plurality of second thin grids 302 arranged at intervals along the first direction X, the plurality of second thin grids 302 extending along the second direction Y, the second thin grids 302 located on the back surface 320, and the number of the second thin grids 302 being 80 to 400.

[0111] The solar cell may further include a plurality of first spot weld groups 303 arranged along the second direction Y, the first spot weld groups 303 being located on the front surface 310, each first spot weld group 303 including a plurality of first spot welds 313, the plurality of first spot welds 313 being arranged along the first direction X, and each first spot weld 313 being connected to one first thin grid 301.

[0112] In the embodiment of the present disclosure, the base 300 is provided, and the base 300 collects light and generates photo-generated carriers. By providing first thin grids 301 located on the front surface 310 and setting the number of first thin grids 301 to 70 to 150, the carrier collection capability increases as the number of first thin grids 301 increases, but the light blocking effect on the front surface 310 of the solar cell also increases, reducing the luminous flux irradiating the surface of the base 300 and reducing the number of photo-generated carriers generated in the base 300. By setting the number of first thin grids 301 to 70 to 150, the solar cell has a certain carrier collection capability and the light blocking effect of the first thin grids 301 on the surface of the base 300 can be reduced. By providing second thin grids 302 located on the back surface 320 and setting the number of second thin grids 302 to 80 to 400, the carrier collection capability increases as the number of second thin grids 302 increases, but the required materials are increased and the cost increases. As a result, by setting the number of second thin grids 302 to 80 to 400, the solar cell has a certain carrier collection capability and the cost of the solar cell can be reduced. By providing first spot weld group 303 located on front surface 310 and arranging first spot weld group 303 to include multiple first spot welds 313, it is possible to control the connection between first spot welds 313 and first thin grid 301 and to facilitate the connection between first thin grid 301 and the main grid or PV relay.

[0113] In some embodiments, the solar cell is a single-sided cell, with the front surface 310 of the base 300 serving as a light-receiving surface for receiving incident light and the back surface 320 serving as a backlight surface. In some embodiments, the solar cell is a double-sided cell, with both the front surface 310 and the back surface 320 of the base 300 serving as light-receiving surfaces for receiving incident light. As can be appreciated, the backlight surface in the embodiments of the present disclosure can also receive incident light, but is defined as a backlight surface because the light-receiving level of the incident light is weaker than the light-receiving level of the light-receiving surface.

[0114] In some embodiments, the number of the first thin grids 301 may be 70 to 100, such as 77, 83, 89, or 95. As can be seen, compared to the number of the first thin grids 301 being 70 to 150, setting the number of the first thin grids 301 to 70 to 100 can further reduce shading of the surface of the solar cell without significantly affecting the photo-generated carrier collection ability of the first thin grids 301.

[0115] In some embodiments, the number of the first thin grids 301 may be 70 to 85, such as 71, 75, 79, or 83. As can be seen, when the number of the first thin grids 301 exceeds 85, the carrier collection ability of the first thin grids 301 is not improved as expected. For example, when the number of the first thin grids 301 is 70 to 85, the total carrier collection ability of the first thin grids 301 is 1. When the number of the first thin grids 301 is 85 to 100, the total carrier collection ability of the first thin grids 301 is 1.3. When the number of the first thin grids 301 is 100 to 150, the total carrier collection ability of the first thin grids 301 is 1.4. That is, as the number of the first thin grids 301 increases, the improvement rate of the total carrier collection ability of the first thin grids 301 decreases, and as the number of the first thin grids 301 increases, the light-blocking area of the first thin grids 301 continues to increase. Therefore, by setting the number of first thin grids 301 to 70 to 85, it is possible to further reduce shading of the surface of the solar cell without significantly affecting the photo-generated carrier collection ability of the first thin grids 301.

[0116] In other words, as the number of first thin grids 301 increases, the light-blocking area of the first thin grids 301 becomes directly proportional to the number of first thin grids 301. That is, the greater the number of first thin grids 301, the larger the light-blocking area of the first thin grids 301. There is a positive correlation between the total carrier collection ability of the first thin grids 301 and the increase in the number of first thin grids 301, and as the number of first thin grids 301 increases, the slope of the curve relating the total carrier collection ability of the first thin grids 301 to the number of first thin grids 301 gradually decreases. That is, once the number of first thin grids 301 increases to a certain extent, the negative impact of the increase in the number of first thin grids 301 becomes greater than the positive impact of the increase in the number of first thin grids 301, so the number of first thin grids 301 can be set to 70 to 85.

[0117] The total carrier collection capacity of the first thin grid 301 refers to the sum of the photo-generated carriers collected by all the first thin grids 301 within a unit time.

[0118] In some embodiments, the width of the first thin grid 301 may be 10 to 30 μm, such as 11.5 μm, 15 μm, 18 μm, 21 μm, or 27 μm. As can be seen, the wider the first thin grid 301, the higher the carrier collection capability of the solar cell. Similarly, the wider the first thin grid 301, the larger the light-blocking area on the front surface 310 of the base 300. Therefore, by setting the width of the first thin grid 301 located on the front surface 310 of the base 300 to 10 to 30 μm, it is possible to achieve both the carrier collection capability and the light-blocking area of the solar cell, thereby improving the performance of the solar cell.

[0119] In some embodiments, the width of the first thin grid 301 may be 11 to 15 μm, such as 12 μm, 13 μm, or 14 μm. For the first thin grid 301, the width of the first thin grid 301 is directly proportional to the cost of the first thin grid 301, and the slope of the curve between the total carrier collection ability of the first thin grid 301 and the width of the first thin grid 301 gradually decreases. Therefore, by setting the width of the first thin grid 301 to 11 to 15 μm, the carrier collection ability of the first thin grid 301 can be maximized.

[0120] In some embodiments, the height of the first thin grid 301 may be 6 to 30 μm, such as 7 μm, 11 μm, 15 μm, 17 μm, 20 μm, or 25 μm, preferably 7 to 20 μm, and more preferably 8 to 16 μm. As can be understood, the higher the height of the first thin grid 301, the easier it is to weld the first thin grid 301 to the main grid or the PV relay. Also, the higher the first thin grid 301, the more material is consumed by the first thin grid 301. Therefore, by setting the height of the first thin grid 301 located on the front surface 310 of the base 300 to 6 to 30 μm, the difficulty of the solar cell manufacturing process and the cost of the solar cell are taken into consideration. On the other hand, when a solar cell receives sunlight, the sunlight it receives daily may not be perpendicularly incident, and the sunlight that is not perpendicularly incident will inevitably be affected by the height of the first thin grid 301 and part of it will be blocked, and the higher the height of the first thin grid 301, the more sunlight may be blocked. Therefore, by setting the height of the first thin grid 301 located on the front surface 310 of the base 300 to 6 to 30 μm, the light-blocking area of the front surface 310 of the base 300 can be reduced.

[0121] In some embodiments, the height of the first thin grid 301 may be 7 to 25 μm, such as 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, 22 μm, or 25 μm, preferably 8 to 20 μm, and more preferably 9 to 16 μm. For the first thin grid 301, the height of the first thin grid 301 is directly proportional to the cost of the first thin grid 301, and the slope of the curve between the welding capacity of the first thin grid 301 and the height of the first thin grid 301 gradually decreases. Therefore, by setting the height of the first thin grid 301 to 7 to 25 μm, the welding capacity of the first thin grid 301 can be maximized.

[0122] In some embodiments, the number of second thin grids 302 may be 85 to 200, such as 100, 120, 150, or 180. As can be appreciated, the greater the number of second thin grids 302, the greater the carrier collection capability of the solar cell; similarly, the greater the number of second thin grids 302, the greater the material consumed by the second thin grids 302. Therefore, by setting the number of second thin grids 302 to 85 to 200, the carrier collection capability of the solar cell can be improved and the cost required for manufacturing the solar cell can be reduced.

[0123] In some embodiments, the number of second thin grids 302 is 100 to 200. As can be seen, for the second thin grids 302, the number of second thin grids 302 is directly proportional to the cost of the second thin grids 302, but the slope of the curve between the total carrier collection capacity of the second thin grids 302 and the number of second thin grids 302 gradually decreases. That is, when the number of second thin grids 302 increases to a certain extent, the negative impact of increasing the number of second thin grids 302 becomes greater than the positive impact of increasing the number of second thin grids 302.

[0124] In some embodiments, the width of the second thin grid 302 may be 15 to 50 μm, such as 16 μm, 21 μm, 25 μm, 28 μm, 35 μm, 43 μm, or 47 μm. As can be appreciated, the wider the second thin grid 302 is on the back surface 320 of the base 300, the stronger the carrier collection capability of the solar cell. Similarly, the wider the second thin grid 302 is, the more material the second thin grid 302 consumes. Therefore, by setting the width of the second thin grid 302 located on the back surface 320 of the base 300 to 15 to 50 μm, it is possible to achieve both the carrier collection capability of the solar cell and the cost required for manufacturing the solar cell.

[0125] In some embodiments, the width of the second thin grid 302 may be 16 to 27 μm, such as 18 μm, 21 μm, or 26 μm. For the second thin grid 302, the width of the second thin grid 302 is directly proportional to the cost of the second thin grid 302, but the slope of the curve between the total carrier collection ability of the second thin grid 302 and the cost of the second thin grid 302 gradually decreases. Therefore, by setting the width of the second thin grid 302 to 16 to 27 μm, the carrier collection ability of the second thin grid 302 can be maximized.

[0126] In some embodiments, the height of the second thin grid 302 may be 4 to 25 μm, such as 5 μm, 8 μm, 11 μm, 14 μm, 16 μm, 18 μm, or 22 μm, and preferably 6 to 18 μm. The higher the second thin grid 302, the easier it is to weld the second thin grid 302 to the PV wafer. At the same time, the higher the second thin grid 302, the more material is consumed by the second thin grid 302. Therefore, by setting the height of the second thin grid 302 located on the rear surface 320 of the base 300 to 4 to 25 μm, the cost of the solar cell can be reduced while taking into consideration the difficulty of the solar cell manufacturing process.

[0127] In some embodiments, the height of the second thin grid 302 may be 6 to 15 μm, such as 8 μm, 10 μm, 12 μm, or 13 μm, and preferably 9 to 12 μm. For the second thin grid 302, the height of the second thin grid 302 is directly proportional to the cost of the second thin grid 302, but the slope of the curve between the welding capacity of the second thin grid 302 and the height of the second thin grid 302 gradually decreases. Therefore, by setting the height of the second thin grid 302 to 6 to 15 μm, the welding capacity of the second thin grid 302 can be maximized.

[0128] In some embodiments, the height of the second thin grids 302 is inversely proportional to the number of second thin grids 302. That is, the greater the number of second thin grids 302, the shorter the height of the second thin grids 302, and vice versa. This reduces the total amount of material used for the second thin grids 302, thereby lowering the cost of the solar cell.

[0129] In some embodiments, the width of the second thin grids 302 is inversely proportional to the number of second thin grids 302. That is, the greater the number of second thin grids 302, the smaller the width of the second thin grids 302, and vice versa. This reduces the total amount of material used for the second thin grids 302, thereby lowering the cost of the solar cell.

[0130] In some embodiments, the number of first spot weld groups 303 may be 12 to 26, such as 13, 17, 20, 23, or 25. The greater the number of first spot weld groups 303, the easier it is to connect the PV reflex or main grid to the first thin grid 301 on the front surface 310. For solutions without a main grid on the back surface 320, the easier it is to connect the PV reflex. For solutions with a main grid on the back surface 320, the easier it is to connect the main grid to the first thin grid 301. However, the greater the number of first spot weld groups 303, the greater the impact on light absorption by the front surface 310 and the greater the amount of material consumed. Setting the number of first spot weld groups 303 to 12 to 26 simplifies the solar cell manufacturing process and reduces the cost required for manufacturing the solar cell.

[0131] In some embodiments, the number of first spot weld groups 303 is 15 to 22. By setting the number of first spot weld groups 303 to 15 to 22, the difficulty of the solar cell manufacturing process can be further reduced, and the manufacturing cost of the solar cell can be reduced.

[0132] As shown in FIG. 14, FIG. 14 is a diagram illustrating another front structure of the solar cell provided in one embodiment of the present disclosure.

[0133] In some embodiments, the laser may further include a plurality of first main grids 304 arranged along the second direction Y, the first main grids 304 being located on the front surface 310 and connected to the first group of spot welds 303. By providing a plurality of first main grids 304, the photogenerated carriers collected on the first thin grid 301 can be collected, contributing to the output of photogenerated carriers.

[0134] In some embodiments, the number of first main grids 304 is equal to the number of first spot weld groups 303, and each first main grid 304 is connected to one first spot weld group 303. In other words, each first spot weld group 303 is connected to a corresponding first main grid, which can further increase the carrier collection rate of the solar cell.

[0135] As shown in FIG. 15, FIG. 15 is a diagram illustrating another front structure of the solar cell provided in one embodiment of the present disclosure.

[0136] In some embodiments, at least one first spot weld group 303 is spaced between two adjacent first main grids 304. In other words, the number of first spot weld groups 303 is less than the number of first main grids 304. As can be appreciated, the greater the number of first main grids 304, the faster the carrier collection rate. However, the greater the number of first main grids 304, the greater the front surface 310 of the base 300 that is shielded, which may reduce the generation rate of photogenerated carriers in the base 300.

[0137] In some embodiments, the number of first main grids 304 is between 4 and 11. As can be appreciated, the greater the number of first main grids 304, the more accurate the test results for the solar cells will be, but the greater the number of first main grids 304, the more light will be blocked from the solar cells and the more slurry will be used. Therefore, by setting the number of first main grids 304 to between 4 and 11, the accuracy of the test for the solar cells can be improved, while also improving the performance of the solar cells and reducing the cost of the solar cells.

[0138] As shown in FIGS. 15 and 16, FIG. 16 is a diagram showing another rear structure of the solar cell provided in one embodiment of the present disclosure.

[0139] In some embodiments, the solar cell further includes a plurality of second spot weld groups 305 arranged along the second direction Y and a plurality of second main grids 306 arranged along the second direction Y, wherein the second spot weld groups 305 are located on the back surface 320, each second spot weld group 305 includes a plurality of second spot welds 315, the plurality of second spot welds 315 are arranged along the first direction X, one second spot weld 315 is connected to one second thin grid 302, and an orthogonal projection of the first spot weld group 303 on the front surface 310 is offset from an orthogonal projection of the second spot weld group 305 on the front surface 310, and a second main grid 306 is located on the back surface 320, and the second main grid 306 is connected to the second spot weld group 305, and an orthogonal projection of the first main grid 304 on the front surface 310 is offset from an orthogonal projection of the second main grid 306 on the front surface 310.

[0140] By positioning the second spot weld group 305 on the back surface 320, it is possible to easily connect the second main grid 306 on the back surface to the second spot weld group 305, and also to easily connect the solar cell to the PV module during the process of forming the solar cell into a photovoltaic module. By positioning the second main grid 306, the carrier collection capability of the solar cell can be further improved. By positioning the first main grid 304 so that its orthogonal projection on the front surface 310 is offset from that of the second main grid 306, testing accuracy can be improved.

[0141] As can be seen, if the orthogonal projection on the front surface 310 of the first main grid 304 and the orthogonal projection on the front surface 310 of the second main grid 306 are completely overlapped, the test probes will always test the same positions on the front surface 310 and the back surface 320 during testing, resulting in inaccurate test results. By setting the orthogonal projection on the front surface 310 of the first main grid 304 and the orthogonal projection on the front surface 310 of the second main grid 306 so that they are offset, different positions can be tested during testing, thereby improving test accuracy.

[0142] In some embodiments, the number of second main grids 306 is equal to the number of second spot welds 305, and each second main grid 306 is connected to one second spot weld group 305. In other words, each second spot weld group 305 is connected to a corresponding second main grid 306, which can further increase the carrier collection rate of the solar cell.

[0143] As shown in FIG. 17, FIG. 17 is a diagram illustrating another rear structure of the solar cell provided in one embodiment of the present disclosure.

[0144] In some embodiments, the solar cell further includes a plurality of second spot weld groups 305 arranged along the second direction Y. The second spot weld groups 305 are arranged on the back surface 320, each of which includes a plurality of second spot welds 315. The plurality of second spot welds 315 are arranged along the first direction X, with each second spot weld 315 connected to a second thin grid 302. The front surface 310 and the back surface 320 are free of main grids. In other words, a battery without a main grid may be configured. Because the main grid covers a portion of the solar cell, it blocks some sunlight, preventing sunlight irradiating the main grid from being converted into electrical energy, thereby reducing the performance of the solar cell. Installing a battery without a main grid can improve the performance of the solar cell. The provision of the first spot weld groups 303 and the second spot weld groups 305 facilitates connection between the solar cell and the PV relay.

[0145] In some embodiments, the solar cell may be a whole cell, a two-part cell, or a three-part cell, where a whole cell refers to a cell made of one complete substrate, a two-part cell refers to a cell obtained by cutting a whole cell into two pieces, and a three-part cell refers to a cell obtained by cutting a whole cell into three pieces.

[0146] In the embodiments of the present disclosure, the explanation is mainly given using two-divided cells as an example, but the embodiments of the present disclosure are not limited to two-divided cells, and whole cells or three-divided cells may also be used.

[0147] In some embodiments, the solar cell includes, but is not limited to, any one of a PERC cell (Passivated Emitter Rear Cell), a TOPCon cell (Tunnel Oxide Passivated Contact), a HIT / HJT cell (Hetero Junction Technology), a perovskite solar cell, and a stacked cell. The stacked cell includes, but is not limited to, a stacked cell of a perovskite solar cell and a crystalline silicon cell, a stacked cell of a perovskite solar cell and a perovskite solar cell, and a stacked cell of a perovskite solar cell and a thin film cell.

[0148] In an embodiment of the present disclosure, a base 300 is provided, which collects light and generates photo-generated carriers. First thin grids 301 are provided on the front surface 310, and the number of first thin grids 301 is set to 70 to 150. The greater the number of first thin grids 301, the higher the carrier collection capability, but the stronger the light-blocking effect on the front surface 310 of the solar cell, reducing the luminous flux irradiating the surface of the base 300 and reducing the number of photo-generated carriers generated in the base 300. Thus, by setting the number of first thin grids 301 to 70 to 150, the solar cell has a certain carrier collection capability, while the light-blocking effect of the first thin grids 301 on the surface of the base 300 can be reduced. Second thin grids 302 are provided on the back surface 320, and the number of second thin grids 302 is set to 80 to 400. The greater the number of second thin grids 302, the higher the carrier collection capability, but the more materials are consumed and the cost increases. As a result, by setting the number of second thin grids 302 to 80 to 400, the solar cell has a certain carrier collection capability and the cost of the solar cell can be reduced. By providing first spot weld group 303 located on front surface 310 and arranging first spot weld group 303 to include multiple first spot welds 313, it is possible to control the connection between first spot welds 313 and first thin grid 301 and to facilitate the connection between first thin grid 301 and the main grid or PV relay.

[0149] Another embodiment of the present disclosure further provides a photovoltaic module, which includes some or all of the embodiments of the solar cell described above. Hereinafter, the photovoltaic module provided in another embodiment of the present disclosure will be described with reference to the drawings. For the same or corresponding parts as those in the above embodiments, please refer to the corresponding descriptions of the above embodiments. Hereinafter, the description will not be repeated.

[0150] As shown in Figures 18 and 19, Figure 18 is a diagram showing the structure of a photovoltaic module provided in an embodiment of the present disclosure, and Figure 19 is a cross-sectional view along the M1M2 direction of Figure 18 provided in one embodiment of the present disclosure.

[0151] In some embodiments, the photovoltaic module may include a cell string, with the cell string comprising solar cells 407 connected in series, and the solar cells 407 may include the solar cells in some or all of the embodiments described above.

[0152] The photovoltaic module may further include an encapsulation layer 409 for covering the surface of the cell string.

[0153] The photovoltaic module may further include a cover plate 400 for covering the surface of the encapsulation layer 409 remote from the cell string.

[0154] In some embodiments, the encapsulating layer 409 includes a first encapsulating layer (not shown) and a second encapsulating layer (not shown), where the first encapsulating layer covers one of the front surface and the back surface of the battery cell, and the second encapsulating layer covers the other of the front surface and the back surface of the battery cell. Specifically, at least one of the first encapsulating layer and the second encapsulating layer may be an organic encapsulating layer such as a polyvinyl butyral (PVB) adhesive film, an ethylene-vinyl acetate copolymer (EVA) adhesive film, a polyethylene-octene copolymer (polyolefin thermoplastic elastomer (POE)) adhesive film, or a polyethylene glycol terephthalate (PET) adhesive film.

[0155] As can be seen, there is a boundary between the first sealing layer and the second sealing layer before the lamination process is performed, and after the lamination process is performed, the concepts of the first sealing layer and the second sealing layer disappear in the molded photovoltaic module, and the first sealing layer and the second sealing layer are integrated to form sealing layer 207.

[0156] In some embodiments, the cover plate 400 may be a cover plate with a light-transmitting function, such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 400 facing the sealing layer 409 may be an uneven surface, thereby improving the utilization efficiency of incident light. The cover plate 400 includes a first cover plate and a second cover plate, where the first cover plate faces the first sealing layer and the second cover plate faces the second sealing layer.

[0157] In some embodiments, the photovoltaic module further includes a PV ribbon 401 connecting two adjacent solar cells 407 .

[0158] Those skilled in the art will understand that the above embodiments are specific examples for realizing the present disclosure, but that various changes in form and details are possible in practice without departing from the scope of the present disclosure. Since anyone skilled in the art can make changes and modifications without departing from the scope of the present disclosure, the scope of protection of the present disclosure should be based on the scope limited by the claims.

Claims

1. a cell string; a sealing layer for covering a surface of the cell string; and a cover plate for covering a surface of the sealing layer away from the cell string; The cell string comprises solar cells connected in series, each solar cell including a base, a plurality of thin grids arranged at intervals along a first direction, a plurality of groups of spot welds arranged along a second direction, a plurality of main grids arranged along the second direction, and a PV ribbon, wherein the base has a central region and peripheral regions located on both sides of the central region, the plurality of thin grids extend along the second direction, the group of spot welds includes a plurality of spot welds, the plurality of spot welds are arranged along the first direction, and one of the plurality of spot welds is located in the central region of one of the groups of spot welds. the number of spot welds is equal to the number of the thin grids located in the central region, and the spot welds located in the central region are connected to the thin grids in a one-to-one correspondence; the main grid is connected to all of the spot welds in the group of spot welds or to some of the spot welds in the group of spot welds, and at least one group of spot welds not connected to the main grid is present between two adjacent main grids; the PV ribbons connect two adjacent solar cells, and each PV ribbon is connected to a corresponding one of the spot weld groups of the solar cells; The spot welded portion includes two end portions facing each other along the second direction and a main body portion connecting the two end portions, wherein length dimensions of the two end portions in the first direction are greater than length dimensions of the main body portion in the first direction, and width dimensions of the two end portions in the second direction are smaller than width dimensions of the main body portion in the second direction. A photovoltaic module characterized by:

2. Between any two adjacent main grids, there is a group of spot welds that is not connected to at least one of the main grids.

2. The photovoltaic module of claim 1.

3. Between some two adjacent main grids, there is one group of spot welds that is not connected to the main grid, and between some two adjacent main grids, there are multiple groups of spot welds that are not connected to the main grid.

3. The photovoltaic module of claim 2.

4. the main grid includes a first main grid and a second main grid; one first main grid is connected to all of the spot welds in one group of spot welds; one second main grid is connected to some of the spot welds in one of the spot weld group; 2. The photovoltaic module of claim 1.

5. At least one group of spot welds is present between the first main grid and the second main grid that are adjacent to each other and is not connected to the main grid.

5. The photovoltaic module of claim 4.

6. a width dimension of the first main grid in the second direction being larger than a width dimension of the second main grid in the second direction; 5. The photovoltaic module of claim 4.

7. the base includes opposing front and back surfaces; the fine grid, the group of spot welds, and the main grid are provided on the front surface and the back surface, respectively, and an orthogonal projection on the front surface of the main grid at least a portion of which is located on the front surface does not overlap with an orthogonal projection on the front surface of the main grid at least a portion of which is located on the back surface; 2. The photovoltaic module of claim 1.

8. the base includes opposing front and back surfaces, the thin grid, the group of spot welds, and the main grid are provided on the front surface, and the thin grid and the group of spot welds are provided on the back surface; 2. The photovoltaic module of claim 1.

9. The number of the spot weld groups is N, the number of the main grids is n, where N / 4≦n<N, and both n and N are positive integers.

2. The photovoltaic module of claim 1.

10. The number of the spot weld groups is 15 to 22.

10. The photovoltaic module according to claim 1.

11. The number of the main grids is 4 to 11.

2. The photovoltaic module of claim 1.

12. an area of an orthogonal projection of the spot weld at the base of the central region that is closest to the peripheral region is greater than an area of an orthogonal projection of the spot weld at the base that is farthest from the peripheral region of the central region; 2. The photovoltaic module of claim 1.

13. the base includes a front surface and a back surface, and the plurality of thin grids include a plurality of first thin grids arranged at intervals along the first direction and a plurality of second thin grids arranged at intervals along the first direction; a plurality of the first thin grids extending along the second direction, the first thin grids being located on the front surface, and the number of the first thin grids being 70 to 150; a plurality of the second thin grids extend along the second direction, the second thin grids are located on the back surface, and the number of the second thin grids is 80 to 400; the plurality of spot weld groups includes a plurality of first spot weld groups arranged along the second direction, the first spot weld groups are located on the front surface, each of the first spot weld groups includes a plurality of first spot welds, the plurality of first spot welds are arranged along the first direction, and one of the first spot welds is connected to one of the first thin grids; 2. The photovoltaic module of claim 1.

14. the width of the first thin grid is 10 to 30 μm and / or the width of the second thin grid is 15 to 50 μm; 14. The photovoltaic module of claim 13.

15. the height of the first thin grid is 6 to 30 μm and / or the height of the second thin grid is 4 to 25 μm; 14. The photovoltaic module of claim 13.

16. the number of the first spot welds in the group is 12 to 26; 14. The photovoltaic module of claim 13.

17. the plurality of main grids include a plurality of first main grids arranged along the second direction, the first main grids being located on the front surface, the first main grids being connected to the first spot welds group, and at least one first spot welds group not connected to the main grids being located between two adjacent first main grids; 14. The photovoltaic module of claim 13.

18. the plurality of spot weld groups include a plurality of second spot weld groups arranged along the second direction, and the plurality of main grids include a plurality of second main grids arranged along the second direction; wherein the second spot weld groups are located on the back surface, each of the second spot weld groups includes a plurality of second spot welds, the plurality of second spot welds are arranged along the first direction, one second spot weld is connected to one second thin grid, and an orthogonal projection of the first spot weld groups on the front surface is misaligned with an orthogonal projection of the second spot weld groups on the front surface; the second main grid is located on the back surface, the second main grid is connected to the second spot weld group, and an orthogonal projection of the first main grid on the front surface is offset from an orthogonal projection of the second main grid on the front surface; 18. The photovoltaic module of claim 17.

Images