Solar cell unit and method for manufacturing a solar power generation module

Abstract

The present invention provides a solar cell unit, which includes conductive connection strips arranged on both sides of the battery cell and parallel to each other. The front and back surfaces of the battery cell are each connected to one conductive connection strip by a plurality of metal wires. The present invention also provides a method for manufacturing two types of solar power generation modules. The present invention can reduce the silver consumption on the outer surface of the battery cell and the light shielding of the metal wires, and improve the manufacturing speed of the solar power generation module. During the arrangement process of the battery cells, the present invention can realize the simultaneous arrangement of a plurality of battery cells and improve the arrangement speed. The present invention can reduce the arrangement accuracy of the battery cells. The arrangement process does not require high-precision positioning of vision and robots, and the effective arrangement of the battery cells can be realized by simple mechanical positioning. The solution of the present invention is applied to a stacked grid battery having a stacked grid structure. The photo-generated current of the stacked grid battery flows vertically from inside the battery cell through an ultrathin seed layer and directly reaches the metal wire, without a lateral transmission process, with small resistance loss, saving the consumption of precious metal silver and avoiding the light shielding by the silver grid wire.

Description

Technical Field

[0001] The present invention relates to a solar cell unit and its use.

Background Art

[0002] In the conventional silicon solar cell industry chain, battery cells are manufactured using silicon sheets. A metal pattern for collecting current is prepared in advance on the outer surface of the battery cell. The pattern for collecting current is a fine grid. Considering both light shielding and current transmission loss comprehensively, the aspect ratio of the fine grid should be as large as possible. The pattern used for collecting the series current of the battery cell and the fine grid current is the main grid. To some extent, as the number of main grid lines increases, the amount of silver material used for the fine grid lines can be reduced. At the same time, the width of the fine grid lines can be designed to be narrower, and the thermal resistance loss of the fine grid decreases. While reducing the silver consumption of the battery cell, the efficiency is improved. Therefore, the main grid of the battery cell has been developing in the direction of increasing more and more. At the module end, the more the number of main grids, the more the number of welding strips connecting between battery cells, the thinner they are required to be, and the greater the difficulty of module manufacturing and process control. Currently, the multi-main grid battery series in the market mainly uses round wire welding strips or triangular welding strips, which can play the role of connecting circuits. At the same time, the light reflection on its outer surface can be reused secondarily to improve the light utilization rate of the module. The number of main grids of the multi-main grid is mainly 9 - 20 main grids. Compared with the number of battery fine grids and the width of the battery cell, the number of main grids and the actual light shielding area of the welding strip are still relatively small, and the influence on the light utilization rate of the whole module is relatively limited. Therefore, there are not very strict and specific requirements for the welding strip itself, such as the chamfering of the triangular welding strip and the reflectivity requirement of the outer surface of the welding strip.

[0003] Conventional solar power generation modules have the following defects.

[0004] The current path of the battery cell is complex. The photo-generated current is collected from within the battery cell substrate to the fine grid lines, transmitted horizontally by the fine grid lines to the main grid lines, vertically transmitted to the welding zone, and further transmitted out of the battery cell by the welding zone.

[0005] In the metallization of the battery cell, the consumption of silver is too high.

[0006] The metal light-shielding area on the outer surface of the battery cell is large, which affects the efficiency of the battery and the module.

[0007] The current of the battery cell is collected by the transmission of the fine grid metal on the outer surface, and the thermal resistance loss during the transmission process reduces the output power of the battery and the module.

[0008] The manufacturing speed of the photovoltaic module is slow. The battery cells in the module are connected in series by connecting the front and back surfaces of adjacent battery cells with a single welding zone respectively. This connection method is difficult to improve significantly after the manufacturing speed of the module reaches a certain level.

[0009] The light utilization rate of the gap between battery cells in the conventional module is low.

Summary of the Invention

[0010] To solve the deficiencies of the prior art, the present invention provides a solar cell unit, which includes a battery cell, and a first conductive connection strip and a second conductive connection strip respectively installed on both sides of the battery cell. The first conductive connection strip and the second conductive connection strip are parallel to each other.

[0011] The surface of the above battery cell is connected to the bottom surface of the first conductive connection strip by a plurality of first metal lines parallel to each other. Each first metal line is fixedly connected to the bottom surface of the first conductive connection strip by an electrical connection material respectively. Each first metal line is also fixedly connected to the surface of the battery cell by an electrical connection material respectively, and the end of each first metal line away from the first conductive connection strip does not extend outside the battery cell.

[0012] The back surface of the battery cell is connected to the top surface of the second conductive connection strip by a plurality of second metal wires that are parallel to each other. Each second metal wire is fixedly connected to the top surface of the second conductive connection strip by an electrical connection material. Each second metal wire is also fixedly connected to the back surface of the battery cell by an electrical connection material, and the end of each second metal wire that is away from the second conductive connection strip does not extend outside the battery cell.

[0013] Preferably, the electrical connection materials on the bottom surface of the first conductive connection strip and the top surface of the second conductive connection strip can be remelted and solidified again during the lamination process of the module.

[0014] For the specific content of the solar cell unit of the present invention, refer to Example 1.

[0015] The present invention further provides two manufacturing methods for solar power generation modules, all of which employ the above solar cell units. For the specific process, refer to Example 2 and Example 3.

[0016] The advantages and beneficial effects of the present invention are as follows.

[0017] The solar cell unit of the present invention combines a metal wire (first metal wire, second metal wire) and a conductive connection strip (first conductive connection strip, second conductive connection strip) with the battery cell and can be regarded as an integral unit, which is a single battery cell unit. The entire process from the battery cell unit to the solar cell module is the manufacturing process of the solar cell module. Since the metal wires (first metal wire, second metal wire) that concentrate and transmit all the current in the battery cell and the conductive connection strips (first conductive connection strip, second conductive connection strip) used for connection between the battery cells are pre-connected, the module craftsmanship is relatively simple compared with the conventional module craftsmanship.

[0018] In the structure of the solar cell unit of the present invention, the current on the outer surface (front surface of the cell, back surface of the cell) of the cell can be directly collected and transmitted by metal wires (first metal wire, second metal wire). There can be a large number of metal wires on the outer surface of the cell, which can be super-dense. For example, for a cell with a width of 166 mm, the number of metal wires on its outer surface can exceed 120. The conventional module series welding process and module packaging process cannot realize the packaging of the above-mentioned structure module. The biggest difference between the module manufacturing method of the present invention and the conventional module manufacturing method is that the conventional series welding process is not required. The conventional series welding process cannot meet the needs of the cell series connection process including such a large number of metal wires. The present invention first combines metal wires (first metal wire, second metal wire) and conductive connection strips (first conductive connection strip, second conductive connection strip) with the cell to form an independent solar cell unit, and also connects the head and tail of the solar cell unit to realize a cell series including a large number of metal wires while simplifying the connection process. And in the process of arranging the cells, the present invention can realize the simultaneous arrangement of a plurality of cells and improve the arrangement speed. In addition, the present invention can reduce the arrangement accuracy of the cells. The arrangement process does not require high-precision positioning of vision and robots, and the effective arrangement of the cells can be realized by simple mechanical positioning.

[0019] The present invention proposes an effective connection method for a large number of ultra-fine metal wires, which is used to realize the electrical connection between cells. The metal wires (first metal wire, second metal wire) are sandwiched in the middle by a pair of conductive connection strips (first conductive connection strip, second conductive connection strip), and then welded at a high temperature by a laminator to simply and effectively realize the connection between the thin metal wires, ensuring that the current between the cells is effectively transmitted to each metal wire.

[0020] For a battery whose outer surface is a transparent conductive oxide (TCO) (e.g., HJT (heterojunction with intrinsic thin layer) battery), the metal wires (first metal wire, second metal wire) can directly form an electrical connection with the TCO by means of conductive rubber or alloy, etc. For a battery without TCO on its outer surface, the metal wires (first metal wire, second metal wire) can form an electrical connection with the metal grid lines on the outer surface of the battery by means of conductive rubber or alloy, etc. The above structure is suitable for most solar cell units of the type having a metal pattern on the outer surface or the type without a metal pattern on the outer surface but collecting current by means of TCO. For example, PERC (passivated emitter and rear cell), TOPCon (tunnel oxide passivated contact), HJT, etc. can be used.

[0021] The photo-generated current of the solar cell unit of the present invention gathers on the outer surface (front surface and back surface of the battery cell) of the battery cell and is transmitted to the metal wires (first metal wire, second metal wire), and it does not need to pass through the fine grid. The metal wires (first metal wire, second metal wire) have a very low electrical resistance compared with the fine grid, so that the current can greatly reduce the heat resistance loss during transmission in the metal wires (first metal wire, second metal wire). The loss is reduced and the output power of the module is increased.

[0022] The present invention can reduce the consumption of silver paste in the battery module. The current on the outer surface (front surface and back surface of the battery cell) of the battery cell is collected and transmitted by the metal wires (first metal wire, second metal wire). The silver paste only serves to connect the metal wires and the battery cell. The current in the silver paste is designed to be transmitted only in the longitudinal direction perpendicular to the outer surface of the battery cell without performing lateral transmission. Without the need for stacking a large number of silver pastes, the lateral transmission resistance is reduced, the height of the silver paste can be reduced to 5 μm or less, and the consumption of silver paste can also be greatly reduced. Whether it is PERC, TOPCon, HJT or other batteries, the silver consumption can be greatly reduced, and it can be reduced by more than 80% at most.

[0023] Conventional battery fine grids and welding strips have a shading rate of 3% to 5%, resulting in serious shading losses. In the present invention, the cross-sectional shape of the metal wires (first metal wire, second metal wire) on the outer surface of the battery cell is preferentially selected to have a highly reflective triangular structure, so that direct light is reflected by the outer surface of the metal wires and finally reaches the battery cell, where it is absorbed. Therefore, the metal wires do not block the incident light on the outer surface of the battery cell, resulting in a high light-receiving rate of the battery module and naturally high efficiency of the battery module.

[0024] The inter-cell conductive connecting strips (first conductive connecting strip, second conductive connecting strip) of the present invention have a highly reflective sawtooth structure, which causes secondary total reflection of incident light and finally returns it to the battery cell, improving the utilization of light between the battery cells. Currently, there is no simple, effective, and convenient method of utilizing incident light between cells on the market, but the inter-cell conductive connecting strips (first conductive connecting strip, second conductive connecting strip) designed in this invention can achieve simple operation and effective utilization.

[0025] As can be seen from the above, the present invention significantly reduces the silver consumption on the outer surface of the battery cell and the light shielding of the metal wire, and also significantly improves the manufacturing speed of the photovoltaic module.

[0026] The solution of the present invention can be applied to a stacked grid battery having a stacked grid structure, as shown in FIG. 4. The stacked grid structure includes an ultra-thin seed layer in the form of grid lines disposed on the outer surface of the battery cell, and metal lines disposed on the ultra-thin seed layer. The metal lines are parallel to the ultra-thin seed layer on which they are located, and the width of the metal lines is not smaller than the width of the ultra-thin seed layer on which they are located. The thickness of the ultra-thin seed layer is ≦5 μm. Specifically, as shown in FIG. 5, the metal lines are fixedly connected to the ultra-thin seed layer on which they are located by a conductive connecting material. More specifically, the metal lines are fixedly connected to the ultra-thin seed layer on which they are located by methods such as welding, conductive curing adhesive connection, or conductive tape connection.

[0027] The ultra-thin seed layer is primarily used to collect and vertically direct the photo-generated current within the battery cell substrate, and the metal lines are primarily used to output the photo-generated current from the battery cell.

[0028] Specifically, the optical generation current transmission path of the stacked grid battery is collected from the battery cell body into the grid line-shaped ultra-thin seed layer, and is further transmitted from the grid line-shaped ultra-thin seed layer to the metal wire in the vertical direction, and is further transmitted from the battery cell by the metal wire. It is not necessary to perform current lateral transmission by the grid line-shaped ultra-thin seed layer.

[0029] The structure of the stacked grid battery is simple, the current transmission path is short, the battery cell body, the ultra-thin seed layer, and the metal wire are vertically overlapped integrally, and the optical generation current flows vertically from the inside of the battery cell through the ultra-thin seed layer and directly reaches the metal wire. There is no lateral transmission process, the electrical resistance loss is small, the consumption of precious metal silver for lateral transmission can be saved, and the light shielding by the silver grid line can be avoided or reduced.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0031] Hereinafter, specific embodiments of the present invention will be further described with reference to the accompanying drawings and examples. The following examples are for more clearly explaining the technical solution of the present invention and do not limit the protection scope of the present invention.

[0032] The specific implementation technical solution of the present invention is as follows. (Example 1) As shown in FIGS. 1 and 2, the present invention provides a solar cell unit, including a rectangular battery cell, a first conductive connection strip and a second conductive connection strip respectively arranged on both sides of the battery cell. The first conductive connection strip and the second conductive connection strip are parallel to a pair of side lines of the battery cell, and the first conductive connection strip and the second conductive connection strip are symmetrically arranged. The distances between the first conductive connection strip, the second conductive connection strip and the battery cell are all 5 mm or less (preferably 0.5 - 5 mm).

[0033] The surface of the above battery cell is connected to the bottom surface of the first conductive connection strip through a plurality of first metal lines arranged parallel to each other and at intervals. Each first metal line is perpendicular to the first conductive connection strip. The line width of each first metal line is 0.05 - 0.2 mm. The distance between two adjacent first metal lines is 1 - 3 mm. Each first metal line is fixedly connected to the bottom surface of the first conductive connection strip by an electrical connection material respectively. Each first metal line is also fixedly connected to the surface of the battery cell by an electrical connection material respectively. One end of each first metal line away from the first conductive connection strip does not extend outside the above battery cell.

[0034] The back surface of the above battery cell is connected to the top surface of the second conductive connection strip through a plurality of second metal lines arranged parallel to each other and at intervals. Each second metal line is perpendicular to the second conductive connection strip. The line width of each second metal line is 0.05 - 0.2 mm. The distance between two adjacent second metal lines is 1 - 3 mm. Each second metal line is fixedly connected to the top surface of the second conductive connection strip by an electrical connection material respectively. Each second metal line is also fixedly connected to the back surface of the battery cell by an electrical connection material respectively. One end of each second metal line away from the second conductive connection strip does not extend outside the above battery cell.

[0035] Specifically: The above electrical connection material can adopt conductive rubber (for example, a colloidal material filled with conductive particles), conductive paste (for example, silver paste), solder (for example, solder or other alloy materials) or other conductive adhesive materials.

[0036] The cross-sectional shape of the first metal wire and the second metal wire is triangular, circular, semicircular, trapezoidal, rectangular, etc. Preferably, the cross-sectional shape of the first metal wire and the second metal wire is triangular, the chamfering R of the apex angle of the triangle is ≦0.03 mm, all base angles of the triangle are >45°, and the width of the base of the triangle is 0.05 to 0.2 mm.

[0037] The outer surfaces of the first metal wire and the second metal wire may be highly reflective surfaces with a reflectance of 80% or more.

[0038] The cross-sectional shapes of the first conductive connecting strip and the second conductive connecting strip may be triangular, circular, semicircular, trapezoidal, rectangular, sawtooth, etc. Preferably, a reflective structure with a reflectance of ≥ 80% is provided on a bottom surface of the first conductive connecting strip that connects to the plurality of first metal lines. Preferably, a reflective structure with a reflectance of ≥ 80% is provided on a top surface of the second conductive connecting strip that connects to the plurality of second metal lines. The reflective structure may be a triangular sawtooth structure, with an apex angle of 90-140 degrees and a chamfered apex angle of R ≤ 0.05 mm.

[0039] Example 2 Based on Example 1, the differences are as follows: The surface of the battery cell is an insulating surface, and an ultra-thin seed layer for conducting current is provided on the surface of the battery cell, and the first metal wire is fixedly connected to the seed layer by an electrical connection material. Preferably, the thickness of the seed layer is ≦5 μm. The seed layer can be directly used in the metallization electroplating process.

[0040] Example 3 Based on Example 1, the differences are as follows: The above battery cell has a laminated grid structure. The laminated grid structure includes a grid-line-shaped ultra-thin seed layer provided on the outer surface of the battery cell and a metal wire provided on top of the ultra-thin seed layer. The metal wire is parallel to the ultra-thin seed layer where it is located, and the width of the metal wire is not smaller than the width of the ultra-thin seed layer where it is located. The thickness of the ultra-thin seed layer is ≦5um. The metal wire and the ultra-thin seed layer where it is located are fixedly connected by a conductive connection material. Specifically, the metal wire and the ultra-thin seed layer where it is located are fixedly connected by means such as welding, conductive cured adhesive connection, or conductive tape connection.

[0041] More specifically: The above ultra-thin seed layer includes a plurality of first ultra-thin seed layers provided on the surface of the battery cell and corresponding one-to-one with the first metal wires, and a plurality of second ultra-thin seed layers provided on the back surface of the battery cell and corresponding one-to-one with the second metal wires.

[0042] The above first metal wire is laminated on the corresponding first ultra-thin seed layer. The first metal wire is parallel to the first ultra-thin seed layer where it is located, and the width of the first metal wire is not smaller than the width of the first ultra-thin seed layer where it is located. The thickness of the first ultra-thin seed layer is ≦5μm. The first metal wire and the first ultra-thin seed layer where it is located are fixedly connected by a conductive connection material. Specifically, the first metal wire and the first ultra-thin seed layer where it is located are fixedly connected by means such as welding, conductive cured adhesive connection, or conductive tape connection.

[0043] The above second metal wire is laminated on the corresponding second ultra-thin seed layer. The second metal wire is parallel to the second ultra-thin seed layer where it is located, and the width of the second metal wire is not smaller than the width of the second ultra-thin seed layer where it is located. The thickness of the second ultra-thin seed layer is ≦5μm. The second metal wire and the second ultra-thin seed layer where it is located are fixedly connected by a conductive connection material. Specifically, the second metal wire and the second ultra-thin seed layer where it is located are fixedly connected by means such as welding, conductive cured adhesive connection, or conductive tape connection.

[0044] (Example 4) As shown in FIG. 3, the present invention further provides a method for manufacturing a solar cell module using the solar cell of Example 1, Example 2 or Example 3, wherein the electrical connection materials on the bottom surface of the first conductive connection strip and the top surface of the second conductive connection strip can be remelted and cured during the lamination process of the module, and the method includes the following steps.

[0045] 1) Lay a solar photovoltaic panel (for example, a solar photovoltaic glass) and a surface rubber film. The dimensions of the surface rubber film and the solar photovoltaic panel basically coincide, and the surface rubber film is laid flat on the solar photovoltaic panel.

[0046] 2) A robot arm or a mechanical suction cup is used to grip the solar cell unit (it may grip one solar photovoltaic unit or a plurality of units simultaneously), and the solar cell unit is laid flat on the surface rubber film according to the module circuit connection structure to form a battery string. And in a single battery string, the first conductive connection strip of the solar cell unit is laminated on the second conductive connection strip of the adjacent solar cell unit. At this time, the first metal wire on the bottom surface of the first conductive connection strip and the second metal wire on the top surface of the second conductive connection strip are sandwiched between the first conductive connection strip and the second conductive connection strip, ensuring the effectiveness of the connection between adjacent battery cells in the battery string. Since the electrical connection on the outer surface of the battery cell is completed (each first metal wire is fixedly connected to the surface of the battery cell, and each second metal wire is fixedly connected to the back surface of the battery cell), it is only necessary to realize the electrical connection between the solar cell units in the above process. Therefore, the accuracy requirements for gripping and arranging the battery cells are very low, so that a plurality of sheets can be gripped simultaneously, improving the arrangement speed of the sheets. The laminated first conductive connection strip and the second conductive connection strip form a conductive connection strip pair.

[0047] 3) Weld the bus bar and the electrode lead wire. The bus bar is used to connect the battery strings to complete the entire circuit of the module, and the lead wire is welded at the lead-out position and used to connect to the external junction box.

[0048] 4) Lay the back rubber film and the solar power generation back panel (it may also be back panel glass). At this time, a laminated component waiting for lamination is formed.

[0049] 5) Put the laminated component into a laminator and laminate it to press and integrally bond the laminated component. The lamination temperature is 130 - 160 °C. During the lamination process, the electrical connection material between the conductive connection strip pairs is melted, and the conductive connection strip pairs and the first metal wire and the second metal wire between the above-mentioned conductive connection strip pairs are integrally fixedly connected to achieve stable electrical connection of adjacent battery cells.

[0050] 6) Attach and solidify the junction box and the module frame.

[0051] (Example 5) As shown in Figure 3, the present invention further provides a method for manufacturing a solar power generation module using the solar power generation cell of Example 1, Example 2 or Example 3, including the following steps.

[0052] 1) Lay the solar power generation panel (for example, solar power generation glass) and the surface rubber film. The dimensions of the surface rubber film and the solar power generation panel basically match, and the surface rubber film is laid flat on the solar power generation panel.

[0053] 2) The robotic arm or mechanical suction cup is used to grip the solar cell unit (it may grip one solar power generation unit or multiple units simultaneously), and the solar cell unit is laid flat on the surface rubber film by the module circuit connection structure to form a battery string. Then, in a single battery string, the first conductive connection strip of the solar cell unit is laminated on the second conductive connection strip of the adjacent solar cell unit. At this time, the first metal wire on the bottom surface of the first conductive connection strip and the second metal wire on the top surface of the second conductive connection strip are sandwiched between the first conductive connection strip and the second conductive connection strip, ensuring the effectiveness of the connection between adjacent battery cells in the battery string. Since the electrical connection on the outer surface of the battery cell is completed (each first metal wire is fixedly connected to the surface of the battery cell, and each second metal wire is fixedly connected to the back surface of the battery cell), it is only necessary to realize the electrical connection between the solar cell units in the above process. Therefore, the accuracy requirements for gripping and arranging the battery cells are very low, so that multiple sheets can be gripped simultaneously, improving the sheet arrangement speed. The laminated first conductive connection strip and second conductive connection strip form a pair of conductive connection strips.

[0054] 3) Heat the electrical connection material between the pair of conductive connection strips, melt and solidify the electrical connection material between the pair of conductive connection strips, and integrally and fixedly connect the pair of conductive connection strips and the first metal wire and the second metal wire between the pair of conductive connection strips to achieve a stable electrical connection between adjacent battery cells.

[0055] 4) Weld the bus bar and the electrode lead wire. The bus bar is used to connect the battery strings to complete the entire circuit of the module, and the lead wire is welded at the lead-out position and used to connect to the external junction box.

[0056] 5) Lay the back rubber film and the solar power generation back panel (it may also be back panel glass). At this time, a laminated component waiting for lamination is formed.

[0057] 6) Put the laminated component into a laminator for lamination, and press and bond the laminated component to integrally combine it.

[0058] 7) Attach and solidify the junction box and the module frame.

[0059] The above are only preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can be made, and these improvements and modifications should also be regarded as within the protection scope of the present invention.

Claims

1. A solar cell unit, comprising: a battery cell, and a first conductive connection strip and a second conductive connection strip disposed on both sides of the battery cell respectively, the first conductive connection strip and the second conductive connection strip being parallel to each other, the surface of the battery cell is connected to the bottom surface of the first conductive connection strip by a plurality of first metal wires parallel to each other, each first metal wire is fixedly connected to the bottom surface of the first conductive connection strip by an electrical connection material, each first metal wire is also fixedly connected to the surface of the battery cell by an electrical connection material, and one end of each first metal wire away from the first conductive connection strip does not extend outside the battery cell, the back surface of the battery cell is connected to the top surface of the second conductive connection strip by a plurality of second metal wires parallel to each other, each second metal wire is fixedly connected to the top surface of the second conductive connection strip by an electrical connection material, each second metal wire is also fixedly connected to the back surface of the battery cell by an electrical connection material, and one end of each second metal wire away from the second conductive connection strip does not extend outside the battery cell. A solar cell unit characterized by this.

2. The electrical connection material uses conductive rubber, conductive paste, or solder. The solar cell unit according to claim 1, characterized by this.

3. The battery cell is rectangular, the first conductive connection strip and the second conductive connection strip are parallel to a pair of side lines of the battery cell, and each first metal wire and each second metal wire are parallel to the other pair of side lines of the battery cell. The solar cell unit according to claim 1, characterized by this.

4. The first conductive connection strip and the second conductive connection strip are provided symmetrically. The solar cell unit according to claim 1, characterized by this.

5. The plurality of first metal wires are arranged at equal intervals, the interval between two adjacent first metal wires is 1 to 3 mm, the plurality of second metal wires are arranged at equal intervals, and the interval between two adjacent second metal wires is 1 to 3 mm. The solar cell unit according to claim 1, characterized by this.

6. The wire widths of the first metal wire and the second metal wire are 0.05 to 0.2 mm. The solar cell unit according to claim 1, characterized by this.

7. The cross-sectional shapes of the first metal wire and the second metal wire are triangular, circular, semi-circular, trapezoidal, or rectangular. The solar cell unit according to claim 1, characterized by this.

8. 2. The solar cell unit of claim 1, wherein the cross-sectional shape of the first metal wire and the second metal wire is triangular, the chamfering R of the apex angle of the triangle is less than or equal to 0.03 mm, the base angles of the triangle are all greater than 45°, and the width of the base of the triangle is 0.05 to 0.2 mm.

9. 2. The solar cell unit according to claim 1, wherein the outer surfaces of the first metal wire and the second metal wire are highly reflective surfaces with a reflectance of 80% or more.

10. 2. The solar cell unit according to claim 1, wherein the distance between the first conductive connecting strip and the battery cell and the distance between the second conductive connecting strip and the battery cell are 5 mm or less.

11. 2. The solar cell unit according to claim 1, wherein the cross-sectional shape of the first conductive connecting strip and the cross-sectional shape of the second conductive connecting strip are triangular, circular, semicircular, trapezoidal, rectangular, or sawtooth.

12. 2. The solar cell unit of claim 1, wherein a bottom surface of the first conductive connecting strip that connects to the plurality of first metal lines is provided with a reflective structure having a reflectivity of ≥ 80%, and a top surface of the second conductive connecting strip that connects to the plurality of second metal lines is provided with a reflective structure having a reflectivity of ≥ 80%.

13. 13. The solar cell unit according to claim 12, wherein the reflective structure is a triangular sawtooth structure, and the sawtooth has an apex angle of 90 to 140 degrees, and the apex angle chamfer has R≦0.05 mm.

14. 2. The solar cell unit according to claim 1, wherein the surface of the battery cell is an insulating surface, and a seed layer for conducting current is provided on the surface of the battery cell, and the first metal wire is fixedly connected to the seed layer by an electrical connection material.

15. the battery cell has a stacked grid structure, the stacked grid structure including an ultra-thin seed layer in the form of grid lines provided on the outer surface of the battery cell, and metal lines provided on the ultra-thin seed layer, the metal lines being parallel to the ultra-thin seed layer on which they are located, and the width of the metal lines is not smaller than the width of the ultra-thin seed layer on which they are located; 2. The solar cell unit of claim 1, wherein the ultra-thin seed layer includes a plurality of first ultra-thin seed layers provided on the surface of the battery cell and corresponding one-to-one to the first metal wires, and a plurality of second ultra-thin seed layers provided on the back surface of the battery cell and corresponding one-to-one to the second metal wires.

16. 16. The solar cell unit of claim 15, wherein the ultra-thin seed layer has a thickness of ≦5 μm.

17. The solar cell unit according to claim 15, wherein a fixed connection is established between the metal wire and the ultra-thin seed layer in which the metal wire is located by means of a conductive connection material.

18. The solar cell unit according to claim 15, wherein the metal wire and the ultra-thin seed layer in which the metal wire is located are fixedly connected by means of welding, conductive cured adhesive connection, or conductive tape connection.

19. A method for manufacturing a solar power generation module, which employs the solar cell unit according to any one of claims 1 to 18, 1) Lay a solar power generation panel and a surface rubber film, 2) Grasp the solar cell unit and lay the solar cell unit flat on the surface rubber film by means of a module circuit connection structure to form a battery string. In a single battery string, the first conductive connection strip of the solar cell unit is laminated on the second conductive connection strip of an adjacent solar cell unit. At this time, the first metal wire on the bottom surface of the first conductive connection strip and the second metal wire on the top surface of the second conductive connection strip are sandwiched between the first conductive connection strip and the second conductive connection strip, and the laminated first conductive connection strip and second conductive connection strip constitute a pair of conductive connection strips, 3) Weld the bus bar and the electrode lead wire, 4) Lay the back rubber film and the solar power generation back panel. At this time, a laminated component waiting for lamination is formed, 5) Put the laminated component into a laminator for lamination to integrally bond the laminated component. During the lamination process, the electrical connection material between the pair of conductive connection strips is melted, and the pair of conductive connection strips and the first metal wire and second metal wire between the pair of conductive connection strips are integrally fixedly connected, 6) Install the junction box and the module frame, A method for manufacturing a solar power generation module, characterized by including the above steps.

20. A method for manufacturing a solar power generation module, which employs the solar cell unit according to any one of claims 1 to 18, 1) Lay a solar power generation panel and a surface rubber film, 2) Grasp the solar cell unit and lay the solar cell unit flat on the surface rubber film by the module circuit connection structure to form a battery string. In a single battery string, stack the first conductive connection strip of the solar cell unit on the second conductive connection strip of the adjacent solar cell unit. At this time, the first metal wire on the bottom surface of the first conductive connection strip and the second metal wire on the top surface of the second conductive connection strip are sandwiched between the first conductive connection strip and the second conductive connection strip, and the stacked first conductive connection strip and second conductive connection strip constitute a pair of conductive connection strips. 3) Heat the electrical connection material between the pair of conductive connection strips, melt and solidify it to integrally and fixedly connect the pair of conductive connection strips and the first metal wire and the second metal wire between the pair of conductive connection strips. 4) Weld the bus bar and the electrode lead wire. 5) Lay the back rubber film and the solar power generation back panel. At this time, a laminated component waiting for lamination is formed. 6) Put the laminated component into a laminator for lamination to integrally bond the laminated component. 7) Install the junction box and the module frame. A manufacturing method of a solar power generation module, characterized by including the above steps.

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