Solar cell and photovoltaic module

Abstract

The invention discloses a solar cell and a photovoltaic module, and belongs to the technical field of photovoltaic modules. The solar cell piece comprises a cell piece, the surface of the cell piece is provided with a first fine grid and a second fine grid which extend in the first direction, the surface of the cell piece is provided with a first area and a second area, the second area and the second area extend in the second direction, and the surface roughness of the first area is larger than that of the second area; the first electric connection disc is arranged in the first area of the battery piece, the first electric connection disc is connected to the at least one first fine grid, and the first electric connection disc has a first projection on the plane where the battery piece is located; the second electric connection disc is arranged in the second area of the battery piece, the second electric connection disc is connected to at least one second fine grid, the second electric connection disc has a second projection on the plane where the battery piece is located, and the area of the first projection is smaller than that of the second projection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic, in particular to a solar cell and a photovoltaic module. BACKGROUND

[0002] The solar cell as a core component of the photovoltaic module can convert solar energy into electrical energy. The surface of the cell is provided with a fine grid, which collects the carriers generated by the cell. The photovoltaic module also includes an electrical connector, which is arranged on the surface of the cell and is electrically connected to the fine grid to collect the carriers collected by the fine grid and transmit the collected carriers to the external circuit.

[0003] In related technologies, a solder pad is arranged between the fine grid and the electrical connector, and the solder pad is welded with the electrical connector to improve the reliability of the electrical connection between the electrical connector and the cell.

[0004] However, the solder pad is usually made of metal such as tin and silver. The arrangement of the solder pad results in high manufacturing cost of the cell, which in turn results in high cost of the photovoltaic module, affecting the product competitiveness of the photovoltaic module. SUMMARY

[0005] The present application discloses a solar cell and a photovoltaic module to solve or at least partially solve the problem that the manufacturing cost of the cell is too high, resulting in high cost of the photovoltaic module, affecting the product competitiveness of the photovoltaic module.

[0006] To solve the above technical problems, the present application is implemented as follows: In a first aspect, the present application discloses a solar cell, which comprises a cell, a first fine grid and a second fine grid arranged on the surface of the cell and extending in a first direction, a first region and a second region on the surface of the cell, the first region and the second region extending in a second direction, the surface roughness of the first region being greater than that of the second region, and the second direction intersecting the first direction; a first electrical connection pad arranged on the first region of the cell, the first electrical connection pad being connected to at least one of the first fine grid, the first electrical connection pad having a first projection on the plane of the cell; and a second electrical connection pad arranged on the second region of the cell, the second electrical connection pad being connected to at least one of the second fine grid, the second electrical connection pad having a second projection on the plane of the cell, the area of the first projection being smaller than that of the second projection.

[0007] In some embodiments, the first electrical connecting pad comprises at least one first sub-electrical connecting pad having a third projection on the plane of the cell; and the second electrical connecting pad comprises at least one second sub-electrical connecting pad having a fourth projection on the plane of the cell, wherein the area of the third projection is smaller than the area of the fourth projection.

[0008] In some embodiments, along the second direction, the cell has a first side and a second side arranged oppositely; the first sub-electrical connecting pad is arranged at a position close to the first side and / or the second side in the first region; and / or the second sub-electrical connecting pad is arranged at a position close to the first side or the second side in the second region.

[0009] In some embodiments, the first electrical connecting pad further comprises at least one third sub-electrical connecting pad, which is arranged in the first region of the cell and spaced apart from the first sub-electrical connecting pad along the second direction; and / or the second electrical connecting pad further comprises at least one fourth sub-electrical connecting pad, which is arranged in the second region of the cell and spaced apart from the second sub-electrical connecting pad along the second direction.

[0010] In some embodiments, the first sub-electrical connecting pad is arranged at a position close to the first side and / or the second side in the first region; the third sub-electrical connecting pad comprises a plurality of third sub-electrical connecting pads, which are arranged in the first region and spaced apart from the first sub-electrical connecting pad along the second direction and away from the first side or the second side; and / or the second sub-electrical connecting pad is arranged at a position close to the first side and / or the second side in the second region; the fourth sub-electrical connecting pad comprises a plurality of fourth sub-electrical connecting pads, which are arranged in the second region and spaced apart from the second sub-electrical connecting pad along the second direction and away from the first side or the second side.

[0011] In some embodiments, the third sub-electrical connecting pad has a fifth projection on the plane of the cell, and the fourth sub-electrical connecting pad has a sixth projection on the plane of the cell; the area of the fifth projection is smaller than the area of the sixth projection; or the area of the fifth projection is equal to the area of the sixth projection.

[0012] In some embodiments, the area of the fifth projection is smaller than the area of the third projection, and the area of the sixth projection is smaller than the area of the fourth projection; or the area of the fifth projection is smaller than the area of the third projection, and the area of the sixth projection is equal to the area of the fourth projection.

[0013] In some embodiments, the first electrical connecting pad further comprises at least one fifth sub-electrical connecting pad, the fifth sub-electrical connecting pad is arranged in the first region of the battery piece and spaced apart from the first sub-electrical connecting pad and the third sub-electrical connecting pad along the second direction; and / or, the second electrical connecting pad further comprises at least one sixth sub-electrical connecting pad, the sixth sub-electrical connecting pad is arranged in the second region of the battery piece and spaced apart from the second sub-electrical connecting pad and the fourth sub-electrical connecting pad along the second direction.

[0014] In some embodiments, the fifth sub-electrical connecting pad has a seventh projection on the plane of the battery piece, the sixth sub-electrical connecting pad has an eighth projection on the plane of the battery piece; the area of the seventh projection is smaller than the area of the eighth projection; or, the area of the seventh projection is equal to the area of the eighth projection.

[0015] In some embodiments, the area of the seventh projection is smaller than the area of the third projection and the area of the fifth projection, and the area of the eighth projection is smaller than the area of the fourth projection and the area of the sixth projection.

[0016] In some embodiments, the first sub-electrical connecting pad is arranged at a position close to the first side edge and / or the second side edge in the first region; the third sub-electrical connecting pad and the fifth sub-electrical connecting pad each comprise a plurality of sub-electrical connecting pads, the plurality of third sub-electrical connecting pads and the plurality of fifth sub-electrical connecting pads are arranged in the first sub-electrical connecting pad away from the first side edge or the second side edge along the second direction; and / or, the second sub-electrical connecting pad is arranged at a position close to the first side edge and / or the second side edge in the second region; the fourth sub-electrical connecting pad and the sixth sub-electrical connecting pad each comprise a plurality of sub-electrical connecting pads, the plurality of fourth sub-electrical connecting pads and the plurality of sixth sub-electrical connecting pads are arranged in the second sub-electrical connecting pad away from the first side edge or the second side edge along the second direction.

[0017] In some embodiments, the battery piece further comprises: a first end connecting portion, the first end connecting portion is arranged in the first region of the battery piece, the first end connecting portion is located between the first electrical connecting pad and the first side edge, and / or the first end connecting portion is located between the first electrical connecting pad and the second side edge; and / or, a second end connecting portion, the second end connecting portion is arranged in the second region of the battery piece, the second end connecting portion is located between the second electrical connecting pad and the first side edge, and / or the second end connecting portion is located between the second electrical connecting pad and the second side edge.

[0018] In some embodiments, the first end connecting part is a strip structure, the first end connecting part extends along the second direction, and one end of the first end connecting part is connected with the first electric connecting pad; and / or, the second end connecting part is a strip structure, the second end connecting part extends along the second direction, and one end of the second end connecting part is connected with the second electric connecting pad.

[0019] In some embodiments, along the direction from the first electric connecting pad to the first side edge, the width of the first end connecting part along the first direction gradually decreases; and / or, along the direction from the second electric connecting pad to the first side edge, the width of the second end connecting part along the first direction gradually decreases.

[0020] In some embodiments, the first end connecting part has a ninth projection on the plane where the solar cell is located, the second end connecting part has a tenth projection on the plane where the solar cell is located, and the area of the ninth projection is smaller than the area of the tenth projection.

[0021] In some embodiments, the first end connecting part comprises at least one first electric connecting point, and the first electric connecting point is spaced apart from the first electric connecting pad along the second direction; and / or, the second end connecting part comprises at least one second electric connecting point, and the second electric connecting point is spaced apart from the second electric connecting pad along the second direction.

[0022] In some embodiments, the first electric connecting point has an eleventh projection on the plane where the solar cell is located, the second electric connecting point has a twelfth projection on the plane where the solar cell is located, and the area of the eleventh projection is smaller than the area of the twelfth projection.

[0023] In some embodiments, along the second direction, the solar cell has a first side edge and a second side edge arranged oppositely; from the first side edge and / or the second side edge towards the center of the solar cell, the area of a first projection of an Nth first electric connecting pad on the plane where the solar cell is located is smaller than the area of a second projection of an Nth second electric connecting pad on the plane where the solar cell is located; wherein N is a positive integer, and satisfies 1≤N≤6.

[0024] In some embodiments, along the thickness direction of the solar cell, the solar cell has a first surface and a second surface arranged oppositely, the first region is arranged on the first surface of the solar cell, and the second region is arranged on the second surface of the solar cell.

[0025] In some embodiments, the first surface is a front surface of the battery piece, and the first region has a first pyramid structure of the front surface of the battery piece; the battery piece comprises a silicon substrate, and the first region has a first intrinsic amorphous silicon layer, a first doped amorphous silicon layer, and a first transparent conductive layer which are sequentially stacked on the silicon substrate; or the first region has a first tunneling layer and a first doped polysilicon layer which are sequentially stacked on the silicon substrate; or the first region has a doped diffusion layer which is stacked on the silicon substrate; the second surface is a back surface of the battery piece, and the second region has a first polished surface of the back surface of the battery piece, or the second region has a second pyramid structure of the back surface of the battery piece; the second region has a second intrinsic amorphous silicon layer, a second doped amorphous silicon layer, and a second transparent conductive layer which are sequentially stacked on the silicon substrate; or the second region has a second tunneling layer and a second doped polysilicon layer which are sequentially stacked on the silicon substrate.

[0026] In some embodiments, along a thickness direction of the battery piece, the battery piece has a first surface and a second surface which are oppositely arranged; the first region and the second region are both arranged on the second surface of the battery piece.

[0027] In some embodiments, the second surface is a back surface of the battery piece, the first region has a third pyramid structure of the back surface of the battery piece, and the second region has a second polished surface of the back surface of the battery piece; the battery piece comprises a silicon substrate, the first region has a third intrinsic amorphous silicon layer, a third doped amorphous silicon layer, and a third transparent conductive layer which are sequentially stacked on the silicon substrate, and the second region has a third tunneling layer and a third doped polysilicon layer which are sequentially stacked on the silicon substrate; or the first region has a third polished surface of the back surface of the battery piece, and the second region has a fourth polished surface of the back surface of the battery piece; the first region has a fourth tunneling layer which is stacked on the silicon substrate, and the second region has a fifth tunneling layer which is stacked on the silicon substrate.

[0028] In some embodiments, the first fine grid comprises a plurality of first sub-fine grids, each of the plurality of first sub-fine grids extends along the first direction, and two adjacent first sub-fine grids are arranged at intervals along the first direction; the first electrical connecting pad is located between the two adjacent first sub-fine grids, and end portions of the first sub-fine grids on both sides of the first electrical connecting pad overlap the first electrical connecting pad away from the battery piece along a thickness direction of the battery piece.

[0029] In some embodiments, the first sub-electric connecting pad has a length along the first direction L1 satisfying 0.7mm≤L1≤1.3mm, and a width along the second direction L2 satisfying 0.8mm≤L2≤1.4mm; and / or, the second sub-electric connecting pad has a length along the first direction L3 satisfying 0.8mm≤L3≤1.4mm, and a width along the second direction L4 satisfying 0.9mm≤L4≤1.5mm.

[0030] In some embodiments, the first sub-electric connecting pad has a width along the second direction greater than a width of the first fine grid along the second direction; and / or, the second sub-electric connecting pad has a width along the second direction greater than a width of the second fine grid along the second direction.

[0031] In some embodiments, the third sub-electric connecting pad has a length along the first direction L5 satisfying 0.7mm≤L5≤1.3mm, and a width along the second direction L6 satisfying 0.03mm≤L6≤0.35mm; and / or, the fourth sub-electric connecting pad has a length along the first direction L7 satisfying 0.8mm≤L7≤1.4mm, and a width along the second direction L8 satisfying 0.025mm≤L8≤0.15mm.

[0032] In some embodiments, the third sub-electric connecting pad has a width along the second direction greater than a width of the first fine grid along the second direction; and / or, the fourth sub-electric connecting pad has a width along the second direction greater than a width of the second fine grid along the second direction.

[0033] In some embodiments, the fifth sub-electric connecting pad has a length along the first direction L9 satisfying 0.7mm≤L9≤1.3mm, and a width along the second direction L10 satisfying 0.03mm≤L10≤0.35mm; and / or, the sixth sub-electric connecting pad has a length along the first direction L11 satisfying 0.8mm≤L11≤1.4mm, and a width along the second direction L12 satisfying 0.025mm≤L12≤0.15mm.

[0034] In some embodiments, the fifth sub-electric connecting pad has a width along the second direction greater than a width of the first fine grid along the second direction; and / or, the sixth sub-electric connecting pad has a width along the second direction greater than a width of the second fine grid along the second direction.

[0035] In a second aspect, the application also discloses a photovoltaic module, comprising the solar cell sheet according to the first aspect; a first electrical connector, which is arranged on the first region of the cell sheet and is electrically connected to the first electrical connecting pad; and a second electrical connector, which is arranged on the second region of the cell sheet and is electrically connected to the second electrical connecting pad.

[0036] The application discloses a solar cell sheet and a photovoltaic module. The solar cell sheet comprises a cell sheet, a first fine grid and a second fine grid arranged on the surface of the cell sheet and extending along a first direction, a first region and a second region of the surface of the cell sheet, the first region and the second region extending along a second direction, the surface roughness of the first region being greater than that of the second region, a first electrical connecting pad arranged on the first region of the cell sheet, the first electrical connecting pad being connected to at least one first fine grid, the first electrical connecting pad having a first projection on the plane of the cell sheet, and a second electrical connecting pad arranged on the second region of the cell sheet, the second electrical connecting pad being connected to at least one second fine grid, the second electrical connecting pad having a second projection on the plane of the cell sheet, the area of the first projection being less than that of the second projection.

[0037] The solar cell disclosed in the embodiments of the present application has a first fine grid and a second fine grid extending along a first direction arranged on the surface of the cell to collect the carriers generated by the cell through the first fine grid and the second fine grid. The surface of the cell is divided into a first region and a second region, and the surface roughness of the first region is greater than that of the second region. A first electric connecting pad is arranged on the first region of the cell, and the first electric connecting pad is connected to at least one first fine grid to collect the carriers collected by the first fine grid, and the first electric connecting pad has a first projection in the plane of the cell. A second electric connecting pad is arranged on the second region of the cell, and the second electric connecting pad is connected to at least one second fine grid to collect the carriers collected by the second fine grid, and the second electric connecting pad has a second projection in the plane of the cell. The area of the first projection is set to be smaller than the area of the second projection. It can be understood that the area of the first electric connecting pad is smaller than the area of the second electric connecting pad, because the surface roughness of the first electric connecting pad is greater than that of the second electric connecting pad. When the electrical connection reliability (such as pull force, contact resistance, etc.) between the first electric connecting pad and the at least one first fine grid, and the electrical connection reliability (such as pull force, contact resistance, etc.) between the second electric connecting pad and the at least one second fine grid are guaranteed, the amount of material of the first electric connecting pad can be reduced, and the amount of material in the two regions does not need to be the same as in the prior art. Because the surface roughness is different, the pull force and the contact resistance of the first electric connecting pad in the region with greater surface roughness are relatively superior to those of the second electric connecting pad in the region with smaller surface roughness. Therefore, under the same conditions, the area of the first electric connecting pad in the region with greater surface roughness can be smaller, and less material can be used. In this way, the preparation cost of the cell is reduced, thereby reducing the preparation cost of the photovoltaic module and improving the product competitiveness of the photovoltaic module. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 A schematic diagram of a partial structure of a solar cell Figure 1 ; Figure 2 A schematic diagram of a partial structure of a solar cell Figure 2 ; Figure 3 A schematic diagram of a partial structure of a solar cell Figure 3 ; Figure 4 A schematic diagram of a partial structure of a solar cell Figure 4 ; Figure 5 A schematic diagram of a partial structure of a solar cell Figure 5 ; Figure 6A schematic diagram showing a partial structure of the solar cell in the embodiment of the present application Figure 6 ; Figure 7 A schematic diagram showing a partial structure of the solar cell in the embodiment of the present application Figure 7 ; Figure 8 A schematic diagram showing a partial structure of the solar cell in the embodiment of the present application Figure 8 ; Figure 9 A schematic diagram showing a partial structure of the solar cell in the embodiment of the present application Figure 9 ; Figure 10 A schematic diagram showing a partial structure of the second area of the bifacial solar cell in the embodiment of the present application Figure 11 A schematic diagram showing a partial structure of the first area of the bifacial solar cell in the embodiment of the present application Figure 12 A sectional view of the bifacial photovoltaic module in the embodiment of the present application Figure 13 A schematic diagram showing a structure of the back contact photovoltaic module in the embodiment of the present application

[0039] Reference signs: 10: cell; 11: first area; 12: second area; 13: first side edge; 14: first fine grid; 15: second fine grid 20: first electric connecting pad; 21: first sub-electric connecting pad; 22: third sub-electric connecting pad; 23: fifth sub-electric connecting pad 30: second electric connecting pad; 31: second sub-electric connecting pad; 32: fourth sub-electric connecting pad; 33: sixth sub-electric connecting pad 40: first end connecting part; 41: first electric connecting point 50: second end connecting part; 51: second electric connecting point 60: first electric connecting member 70: second electric connecting member X: first direction; Y: second direction DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present application.

[0041] It should be understood that every feature, structure, characteristic, and / or

[0042] As shown in Figure 1 , Figure 2 , Figure 4 , Figure 5 The embodiment of the present application discloses a solar cell, which comprises a cell, the surface of the cell 10 is provided with a first fine grid 14 and a second fine grid 15 extending along a first direction X, the surface of the cell 10 has a first area 11 and a second area 12, the first area 11 and the second area 12 both extend along a second direction Y, the surface roughness of the first area 11 is greater than that of the second area 12, and the second direction Y intersects the first direction X; a first electrical connecting plate 20 is arranged on the first area 11 of the cell 10, the first electrical connecting plate 20 is connected to at least one first fine grid 14, and the first electrical connecting plate 20 has a first projection on the plane of the cell 10; a second electrical connecting plate 30 is arranged on the second area 12 of the cell 10, the second electrical connecting plate 30 is connected to at least one second fine grid 15, and the second electrical connecting plate 30 has a second projection on the plane of the cell 10, and the area of the first projection is smaller than that of the second projection.

[0043] The embodiment of the present application discloses a solar cell, which is a core component of a photovoltaic module and can convert solar energy into electrical energy. The solar cell can be a back contact type solar cell and can be a double-sided solar cell. In the embodiment of the present application, the specific type of the solar cell is not limited too much, and in actual application, a technician can select as needed.

[0044] As shown in Figure 1 , Figure 2 , Figure 4 , Figure 5 The surface of the cell 10 is provided with a first fine grid 14 and a second fine grid 15 extending along a first direction X to collect the carriers generated by the cell 10 through the first fine grid 14 and the second fine grid 15. Exemplarily, when the cell 10 is a double-sided cell, the first fine grid 14 can be arranged on the front surface of the cell 10, and the second fine grid 15 is arranged on the back surface of the cell 10. Alternatively, when the cell 10 is a back contact type cell, the first fine grid 14 and the second fine grid 15 both extend along the first direction X and are alternately and spacedly arranged on the back surface of the cell 10 along the second direction Y.

[0045] In the embodiments of the present application, the surface of the battery piece 10 is provided with a first area 11 and a second area 12, and the first area 11 and the second area 12 both extend along the second direction Y. For example, when the battery piece 10 is a double-sided battery piece, the first area 11 can be arranged on the front surface of the battery piece 10, and the second area 12 can be arranged on the back surface of the battery piece 10. Alternatively, when the battery piece 10 is a back contact type battery piece, the first area 11 and the second area 12 both extend along the second direction Y and are alternately and spacedly arranged on the back surface of the battery piece 10 along the first direction X.

[0046] In the embodiments of the present application, the surface roughness of the first area 11 is greater than the surface roughness of the second area 12. The surface roughness refers to the unevenness of the micro-geometric shape of the surface of the first area 11 and the second area 12, which is characterized by the fluctuation of micro-peak and valley. It should be noted that the surface of the first area 11 or the second area 12, whether it is a pyramid pattern or a polished surface pattern, has its own surface roughness.

[0047] In practice, the surface morphology of the first area 11 and the second area 12 can be obtained by observing interference fringes through a microscope using the principle of light wave interference, so as to determine the surface roughness of the first area 11 and the second area 12. Alternatively, the surface roughness of the first area 11 and the second area 12 can be measured by a laser heat dissipation method. Specifically, the scattering mode of laser on the first area 11 and the second area 12 can be analyzed to deduce the surface roughness of the first area 11 and the second area 12. Alternatively, the surface structure of a material can be studied by detecting the extremely weak interatomic interaction force between the surface of a sample to be measured and a micro force sensitive element through an atomic force microscope. The surface morphology structure information and the surface roughness information can be obtained by using a sensor to detect these changes, so as to determine the surface roughness of the first area 11 and the second area 12.

[0048] As Figure 1 , Figure 2 , Figure 4 , Figure 5As shown, the solar cell disclosed by the embodiment of the present application further comprises a first electrical connecting pad 20 and a second electrical connecting pad 30. The first electrical connecting pad 20 is arranged on the first region 11 of the solar cell 10, and the first electrical connecting pad 20 is connected to the at least one first fine grid 14. The at least one first fine grid 14 is connected to the first electrical connecting member 60 through the first electrical connecting pad 20, so as to improve the reliability of the electrical connection between the first electrical connecting member 60 and the first fine grid 14. The second electrical connecting pad 30 is arranged on the second region 12 of the solar cell 10, and the second electrical connecting pad 30 is connected to the at least one second fine grid 15. The at least one second fine grid 15 is connected to the second electrical connecting member 70 through the second electrical connecting pad 30, so as to improve the reliability of the electrical connection between the second electrical connecting member 70 and the second fine grid 15. The first electrical connecting pad 20 includes but is not limited to a first solder pad and a first pad point. The second electrical connecting pad 30 includes but is not limited to a second solder pad and a second pad point. The first electrical connecting pad 20 is used to electrically connect the first electrical connecting member 60 and the first fine grid 14, so as to improve the reliability of the electrical connection between the first electrical connecting member 60 and the first fine grid 14. The second electrical connecting pad 30 is used to electrically connect the second electrical connecting member 70 and the second fine grid 15, so as to improve the reliability of the electrical connection between the second electrical connecting member 70 and the second fine grid 15.

[0049] It should be noted that the first electrical connecting pad 20 in the embodiment of the present application has a first projection on the plane of the solar cell 10, and the second electrical connecting pad 30 has a second projection on the plane of the solar cell 10. The area of the first projection is smaller than the area of the second projection. It can be understood that the area of the first electrical connecting pad 20 is smaller than the area of the second electrical connecting pad 30, because the surface roughness of the first electrical connecting pad 20 is greater than the surface roughness of the second electrical connecting pad 30. When the electrical connection reliability (such as pulling force and contact resistance) between the first electrical connecting pad 20 and the at least one first fine grid 14 and the electrical connection reliability (such as pulling force and contact resistance) between the second electrical connecting pad 30 and the at least one second fine grid 15 are guaranteed, the amount of material of the first electrical connecting pad 20 can be reduced, and the same amount of material in the two regions does not need to be used according to the prior art. Because the surface roughness is different, the pulling force and the contact resistance of the first electrical connecting pad 20 in the region with greater surface roughness are relatively superior to the pulling force and the contact resistance of the second electrical connecting pad 30 in the region with smaller surface roughness. Therefore, under the same conditions, the area of the first electrical connecting pad 20 in the region with greater surface roughness can be smaller, and less material can be used. In this way, the preparation cost of the solar cell 10 is reduced, thereby reducing the preparation cost of the photovoltaic module and improving the product competitiveness of the photovoltaic module.

[0050] In some embodiments, as Figure 3 , Figure 6 , Figure 7As shown in FIG. 1, the first electric connecting plate 20 includes at least one first sub electric connecting plate 21, and the first sub electric connecting plate 21 has a third projection in the plane of the battery piece 10; the second electric connecting plate 30 includes at least one second sub electric connecting plate 31, and the second sub electric connecting plate 31 has a fourth projection in the plane of the battery piece 10, and the area of the third projection is less than the area of the fourth projection.

[0051] In the embodiments of the present application, as shown in FIG. 1, Figure 3 , Figure 6 , Figure 7 As shown in FIG. 1, the first electric connecting plate 20 includes at least one first sub electric connecting plate 21, and the second electric connecting plate 30 includes at least one second sub electric connecting plate 31, and the third projection of the first sub electric connecting plate 21 in the plane of the battery piece 10 is set to be less than the fourth projection of the second sub electric connecting plate 31 in the plane of the battery piece 10. That is, the area of the first sub electric connecting plate 21 is less than the area of the second sub electric connecting plate 31, and while ensuring the electrical connection reliability between the first sub electric connecting plate 21 and the first fine grid 14 and the electrical connection reliability between the second sub electric connecting plate 31 and the second fine grid 15, the material usage of the first sub electric connecting plate 21 is reduced, thereby reducing the preparation cost of the battery piece 10, reducing the preparation cost of the photovoltaic module, and improving the product competitiveness of the photovoltaic module.

[0052] The specific effect analysis can refer to the effect analysis of the first electric connecting plate 20 and the second electric connecting plate 30 above. Especially in the case where there are multiple first sub electric connecting plates 20 and second sub electric connecting plates 31 on one battery piece 10, the cost saving of the material can be significantly improved, and the preparation cost of the battery piece can be greatly reduced, and the product competitiveness of the photovoltaic module can be significantly improved.

[0053] In some embodiments, as shown in FIG. 1, Figure 3 , Figure 6 , Figure 7 As shown in FIG. 1, along the second direction Y, the battery piece 10 has a first side edge 13 and a second side edge 13 arranged oppositely; the first sub electric connecting plate 21 is arranged at a position close to the first side edge 13 and / or the second side edge of the first region 11; and / or, the second sub electric connecting plate 31 is arranged at a position close to the first side edge 13 or the second side edge of the second region 12.

[0054] The solar battery piece disclosed in the embodiments of the present application can be a rectangular battery piece or a quasi-rectangular battery piece. The quasi-rectangular battery piece refers to a rectangular battery piece provided with a chamfer. Along the second direction Y, the battery piece 10 has a first side edge 13 and a second side edge arranged oppositely.

[0055] The first sub-electric connecting pad 21 can be arranged at the position close to the first side edge 13 of the first area 11, or the first sub-electric connecting pad 21 can be arranged at the position close to the second side edge of the first area 11, or the first sub-electric connecting pad 21 can be arranged at the position close to the first side edge 13 and the position close to the second side edge of the first area 11. It can be understood that the first sub-electric connecting pad 21 is a large PAD point, the first sub-electric connecting pad 21 can not only fix the first electric connecting piece 60 at the position close to the first side edge 13 and / or the second side edge of the first area 11, but also fix the end of the first electric connecting piece 60, avoid the end of the first electric connecting piece 60 forming a free end, contacting and conducting with the second electric connecting piece 70 or the second fine grid 15, and causing the photovoltaic module to appear a local short circuit phenomenon. In addition, the first sub-electric connecting pad 21 can also collect the carriers generated by the solar cell 10 close to the first side edge 13 and / or the second side edge, and transmit the collected carriers to the external circuit, so as to improve the collection efficiency of the carriers and ensure the photoelectric conversion efficiency of the solar cell.

[0056] In the embodiment of the application, the second sub-electric connecting pad 31 can be arranged at the position close to the first side edge 13 of the second area 12, or the second sub-electric connecting pad 31 can be arranged at the position close to the second side edge of the second area 12, or the second sub-electric connecting pad 31 can be arranged at the position close to the first side edge 13 and the position close to the second side edge of the second area 12. It can be understood that the second sub-electric connecting pad 31 is a large PAD point, the second sub-electric connecting pad 31 can not only fix the second electric connecting piece 70 at the position close to the first side edge 13 and / or the second side edge of the second area 12, but also fix the end of the second electric connecting piece 70, avoid the end of the second electric connecting piece 70 forming a free end, contacting and conducting with the first electric connecting piece 60 or the first fine grid 14, and causing the photovoltaic module to appear a local short circuit phenomenon, and affecting the photoelectric conversion efficiency of the photovoltaic module. In addition, the second sub-electric connecting pad 31 can also collect the carriers generated by the solar cell 10 close to the first side edge 13 and / or the second side edge, and transmit the collected carriers to the external circuit, so as to improve the collection efficiency of the carriers and ensure the photoelectric conversion efficiency of the solar cell.

[0057] In some embodiments, as shown in FIGS. 1 to 3, the first electric connecting pad 20 includes at least one first sub-electric connecting pad 21, and the second electric connecting pad 30 includes at least one second sub-electric connecting pad 31. Figure 3 、 Figure 6 、 Figure 7 As shown in FIGS. 1 to 3, the first electric connecting pad 20 further includes at least one third sub-electric connecting pad 22, and the third sub-electric connecting pad 22 is arranged at the first area 11 of the solar cell 10 in the second direction Y and is spaced apart from the first sub-electric connecting pad 21; and / or the second electric connecting pad 30 further includes at least one fourth sub-electric connecting pad 32, and the fourth sub-electric connecting pad 32 is arranged at the second area 12 of the solar cell 10 in the second direction Y and is spaced apart from the second sub-electric connecting pad 31.

[0058] The first electric connection pad 20 in the embodiment of the present application further comprises a third sub-electric connection pad 22 arranged in the first region 11 in the second direction Y and spaced from the first sub-electric connection pad 21. The third sub-electric connection pad 22 can include only one or multiple. Here, the specific number of the third sub-electric connection pad 22 is not limited too much. In actual application, the specific number of the third sub-electric connection pad 22 can be set by the technician according to the need.

[0059] In the embodiment of the present application, the first electric connection pad 20 fixes the first electric connection piece 60 to the first region 11 of the solar cell 10 through the first sub-electric connection pad 21 and the third sub-electric connection pad 22, so that the first sub-electric connection pad 21 and the third sub-electric connection pad 22 electrically connect the first electric connection piece 60 and the first fine grid 14 together, collect the carriers collected by the first fine grid 14, and transmit the collected carriers to the external circuit, thereby ensuring the photoelectric conversion efficiency of the solar cell.

[0060] The second electric connection pad 30 in the embodiment of the present application further comprises a fourth sub-electric connection pad 32 arranged in the second region 12 in the second direction Y and spaced from the second sub-electric connection pad 31. The fourth sub-electric connection pad 32 can include only one or multiple. Here, the specific number of the fourth sub-electric connection pad 32 is not limited too much. In actual application, the specific number of the fourth sub-electric connection pad 32 can be set by the technician according to the need.

[0061] In the embodiment of the present application, the second electric connection pad 30 fixes the second electric connection piece 70 to the second region 12 of the solar cell 10 through the second sub-electric connection pad 31 and the fourth sub-electric connection pad 32, so that the second sub-electric connection pad 31 and the fourth sub-electric connection pad 32 electrically connect the second electric connection piece 70 and the second fine grid 15 together, collect the carriers collected by the second fine grid 15, and transmit the collected carriers to the external circuit, thereby ensuring the photoelectric conversion efficiency of the solar cell.

[0062] In some embodiments, as shown in Figure 3 , Figure 6 , Figure 7 The first sub-electric connection pad 21 is arranged at a position close to the first side edge 13 and / or the second side edge in the first region 11; the third sub-electric connection pad 22 includes multiple, and the multiple third sub-electric connection pads 22 are arranged in the second direction Y at positions away from the first side edge 13 or the second side edge of the first sub-electric connection pad 21; and / or, the second sub-electric connection pad 30 is arranged at a position close to the first side edge 13 and / or the second side edge in the second region 12; the fourth sub-electric connection pad 32 includes multiple, and the multiple fourth sub-electric connection pads 32 are arranged in the second direction Y at positions away from the first side edge 13 or the second side edge of the second sub-electric connection pad 31.

[0063] Exemplarily, the first sub-electric connecting pad 21 is arranged at a position close to the first side edge 13 of the first region 11, and the plurality of third sub-electric connecting pads 22 are arranged at positions away from the first side edge 13 of the first sub-electric connecting pad 21 along the second direction Y. Alternatively, the first sub-electric connecting pad 21 is arranged at a position close to the second side edge of the first region 11, and the plurality of third sub-electric connecting pads 22 are arranged at positions away from the second side edge of the first sub-electric connecting pad 21 along the second direction Y. Alternatively, the first sub-electric connecting pad 21 includes two, one first sub-electric connecting pad 21 is arranged at a position close to the first side edge 13 of the first region 11, and the other first sub-electric connecting pad 21 is arranged at a position close to the second side edge of the first region 11, and the plurality of third sub-electric connecting pads 22 are arranged between the two first sub-electric connecting pads 21 along the second direction Y.

[0064] It can be understood that the third sub-electric connecting pad 22 is a middle PAD point with a smaller projection area than the first sub-electric connecting pad 21, and the first electric connecting piece 60 is fixed to the first region 11 of the battery piece 10 through the first sub-electric connecting pad 21 and the third sub-electric connecting pad 22. The first sub-electric connecting pad 21 can fix the end of the first electric connecting piece 60, and the third sub-electric connecting pad 22 can fix the middle part of the first electric connecting piece 60, thereby ensuring the reliability of the electrical connection between the first electric connecting piece 60 and the first fine grid 14, improving the collection efficiency of the carriers, and ensuring the photoelectric conversion efficiency of the solar battery piece. The plurality of third sub-electric connecting pads 22 are arranged at intervals, which can regularly apply stress to the battery piece by the first electric connecting piece 60, avoid stress concentration in one area, and make the stress more evenly distributed, thereby reducing the risk of hidden cracking of the battery piece.

[0065] Exemplarily, the second sub-electric connecting pad 31 is arranged at a position close to the first side edge 13 of the second region 12, and the plurality of fourth sub-electric connecting pads 32 are arranged at positions away from the first side edge 13 of the second sub-electric connecting pad 31 along the second direction Y. Alternatively, the second sub-electric connecting pad 31 is arranged at a position close to the second side edge of the second region 12, and the plurality of fourth sub-electric connecting pads 32 are arranged at positions away from the second side edge of the second sub-electric connecting pad 31 along the second direction Y. Alternatively, the second sub-electric connecting pad 31 includes two, one second sub-electric connecting pad 31 is arranged at a position close to the first side edge 13 of the second region 12, and the other second sub-electric connecting pad 31 is arranged at a position close to the second side edge of the second region 12, and the plurality of fourth sub-electric connecting pads 32 are arranged between the two second sub-electric connecting pads 31 along the second direction Y.

[0066] It can be understood that the fourth sub-electric connecting pad 32 is a middle PAD point with a smaller projection area than the second sub-electric connecting pad 31. The second electric connecting piece 70 is fixed to the second area 12 of the battery piece 10 through the second sub-electric connecting pad 31 and the fourth sub-electric connecting pad 32. The second sub-electric connecting pad 31 can fix the end of the second electric connecting piece 70, and the fourth sub-electric connecting pad 32 can fix the middle part of the second electric connecting piece 70, thereby ensuring the reliability of the electrical connection between the second electric connecting piece 70 and the second fine grid 15, improving the collection efficiency of the carriers, and ensuring the photoelectric conversion efficiency of the solar cell piece. The plurality of fourth sub-electric connecting pads 32 are arranged at intervals, which can regularly apply stress to the battery piece by the second electric connecting piece 70, avoid stress concentration in one area, make the stress more evenly distributed, and reduce the risk of hidden cracking of the battery piece.

[0067] In some embodiments, the third sub-electric connecting pad 22 has a fifth projection on the plane of the battery piece 10, and the fourth sub-electric connecting pad 32 has a sixth projection on the plane of the battery piece 10. The area of the fifth projection is smaller than the area of the sixth projection, or the area of the fifth projection is equal to the area of the sixth projection.

[0068] In the embodiments of the present application, the area of the fifth projection of the third sub-electric connecting pad 22 on the plane of the battery piece 10 is set to be smaller than the area of the sixth projection of the fourth sub-electric connecting pad 32 on the plane of the battery piece 10. It can be understood that the area of the third sub-electric connecting pad 22 is smaller than the area of the fourth sub-electric connecting pad 32, so as to reduce the material usage of the third sub-electric connecting pad 22 while ensuring the electrical connection reliability between the third sub-electric connecting pad 22 and the at least one first fine grid 14, and the electrical connection reliability between the fourth sub-electric connecting pad 32 and the at least one second fine grid 15. In this way, the preparation cost of the battery piece 10 is reduced, thereby reducing the preparation cost of the photovoltaic module and improving the product competitiveness of the photovoltaic module.

[0069] The specific effect analysis can refer to the effect analysis of the first electric connecting pad 20 and the second electric connecting pad 30 above. Especially in the case where there are a plurality of third sub-electric connecting pads 22 and fourth sub-electric connecting pads 32 on one battery piece 10, the cost saving of the material can be significantly improved, and the preparation cost of the battery piece can be greatly reduced, thereby significantly improving the product competitiveness of the photovoltaic module.

[0070] Or, the fifth projected area of the third sub-electric connecting pad 22 on the plane of the battery piece 10 is set to be equal to the sixth projected area of the fourth sub-electric connecting pad 32 on the plane of the battery piece 10. It can be understood that the area of the third sub-electric connecting pad 22 is equal to the area of the fourth sub-electric connecting pad 32, so as to ensure that the third sub-electric connecting pad 22 can electrically connect the first electric connecting piece 60 and the at least one first fine grid 14 together, the fourth sub-electric connecting pad 32 can electrically connect the second electric connecting piece 70 and the at least one second fine grid 15 together, the carriers collected by the first fine grid 14 through the first electric connecting piece 60 are collected, the carriers collected by the second fine grid 15 through the second electric connecting piece 70 are collected, and the photoelectric conversion efficiency of the solar cell piece is ensured.

[0071] Further, since the area of the first sub-electric connecting pad 21 is less than the area of the second sub-electric connecting pad 31, and the area of the third sub-electric connecting pad 22 is equal to the area of the fourth sub-electric connecting pad 32. That is, the sum of the areas of the first sub-electric connecting pad 21 and the third sub-electric connecting pad 22 is still less than the sum of the areas of the second sub-electric connecting pad 31 and the fourth sub-electric connecting pad 32, and therefore, the material usage of the electric connecting pad in the first area 11 is still less than the material usage of the electric connecting pad in the second area 12, thereby helping to reduce the preparation cost of the solar cell piece, reduce the preparation cost of the photovoltaic module, and improve the product competitiveness of the photovoltaic module. It can also prevent the projected area of the third sub-electric connecting pad 22 from being too small, reduce the subsequent process precision and difficulty, and ensure the reliability and yield of the product.

[0072] In some embodiments, the fifth projected area is less than the third projected area, and the sixth projected area is less than the fourth projected area; or, the fifth projected area is less than the third projected area, and the sixth projected area is equal to the fourth projected area.

[0073] In the embodiments of the present application, the fifth projected area of the third sub-electric connecting pad 22 on the plane of the battery piece 10 is set to be less than the third projected area of the first sub-electric connecting pad 21 on the plane of the battery piece 10, and the sixth projected area of the fourth sub-electric connecting pad 32 on the plane of the battery piece 10 is set to be less than the fourth projected area of the second sub-electric connecting pad 31 on the plane of the battery piece 10. That is, the area of the third sub-electric connecting pad 22 is less than the area of the first sub-electric connecting pad 21, and the area of the fourth sub-electric connecting pad 32 is less than the area of the second sub-electric connecting pad 21. Therefore, the material usage of the third sub-electric connecting pad 22 is less than the material usage of the first sub-electric connecting pad 21, and the material usage of the fourth sub-electric connecting pad 32 is less than the material usage of the second sub-electric connecting pad 31, so as to further reduce the preparation cost of the battery piece 10, reduce the preparation cost of the photovoltaic module, and improve the product competitiveness of the photovoltaic module.

[0074] Alternatively, the area of the fifth projection of the third sub-electric connecting pad 22 on the plane of the battery piece 10 is set to be less than the area of the third projection of the first electric connecting pad 21 on the plane of the battery piece 10, and the area of the sixth projection of the fourth sub-electric connecting pad 32 on the plane of the battery piece 10 is set to be equal to the area of the fourth projection of the second sub-electric connecting pad 31 on the plane of the battery piece 10. That is, the area of the third sub-electric connecting pad 22 is less than the area of the first sub-electric connecting pad 21, and the area of the fourth sub-electric connecting pad 32 is equal to the area of the second sub-electric connecting pad 21. In this way, the amount of material of the third sub-electric connecting pad 22 is reduced, thereby reducing the preparation cost of the solar battery piece.

[0075] In some embodiments, as shown in Figure 8 and Figure 9 The first electric connecting pad 20 further includes at least one fifth sub-electric connecting pad 23 arranged in the first region 11 of the battery piece 10 and spaced apart from the first sub-electric connecting pad 21 and the third sub-electric connecting pad 22 along the second direction Y, and / or the second electric connecting pad 30 further includes at least one sixth sub-electric connecting pad 33 arranged in the second region 12 of the battery piece 10 and spaced apart from the second sub-electric connecting pad 31 and the fourth sub-electric connecting pad 32 along the second direction Y.

[0076] As shown in Figure 8 and Figure 9 The first electric connecting pad 20 in the embodiments of the present application further includes the fifth sub-electric connecting pad 23 arranged in the first region 11 and spaced apart from the first sub-electric connecting pad 21 and the third sub-electric connecting pad 22 along the second direction Y. The fifth sub-electric connecting pad 23 can include only one or multiple. Here, the specific number of the fifth sub-electric connecting pad 23 is not limited too much, and in actual application, the specific number of the fifth sub-electric connecting pad 23 can be set by the technician as needed.

[0077] In the embodiments of the present application, the first electric connecting pad 21, the third sub-electric connecting pad 22 and the fifth sub-electric connecting pad 23 fix the first electric connecting piece 60 to the first region 11 of the battery piece 10, so that the first electric connecting pad 21, the third sub-electric connecting pad 22 and the fifth sub-electric connecting pad 23 electrically connect the first electric connecting piece 60 and the first fine grid 14 together, collect the carriers collected by the first fine grid 14, and transmit the collected carriers to the external circuit, thereby ensuring the photoelectric conversion efficiency of the solar battery piece.

[0078] The second electric connecting plate 30 in the embodiment of the present application further comprises a sixth sub-electric connecting plate 33 arranged in the second region 12 and spaced apart from the second sub-electric connecting plate 31 and the fourth sub-electric connecting plate 32 in the second direction Y. The sixth sub-electric connecting plate 33 can include only one or multiple. Here, the specific number of the sixth sub-electric connecting plate 33 is not limited too much, and in actual application, the specific number of the sixth sub-electric connecting plate 33 can be set according to the needs of the technicians.

[0079] In the embodiment of the present application, the second electric connecting piece 70 is fixed to the second region 12 of the battery piece 10 through the second sub-electric connecting plate 31, the fourth sub-electric connecting plate 32 and the sixth sub-electric connecting plate 33, so that the second sub-electric connecting plate 31, the fourth sub-electric connecting plate 32 and the sixth sub-electric connecting plate 33 electrically connect the second electric connecting piece 70 and the second fine grid 15 together, collect the carriers collected by the second fine grid 15, and transmit the collected carriers to the external circuit, thereby ensuring the photoelectric conversion efficiency of the solar cell piece.

[0080] In some embodiments, the fifth sub-electric connecting plate 23 has a seventh projection in the plane of the battery piece 10, and the sixth sub-electric connecting plate 33 has an eighth projection in the plane of the battery piece 10; the area of the seventh projection is smaller than the area of the eighth projection; or the area of the seventh projection is equal to the area of the eighth projection.

[0081] In the embodiment of the present application, the area of the seventh projection of the fifth sub-electric connecting plate 23 in the plane of the battery piece 10 is set to be smaller than the area of the eighth projection of the sixth sub-electric connecting plate 33 in the plane of the battery piece 10. It can be understood that the area of the fifth sub-electric connecting plate 23 is smaller than the area of the sixth sub-electric connecting plate 33, so as to reduce the material consumption of the fifth sub-electric connecting plate 23 while ensuring the electrical connection reliability between the fifth sub-electric connecting plate 23 and the at least one first fine grid 14 and the electrical connection reliability between the sixth sub-electric connecting plate 33 and the at least one first fine grid 14. In this way, the preparation cost of the battery piece 10 is reduced, thereby reducing the preparation cost of the photovoltaic module and improving the product competitiveness of the photovoltaic module.

[0082] The specific effect analysis can refer to the effect analysis of the first and second electric connecting pads 20 and 30 above. Especially in the case where there are multiple fifth and sixth sub-electric connecting pads 23 and 33 on one battery piece 10, the material cost saving can be significantly improved, and the preparation cost of the battery piece can be greatly reduced, and the product competitiveness of the photovoltaic module can be significantly improved. Alternatively, the seventh projected area of the fifth sub-electric connecting pad 23 on the plane of the battery piece 10 is set to be equal to the eighth projection of the sixth sub-electric connecting pad 33 on the plane of the battery piece 10. It can be understood that the area of the fifth sub-electric connecting pad 23 is equal to the area of the sixth sub-electric connecting pad 33, so that the fifth sub-electric connecting pad 23 can electrically connect the first electric connecting piece 60 and at least one first fine grid 14 together, and the sixth sub-electric connecting pad 33 can electrically connect the second electric connecting piece 70 and at least one second fine grid 15 together, thereby collecting the carriers collected by the first fine grid 14 through the first electric connecting piece 60 and collecting the carriers collected by the second fine grid 15 through the second electric connecting piece 70, and ensuring the photoelectric conversion efficiency of the solar cell piece. It can also prevent the projected area of the fifth sub-electric connecting pad 23 from being too small, reduce the subsequent process precision and difficulty, and ensure the reliability and yield of the product.

[0083] Further, since the area of the first sub-electric connecting pad 21 is smaller than the area of the second sub-electric connecting pad 31, the area of the third sub-electric connecting pad 22 is smaller than the area of the fourth sub-electric connecting pad 32, or the area of the third sub-electric connecting pad 22 is equal to the area of the fourth sub-electric connecting pad 32. That is, the sum of the areas of the first, third and fifth sub-electric connecting pads 21, 22 and 23 is still smaller than the sum of the areas of the second, fourth and sixth sub-electric connecting pads 31, 32 and 33, and thus the material usage of the electric connecting pads in the first area 11 is still smaller than the material usage of the electric connecting pads in the second area 12, thereby helping to reduce the preparation cost of the solar cell piece, the preparation cost of the photovoltaic module, and the product competitiveness of the photovoltaic module.

[0084] In some embodiments, the seventh projected area is smaller than the third and fifth projected areas, and the eighth projected area is smaller than the fourth and sixth projected areas.

[0085] In the embodiments of the present application, the seventh projected area of the fifth sub-electric connecting pad 23 on the plane of the battery piece 10 is set to be smaller than the fifth projected area of the third sub-electric connecting pad 22 on the plane of the battery piece 10 and the third projected area of the first sub-electric connecting pad 21 on the plane of the battery piece 10. That is, the area of the fifth sub-electric connecting pad 23 is smaller than the area of the third sub-electric connecting pad 22, and the area of the fifth sub-electric connecting pad 23 is also smaller than the area of the first sub-electric connecting pad 21.

[0086] And, the area of the eighth projection of the sixth sub-electric connecting pad 33 on the plane of the battery piece 10 is set to be less than the area of the sixth projection of the fourth sub-electric connecting pad 32 on the plane of the battery piece 10, and the area of the fourth projection of the second sub-electric connecting pad 31 on the plane of the battery piece 10. That is, the area of the sixth sub-electric connecting pad 33 is less than the area of the fourth sub-electric connecting pad 32, and the area of the sixth sub-electric connecting pad 33 is also less than the area of the second sub-electric connecting pad 31.

[0087] Through the above setting, the material usage of the fifth sub-electric connecting pad 23 is less than the material usage of the third sub-electric connecting pad 22 and the material usage of the first sub-electric connecting pad 21, and the material usage of the sixth sub-electric connecting pad 33 is less than the material usage of the fourth sub-electric connecting pad 32 and the material usage of the second sub-electric connecting pad 31, so as to further reduce the preparation cost of the battery piece 10, reduce the preparation cost of the photovoltaic module, and improve the product competitiveness of the photovoltaic module.

[0088] The specific effect analysis can refer to the effect analysis of the first electric connecting pad 20 and the second electric connecting pad 30 above. Especially in the case that there are multiple fifth sub-electric connecting pads 23 and sixth sub-electric connecting pads 33 on one battery piece 10, the cost saving of the material can be significantly improved, and the preparation cost of the battery piece 10 can be greatly reduced, and the product competitiveness of the photovoltaic module can be significantly improved. In some embodiments, as shown in Figure 8 and Figure 9 The first sub-electric connecting pad 21 is arranged at a position close to the first side edge 13 and / or the second side edge of the first area 11; the third sub-electric connecting pad 22 and the fifth sub-electric connecting pad 23 each include multiple, multiple third sub-electric connecting pads 22 and multiple fifth sub-electric connecting pads 23 are arranged at positions away from the first side edge 13 or the second side edge of the first sub-electric connecting pad 21 along the second direction Y; and / or, the second sub-electric connecting pad 31 is arranged at a position close to the first side edge 13 and / or the second side edge of the second area 12; the fourth sub-electric connecting pad 32 and the sixth sub-electric connecting pad 33 each include multiple, multiple fourth sub-electric connecting pads 32 and multiple sixth sub-electric connecting pads 33 are arranged at positions away from the first side edge 13 or the second side edge of the second sub-electric connecting pad 31 along the second direction Y.

[0089] Exemplarily, the first sub-electric connecting pad 21 is arranged at a position close to the first side edge 13 of the first region 11, and the plurality of third sub-electric connecting pads 22 and the plurality of fifth sub-electric connecting pads 23 are arranged alternately and spaced apart along the second direction Y at positions away from the first side edge 13 of the first sub-electric connecting pad 21. Alternatively, the first sub-electric connecting pad 21 is arranged at a position close to the second side edge of the first region 11, and the plurality of third sub-electric connecting pads 22 and the plurality of fifth sub-electric connecting pads 23 are arranged alternately and spaced apart along the second direction Y at positions away from the second side edge of the first sub-electric connecting pad 21. Alternatively, the first sub-electric connecting pad 21 includes two, one first sub-electric connecting pad 21 is arranged at a position close to the first side edge 13 of the first region 11, and the other first sub-electric connecting pad 21 is arranged at a position close to the second side edge of the first region 11, and the plurality of third sub-electric connecting pads 22 and the plurality of fifth sub-electric connecting pads 23 are arranged alternately and spaced apart along the second direction Y between the two first sub-electric connecting pads 21.

[0090] It can be understood that the fifth sub-electric connecting pad 23 is a small PAD point with a projection area smaller than the first sub-electric connecting pad 21 and the third sub-electric connecting pad 22. By fixing the first electric connecting piece 60 to the first region 11 of the battery piece 10 through the first sub-electric connecting pad 21, the third sub-electric connecting pad 23 and the fifth sub-electric connecting pad 23, the first sub-electric connecting pad 21 can fix the end of the first electric connecting piece 60, and the third sub-electric connecting pad 22 and the fifth sub-electric connecting pad 23 can fix the middle part of the first electric connecting piece 60, thereby ensuring the reliability of the electrical connection between the first electric connecting piece 60 and the first fine grid 14, improving the collection efficiency of the carriers, and ensuring the photoelectric conversion efficiency of the solar cell piece. The plurality of third sub-electric connecting pads 23 and the plurality of fifth sub-electric connecting pads 23 are arranged alternately and spaced apart, which can regularly apply stress to the battery piece by the first electric connecting piece 60, avoid stress concentration in one area, and make the stress more evenly distributed, thereby reducing the risk of hidden cracking of the battery piece.

[0091] Exemplarily, the second sub-electric connecting pad 31 is arranged at a position close to the first side edge 13 of the second region 12, and the plurality of fourth sub-electric connecting pads 32 and the plurality of sixth sub-electric connecting pads 33 are arranged alternately and spaced apart along the second direction Y at positions away from the first side edge 13 of the second sub-electric connecting pad 31. Alternatively, the second sub-electric connecting pad 31 is arranged at a position close to the second side edge of the second region 12, and the plurality of fourth sub-electric connecting pads 32 and the plurality of sixth sub-electric connecting pads 33 are arranged alternately and spaced apart along the second direction Y at positions away from the second side edge of the second sub-electric connecting pad 31. Alternatively, the second sub-electric connecting pad 31 includes two, one second sub-electric connecting pad 31 is arranged at a position close to the first side edge 13 of the second region 12, and the other second sub-electric connecting pad 31 is arranged at a position close to the second side edge of the second region 12, and the plurality of fourth sub-electric connecting pads 32 and the plurality of sixth sub-electric connecting pads 33 are arranged alternately and spaced apart along the second direction Y between the two second sub-electric connecting pads 31.

[0092] It is understood that the sixth sub-electrical connection pad 33 is a smaller PAD point than the second sub-electrical connection pad 31 and the fourth sub-electrical connection pad 32. The second electrical connector 70 is fixed to the second region 12 of the solar cell 10 via the second sub-electrical connection pads 31, 32, and 33. The second sub-electrical connection pad 31 can fix the end of the second electrical connector 70, while the fourth and sixth sub-electrical connection pads 32 and 33 can fix the middle part of the second electrical connector 70. This ensures the reliability of the electrical connection between the second electrical connector 70 and the second fine grid 15, improves the carrier collection efficiency, and ensures the photoelectric conversion efficiency of the solar cell. The multiple fourth sub-electrical connection pads 32 and sixth sub-electrical connection pads 33 are arranged at intervals, allowing the second electrical connector 70 to apply stress to the solar cell in a regular manner, avoiding stress concentration in one area, ensuring a more uniform stress distribution, and reducing the risk of microcracks in the solar cell.

[0093] In some embodiments, such as Figures 7 to 9 As shown, the battery cell 10 also includes a first end connection portion 40, which is disposed in a first region 11 of the battery cell 10 and is located between the first electrical connection disk 20 and the first side 13, and / or, the first end connection portion 40 is located between the first electrical connection disk 20 and the second side; and / or, a second end connection portion 50, which is disposed in a second region 12 of the battery cell 10 and is located between the second electrical connection disk 30 and the first side 13, and / or, the second end connection portion 50 is located between the second electrical connection disk 30 and the second side.

[0094] In the embodiments of this application, such as Figures 7 to 9 As shown, a first end connection portion 40 is provided in the first region 11 of the solar cell 10. The first end connection portion 40 is disposed between the first electrical connection plate 20 and the first side 13, and / or, the first end connection portion 40 is disposed between the first electrical connection plate 20 and the second side. This allows the first end connection portion 40 to collect charge carriers generated near the first side 13 and / or the second side of the solar cell 10, thereby improving the photoelectric conversion efficiency of the solar cell. Furthermore, by providing the first end connection portion 40, the stringer can easily and automatically weld the first electrical connector 60 to the edge of the solar cell 10 when stringing multiple solar cells 10, reducing the stringing difficulty and improving production efficiency.

[0095] Exemplarily, the first end connecting part 40 can be arranged between the first sub electric connecting pad 21 and the first side edge 13. Alternatively, the first end connecting part 40 can be arranged between the first sub electric connecting pad 21 and the second side edge. Alternatively, the first end connecting part 40 includes two, one first end connecting part 40 is arranged between the first sub electric connecting pad 21 and the first side edge 13, and the other first end connecting part 40 is arranged between the first sub electric connecting pad 21 and the second side edge.

[0096] In the embodiments of the present application, the second end connecting part 50 is arranged in the second region 12 of the battery piece 10, the second end connecting part 50 is arranged between the second electric connecting pad 30 and the first side edge 13, and / or the second end connecting part 50 is arranged between the second electric connecting pad 30 and the second side edge. The second end connecting part 50 is used to collect the carriers generated by the battery piece 10 near the first side edge 13 and / or the second side edge, so as to improve the photoelectric conversion efficiency of the solar battery piece. In addition, by arranging the second end connecting part 50, the stringer can easily automatically weld the second electric connecting part 70 to the edge of the battery piece 10 when the stringer is used to string the second electric connecting part 70 on multiple battery pieces 10, thereby reducing the difficulty of stringing and improving the production efficiency.

[0097] Exemplarily, the second end connecting part 50 can be arranged between the second sub electric connecting pad 31 and the first side edge 13. Alternatively, the second end connecting part 50 can be arranged between the second sub electric connecting pad 31 and the second side edge. Alternatively, the second end connecting part 50 includes two, one second end connecting part 50 is arranged between the second sub electric connecting pad 31 and the first side edge 13, and the other second end connecting part 50 is arranged between the second sub electric connecting pad 31 and the second side edge.

[0098] In some embodiments, as shown in Figures 7 to 9 The first end connecting part 40 is in a strip structure, the first end connecting part 40 extends along the second direction Y, and one end of the first end connecting part 50 is connected with the first electric connecting pad 20; and / or the second end connecting part 50 is in a strip structure, the second end connecting part 50 extends along the second direction Y, and one end of the second end connecting part 50 is connected with the second electric connecting pad 30.

[0099] In the embodiments of the present application, as shown in Figures 7 to 9As shown, the first end connecting portion 40 is arranged in a strip structure, and the length direction of the first end connecting portion 40 is the same as the second direction Y. One end of the first end connecting portion 40 is connected with the first electric connecting pad 20, and the other end extends towards the direction close to the first side edge 13 and / or the second side edge. The first end connecting portion 40 collects the carriers generated by the first fine grid 14 close to the first side edge 13 and / or the second side edge of the solar cell sheet 10, and transmits the collected carriers to the first electric connecting piece 60 through the first electric connecting pad 20, and then to the external circuit through the first electric connecting piece 60, so as to ensure the photoelectric conversion efficiency of the solar cell sheet.

[0100] In the embodiments of the present application, as shown in Figures 7 to 9 The second end connecting portion 50 is arranged in a strip structure, and the length direction of the second end connecting portion 50 is the same as the second direction Y. One end of the second end connecting portion 50 is connected with the second electric connecting pad 30, and the other end extends towards the direction close to the first side edge 13 and / or the second side edge. The second end connecting portion 50 collects the carriers generated by the second fine grid 15 close to the first side edge 13 and / or the second side edge of the solar cell sheet 10, and transmits the collected carriers to the second electric connecting piece 70 through the second electric connecting pad 30, and then to the external circuit through the second electric connecting piece 70, so as to ensure the photoelectric conversion efficiency of the solar cell sheet.

[0101] Further, the first end connecting portion 40 and the second end connecting portion 50 are arranged in a strip shape, so that the shape of the first end connecting portion 40 and the second end connecting portion 50 can be highly matched with the shape of the electric connecting piece, so as to increase the welding strength.

[0102] In some embodiments, as shown in Figures 7 to 9 In the direction from the first electric connecting pad 20 to the first side edge 13, the width of the first end connecting portion 40 along the first direction X gradually decreases; and / or, in the direction from the second electric connecting pad 30 to the first side edge 13, the width of the second end connecting portion 50 along the first direction X gradually decreases.

[0103] In the embodiments of the present application, in the direction from the first electric connecting pad 20 to the first side edge 13, the width of the first end connecting portion 40 along the first direction X gradually decreases. That is, the one end of the first end connecting portion 40 close to the first electric connecting pad 20 is wider, and the one end of the first end connecting portion 40 close to the first side edge is narrower. Through the arrangement of the specific structure of the first end connecting portion 40, the area of the first end connecting portion 40 is reduced, the amount of the material of the first end connecting portion 40 is reduced, the preparation cost of the solar cell sheet is reduced, and then the preparation cost of the photovoltaic module is reduced, and the product competitiveness of the photovoltaic module is improved.

[0104] It should be noted that, in the direction from the first electrical connecting pad 20 to the second side edge, the width of the first end connecting part 40 in the first direction X also gradually decreases. Here, no further elaboration.

[0105] In the embodiments of the present application, in the direction from the second electrical connecting pad 30 to the first side edge 13, the width of the second end connecting part 50 in the first direction X gradually decreases. That is, the end of the second end connecting part 50 close to the second electrical connecting pad 30 is wider, and the end of the second end connecting part 50 close to the second side edge is narrower. By setting the specific structure of the second end connecting part 50, the area of the second end connecting part 50 is reduced, the material usage of the second end connecting part 50 is reduced, the preparation cost of the solar cell is reduced, and the preparation cost of the photovoltaic module is further reduced, thereby improving the product competitiveness of the photovoltaic module.

[0106] It should be noted that, in the direction from the second electrical connecting pad 30 to the second side edge, the width of the second end connecting part 50 in the first direction X also gradually decreases. Here, no further elaboration.

[0107] In some embodiments, as shown in Figures 7 to 9 The first end connecting part 40 has a ninth projection on the plane of the cell 10, and the second end connecting part 50 has a tenth projection on the plane of the cell 10. The area of the ninth projection is smaller than the area of the tenth projection.

[0108] In the embodiments of the present application, the area of the ninth projection of the first end connecting part 40 on the plane of the cell 10 is set to be smaller than the area of the tenth projection of the second end connecting part 50 on the plane of the cell 10. That is, the area of the first end connecting part 40 is smaller than the area of the second end connecting part 50. While ensuring the carrier collection efficiency of the first end connecting part 40 on the area close to the first side edge 13 and / or the second side edge of the cell 10, and the carrier collection efficiency of the second end connecting part 50 on the area close to the first side edge 13 and / or the second side edge of the cell 10, the area of the first end connecting part 40 is smaller than the area of the second end connecting part 50, and the material usage of the first end connecting part 40 is smaller. In this way, the preparation cost of the solar cell is reduced, and the preparation cost of the photovoltaic module is further reduced, thereby improving the product competitiveness of the photovoltaic module.

[0109] The specific effect analysis can refer to the above effect analysis of the first electrical connecting pad 20 and the second electrical connecting pad 30. Especially in the case where there are multiple first end connecting parts 40 and second end connecting parts 50 on one cell 10, the cost saving of the material can be significantly improved, the preparation cost of the cell 10 can be greatly reduced, and the product competitiveness of the photovoltaic module can be significantly improved.

[0110] In some embodiments, as shown inFigure 3 and Figure 6 As shown in FIGS. 1 and 2, the first end connecting part 40 includes at least one first electrical connecting point 41 spaced apart from the first electrical connecting pad 20 along the second direction Y, and / or the second end connecting part 50 includes at least one second electrical connecting point 51 spaced apart from the second electrical connecting pad 30 along the second direction Y.

[0111] For example, the first end connecting part 40 can include one first electrical connecting point 41 disposed between the first sub-electrical connecting pad 21 and the first side edge 13. Alternatively, the first end connecting part 40 can include a plurality of first electrical connecting points 41 arranged at intervals between the first sub-electrical connecting pad 21 and the first side edge 13.

[0112] In the embodiments of the present application, the first electrical connecting point 41 collects the carriers collected by the first fine grid 14 near the first side edge 13 and / or the second side edge region of the solar cell sheet 10, and transmits the collected carriers to the first electrical connecting member 60 through the first electrical connecting pad 20, and then to the external circuit through the first electrical connecting member 60, so as to ensure the photoelectric conversion efficiency of the solar cell sheet.

[0113] For example, the second end connecting part 50 can include one second electrical connecting point 51 disposed between the second sub-electrical connecting pad 31 and the first side edge 13. Alternatively, the second end connecting part 50 can include a plurality of second electrical connecting points 51 arranged at intervals between the second sub-electrical connecting pad 31 and the first side edge 13.

[0114] In the embodiments of the present application, the second electrical connecting point 51 collects the carriers collected by the second fine grid 15 near the first side edge 13 and / or the second side edge region of the solar cell sheet 10, and transmits the collected carriers to the second electrical connecting member 70 through the second electrical connecting pad 30, and then to the external circuit through the second electrical connecting member 70, so as to ensure the photoelectric conversion efficiency of the solar cell sheet.

[0115] In some embodiments, as shown in FIGS. 1 and 2, the first electrical connecting point 41 has an eleventh projection on the plane of the solar cell sheet 10, and the second electrical connecting point 51 has a twelfth projection on the plane of the solar cell sheet 10, and the area of the eleventh projection is smaller than the area of the twelfth projection. Figure 3 and Figure 6 As shown in FIGS. 1 and 2, the first electrical connecting point 41 has an eleventh projection on the plane of the solar cell sheet 10, and the second electrical connecting point 51 has a twelfth projection on the plane of the solar cell sheet 10, and the area of the eleventh projection is smaller than the area of the twelfth projection.

[0116] In the embodiments of the present application, the area of the eleventh projection of the first electrical connection point 41 on the plane of the solar cell 10 is set to be smaller than the area of the twelfth projection of the second electrical connection point 51 on the plane of the solar cell 10. Thus, on the basis of ensuring the efficiency of the first electrical connection point 41 in collecting and transmitting carriers, the area of the first electrical connection point 41 is reduced, and the amount of material of the first electrical connection point 41 is reduced. In this way, the preparation cost of the solar cell is reduced, the preparation cost of the photovoltaic module is reduced, and the product competitiveness of the photovoltaic module is improved.

[0117] Specific effect analysis can refer to the above effect analysis of the first electrical connection pad 20 and the second electrical connection pad 30. Especially in the case where there are multiple first electrical connection points 41 and second electrical connection points 51 on one solar cell 10, the cost saving of the material can be significantly improved, the preparation cost of the solar cell 10 can be greatly reduced, and the product competitiveness of the photovoltaic module can be significantly improved.

[0118] In some embodiments, along the second direction Y, the solar cell has a first side edge 13 and a second side edge 14 arranged oppositely; as approaching the center of the solar cell from the first side edge 13 and / or the second side edge 14, the area of the first projection of the Nth first electrical connection pad 20 on the plane of the solar cell 10 is smaller than the area of the second projection of the Nth second electrical connection pad 30 on the plane of the solar cell 10; wherein N is a positive integer, and 1≤N≤6.

[0119] For example: along the second direction Y, it can be understood as along the extension direction of the first electrical connection piece 60 and the second electrical connection piece 70, starting from the first side edge 13 of the solar cell, approaching the center of the solar cell, the area of the first projection of the Nth first electrical connection pad 20 on the plane of the solar cell 10 in the first area 11 is smaller than the area of the second projection of the Nth second electrical connection pad 30 on the plane of the solar cell in the second area 12. Wherein N is a positive integer, and 1≤N≤6. Exemplarily, N is 1, 2, 3, 4, 5 or 6.

[0120] In the embodiments of the present application, in the corresponding area of the solar cell, especially the corresponding area where the force applied by the electrical connection piece (solder strip) to the solar cell is the same or similar, a small-area electrical connection pad is designed for a large-surface-roughness area, and a large-area electrical connection pad is designed for a small-surface-roughness area. When the electrical connection reliability (such as pull force, contact resistance, etc.) is met, the amount of electrical connection pad material is reduced, especially when there are multiple electrical connection pads, the amount of material can be greatly reduced, the cost can be greatly reduced, and the product competitiveness of the photovoltaic module can be improved. In some embodiments, such as Figure 10 and Figure 11As shown, along the thickness direction of the battery piece 10, the battery piece 10 has oppositely arranged first and second surfaces, the first region 11 is arranged on the first surface of the battery piece 10, and the second region 12 is arranged on the second surface of the battery piece 10.

[0121] Along the thickness direction of the battery piece 10, the battery piece 10 has oppositely arranged first and second surfaces. When the first surface is the front surface of the battery piece 10, that is, the surface facing the sunlight, the second surface is the back surface of the battery piece 10, that is, the surface facing away from the sunlight. Or, when the first surface is the back surface of the battery piece 10, that is, the surface facing away from the sunlight, the second surface is the front surface of the battery piece 10, that is, the surface facing the sunlight.

[0122] In the embodiments of the present application, the first region 11 is arranged on the first surface of the battery piece 10, and the second region 12 is arranged on the second surface of the battery piece 10. That is, the first electrical connecting piece 60 is arranged on the first surface of the battery piece 10, and the second electrical connecting piece 70 is arranged on the second surface of the battery piece 10. The solar battery piece is a double-sided solar battery piece, which has the characteristics of stronger structural symmetry and better deformation resistance.

[0123] In some embodiments, the first surface is the front surface of the battery piece 10, and the first region 11 has a first pyramid structure on the first surface of the battery piece 10; the battery piece 10 includes a silicon substrate, and the first region 11 has a first intrinsic amorphous silicon layer, a first doped amorphous silicon layer, and a first transparent conductive layer which are sequentially stacked on the silicon substrate; or, the first region 11 has a first tunneling layer and a first doped polysilicon layer which are sequentially stacked on the silicon substrate; or, the first region 11 has a doped diffusion layer which is stacked on the silicon substrate; the second surface is the back surface of the battery piece 10, and the second region 12 has a first polished surface on the second surface of the battery piece 10, or the second region 12 has a second pyramid structure on the second surface of the battery piece 10; the second region 12 has a second intrinsic amorphous silicon layer, a second doped amorphous silicon layer, and a second transparent conductive layer which are sequentially stacked on the silicon substrate; or, the second region 12 has a second tunneling layer and a second doped polysilicon layer which are sequentially stacked on the silicon substrate.

[0124] In the following, the first surface of the battery piece 10 is taken as the front surface of the battery piece 10, and the second surface of the battery piece 10 is taken as the back surface of the battery piece 10, as an example, to make related description of the solar battery piece disclosed in the embodiments of the present application.

[0125] In the following, the first surface of the battery piece 10 is taken as the front surface of the battery piece 10, and the second surface of the battery piece 10 is taken as the back surface of the battery piece 10, as an example, to make related description of the solar battery piece disclosed in the embodiments of the present application.

[0126] For example, the first region 11 has a first intrinsic amorphous silicon layer, a first doped amorphous silicon layer, and a first transparent conductive layer sequentially stacked on the front side of the silicon substrate. Alternatively, the first region 11 has a first tunneling layer and a first doped polycrystalline silicon layer sequentially stacked on the front side of the silicon substrate. Alternatively, the first region 11 has a doped diffusion layer stacked on the front side of the silicon substrate.

[0127] When the solar cell is a topcon cell, the second region 12 has a first polished surface on the second surface of the cell 10. When the solar cell is a HIT cell, the second region 12 has a second pyramid structure on the second surface of the cell 10.

[0128] For example, the second region 12 may have a second intrinsic amorphous silicon layer, a second doped amorphous silicon layer, and a second transparent conductive layer sequentially stacked on the back side of the silicon substrate. Alternatively, the second region 12 may have a second tunneling layer and a second doped polycrystalline silicon layer sequentially stacked on the back side of the silicon substrate.

[0129] In some embodiments, such as Figure 13 As shown, along the thickness direction of the battery cell 10, the battery cell 10 has a first surface and a second surface disposed opposite to each other; the first region 11 and the second region 12 are both disposed on the second surface of the battery cell 10.

[0130] In this embodiment, both the first region 11 and the second region 12 are disposed on the second surface of the solar cell 10. That is, both the first region 11 and the second region 12 are disposed on the back side of the solar cell 10, and both the first electrical connector 60 and the second electrical connector 70 are disposed on the back side of the solar cell 10. Therefore, this solar cell is a back-contact solar cell. Back-contact solar cells have no grid lines or obstructions on the front side, and have advantages such as high photoelectric conversion efficiency and aesthetically pleasing appearance.

[0131] In some embodiments, the second surface is the back surface of the solar cell 10, the first region 11 has a third pyramid structure on the second surface of the solar cell 10, and the second region 12 has a second polished surface on the second surface of the solar cell 10; the solar cell 10 includes a silicon substrate, the first region 11 has a third intrinsic amorphous silicon layer, a third doped amorphous silicon layer, and a third transparent conductive layer sequentially stacked on the silicon substrate, and the second region 12 has a third tunneling layer and a third doped polycrystalline silicon layer sequentially stacked on the silicon substrate; or, the first region 11 has a third polished surface on the second surface of the solar cell 10, and the second region 12 has a fourth polished surface on the second surface of the solar cell 10; the first region 11 has a fourth tunneling layer stacked on the silicon substrate, and the second region 12 has a fifth tunneling layer stacked on the silicon substrate.

[0132] The solar cell disclosed by the embodiments of the present application is a back contact solar cell, and the second surface of the cell 10 is a back surface. The first region 11 and the second region 12 are both arranged on the back surface of the cell 10.

[0133] When the solar cell is a hybrid back contact cell, the first region 11 has a third pyramidal structure on the second surface of the cell 10, and the second region 12 has a second polished surface on the second surface of the cell 10.

[0134] For example, the first region 11 has a third intrinsic amorphous silicon layer, a third doped amorphous silicon layer and a third transparent conductive layer arranged on the back surface of the silicon substrate in sequence. The second region 12 has a third tunneling layer and a third doped polysilicon layer arranged on the back surface of the silicon substrate in sequence; or the second region 12 has a third tunneling layer, a third doped polysilicon layer and a fourth transparent conductive layer arranged on the back surface of the silicon substrate in sequence.

[0135] When the solar cell is a TBC cell, the first region 11 has a third polished surface on the second surface of the cell 10, and the second region 12 has a fourth polished surface on the second surface of the cell 10. The surface roughness of the third polished surface and the fourth polished surface is different.

[0136] For example, the first region 11 has a fourth tunneling layer arranged on the back surface of the silicon substrate; or the first region 11 has a fourth tunneling layer and a fourth doped polysilicon layer (N-poly layer) arranged on the back surface of the silicon substrate in sequence. The second region 12 has a fifth tunneling layer arranged on the back surface of the silicon substrate; or the second region 12 has a fifth tunneling layer and a fifth doped polysilicon layer (P-poly layer) arranged on the back surface of the silicon substrate in sequence.

[0137] In some embodiments, the first fine grid 14 includes a plurality of first sub-fine grids, the plurality of first sub-fine grids all extend along the first direction X and are arranged at intervals along the first direction X, and the first electrical connecting pad 20 is located between two adjacent first sub-fine grids. Along the thickness direction of the cell 10, the end portions of the first sub-fine grids on both sides of the first electrical connecting pad 20 are overlapped on the side of the first electrical connecting pad 20 away from the cell 10.

[0138] In the embodiments of the present application, the first fine grid 14 includes a plurality of first sub-fine grids, the plurality of first sub-fine grids all extend along the first direction X and are arranged at intervals along the first direction X, so that the first sub-fine grids have a first gap in the first direction X. That is, the first fine grid 14 is discontinuously arranged, so as to reduce the manufacturing difficulty of the first fine grid 14 along the first direction X, and further reduce the preparation cost of the solar cell.

[0139] Further, the above arrangement can reduce the height difference of the first electric connecting pad 20 and the first fine grid 14 along the thickness direction of the solar cell, thereby improving the process yield of the solar cell.

[0140] The first electric connecting pad 20 is arranged in the first gap, and the first sub-fine grids on both sides of the first electric connecting pad 20 are overlapped on the side of the first electric connecting pad 20 away from the solar cell 10, so as to conduct the first sub-fine grids and the first electric connecting pad 20, and the carriers collected by the first sub-fine grids can be transmitted to the first electric connecting pad 20 and then transmitted to the external circuit through the first electric connecting pad 20.

[0141] In some embodiments, the first sub-electric connecting pad 21 has a length L1 along the first direction X, and 0.7mm≤L1≤1.3mm is satisfied, and the first sub-electric connecting pad 21 has a width L2 along the second direction Y, and 0.8mm≤L2≤1.4mm is satisfied; and / or, the second sub-electric connecting pad 31 has a length L3 along the first direction X, and 0.8mm≤L3≤1.4mm is satisfied, and the second sub-electric connecting pad 31 has a width L4 along the second direction Y, and 0.9mm≤L4≤1.5mm is satisfied.

[0142] The first sub-electric connecting pad 21 and the second sub-electric connecting pad 31 in the embodiments of the present application can have a rectangular structure, a square structure, a similar rectangular structure, or a similar square structure. The similar rectangular structure refers to a rectangular structure with chamfered corners, and the similar square structure refers to a square structure with chamfered corners.

[0143] The length L1 of the first sub-electric connecting pad 21 along the first direction X is greater than or equal to 0.7mm and less than or equal to 1.3mm, and the width L2 of the first sub-electric connecting pad 21 along the second direction Y is greater than or equal to 0.8mm and less than or equal to 1.4mm. By setting the length L1 of the first sub-electric connecting pad 21 along the first direction X and the width L2 of the first sub-electric connecting pad 21 along the second direction Y, the size of the first sub-electric connecting pad 21 is as small as possible while ensuring the reliability of the connection between the first sub-electric connecting pad 21, the first fine grid 14 and the first electric connecting piece 60, so as to control the material consumption of the first sub-electric connecting pad 21 and reduce the preparation cost of the solar cell.

[0144] Exemplarily, the length L1 of the first sub-electric connecting pad 21 along the first direction X can be set as 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, etc., and the width L2 of the first sub-electric connecting pad 21 along the second direction Y can be set as 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, etc. Of course, the above are only individual examples of the specific length and width of the first sub-electric connecting pad 21, which are not limiting to the present application. In actual applications, the length and width of the first sub-electric connecting pad 21 can be set as needed by the technicians.

[0145] The length L3 of the second sub-electric connecting pad 31 along the first direction X is greater than or equal to 0.8 mm and less than or equal to 1.4 mm, and the width L4 of the second sub-electric connecting pad 31 along the second direction Y is greater than or equal to 0.9 mm and less than or equal to 1.5 mm. By setting the length L3 of the second sub-electric connecting pad 31 along the first direction X and the width L4 of the second sub-electric connecting pad 31 along the second direction Y, the size of the second sub-electric connecting pad 31 is as small as possible while ensuring the reliability of the connection between the second sub-electric connecting pad 31, the second fine grid 15 and the second electric connecting piece 70, so as to control the material usage of the second sub-electric connecting pad 31 and further reduce the preparation cost of the solar cell piece.

[0146] Exemplarily, the length L3 of the second sub-electric connecting pad 31 along the first direction X can be set as 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, etc., and the width L4 of the second sub-electric connecting pad 31 along the second direction Y can be set as 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc. Of course, the above are only individual examples of the specific length and width of the second sub-electric connecting pad 31, which are not limiting to the present application. In actual applications, the length and width of the second sub-electric connecting pad 31 can be set as needed by the technicians.

[0147] In some embodiments, the width of the first sub-electric connecting pad 21 along the second direction Y is greater than the width of the first fine grid 14 along the second direction Y; and / or, the width of the second sub-electric connecting pad 31 along the second direction Y is greater than the width of the second fine grid 15 along the second direction Y.

[0148] The first sub-electric connecting pad 21 in the embodiment of the present application is a connection point of the first fine grid 14 and the first electric connecting piece 60, and needs to bear a larger carrier density. The width of the first sub-electric connecting pad 21 along the second direction Y is set to be greater than the width of the first fine grid 14 along the second direction Y, which can expand the contact area of the first sub-electric connecting pad 21 and the first fine grid 14, reduce the local carrier congestion, reduce the contact resistance and heat loss, thereby improving the collection efficiency of the carrier and ensuring the photoelectric conversion efficiency of the solar cell piece.

[0149] Similarly, the second sub-electric connecting pad 31 is a connection point of the second fine grid 15 and the second electric connecting piece 70, and needs to bear a larger carrier density. The width of the second sub-electric connecting pad 31 along the second direction Y is set to be greater than the width of the second fine grid 15 along the second direction Y, which can expand the contact area of the second sub-electric connecting pad 31 and the second fine grid 15, reduce the local carrier congestion, reduce the contact resistance and heat loss, thereby improving the collection efficiency of the carrier and ensuring the photoelectric conversion efficiency of the solar cell piece.

[0150] In some embodiments, the length of the third sub-electric connecting pad 22 along the first direction X is L5, which satisfies 0.7mm≤L5≤1.3mm, and the width of the third sub-electric connecting pad 22 along the second direction Y is L6, which satisfies 0.03mm≤L6≤0.35mm; and / or, the length of the fourth sub-electric connecting pad 32 along the first direction X is L7, which satisfies 0.8mm≤L7≤1.4mm, and the width of the fourth sub-electric connecting pad 32 along the second direction Y is L8, which satisfies 0.025mm≤L8≤0.15mm.

[0151] The third sub-electric connecting pad 22 and the fourth sub-electric connecting pad 32 in the embodiment of the present application can be a rectangular structure or a quasi-rectangular structure. The quasi-rectangular structure refers to a rectangular structure provided with a chamfer. For example, the quasi-rectangular structure is a rectangular structure with rounded corners, or the quasi-rectangular structure is a rectangular structure with square corners.

[0152] The length L5 of the third sub-electric connecting pad 22 along the first direction X is greater than or equal to 0.7mm and less than or equal to 1.3mm, and the width L6 of the third sub-electric connecting pad 22 along the second direction Y is greater than or equal to 0.03mm and less than or equal to 0.35mm. By setting the length L5 of the third sub-electric connecting pad 22 along the first direction X and the width L6 of the third sub-electric connecting pad 22 along the second direction Y, the size of the third sub-electric connecting pad 22 is as small as possible while ensuring the reliability of the connection of the third sub-electric connecting pad 22, the first fine grid 14 and the first electric connecting piece 60, so as to control the amount of material of the third sub-electric connecting pad 22, and further reduce the preparation cost of the solar cell piece.

[0153] Exemplarily, the length L5 of the third sub-electric connecting pad 22 along the first direction X can be set as 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, etc., and the width L6 of the third sub-electric connecting pad 22 along the second direction Y can be set as 0.03mm, 0.05mm, 0.08mm, 0.1mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.35mm, etc. Of course, the above are only individual examples of the specific length and width of the third sub-electric connecting pad 22, and are not intended to limit the present application. In actual applications, the length and width of the third sub-electric connecting pad 22 can be set as needed by the technicians.

[0154] The length L7 of the fourth sub-electric connecting pad 32 along the first direction X is greater than or equal to 0.8mm and less than or equal to 1.4mm, and the width L8 of the fourth sub-electric connecting pad 32 along the second direction Y is greater than or equal to 0.025mm and less than or equal to 0.15mm. By setting the length L7 of the fourth sub-electric connecting pad 32 along the first direction X and the width L8 of the fourth sub-electric connecting pad 32 along the second direction Y, the size of the fourth sub-electric connecting pad 32 is as small as possible while ensuring the reliability of the connection between the fourth sub-electric connecting pad 32, the second fine grid 15 and the second electric connecting member 70, so as to control the amount of material of the fourth sub-electric connecting pad 32, thereby reducing the preparation cost of the solar cell piece.

[0155] Exemplarily, the length L7 of the fourth sub-electric connecting pad 32 along the first direction X can be set as 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, etc., and the width L8 of the fourth sub-electric connecting pad 32 along the second direction Y can be set as 0.025mm, 0.05mm, 0.075mm, 0.1mm, 0.125mm, 0.15mm, etc. Of course, the above are only individual examples of the specific length and width of the fourth sub-electric connecting pad 32, and are not intended to limit the present application. In actual applications, the length and width of the fourth sub-electric connecting pad 32 can be set as needed by the technicians.

[0156] In some embodiments, the width of the third sub-electric connecting pad 22 along the second direction Y is greater than the width of the first fine grid 14 along the second direction Y; and / or, the width of the fourth sub-electric connecting pad 32 along the second direction Y is greater than the width of the second fine grid 15 along the second direction Y.

[0157] The third sub-electric connecting pad 22 in the embodiments of the present application is the connection point of the first fine grid 14 and the first electric connecting piece 60, and needs to bear a larger carrier density. The width of the third sub-electric connecting pad 22 along the second direction Y is set to be greater than the width of the first fine grid 14 along the second direction Y, which can expand the contact area of the third sub-electric connecting pad 22 and the first fine grid 14, reduce the local carrier congestion, reduce the contact resistance and heat loss, thereby improving the collection efficiency of the carrier and ensuring the photoelectric conversion efficiency of the solar cell piece.

[0158] Similarly, the fourth sub-electric connecting pad 32 is the connection point of the second fine grid 15 and the second electric connecting piece 70, and needs to bear a larger carrier density. The width of the fourth sub-electric connecting pad 32 along the second direction Y is set to be greater than the width of the second fine grid 15 along the second direction Y, which can expand the contact area of the fourth sub-electric connecting pad 32 and the second fine grid 15, reduce the local carrier congestion, reduce the contact resistance and heat loss, thereby improving the collection efficiency of the carrier and ensuring the photoelectric conversion efficiency of the solar cell piece.

[0159] In some embodiments, the length of the fifth sub-electric connecting pad 23 along the first direction X is L9, which satisfies 0.7mm≤L9≤1.3mm, and the width of the fifth sub-electric connecting pad 23 along the second direction Y is L10, which satisfies 0.03mm≤L10≤0.35mm; and / or, the length of the sixth sub-electric connecting pad 33 along the first direction X is L11, which satisfies 0.8mm≤L11≤1.4mm, and the width of the sixth sub-electric connecting pad 33 along the second direction Y is L12, which satisfies 0.025mm≤L12≤0.15mm.

[0160] The fifth sub-electric connecting pad 23 and the sixth sub-electric connecting pad 33 in the embodiments of the present application can be rectangular structures, or can be quasi-rectangular structures. The quasi-rectangular structure refers to a rectangular structure provided with a chamfer. For example, the quasi-rectangular structure is a rectangular structure with rounded corners, or the quasi-rectangular structure is a rectangular structure with square corners.

[0161] The length L9 of the fifth sub-electric connecting pad 23 along the first direction X is greater than or equal to 0.7mm and less than or equal to 1.3mm, and the width L10 of the fifth sub-electric connecting pad 23 along the second direction Y is greater than or equal to 0.03mm and less than or equal to 0.35mm. By setting the length L9 of the fifth sub-electric connecting pad 23 along the first direction X and the width L10 of the fifth sub-electric connecting pad 23 along the second direction Y, the size of the fifth sub-electric connecting pad 23 is as small as possible while ensuring the reliability of the connection of the fifth sub-electric connecting pad 23, the first fine grid 14 and the first electric connecting piece 60, so as to control the material amount of the fifth sub-electric connecting pad 23, and further reduce the preparation cost of the solar cell piece.

[0162] Exemplarily, the length L9 of the fifth sub-electric connecting pad 23 along the first direction X can be set as 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, etc., and the width L10 of the fifth sub-electric connecting pad 23 along the second direction Y can be set as 0.03mm, 0.05mm, 0.10mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.35mm, etc. Of course, the above are only individual examples of the specific length and width of the fifth sub-electric connecting pad 23, and are not intended to limit the present application. In actual applications, the length and width of the fifth sub-electric connecting pad 23 can be set as needed by the skilled person.

[0163] The length L11 of the sixth sub-electric connecting pad 33 along the first direction X is greater than or equal to 0.8mm and less than or equal to 1.4mm, and the width L12 of the sixth sub-electric connecting pad 33 along the second direction Y is greater than or equal to 0.025mm and less than or equal to 0.15mm. By setting the length L11 of the sixth sub-electric connecting pad 33 along the first direction X and the width L12 of the sixth sub-electric connecting pad 33 along the second direction Y, the size of the sixth sub-electric connecting pad 33 is as small as possible while ensuring the reliability of the connection between the sixth sub-electric connecting pad 33, the second fine grid 15 and the second electric connecting member 70, so as to control the amount of material of the sixth sub-electric connecting pad 33, thereby reducing the preparation cost of the solar cell piece.

[0164] Exemplarily, the length L11 of the sixth sub-electric connecting pad 33 along the first direction X can be set as 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, etc., and the width L12 of the sixth sub-electric connecting pad 33 along the second direction Y can be set as 0.025mm, 0.05mm, 0.07mm, 0.09mm, 0.1mm, 0.12mm, 0.14mm, 0.15mm, etc. Of course, the above are only individual examples of the specific length and width of the sixth sub-electric connecting pad 33, and are not intended to limit the present application. In actual applications, the length and width of the sixth sub-electric connecting pad 33 can be set as needed by the skilled person.

[0165] In some embodiments, the width of the fifth sub-electric connecting pad 23 along the second direction Y is greater than the width of the first fine grid 14 along the second direction Y; and / or, the width of the sixth sub-electric connecting pad 33 along the second direction Y is greater than the width of the second fine grid 15 along the second direction Y.

[0166] The fifth sub-electric connecting pad 23 in the embodiment of the present application is the connection point of the first fine grid 14 and the first electric connecting piece 60, and needs to bear a larger carrier density. The width of the fifth sub-electric connecting pad 23 along the second direction Y is set to be greater than the width of the first fine grid 14 along the second direction Y, so as to expand the contact area of the fifth sub-electric connecting pad 23 and the first fine grid 14, reduce the local carrier congestion, reduce the contact resistance and heat loss, thereby improving the collection efficiency of the carrier and ensuring the photoelectric conversion efficiency of the solar cell piece.

[0167] Similarly, the sixth sub-electric connecting pad 33 is the connection point of the second fine grid 15 and the second electric connecting piece 70, and needs to bear a larger carrier density. The width of the sixth sub-electric connecting pad 33 along the second direction Y is set to be greater than the width of the second fine grid 15 along the second direction Y, so as to expand the contact area of the sixth sub-electric connecting pad 33 and the second fine grid 15, reduce the local carrier congestion, reduce the contact resistance and heat loss, thereby improving the collection efficiency of the carrier and ensuring the photoelectric conversion efficiency of the solar cell piece.

[0168] The embodiment of the present application also discloses a photovoltaic module, which comprises the solar cell piece in the above-mentioned embodiment, a first electric connecting piece 60, the first electric connecting piece 60 being arranged on the first area 11 of the cell piece 10 and being electrically connected with the first electric connecting pad 20, and a second electric connecting piece 70, the second electric connecting piece 70 being arranged on the second area 12 of the cell piece 10 and being electrically connected with the second electric connecting pad 30.

[0169] The embodiment of the present application discloses a photovoltaic module, which comprises the solar cell piece, the first electric connecting piece 60 and the second electric connecting piece 70 in the above-mentioned embodiment. The first electric connecting piece 60 is arranged on the first area 11 of the cell piece 10 and is electrically connected with the first fine grid 14 through the first electric connecting pad 20, so that the carrier collected by the first fine grid 14 can be transmitted to the first electric connecting piece 60 through the first electric connecting pad 20 and then transmitted to an external circuit through the first electric connecting piece 60. The second electric connecting piece 70 is arranged on the second area 12 of the cell piece 10 and is electrically connected with the second fine grid 15 through the second electric connecting pad 30, so that the carrier collected by the second fine grid 15 can be transmitted to the second electric connecting piece 70 through the second electric connecting pad 30 and then transmitted to an external circuit through the second electric connecting piece 70.

[0170] It should be noted that the solar cell piece included in the photovoltaic module has the same structure as the solar cell piece in the above-mentioned embodiment, and has the same or similar beneficial effects, which will not be described here.

[0171] The first electric connecting member 60 includes, but is not limited to, a first solder strip, a first metal wire, etc. The second electric connecting member 70 includes, but is not limited to, a second solder strip, a second metal wire, etc.

[0172] It should be noted that the various embodiments in the specification are described in progressive manner, and each embodiment focuses on the difference from other embodiments, and the same and similar parts between embodiments can be referred to each other.

[0173] Although the optional embodiments of the embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including the optional embodiments and all changes and modifications falling within the scope of the embodiments of the present application.

[0174] Finally, it should be noted that in this document, the relationship terms such as first and second are only used to distinguish one entity from another entity, and do not necessarily require or imply that there is any such actual relationship or order between the entities. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the article or terminal device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such article or terminal device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the article or terminal device including the element.

[0175] The above describes the technical solutions provided by the present application in detail, and the principles and implementation manners of the present application are described by applying specific examples. Meanwhile, for those skilled in the art, according to the principles and implementation manners of the present application, the specific implementation manners and application scope will be changed, and the content of the specification should not be understood as a limitation of the present application.

Claims

1. A solar cell, characterized by, The battery piece has a surface provided with first fine grids and second fine grids extending along a first direction, the surface of the battery piece has a first region and a second region, both of which extend along a second direction intersecting the first direction, the surface roughness of the first region is greater than that of the second region; A first electric connecting pad is arranged on the first region of the battery piece, and the first electric connecting pad is connected to at least one of the first fine grids and has a first projection on the plane of the battery piece; A second electric connecting pad is arranged on the second region of the battery piece, and the second electric connecting pad is connected to at least one of the second fine grids and has a second projection on the plane of the battery piece, the area of the first projection is smaller than that of the second projection. The first electric connecting pad includes at least one first sub-electric connecting pad, and the first sub-electric connecting pad has a third projection on the plane of the battery piece; 2. The solar cell according to claim 1, wherein The second electric connecting pad includes at least one second sub-electric connecting pad, and the second sub-electric connecting pad has a fourth projection on the plane of the battery piece, and the area of the third projection is smaller than that of the fourth projection. Along the second direction, the battery piece has a first side edge and a second side edge arranged oppositely; 3. The solar cell according to claim 2, wherein The first sub-electric connecting pad is arranged on the first region close to the first side edge and / or the second side edge; And / or, the second sub-electric connecting pad is arranged on the second region close to the first side edge or the second side edge. The first electric connecting pad further includes at least one third sub-electric connecting pad, and along the second direction, the third sub-electric connecting pad is arranged in the first region of the battery piece at intervals from the first sub-electric connecting pad; 4. The solar cell of claim 3, wherein, And / or, the second electric connecting pad further includes at least one fourth sub-electric connecting pad, and along the second direction, the fourth sub-electric connecting pad is arranged in the second region of the battery piece at intervals from the second sub-electric connecting pad. The first sub-electric connecting pad is arranged on the first region close to the first side edge and / or the second side edge; 5. The solar cell of claim 4, wherein, The third sub-electric connecting pad includes a plurality of third sub-electric connecting pads, and the plurality of third sub-electric connecting pads are arranged at intervals from the first sub-electric connecting pad away from the first side edge or the second side edge along the second direction; And / or, The second sub-electric connecting pad is arranged on the second region close to the first side edge and / or the second side edge; The fourth sub-electric connecting pad includes a plurality of fourth sub-electric connecting pads, and the plurality of fourth sub-electric connecting pads are arranged at intervals from the second sub-electric connecting pad away from the first side edge or the second side edge along the second direction. The third sub-electric connecting pad has a fifth projection on the plane of the battery piece, and the fourth sub-electric connecting pad has a sixth projection on the plane of the battery piece; 6. The solar cell of claim 4, wherein, The area of the fifth projection is smaller than that of the sixth projection; or the area of the fifth projection is equal to that of the sixth projection. ​ 7. The solar cell of claim 6, wherein, The area of the fifth projection is less than the area of the third projection, and the area of the sixth projection is less than the area of the fourth projection. Alternatively, the area of the fifth projection is less than the area of the third projection, and the area of the sixth projection is equal to the area of the fourth projection.

8. The solar cell of claim 6, wherein, The first electric connecting pad further comprises at least one fifth sub-electric connecting pad, which is arranged in the first area of the battery piece and is spaced apart from the first sub-electric connecting pad and the third sub-electric connecting pad in the second direction. And / or, the second electric connecting pad further comprises at least one sixth sub-electric connecting pad, which is arranged in the second area of the battery piece and is spaced apart from the second sub-electric connecting pad and the fourth sub-electric connecting pad in the second direction.

9. The solar cell of claim 8, wherein, The fifth sub-electric connecting pad has a seventh projection on the plane of the battery piece, and the sixth sub-electric connecting pad has an eighth projection on the plane of the battery piece. The area of the seventh projection is less than the area of the eighth projection, or the area of the seventh projection is equal to the area of the eighth projection.

10. The solar cell of claim 9, wherein, The area of the seventh projection is less than the area of the third projection and the area of the fifth projection, and the area of the eighth projection is less than the area of the fourth projection and the area of the sixth projection.

11. The solar cell of claim 8, wherein, The first sub-electric connecting pad is arranged at a position close to the first side edge and / or the second side edge in the first area. The third sub-electric connecting pad and the fifth sub-electric connecting pad each comprise a plurality of sub-electric connecting pads, and the plurality of third sub-electric connecting pads and the plurality of fifth sub-electric connecting pads are arranged in the first sub-electric connecting pad away from the first side edge or the second side edge in the second direction. And / or, The second sub-electric connecting pad is arranged at a position close to the first side edge and / or the second side edge in the second area. The fourth sub-electric connecting pad and the sixth sub-electric connecting pad each comprise a plurality of sub-electric connecting pads, and the plurality of fourth sub-electric connecting pads and the plurality of sixth sub-electric connecting pads are arranged in the second sub-electric connecting pad away from the first side edge or the second side edge in the second direction.

12. The solar cell of claim 1, wherein, The battery piece further comprises: A first end connecting portion arranged in the first area of the battery piece, the first end connecting portion being located between the first electric connecting pad and the first side edge, and / or the first end connecting portion being located between the first electric connecting pad and the second side edge. And / or, A second end connecting portion arranged in the second area of the battery piece, the second end connecting portion being located between the second electric connecting pad and the first side edge, and / or the second end connecting portion being located between the second electric connecting pad and the second side edge.

13. The solar cell of claim 12, wherein, The first end connecting portion is a strip structure, the first end connecting portion extends in the second direction, and one end of the first end connecting portion is connected to the first electric connecting pad. And / or, the second end connecting portion is a strip structure, the second end connecting portion extends in the second direction, and one end of the second end connecting portion is connected to the second electric connecting pad.

14. The solar cell of claim 13, wherein, The first end connecting part gradually decreases in width along the first direction from the first electrical connecting pad to the first side edge; And / or, the second end connecting part gradually decreases in width along the first direction from the second electrical connecting pad to the first side edge.

15. The solar cell of claim 13, wherein, The first end connecting part has a ninth projection on the plane of the battery piece, and the second end connecting part has a tenth projection on the plane of the battery piece, and the area of the ninth projection is smaller than the area of the tenth projection.

16. The solar cell of claim 12, wherein, The first end connecting part comprises at least one first electrical connecting point, which is spaced apart from the first electrical connecting pad along the second direction; And / or, the second end connecting part comprises at least one second electrical connecting point, which is spaced apart from the second electrical connecting pad along the second direction.

17. The solar cell of claim 16, wherein, The first electrical connecting point has an eleventh projection on the plane of the battery piece, and the second electrical connecting point has a twelfth projection on the plane of the battery piece, and the area of the eleventh projection is smaller than the area of the twelfth projection.

18. The solar cell of claim 1, wherein, The solar battery piece has first and second side edges arranged oppositely along the second direction; The area of the first projection of the Nth first electrical connecting pad on the plane of the battery piece is smaller than the area of the second projection of the Nth second electrical connecting pad on the plane of the battery piece, as the first and / or second side edge approaches the center of the solar battery piece; wherein N is a positive integer, and 1≤N≤6.

19. The solar cell of any one of claims 1-18, wherein, The battery piece has first and second surfaces arranged oppositely along the thickness direction of the battery piece, the first region is arranged on the first surface of the battery piece, and the second region is arranged on the second surface of the battery piece.

20. The solar cell of claim 19, wherein, The first surface is the front surface of the battery piece, and the first region has a first pyramid structure of the first surface of the battery piece; The battery piece comprises a silicon substrate, and the first region has a first intrinsic amorphous silicon layer, a first doped amorphous silicon layer, and a first transparent conductive layer which are sequentially stacked on the silicon substrate; Alternatively, the first region has a first tunneling layer and a first doped polysilicon layer which are sequentially stacked on the silicon substrate; or the first region has a doped diffusion layer which is stacked on the silicon substrate; The second surface is the back surface of the battery piece, and the second region has a first polished surface of the second surface of the battery piece, or the second region has a second pyramid structure of the second surface of the battery piece; The second region has a second intrinsic amorphous silicon layer, a second doped amorphous silicon layer, and a second transparent conductive layer which are sequentially stacked on the silicon substrate; or the second region has a second tunneling layer and a second doped polysilicon layer which are sequentially stacked on the silicon substrate.

21. The solar cell of any one of claims 1-18, wherein, The battery piece has first and second surfaces arranged oppositely along the thickness direction of the battery piece; The first region and the second region are both arranged on the second surface of the battery piece.

22. The solar cell of claim 21, wherein, The second surface is a back surface of the battery piece, the first region has a third pyramidal structure of the second surface of the battery piece, and the second region has a second polished surface of the second surface of the battery piece. The battery piece comprises a silicon substrate, the first region has a third intrinsic amorphous silicon layer, a third doped amorphous silicon layer, and a third transparent conductive layer which are sequentially stacked on the silicon substrate, and the second region has a third tunneling layer and a third doped polysilicon layer which are sequentially stacked on the silicon substrate. Alternatively, the first region has a third polished surface of the second surface of the battery piece, and the second region has a fourth polished surface of the second surface of the battery piece. The first region has a fourth tunneling layer which is stacked on the silicon substrate, and the second region has a fifth tunneling layer which is stacked on the silicon substrate.

23. The solar cell of claim 1, wherein, The first fine grid comprises a plurality of first sub-fine grids, each of the plurality of first sub-fine grids extends along the first direction, and adjacent two first sub-fine grids are arranged at intervals along the first direction. The first electric connecting pad is located between the adjacent two first sub-fine grids, and the end portions of the first sub-fine grids on both sides of the first electric connecting pad overlap the first electric connecting pad away from the battery piece in the thickness direction of the battery piece.

24. The solar cell of claim 2, wherein, The length of the first sub-electric connecting pad along the first direction is L1, and 0.7mm≤L1≤1.3mm is satisfied, and the width of the first sub-electric connecting pad along the second direction is L2, and 0.8mm≤L2≤1.4mm is satisfied. And / or, the length of the second sub-electric connecting pad along the first direction is L3, and 0.8mm≤L3≤1.4mm is satisfied, and the width of the second sub-electric connecting pad along the second direction is L4, and 0.9mm≤L4≤1.5mm is satisfied.

25. The solar cell of claim 24, wherein, The width of the first sub-electric connecting pad along the second direction is greater than the width of the first fine grid along the second direction. And / or, the width of the second sub-electric connecting pad along the second direction is greater than the width of the second fine grid along the second direction.

26. The solar cell of claim 4, wherein, The length of the third sub-electric connecting pad along the first direction is L5, and 0.7mm≤L5≤1.3mm is satisfied, and the width of the third sub-electric connecting pad along the second direction is L6, and 0.03mm≤L6≤0.35mm is satisfied. And / or, the length of the fourth sub-electric connecting pad along the first direction is L7, and 0.8mm≤L7≤1.4mm is satisfied, and the width of the fourth sub-electric connecting pad along the second direction is L8, and 0.025mm≤L8≤0.15mm is satisfied.

27. The solar cell of claim 26, wherein, The width of the third sub-electric connecting pad along the second direction is greater than the width of the first fine grid along the second direction. And / or, the width of the fourth sub-electric connecting pad along the second direction is greater than the width of the second fine grid along the second direction.

28. The solar cell of claim 8, wherein, The length of the fifth sub-electric connecting pad along the first direction is L9, and 0.7mm≤L9≤1.3mm is satisfied, and the width of the fifth sub-electric connecting pad along the second direction is L10, and 0.03mm≤L10≤0.35mm is satisfied. And / or, a length of the sixth sub-electric connecting pad along the first direction is L11, and 0.8mm≤L11≤1.4mm is met, and a width of the sixth sub-electric connecting pad along the second direction is L12, and 0.025mm≤L12≤0.15mm is met.

29. The solar cell of claim 28, wherein, The width of the fifth sub-electric connecting pad along the second direction is greater than the width of the first fine grid along the second direction. And / or, the width of the sixth sub-electric connecting pad along the second direction is greater than the width of the second fine grid along the second direction.

30. A photovoltaic module, comprising: The solar cell sheet includes the solar cell sheet according to any one of claims 1-29. A first electric connecting piece is arranged at the first region of the solar cell sheet, and the first electric connecting piece is electrically connected with the first electric connecting pad. A second electric connecting piece is arranged at the second region of the solar cell sheet, and the second electric connecting piece is electrically connected with the second electric connecting pad.

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