Back-contact battery string, back-contact battery assembly, and back-contact battery system

Abstract

The present invention belongs to the technical field of solar cells, and in particular relates to a back-contact cell string, a back-contact cell assembly, and a back-contact cell system. The back-contact cell string includes: at least one cell, the cell including a P-type doped region provided with a positive fine grid line and an N-type doped region provided with a negative fine grid line, a first positive insulating block array and a second positive insulating block array are provided on the positive fine grid line, a first parallel positive insulating block and a second parallel positive insulating block are provided on the negative fine grid line, a first negative insulating block array and a second negative insulating block array are provided on the first parallel negative insulating block and a second parallel negative insulating block are provided on the second parallel negative insulating block. The present invention can improve the photoelectric conversion efficiency of the cell and reduce metal consumption; in addition, it can prevent the cell from being damaged, reduce the stress of the cell assembly, and improve its reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and in particular relates to a back-contact cell string, a back-contact cell assembly and a back-contact cell system. Background Art

[0002] Solar cells are semiconductor devices that convert light energy into electrical energy. Low production costs and high energy conversion efficiency have always been the goals of the solar cell industry. For conventional solar cells, the emitter and base contact electrodes are located on the front and back of the cell, respectively. The front side of the cell is the light-receiving side, and coverage of the metal emitter contact electrode on the front side will inevitably cause some incident sunlight to be reflected and blocked by the metal electrode, resulting in some optical loss. The metal electrode coverage of the front side of a typical crystalline silicon solar cell is approximately 7%. Reducing the metal electrode coverage on the front side can directly improve the cell's energy conversion efficiency.

[0003] To address this issue, the industry has introduced a back-contact solar cell. A back-contact solar cell places both the emitter and base contact electrodes on the back (non-light-receiving) side of the cell. This allows for a wider metal grid on the back, reducing series resistance and improving the fill factor. This unobstructed front-facing cell not only offers high conversion efficiency but also looks more aesthetically pleasing. Components with full back-contact electrodes are also easier to assemble.

[0004] Existing back-contact solar cells use fine grid lines on the positive and negative electrodes to separate holes and electrons, which are then collected through a main grid. However, the presence of a main grid results in poor hole-electron separation at the corresponding locations, resulting in efficiency loss. However, the absence of a main grid increases series resistance, making current collection difficult. Furthermore, the high metal consumption of the main grid significantly increases battery production costs. Furthermore, back-contact solar cells are often assembled using solder ribbons, which require high temperatures and can damage the cells. The solder ribbons also cause stress on the cells, leading to hidden cracks and significantly reducing their reliability. Summary of the Invention

[0005] The present invention provides a back-contact battery string, aiming to solve the technical problems of low efficiency and high cost of existing back-contact batteries, and the tendency to cause damage and stress to the batteries during assembly.

[0006] The present invention is implemented by providing a back-contact cell string, the back-contact cell string comprising:

[0007] At least one battery cell, each of the battery cells comprising alternatingly arranged P-type doping regions and N-type doping regions, the P-type doping regions being provided with positive electrode fine grid lines, and the N-type doping regions being provided with negative electrode fine grid lines;

[0008] The positive electrode fine grid lines are provided with a first positive electrode insulating block array and a second positive electrode insulating block array in a vertical direction thereof, and the second positive electrode insulating block array is located between two adjacent first positive electrode insulating block arrays;

[0009] The first positive insulating block array includes first parallel positive insulating blocks arranged at intervals on the positive fine grid lines, and the second positive insulating block array includes second parallel positive insulating blocks arranged at intervals, and the second parallel positive insulating blocks are arranged on the positive fine grid lines where the first parallel positive insulating blocks are not arranged;

[0010] The first parallel positive electrode insulating block and the second parallel positive electrode insulating block are both provided with a first conductive segment connecting two adjacent negative electrode thin grid lines;

[0011] The negative electrode fine grid lines are provided with a first negative electrode insulating block array and a second negative electrode insulating block array in a vertical direction thereof, wherein the second negative electrode insulating block array is located between two adjacent first negative electrode insulating block arrays;

[0012] The first negative electrode insulating block array includes first parallel negative electrode insulating blocks arranged at intervals on the negative electrode fine grid lines, and the second negative electrode insulating block array includes second parallel negative electrode insulating blocks arranged at intervals, and the second parallel negative electrode insulating blocks are arranged on the negative electrode fine grid lines where the first parallel negative electrode insulating blocks are not arranged;

[0013] The first parallel negative electrode insulating block and the second parallel negative electrode insulating block are both provided with a second conductive segment connecting two adjacent positive electrode fine grid lines;

[0014] The first conductive segment located at the first edge of the first battery cell is connected to the second conductive segment at the edge of the second battery cell adjacent to the first battery cell;

[0015] The second conductive segment located at a second edge opposite to the first edge is connected to the first conductive segment at an edge of a third battery cell adjacent to the first battery cell.

[0016] Furthermore, the back-contact cell string further includes a first conductive bus bar at one end thereof and a second conductive bus bar at the other end thereof, the first conductive segments are connected to the first conductive bus bar, and the second conductive segments are connected to the second conductive bus bar.

[0017] Furthermore, the battery cells are connected via interconnection bars.

[0018] Furthermore, the first conductive segment and / or the second conductive segment includes a metal film and a composite film partially wrapping the metal film.

[0019] Furthermore, the composite film is a POE film, an EVA film, a PVB film, or a co-extruded film composed of POE and EVA.

[0020] Furthermore, the first conductive segment and / or the second conductive segment is a metal film.

[0021] Furthermore, the positive electrode fine grid line is an aluminum grid line, a silver grid line, a silver-aluminum grid line, a copper grid line, or a silver-clad copper grid line.

[0022] Furthermore, the negative electrode fine grid line is an aluminum grid line, a silver grid line, a silver-aluminum grid line, a copper grid line, or a silver-clad copper grid line.

[0023] The present invention also provides a back-contact battery assembly, which includes the back-contact battery string described above.

[0024] The present invention also provides a back-contact battery system, which includes the back-contact battery assembly described above.

[0025] The beneficial effects of the present invention are that the battery cells of the back-contact battery string do not need to be provided with a main grid, and the photoelectric conversion efficiency of the battery cells is high; the positive fine grid lines are conductively connected through the second conductive segment, and the second conductive segment is arranged at intervals, and the negative fine grid lines are conductively connected through the first conductive segment, and the first conductive segment is also arranged at intervals, which can reduce metal consumption and greatly reduce the cost of the battery cells; in addition, the back-contact battery string can be made into a film structure and directly pasted to form a battery assembly without going through a high-temperature welding process, thereby avoiding damage to the battery cells; the back-contact battery string does not need to be connected through a welding ribbon, thereby avoiding stress problems in the battery cells and greatly improving the reliability of the battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of a battery cell provided by an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of a back-contact battery string provided by an embodiment of the present invention;

[0028] Figure 3 is based on Figure 2 Enlarged view of part A;

[0029] Figure 4 Schematic diagram of a back-contact battery string provided with a first bus bar and a second bus bar according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] The back-contact battery string of the present invention includes at least one battery cell, and the battery cell includes a P-type doped region provided with a positive fine grid line and an N-type doped region provided with a negative fine grid line. The positive fine grid line is conductively connected through the second conductive segment and is insulated by the first positive insulating block array and the second positive insulating block array. The negative fine grid line is conductively connected through the first conductive segment and is insulated by the first negative insulating block array and the second negative insulating block array. Adjacent battery cells are also conductively connected through the first conductive segment and the second conductive segment. The battery cells of the back-contact battery string do not need to be provided with a main grid, and the photoelectric conversion efficiency of the battery cells is high; the positive fine grid line is conductively connected through the second conductive segment, and the second conductive segment is arranged at intervals; the negative fine grid line is conductively connected through the first conductive segment, and the first conductive segment is also arranged at intervals, which can reduce metal consumption and greatly reduce the cost of the battery cells; in addition, the back-contact battery string can be made into a film structure and directly attached to form a battery assembly without going through a high-temperature welding process, thereby avoiding damage to the battery cells; the back-contact battery string does not need to be connected through a welding ribbon, thereby avoiding stress problems in the battery cells and greatly improving the reliability of the battery cells.

[0032] Example 1

[0033] refer to Figures 1 to 3 , this embodiment 1 provides a back-contact battery string, the back-contact battery string comprising:

[0034] At least one battery cell 100, each of the battery cells 100 includes alternating P-type doping regions and N-type doping regions, the P-type doping regions are provided with positive electrode fine grid lines 11, and the N-type doping regions are provided with negative electrode fine grid lines 12;

[0035] The positive electrode fine grid line 11 is provided with a first positive electrode insulating block array 21 and a second positive electrode insulating block array 22 in a vertical direction thereof, and the second positive electrode insulating block array 22 is located between two adjacent first positive electrode insulating block arrays 21;

[0036] The first positive insulating block array 21 includes first parallel positive insulating blocks 211 spaced apart on the positive thin grid lines 11, and the second positive insulating block array 22 includes second parallel positive insulating blocks 221 spaced apart, wherein the second parallel positive insulating blocks 221 are disposed on the positive thin grid lines 11 where the first parallel positive insulating blocks 211 are not disposed.

[0037] The first parallel positive electrode insulating block 211 and the second parallel positive electrode insulating block 221 are both provided with a first conductive segment 31 connecting two adjacent negative electrode thin gate lines 12;

[0038] The negative electrode thin gate line 12 is provided with a first negative electrode insulating block array 23 and a second negative electrode insulating block array 24 in a vertical direction thereof, and the second negative electrode insulating block array 24 is located between two adjacent first negative electrode insulating block arrays 23;

[0039] The first negative electrode insulating block array 23 includes first parallel negative electrode insulating blocks 231 spaced apart on the negative electrode thin gate lines 12, and the second negative electrode insulating block array 24 includes second parallel negative electrode insulating blocks 241 spaced apart, wherein the second parallel negative electrode insulating blocks 241 are disposed on the negative electrode thin gate lines 12 where the first parallel negative electrode insulating blocks 231 are not disposed.

[0040] The first parallel negative electrode insulating block 231 and the second parallel negative electrode insulating block 241 are both provided with a second conductive segment 32 connecting two adjacent positive electrode fine gate lines 11;

[0041] The first conductive segment 31 located at the first edge of the first cell is connected to the second conductive segment 32 at the edge of the second cell adjacent to the first cell;

[0042] The second conductive segment 32 located at a second edge opposite to the first edge is connected to the first conductive segment 31 at an edge of a third battery cell adjacent to the first battery cell.

[0043] In this embodiment, a back-contact battery string is a battery string formed by connecting at least one battery cell 100 in series. The back-contact battery string may include two battery cells 100, three battery cells 100, or a larger number of battery cells 100 connected in series. The number of battery cells 100 required to be connected in series can be determined based on actual usage. The battery cells 100 located at the two ends of the back-contact battery string are defined as end battery cells 100. When the back-contact battery string consists of multiple battery cells 100 connected in series, the battery cell 100 connected in series between the two end battery cells 100 is defined as an inner battery cell 100.

[0044] As one example of the present invention, a cell 100 comprises, from top to bottom, a front passivation and anti-reflection layer, a silicon substrate, a back tunneling layer, alternating P-type and N-type doped regions, a back passivation layer, and battery electrodes. The P-type and N-type doped regions are arranged on the lower surface of the back tunneling layer. The battery electrodes include a positive electrode fine grid line 11 that contacts the P-type doped region and a negative electrode fine grid line 12 that contacts the N-type doped region.

[0045] An insulating region is provided between the P-type and N-type doped regions. The insulating region can be a non-conductive tape or insulating film, or another suitable non-conductive shielding cover or lid. The insulating region can comprise materials such as polypropylene or polyethylene, and may also include an acrylic adhesive layer. The insulating region is sandwiched between each P-type and N-type doped region, and its insulating effect prevents contact and short circuits between the positive fine gate lines 11 in the P-type doped region and the negative fine gate lines 12 in the N-type doped region.

[0046] The positive electrode fine grid line 11 is provided with a first positive electrode insulating block array 21 and a second positive electrode insulating block array 22 in its vertical direction. There are multiple first positive electrode insulating block arrays 21 and second positive electrode insulating block arrays 22. The first positive electrode insulating block arrays 21 and the second positive electrode insulating block arrays 22 are alternately arranged. The second positive electrode insulating block array 22 is located between adjacent first positive electrode insulating block arrays 21, and the first positive electrode insulating block array 21 is also located between adjacent second positive electrode insulating block arrays 22. The end of the positive electrode fine grid line 11 may be the first positive electrode insulating block array 21 or the second positive electrode insulating block array 22.

[0047] The first positive electrode insulating block array 21 includes first parallel positive electrode insulating blocks 211 spaced apart on the positive electrode fine grid lines 11. Figure 1 As shown, in the same first positive electrode insulating block array 21, there are multiple first parallel positive electrode insulating blocks 211, and in the horizontal direction, each first parallel positive electrode insulating block 211 is spaced apart on the positive electrode fine grid line 11. The second positive electrode insulating block array 22 includes second parallel positive electrode insulating blocks 221 spaced apart on the positive electrode fine grid line 11, as shown in FIG. Figure 1 As shown, in the same second positive insulating block array 22, multiple second parallel positive insulating blocks 221 are provided, and in the horizontal direction, each second parallel positive insulating block 221 is spaced apart on the positive fine grid lines 11. Furthermore, the second parallel positive insulating blocks 221 are provided on the positive fine grid lines 11 that are not provided with the first parallel positive insulating blocks 211. In other words, the first parallel positive insulating blocks 211 and the second parallel positive insulating blocks 221 do not appear simultaneously on the same positive fine grid line 11. The first parallel positive insulating blocks 211 and the second parallel positive insulating blocks 221, at their respective corresponding positions, insulate the positive fine grid lines 11.

[0048] The first parallel positive insulating block 211 and the second parallel positive insulating block 221 are both provided with a first conductive segment 31 connecting two adjacent negative thin gate lines 12. The first conductive segments 31, at their respective corresponding positions, provide conductive connections to adjacent negative thin gate lines 12.

[0049] The negative electrode fine grid line 12 is provided with a first negative electrode insulating block array 23 and a second negative electrode insulating block array 24 in its vertical direction. There are multiple first negative electrode insulating block arrays 23 and second negative electrode insulating block arrays 24. The first negative electrode insulating block arrays 23 and the second negative electrode insulating block arrays 24 are alternately arranged. The second negative electrode insulating block array 24 is located between adjacent first negative electrode insulating block arrays 23, and the first negative electrode insulating block array 23 is also located between adjacent second negative electrode insulating block arrays 24. The end of the negative electrode fine grid line 12 may be the first negative electrode insulating block array 23 or the second negative electrode insulating block array 24.

[0050] The first negative electrode insulating block array 23 includes first parallel negative electrode insulating blocks 231 spaced apart on the negative electrode fine grid lines 12. Figure 1 As shown, in the same first negative electrode insulating block array 23, a plurality of first parallel negative electrode insulating blocks 231 are provided, and in the horizontal direction, each first parallel negative electrode insulating block 231 is spaced apart on the negative electrode fine grid line 12. The second negative electrode insulating block array 24 includes second parallel negative electrode insulating blocks 241 spaced apart on the negative electrode fine grid line 12, as shown in FIG. Figure 1 As shown, in the same second negative electrode insulating block array 24, multiple second parallel negative electrode insulating blocks 241 are provided, and in the horizontal direction, each second parallel negative electrode insulating block 241 is spaced apart on the negative electrode fine grid line 12. Furthermore, the second parallel negative electrode insulating blocks 241 are provided on the negative electrode fine grid line 12 that is not provided with the first parallel negative electrode insulating blocks 231. In other words, the first parallel negative electrode insulating blocks 231 and the second parallel negative electrode insulating blocks 241 do not appear simultaneously on the same negative electrode fine grid line 12. The first parallel negative electrode insulating blocks 231 and the second parallel negative electrode insulating blocks 241, at their respective corresponding positions, provide insulation for the negative electrode fine grid line 12.

[0051] Second conductive segments 32 for connecting two adjacent positive thin gate lines 11 are provided on the first parallel negative insulating block 231 and the second parallel negative insulating block 241. The second conductive segments 32 connect adjacent positive thin gate lines 11 at their respective corresponding positions.

[0052] The first conductive segment 31 located at the first edge of the first cell is connected to the second conductive segment 32 at the edge of the second cell adjacent to the first cell. The first conductive segment 31 and the second conductive segment 32 conduct electricity in the first and second cells, achieving a negative-to-positive polarity flow. The second conductive segment 32 located at the second edge opposite the first edge is connected to the first conductive segment 31 at the edge of the third cell adjacent to the first cell. The second conductive segment 32 and the first conductive segment 31 conduct electricity in the first and third cells, achieving a positive-to-negative polarity flow.

[0053] It should be noted that the first battery cell is adjacent to the second battery cell and the third battery cell respectively, which can be as follows: Figure 1 The left-right adjacent arrangement shown may also be top-to-bottom adjacent arrangement, depending on the placement of the battery cells 100. Furthermore, the terms "first," "second," and "third" in the first, second, and third battery cells are merely used to distinguish the battery cells 100, and do not limit the number of battery cells 100. In other words, a back-contact battery string is not limited to having only three battery cells 100.

[0054] In the present invention, the back-contact battery string includes at least one battery cell 100, and the battery cell 100 includes a P-type doped region provided with a positive fine grid line 11 and an N-type doped region provided with a negative fine grid line 12. The positive fine grid line 11 is conductively connected through the second conductive segment 32 and is insulated by the first positive insulating block array 21 and the second positive insulating block array 22. The negative fine grid line 12 is conductively connected through the first conductive segment 31 and is insulated by the first negative insulating block array 23 and the second negative insulating block array 24. Adjacent battery cells 100 are also conductively connected through the first conductive segment 31 and the second conductive segment 32. The cell 100 of the back-contact cell string does not need to be provided with a main grid, and the photoelectric conversion efficiency of the cell 100 is high; the positive electrode fine grid line 11 is conductively connected through the second conductive segment 32, and the second conductive segment 32 is arranged at intervals, and the negative electrode fine grid line 12 is conductively connected through the first conductive segment 31, and the first conductive segment 31 is also arranged at intervals, which can reduce metal consumption and greatly reduce the cost of the cell 100; in addition, the back-contact cell string can be made into a film structure and directly pasted to form a battery assembly without going through a high-temperature welding process, thereby avoiding damage to the cell 100; the back-contact cell string does not need to be connected through a welding ribbon, thereby avoiding stress problems in the cell 100 and greatly improving the reliability of the cell 100.

[0055] Example 2

[0056] refer to Figure 4 Based on the first embodiment, the back-contact cell string of the second embodiment further includes a first conductive bus bar located at one end thereof and a second conductive bus bar located at the other end thereof, wherein the first conductive segment 31 is connected to the first conductive bus bar, and the second conductive segment 32 is connected to the second conductive bus bar.

[0057] In this embodiment, in each cell 100 of the back-contact cell string, the current guided by the negative electrode fine grid lines 12 is collected and aggregated to the first conductive bus bar through the first conductive segment 31, and the current guided by the positive electrode fine grid lines 11 is collected and aggregated to the second conductive bus bar through the second conductive segment 32. Figure 4When the first conductive busbar and the second conductive busbar are provided, the first conductive segments 31, the second conductive segments 32, the first positive electrode insulating block array 21, the second positive electrode insulating block array 22, the first negative electrode insulating block array 23 and the second negative electrode insulating block array 24 of adjacent battery cells 100 are arranged in the same manner and are translationally symmetrical. Figure 2 When the first conductive bus bar and the second conductive bus bar are not provided, the first conductive segments 31, the second conductive segments 32, the first positive insulating block array 21, the second positive insulating block array 22, the first negative insulating block array 23 and the second negative insulating block array 24 of adjacent battery cells 100 are arranged differently and are mirror-symmetrical.

[0058] Example 3

[0059] Based on the first embodiment, the battery cells 100 of the third embodiment are connected via interconnection bars, which collect the currents of the battery cells 100 and realize the series connection of the battery cells 100 .

[0060] Example 4

[0061] On the basis of the first embodiment, the first conductive segment 31 and / or the second conductive segment 32 of the fourth embodiment includes a metal film and a composite film partially wrapping the metal film.

[0062] This embodiment can be implemented by: the first conductive segment 31 including a metal film and a composite film partially encapsulating the metal film. Alternatively, the second conductive segment 32 including a metal film and a composite film partially encapsulating the metal film. Alternatively, both the first conductive segment 31 and the second conductive segment 32 including a metal film and a composite film partially encapsulating the metal film.

[0063] The metal film contains a conductive material (such as a metal such as copper, aluminum, or other suitable conductive material, with or without a coating such as tin, silver, nickel, or an organic solderability protectant), and the composite film covers the end of the metal film away from the positive electrode fine grid lines 11 and the negative electrode fine grid lines 12. At this time, when the battery cells 100 are connected in series to form a battery string through the first conductive segments 31 and the second conductive segments 32, the first conductive segments 31 and the second conductive segments 32 can be attached to the battery cells 100 by gluing. The composite film can more tightly connect the first conductive segments 31 and the second conductive segments 32 to the negative electrode fine grid lines 12 and the positive electrode fine grid lines 11 on the battery cells 100, thereby solving the problem of warping of the battery cells 100 caused by stress.

[0064] Example 5

[0065] On the basis of Example 4, the composite film of Example 5 is a POE film, an EVA film, a PVB film, or a co-extruded film composed of POE and EVA.

[0066] Among them, POE (full name in English is Polyolefin elastomer) refers to polyolefin elastomer, EVA (full name in English is Ethylene Vinyl Acetate Copolymer) refers to polyethylene-polyvinyl acetate copolymer, and PVB (full name in English is polyvinyl butyral) refers to polyvinyl butyral.

[0067] Example 6

[0068] Based on the first embodiment, the first conductive segment 31 and / or the second conductive segment 32 of the sixth embodiment is a metal film.

[0069] This embodiment can be implemented in such a way that the first conductive segment 31 is a metal film, the second conductive segment 32 is a metal film, and both the first conductive segment 31 and the second conductive segment 32 are metal films.

[0070] The first conductive segment 31 can be connected to the adjacent negative electrode thin grid line 12 by pasting, and the second conductive segment 32 can be connected to the adjacent positive electrode thin grid line 11 by pasting.

[0071] Example 7

[0072] On the basis of the first embodiment, the positive electrode fine grid line 11 of the seventh embodiment is an aluminum grid line, a silver grid line, a silver-aluminum grid line, a copper grid line, or a silver-clad copper grid line.

[0073] Example 8

[0074] On the basis of the first embodiment, the negative electrode fine grid lines 12 of the eighth embodiment are aluminum grid lines, silver grid lines, silver-aluminum grid lines, copper grid lines, or silver-clad copper grid lines.

[0075] In conjunction with the seventh embodiment, the positive electrode fine grid line 11 or the negative electrode fine grid line 12 is an aluminum grid line, a silver grid line, a silver-aluminum grid line, a copper grid line, or a silver-clad copper grid line. It can be understood that in the embodiment of the present invention, it is possible to select the positive electrode fine grid line 11 and the negative electrode fine grid line 12 to select the same or different metal types of grid lines, for example, the positive electrode fine grid line 11 and the negative electrode fine grid line 12 are both aluminum grid lines; or the positive electrode fine grid line 11 is aluminum grid line, and the negative electrode fine grid line 12 is silver grid line. When the positive electrode fine grid line 11 or the negative electrode fine grid line 12 is an aluminum grid line or a silver grid line, the aluminum grid line or the silver grid line is printed on the P-type doping area or the N-type doping area by screen printing; when the positive electrode fine grid line 11 or the negative electrode fine grid line 12 is a copper grid line, it is plated on the P-type doping area or the N-type doping area by electroplating or evaporation.

[0076] Embodiment 9

[0077] This ninth embodiment provides a back-contact battery assembly, which includes the back-contact battery strings described in the first to eighth embodiments.

[0078] Specifically, the assembly process of the back contact battery assembly includes the following steps:

[0079] 1. Cell Sorting: Because solar cell production lines are highly random, the performance of the cells produced varies. To effectively group cells 100 with consistent or similar performance, they should be sorted based on the performance parameters measured during battery testing. This improves cell utilization and produces high-quality battery modules. Battery testing measures the output parameters (current and voltage) of the cells.

[0080] 2. Series connection: The first conductive segment 31, the second conductive segment 32, the first positive insulating block array 21, the second positive insulating block array 22, the first negative insulating block array 23 and the second negative insulating block array 24 are arranged on the battery cell 100 to realize the series connection of each battery cell 100.

[0081] 3. Lamination: After the back is connected in series and passed the inspection, the glass, cut EVA film / POE film, battery string, EVA film / POE film, glass fiber, and backplane / glass are laid from bottom to top in sequence. During the laying process, the relative positions of the battery string and the glass and other materials are ensured, and the distance between the battery cells 100 is adjusted.

[0082] 4. Component lamination: Place the stacked cells 100 into a laminator, remove the air from the components by vacuuming, then heat to melt the EVA to bond the cells, glass, and backplane together, and finally cool and remove the components.

[0083] 5. Trimming: During lamination, EVA melts and extends outward due to pressure and solidifies to form burrs, so the burrs should be trimmed after lamination.

[0084] 6. Framing: The aluminum frame is installed on the module to increase the strength of the module, further seal the battery module, and extend the battery life. The gap between the frame and the glass module is filled with silicone resin, and the frames are connected with angle keys.

[0085] 7. Bonding junction box: Bond a box to the leads on the back of the component to facilitate the connection between the battery and other devices or between batteries.

[0086] 8. Component testing: Test and calibrate the output power of the battery, test its output characteristics, and determine the quality level of the component.

[0087] 9. High voltage test: A certain voltage is applied between the component frame and the electrode lead to test the pressure resistance and insulation strength of the component to ensure that the component is not damaged under harsh natural conditions (such as lightning strikes).

[0088] In the back-contact battery string of the present invention, the back-contact battery string includes at least one battery cell 100, and the battery cell 100 includes a P-type doped region provided with a positive fine grid line 11 and an N-type doped region provided with a negative fine grid line 12. The positive fine grid line 11 is conductively connected through the second conductive segment 32 and is insulated by the first positive insulating block array 21 and the second positive insulating block array 22. The negative fine grid line 12 is conductively connected through the first conductive segment 31 and is insulated by the first negative insulating block array 23 and the second negative insulating block array 24. Adjacent battery cells 100 are also conductively connected through the first conductive segment 31 and the second conductive segment 32. The cell 100 of the back-contact cell string does not need to be provided with a main grid, and the photoelectric conversion efficiency of the cell 100 is high; the positive electrode fine grid line 11 is conductively connected through the second conductive segment 32, and the second conductive segment 32 is arranged at intervals, and the negative electrode fine grid line 12 is conductively connected through the first conductive segment 31, and the first conductive segment 31 is also arranged at intervals, which can reduce metal consumption and greatly reduce the cost of the cell 100; in addition, the back-contact cell string can be made into a film structure and directly pasted to form a battery assembly without going through a high-temperature welding process, thereby avoiding damage to the cell 100; the back-contact cell string does not need to be connected through a welding ribbon, thereby avoiding stress problems in the cell 100 and greatly improving the reliability of the cell 100.

[0089] Example 10

[0090] The tenth embodiment provides a back-contact battery system, which includes the back-contact battery assembly as described in the ninth embodiment.

[0091] In the back-contact battery string of the present invention, the back-contact battery string includes at least one battery cell 100, and the battery cell 100 includes a P-type doped region provided with a positive fine grid line 11 and an N-type doped region provided with a negative fine grid line 12. The positive fine grid line 11 is conductively connected through the second conductive segment 32 and is insulated by the first positive insulating block array 21 and the second positive insulating block array 22. The negative fine grid line 12 is conductively connected through the first conductive segment 31 and is insulated by the first negative insulating block array 23 and the second negative insulating block array 24. Adjacent battery cells 100 are also conductively connected through the first conductive segment 31 and the second conductive segment 32. The cell 100 of the back-contact cell string does not need to be provided with a main grid, and the photoelectric conversion efficiency of the cell 100 is high; the positive electrode fine grid line 11 is conductively connected through the second conductive segment 32, and the second conductive segment 32 is arranged at intervals, and the negative electrode fine grid line 12 is conductively connected through the first conductive segment 31, and the first conductive segment 31 is also arranged at intervals, which can reduce metal consumption and greatly reduce the cost of the cell 100; in addition, the back-contact cell string can be made into a film structure and directly pasted to form a battery assembly without going through a high-temperature welding process, thereby avoiding damage to the cell 100; the back-contact cell string does not need to be connected through a welding ribbon, thereby avoiding stress problems in the cell 100 and greatly improving the reliability of the cell 100.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A back contact battery string, characterized in that: The back contact cell string comprises: At least one battery cell, each of the battery cells comprising alternatingly arranged P-type doping regions and N-type doping regions, the P-type doping regions being provided with positive electrode fine grid lines, and the N-type doping regions being provided with negative electrode fine grid lines; The positive electrode fine grid lines are provided with a first positive electrode insulating block array and a second positive electrode insulating block array in a vertical direction thereof, and the second positive electrode insulating block array is located between two adjacent first positive electrode insulating block arrays; The first positive insulating block array includes first parallel positive insulating blocks arranged at intervals on the positive fine grid lines, and the second positive insulating block array includes second parallel positive insulating blocks arranged at intervals, and the second parallel positive insulating blocks are arranged on the positive fine grid lines where the first parallel positive insulating blocks are not arranged; The first parallel positive electrode insulating block and the second parallel positive electrode insulating block are both provided with a first conductive segment connecting two adjacent negative electrode thin grid lines; The negative electrode fine grid lines are provided with a first negative electrode insulating block array and a second negative electrode insulating block array in a vertical direction thereof, wherein the second negative electrode insulating block array is located between two adjacent first negative electrode insulating block arrays; The first negative electrode insulating block array includes first parallel negative electrode insulating blocks arranged at intervals on the negative electrode fine grid lines, and the second negative electrode insulating block array includes second parallel negative electrode insulating blocks arranged at intervals, and the second parallel negative electrode insulating blocks are arranged on the negative electrode fine grid lines where the first parallel negative electrode insulating blocks are not arranged; The first parallel negative electrode insulating block and the second parallel negative electrode insulating block are both provided with a second conductive segment connecting two adjacent positive electrode fine grid lines; The first conductive segment located at the first edge of the first battery cell is connected to the second conductive segment at the edge of the second battery cell adjacent to the first battery cell; The second conductive segment located at a second edge opposite to the first edge is connected to the first conductive segment at an edge of a third battery cell adjacent to the first battery cell.

2. The back contact cell string according to claim 1, wherein: The back-contact cell string further includes a first conductive bus bar at one end thereof and a second conductive bus bar at the other end thereof, the first conductive segments are connected to the first conductive bus bar, and the second conductive segments are connected to the second conductive bus bar.

3. The back contact cell string according to claim 1, wherein: The battery cells are connected via interconnection bars.

4. The back contact cell string according to claim 1, wherein: The first conductive segment and / or the second conductive segment includes a metal film and a composite film partially wrapping the metal film.

5. The back contact cell string according to claim 4, wherein: The composite film is a POE film, an EVA film, a PVB film, or a co-extruded film composed of POE and EVA.

6. The back contact cell string according to claim 1, wherein: The first conductive segment and / or the second conductive segment is a metal film.

7. The back contact cell string according to claim 1, wherein: The positive electrode fine grid line is an aluminum grid line, a silver grid line, a silver-aluminum grid line, a copper grid line, or a silver-clad copper grid line.

8. The back contact cell string according to claim 1, wherein: The negative electrode fine grid line is an aluminum grid line, a silver grid line, a silver-aluminum grid line, a copper grid line, or a silver-clad copper grid line.

9. A back contact battery assembly, characterized in that: The back-contact cell assembly comprises the back-contact cell string according to any one of claims 1 to 8.

10. A back contact battery system, characterized in that: The back-contact battery system includes the back-contact battery assembly of claim 9.

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