Back contact battery assembly
By using an alternating and partially overlapping cell design, combined with electrical isolation from the protective adhesive layer, the problem of insufficient light-receiving area in back-contact cell modules is solved, achieving efficient light energy utilization and low-cost production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 陕西众森电能科技有限公司
- Filing Date
- 2026-02-03
- Publication Date
- 2026-04-21
AI Technical Summary
In the current back-contact battery module, the gap between adjacent battery strings during the encapsulation process occupies the effective light-receiving area of the module, which limits the improvement of the "screen ratio" of back-contact batteries at the module level and cannot fully release the optical advantages.
The design employs alternating first and second battery strings with partial overlap between the battery cells to create a seamless joint, increasing the light-receiving area. Electrical isolation is achieved through a protective adhesive layer to avoid the risk of short circuits.
It significantly improves the light-receiving area ratio and output power of the back-contact battery module, reduces production costs, maintains the safety and stability of the module, and is compatible with existing manufacturing processes without the need for additional equipment adjustments.
Smart Images
Figure CN121908642A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of photovoltaic cell technology, and more specifically, to a back-contact cell module. Background Technology
[0002] As the global photovoltaic industry continues to demand higher power generation efficiency and power density, high-efficiency battery technology has become the core focus of industry competition. Back-contact batteries, as a groundbreaking photovoltaic cell structure, completely eliminate the need for traditional front-side grid lines due to their design where all electrodes are integrated on the back of the cell. This fundamentally eliminates optical losses caused by grid line shading, significantly improving light absorption efficiency. It has become a key technological path to achieving the ultimate conversion efficiency of photovoltaic modules and is widely used in high-efficiency photovoltaic power plants, distributed photovoltaic systems, and other scenarios.
[0003] However, current mainstream back-contact module packaging solutions still face technical bottlenecks. During the module packaging process, after the cells are strung together to form a cell string, gaps remain between adjacent cell strings. These gaps serve two purposes: firstly, to avoid the risk of short circuits caused by electrode contact between cell strings, and secondly, to provide space for interconnect and encapsulation materials such as solder ribbons and encapsulation films. The existence of these gaps results in the occupation of the module's effective light-receiving area, limiting further improvements in the "screen-to-body ratio" of back-contact cells at the module level, and preventing the full realization of the inherent optical advantages of the back-contact structure's lack of front-side obstruction. Summary of the Invention
[0004] The purpose of this application is to address the shortcomings of the prior art by providing a back contact battery assembly that has a higher light-receiving area ratio, high output power, and low production cost.
[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows: This application provides a back-contact battery assembly, including: a first battery string and a second battery string alternately arranged along a first direction; the first battery string includes a first battery cell and a second battery cell alternately arranged along a second direction, the second direction being perpendicular to the first direction, with adjacent first and second battery cells partially overlapping to form a first overlapping region; the second battery string includes a third battery cell and a fourth battery cell alternately arranged along the second direction, with adjacent third and fourth battery cells partially overlapping to form a second overlapping region; the positions of the first battery cells in the first battery string correspond one-to-one with the positions of the third battery cells in the adjacent second battery string, and the positions of the second battery cells in the first battery string correspond one-to-one with the positions of the fourth battery cells in the adjacent second battery string; adjacent first and third battery cells partially overlap to form a third overlapping region, and adjacent second and fourth battery cells partially overlap to form a fourth overlapping region; the first, second, third, and fourth overlapping regions no longer overlap with each other.
[0006] Optionally, the third overlapping region is provided with a first protective adhesive layer, and the fourth overlapping region is provided with a second protective adhesive layer. The first protective adhesive layer is located between the first battery cell and the third battery cell, and the second protective adhesive layer is located between the second battery cell and the fourth battery cell.
[0007] Optionally, both the first protective adhesive layer and the second protective adhesive layer are insulating adhesive layers or both are insulating adhesive layers; or, both the first protective adhesive layer and the second protective adhesive layer are two layers, with one first protective adhesive layer being an insulating adhesive layer and the other first protective adhesive layer being an insulating adhesive layer, and one second protective adhesive layer being an insulating adhesive layer and the other second protective adhesive layer being an insulating adhesive layer; the withstand voltage of both the first protective adhesive layer and the second protective adhesive layer is greater than 20V.
[0008] Optionally, the first protective adhesive layer is located on the back of the first battery cell and / or the front of the third battery cell, and the second protective adhesive layer is located on the back of the second battery cell and / or the front of the fourth battery cell.
[0009] Optionally, the first, second, third, and fourth battery cells are rectangular, with the long side of the first battery cell overlapping the long side of the second battery cell, the short side of the first battery cell overlapping the short side of the third battery cell, and the short side of the second battery cell overlapping the long side of the fourth battery cell.
[0010] Optionally, two chamfers are provided on one long side of the first battery cell, or four chamfers are provided on both long sides of the first battery cell; two chamfers are provided on one long side of the second battery cell, or four chamfers are provided on both long sides of the second battery cell; two chamfers are provided on one long side of the third battery cell, or four chamfers are provided on both long sides of the third battery cell; two chamfers are provided on one long side of the fourth battery cell, or four chamfers are provided on both long sides of the fourth battery cell.
[0011] Optionally, the first, second, third, and fourth battery cells each have two chamfers on one long side.
[0012] Optionally, the first, second, third, and fourth battery cells each have two chamfers on their two long sides.
[0013] Optionally, the first battery string includes two first sub-battery strings of equal length, the polarities of the two first sub-battery strings being symmetrically arranged along the center point in the second direction; the second battery string includes two second sub-battery strings of equal length, the polarities of the two second sub-battery strings being symmetrically arranged along the center point in the second direction.
[0014] Optionally, the first and second battery cells are electrically connected by a first welding strip, the third and fourth battery cells are electrically connected by a second welding strip, and the first and second battery strings are electrically connected by a busbar.
[0015] The beneficial effects of this application include: This application provides a back-contact battery assembly, comprising: a first battery string and a second battery string alternately arranged along a first direction; the first battery string includes a first battery cell and a second battery cell alternately arranged along a second direction, the second direction being perpendicular to the first direction, with adjacent first and second battery cells partially overlapping to form a first overlapping region; the second battery string includes a third battery cell and a fourth battery cell alternately arranged along the second direction, with adjacent third and fourth battery cells partially overlapping to form a second overlapping region; the positions of the first battery cells in the first battery string correspond one-to-one with the positions of the third battery cells in the adjacent second battery string, and the positions of the second battery cells in the first battery string correspond one-to-one with the positions of the fourth battery cells in the adjacent second battery string; adjacent first and third battery cells partially overlap to form a third overlapping region, and adjacent second and fourth battery cells partially overlap to form a fourth overlapping region; the first, second, third, and fourth overlapping regions no longer overlap with each other. This back-contact solar module effectively increases the light-receiving area ratio by arranging the first, second, third, and fourth solar cells in a super-dense or even seamless manner on a planar projection. This allows for more efficient utilization of incident sunlight and significantly improves the output power of the back-contact solar module. Furthermore, this back-contact solar module is compatible with existing crystal pulling and module manufacturing processes. It can continue to use current-specification monocrystalline silicon rods for cell production, and the overall module size after cell arrangement remains consistent with existing standards. This eliminates the need for redesigning glass, frames, and other auxiliary materials, thus avoiding additional production line modifications and equipment adjustment costs. In addition, while maintaining the silicon rod size, the partial overlap between the cells allows for a suitable increase in cell size, which helps reduce edge waste during the cutting process, increases the silicon rod yield, and ultimately reduces the silicon material cost per unit of module power output. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the structure of the back contact battery assembly provided in the embodiments of this application; Figure 2 for Figure 1 A magnified view of a portion of point A in the middle; Figure 3 This is a three-dimensional structural diagram of the overlapping area of the battery cells provided in an embodiment of this application; Figure 4 This is one of the battery arrangement methods for the back contact battery assembly provided in the embodiments of this application; Figure 5 This is a second battery arrangement method for the back contact battery assembly provided in the embodiments of this application; Figure 6 This is the third battery arrangement method for the back contact battery assembly provided in the embodiments of this application.
[0018] Icons: 10 - Back contact battery assembly; 11 - First battery string; 111 - First battery cell; 112 - Second battery cell; 12 - Second battery string; 121 - Third battery cell; 122 - Fourth battery cell; 131 - First overlapping area; 132 - Second overlapping area; 133 - Third overlapping area; 134 - Fourth overlapping area; 141 - First protective adhesive layer; 142 - Third protective adhesive layer; 15 - Chamfer; 161 - First solder ribbon; 162 - Second solder ribbon; 163 - Busbar; 1631 - Lead-out terminal; 17 - Grid line; X - First direction; Y - Second direction. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0020] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. It should be noted that, unless otherwise specified, the various features in the embodiments of this application can be combined with each other, and the combined embodiments are still within the protection scope of this application.
[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0022] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0023] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0024] Please refer to Figure 1 and Figure 2 This application provides a back-contact battery assembly 10, including: a first battery string 11 and a second battery string 12 alternately arranged along a first direction X. The number of first battery strings 11 and second battery strings 12 is at least one, and the number of first battery strings 11 and second battery strings 12 is equal to or differs by one, to ensure that they can be alternately arranged. The alternating arrangement of the first battery strings 11 and second battery strings 12 along the first direction X means that the first battery strings 11 and second battery strings 12 are arranged along the first direction X in a manner of "first battery string 11 - second battery string 12 - first battery string 11 - second battery string 12...", and the alternating arrangement of the battery cells described below is also arranged in this manner.
[0025] The first battery string 11 includes a first battery cell 111 and a second battery cell 112 alternately arranged along a second direction Y, which is perpendicular to the first direction X. Adjacent first battery cells 111 and second battery cells 112 partially overlap to form a first overlapping region 131. The second battery string 12 includes a third battery cell 121 and a fourth battery cell 122 alternately arranged along the second direction Y. Adjacent third battery cells 121 and fourth battery cells 122 partially overlap to form a second overlapping region 132.
[0026] The number of first battery cells 111, second battery cells 112, third battery cells 121, and fourth battery cells 122 are all multiple, and the number of first battery cells 111 and second battery cells 112 is equal or differs by one; the number of third battery cells 121 and fourth battery cells 122 is equal or differs by one; the number of first battery cells 111 and third battery cells 121 is equal; and the number of second battery cells 112 and fourth battery cells 122 is equal. It can be understood that partial overlap between two adjacent battery cells means that two adjacent battery cells overlap by a portion of their area. For example, the overlap width can range from 0 mm to 3 mm.
[0027] The first battery cell 111 in the first battery string 11 corresponds one-to-one with the third battery cell 121 in the adjacent second battery string 12, and the second battery cell 112 in the first battery string 11 corresponds one-to-one with the fourth battery cell 122 in the adjacent second battery string 12. The adjacent first battery cell 111 and the third battery cell 121 partially overlap to form a third overlapping region 133, and the adjacent second battery cell 112 and the fourth battery cell 122 partially overlap to form a fourth overlapping region 134.
[0028] The first overlapping region 131, the second overlapping region 132, the third overlapping region 133, and the fourth overlapping region 134 no longer overlap with each other. That is, the first overlapping region 131, the second overlapping region 132, the third overlapping region 133, and the fourth overlapping region 134 are separated from each other, and there is no overlapping region between them.
[0029] The aforementioned back-contact solar module 10 effectively increases the proportion of light-receiving area by arranging the first solar cell 111, second solar cell 112, third solar cell 121, and fourth solar cell 122 in a super-dense or even seamless manner on a planar projection. This allows for more efficient utilization of incident sunlight and significantly improves the output power of the back-contact solar module 10. Furthermore, the back-contact solar module 10 is compatible with existing crystal pulling and module manufacturing processes, allowing for continued production of solar cells using current-specification monocrystalline silicon rods. The overall module size after cell arrangement remains consistent with existing standards, eliminating the need for redesigning auxiliary materials such as glass and frames, thus avoiding additional production line modifications and equipment adjustments. In addition, while maintaining the silicon rod size, the partial overlap between solar cells allows for a suitable increase in cell size, which helps reduce edge waste during the cutting process, increases the silicon rod yield, and consequently reduces the silicon material cost per unit power output of the module.
[0030] Alternatively, please refer to Figure 2 and Figure 3The third overlapping region 133 is provided with a first protective adhesive layer 141, and the fourth overlapping region 134 is provided with a second protective adhesive layer 142. The first protective adhesive layer 141 is located between the first battery cell 111 and the third battery cell 121, and the second protective adhesive layer 142 is located between the second battery cell 112 and the fourth battery cell 122.
[0031] The first protective adhesive layer 141 provides electrical isolation between the first solar cell 111 and the third solar cell 121, preventing voltage breakdown and leakage or short circuits in the overlapping area of the first solar cell 111 and the third solar cell 121. The second protective adhesive layer 142 provides electrical isolation between the second solar cell 112 and the fourth solar cell 122, preventing voltage breakdown and leakage or short circuits in the overlapping area of the second solar cell 112 and the fourth solar cell 122, thereby improving the safety and stability of the back contact battery assembly 10. Simultaneously, the protective adhesive layer also provides mechanical cushioning between the solar cells, preventing cell breakage during lamination and improving the structural stability of the back contact battery assembly 10.
[0032] For example, the first protective adhesive layer 141 completely covers the third overlapping area 133, and the second protective adhesive layer completely covers the fourth overlapping area 134, thereby ensuring to a greater extent that the first battery cell 111 and the third battery cell 121, and the second battery cell 112 and the fourth battery cell 122 partially overlap but do not directly contact each other.
[0033] The first protective adhesive layer 141 can be located on the back of the first battery cell 111 or on the front of the third battery cell 121; alternatively, the first protective layer 141 can be located on both the back of the first battery cell 111 and the front of the third battery cell 121, that is, there are two layers of the first protective layer 141, one on the back of the first battery cell 111 and the other on the front of the third battery cell 121, with the two layers of the first protective layer 141 bonded together. Similarly, the second protective adhesive layer 142 can be located on the back of the second battery cell 112 or on the front of the fourth battery cell 122; alternatively, the second protective adhesive layer 142 can be located on both the back of the second battery cell 112 and the front of the fourth battery cell 122.
[0034] Optionally, both the first protective adhesive layer 141 and the second protective adhesive layer are insulating adhesive layers or both are separating adhesive layers. Alternatively, both the first protective adhesive layer 141 and the second protective adhesive layer 142 are two layers, with one first protective adhesive layer 141 being an insulating adhesive layer and the other first protective adhesive layer 141 being a separating adhesive layer, and one second protective adhesive layer 142 being an insulating adhesive layer and the other second protective adhesive layer 142 being a separating adhesive layer.
[0035] The insulating adhesive layer must be located on the back of the solar cell and formed simultaneously during the insulating adhesive printing process. The separating adhesive layer must be located on the front of the solar cell and formed simultaneously during the separating adhesive printing process. No additional equipment is required, and there is no increase in cost.
[0036] Optionally, the voltage withstand strength of both the first and second protective adhesive layers is greater than 20V.
[0037] There is a potential difference between adjacent cells in the back contact battery module 10, and the dense electrode arrangement can easily lead to creepage and leakage. The first and second protective adhesive layers both have a voltage withstand strength greater than 20V, which can isolate the inter-cell potential, resist the working voltage and electrical spikes, avoid micro-short circuits and overheating failure, ensure long-term insulation stability in complex environments, and improve the electrical safety and service life of the back contact battery module 10. Optionally, the first cell 111, the second cell 112, the third cell 121, and the fourth cell 122 are rectangular, with the long side of the first cell 111 overlapping the long side of the second cell 112, the short side of the first cell 111 overlapping the short side of the third cell 121, and the short side of the second cell 112 overlapping the long side of the fourth cell 122.
[0038] Overlapping the long sides of the cells within the same battery string allows for a tighter arrangement of the cells in a direction parallel to the grid lines 17, reducing the front-side shading area and achieving ultra-dense or even seamless splicing. This significantly increases the effective light-receiving area and improves the module's output power. Simultaneously, the long-side overlap shortens the current transmission path, making it more direct and helping to reduce series resistance and power loss. Furthermore, the longer overlap length enhances the mechanical connection strength between the cells, improving the structural stability of the back-contact battery module 10 under thermal expansion and contraction and external stress, thus contributing to improved long-term reliability.
[0039] It should be noted that the rectangular shape of each solar cell does not mean that each cell must be a perfect rectangle; a general rectangular shape is sufficient. Cells are allowed to have features such as 15° chamfers and notches, which can be configured according to actual production needs.
[0040] Optionally, two chamfers 15 are provided on one long side of the first battery cell 111, or four chamfers 15 are provided on both long sides of the first battery cell 111; two chamfers 15 are provided on one long side of the second battery cell 112, or four chamfers 15 are provided on both long sides of the second battery cell 112; two chamfers 15 are provided on one long side of the third battery cell 121, or four chamfers 15 are provided on both long sides of the third battery cell 121; two chamfers 15 are provided on one long side of the fourth battery cell 122, or four chamfers 15 are provided on both long sides of the fourth battery cell 122.
[0041] Setting chamfers 15 on the overlapping battery cells helps to avoid overlap between the first overlapping area 131, the second overlapping area 132, the third overlapping area 133 and the fourth overlapping area 134.
[0042] Alternatively, please refer to Figure 2 and Figure 4 The first battery cell 111, the second battery cell 112, the third battery cell 121 and the fourth battery cell 122 each have two chamfers 15 on one long side.
[0043] Compared to setting four chamfers 15 on each cell, setting two chamfers 15 on each cell can increase the proportion of light-receiving area to a greater extent, thereby increasing the output power of the back contact battery assembly 10.
[0044] Optionally, the long side of the first battery cell 111 without chamfer 15 overlaps with the long side of the second battery cell 112 with chamfer 15. Similarly, the long side of the first battery cell 111 with chamfer 15 overlaps with the long side of the second battery cell 112 without chamfer 15. The long side of the third battery cell 121 with chamfer 15 overlaps with the long side of the fourth battery cell 122 without chamfer 15.
[0045] It is understandable that the adjacent first battery string 11 and second battery string 12 need to be partially misaligned in the first direction X to prevent the overlapping areas of the battery cells from overlapping again.
[0046] Alternatively, please refer to Figure 5 In the first battery cell 111 and the third battery cell 121 corresponding to the positions, the long side of the first battery cell 111 with a chamfer 15 overlaps with the long side of the second battery cell 112 with a chamfer 15, and the long side of the third battery cell 121 without a chamfer 15 overlaps with the long side of the fourth battery cell 122 without a chamfer 15 (e.g. Figure 5 (As shown in the dashed box at point B), or, the long side of the first battery cell 111 without chamfer 15 overlaps with the long side of the second battery cell 112 without chamfer 15, and the long side of the third battery cell 121 with chamfer 15 overlaps with the long side of the fourth battery cell 122 with chamfer 15 (as shown in the dashed box at point B). Figure 5 (As shown in the dashed box at point C).
[0047] In the adjacent first battery string 11 and second battery string 12, two adjacent battery cells along the second direction Y are arranged symmetrically, and two adjacent battery cells along the first direction X are arranged asymmetrically. Furthermore, the adjacent first battery string 11 and second battery string 12 are partially misaligned in the first direction X to prevent overlapping of the overlapping areas of the battery cells.
[0048] It can be understood that the first battery cell 111 and the third battery cell 121 corresponding to the position refer to the first battery cell 111 and the third battery cell 121 that are adjacent along the first direction X.
[0049] Alternatively, please refer to Figure 6 The first battery cell 111, the second battery cell 112, the third battery cell 121 and the fourth battery cell 122 each have two chamfers 15 on their two long sides.
[0050] Compared to setting two chamfers 15 on each cell, setting four chamfers 15 on each cell makes it easier to achieve mutual avoidance between the first overlapping area 131, the second overlapping area 132, the third overlapping area 133 and the fourth overlapping area 134, thus avoiding overlap.
[0051] The above-mentioned chamfer 15 designs and arrangements for the solar cells are only optional solutions. Various chamfer 15 design schemes and arrangements exist for each solar cell. For example, the first solar cell 111 and the second solar cell 112 may have two chamfers 15, while the third solar cell 121 and the fourth solar cell 122 may have four chamfers 15. Alternatively, the first solar cell 111 and the third solar cell 121 may have two chamfers 15, while the second solar cell 112 and the fourth solar cell 122 may have four chamfers 15, etc. Those skilled in the art can make various modifications and variations according to actual needs, as long as the first overlapping area 131, the second overlapping area 132, the third overlapping area 133, and the fourth overlapping area 134 do not overlap.
[0052] Alternatively, please refer to Figure 1 The first battery string 11 includes two first sub-battery strings of equal length, with their polarities symmetrically arranged along the center point in the second direction Y. The second battery string 12 includes two second sub-battery strings of equal length, with their polarities symmetrically arranged along the center point in the second direction Y. This allows for parallel connection of the two sub-battery strings, ensuring that the voltage and current of the two parallel sub-battery strings remain consistent.
[0053] For example, if the polarity arrangement of one of the first sub-battery strings in the second direction Y is "positive-negative-positive-negative-positive-negative", then the polarity arrangement of the other first sub-battery string in the second direction Y is "negative-positive-negative-positive-negative-positive".
[0054] It should be noted that "two sub-cell strings being the same" means that the number of cells in the two sub-cell strings is equal and their arrangement length is equal.
[0055] Optionally, please refer to the following: Figure 3The first battery cell 111 and the second battery cell 112 are electrically connected by the first solder strip 161, the third battery cell 121 and the fourth battery cell 122 are electrically connected by the second solder strip 162, and the first battery string 11 and the second battery string 12 are electrically connected by the busbar 163.
[0056] The first solder strip 161 is simultaneously connected to the grid lines 17 (metal electrodes) of the first battery cell 111 and the second battery cell 112, thereby achieving conductivity between adjacent first battery cells 111 and second battery cells 112. Similarly, the second solder strip 162 is simultaneously connected to the grid lines 17 of the third battery cell 121 and the fourth battery cell 122, thereby achieving conductivity between adjacent third battery cells 121 and fourth battery cells 122.
[0057] In actual manufacturing, one end of the solder ribbon can be fixed to the grid lines 17 on the back of the first solar cell using a welding process (such as laser welding or hot air welding). Subsequently, another solar cell is overlapped on top of the first solar cell with its long side overlapping, and the grid lines 17 on its back are welded to the other end of the solder ribbon. Since the positive and negative electrodes of the back-contact battery are both located on the back, this "cross-cell" connection method allows current to flow from the electrodes of one solar cell, through the solder ribbon, and directly to the electrodes of the adjacent solar cell, thus physically achieving a series connection between the two solar cells.
[0058] Busbar 163 is simultaneously connected to the first solder strip 161 in the first battery string 11 and the second solder strip 162 in the second battery string 12, thereby realizing the series or parallel connection between adjacent first battery strings 11 and second battery strings 12 to achieve the required component voltage and current output.
[0059] In the actual process, the busbar 163 can first be soldered to the output terminal of the first battery string 11 to form a reliable electrical connection. Then, the busbar 163 crosses over to the corresponding solder joint of the second battery string 12 and is soldered again, thus connecting the two battery strings in the circuit. If connected in series, the busbar 163 connects the positive terminal of the first battery string 11 to the negative terminal of the second battery string 12, allowing current to flow sequentially through the two battery strings and increasing the total voltage of the back-contact battery assembly 10. If connected in parallel, the positive terminals of the two battery strings are connected to each other, and the negative terminals to each other, to increase the total current output of the back-contact battery assembly 10. The entire process uses the busbar 163 to concentrate and transmit current, ensuring the stability and efficiency of the internal circuitry of the back-contact battery assembly 10.
[0060] Since the busbar 163 typically covers the back of the solar cells and spans different cell strings, there may be grid lines 17, solder ribbons, or other conductive areas beneath it. To prevent accidental contact between the busbar 163 and these conductive areas, for example, a third insulating layer 142 is provided between the busbar 163 and the first cell string 11 and the second cell string 12. The third insulating layer 142 can prevent short circuits between cell strings and between solar cells, and can also prevent the busbar 163 from being worn due to vibration, thermal expansion and contraction, etc. during lamination or long-term use, thereby maintaining a stable electrical isolation effect and improving the reliability and durability of the back contact battery assembly 10.
[0061] Busbar 163 has a lead-out terminal 1631, which is mainly used to lead out the electrical energy generated by the battery string from the inside of the back contact battery assembly 10 and connect it to the diode in the junction box or the external circuit.
[0062] The above description is merely an optional embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A back-contact battery assembly, characterized in that, include: A first battery string and a second battery string are alternately arranged along a first direction; The first battery string includes first and second battery cells arranged alternately along a second direction, which is perpendicular to the first direction. Adjacent first and second battery cells partially overlap to form a first overlapping area. The second battery string includes third and fourth battery cells arranged alternately along the second direction, with adjacent third and fourth battery cells partially overlapping to form a second overlapping area; The first battery cell in the first battery string corresponds one-to-one with the third battery cell in the adjacent second battery string, and the second battery cell in the first battery string corresponds one-to-one with the fourth battery cell in the adjacent second battery string. The adjacent first battery cell and the third battery cell partially overlap to form a third overlapping area, and the adjacent second battery cell and the fourth battery cell partially overlap to form a fourth overlapping area. The first overlapping region, the second overlapping region, the third overlapping region, and the fourth overlapping region no longer overlap with each other.
2. The back contact battery assembly as described in claim 1, characterized in that, The third overlapping region is provided with a first protective adhesive layer, and the fourth overlapping region is provided with a second protective adhesive layer. The first protective adhesive layer is located between the first battery cell and the third battery cell, and the second protective adhesive layer is located between the second battery cell and the fourth battery cell.
3. The back contact battery assembly as described in claim 2, characterized in that, Both the first protective adhesive layer and the second protective adhesive layer are insulating adhesive layers or both are separating adhesive layers; or, both the first protective adhesive layer and the second protective adhesive layer are two layers, with one layer of the first protective adhesive layer being an insulating adhesive layer and the other layer of the first protective adhesive layer being a separating adhesive layer, one layer of the second protective adhesive layer being an insulating adhesive layer and the other layer of the second protective adhesive layer being a separating adhesive layer. The voltage resistance of both the first and second protective adhesive layers is greater than 20V.
4. The back contact battery assembly as described in claim 2, characterized in that, The first protective adhesive layer is located on the back of the first battery cell and / or the front of the third battery cell, and the second protective adhesive layer is located on the back of the second battery cell and / or the front of the fourth battery cell.
5. The back contact battery assembly as described in claim 1, characterized in that, The first, second, third, and fourth battery cells are rectangular. The long side of the first battery cell overlaps with the long side of the second battery cell, the short side of the first battery cell overlaps with the short side of the third battery cell, and the short side of the second battery cell overlaps with the long side of the fourth battery cell.
6. The back contact battery assembly as described in claim 5, characterized in that, The first battery cell has two chamfers on one long side, or four chamfers on both long sides; the second battery cell has two chamfers on one long side, or four chamfers on both long sides; the third battery cell has two chamfers on one long side, or four chamfers on both long sides; and the fourth battery cell has two chamfers on one long side, or four chamfers on both long sides.
7. The back contact battery assembly as described in claim 6, characterized in that, The first, second, third, and fourth battery cells each have two chamfers on one long side.
8. The back contact battery assembly as described in claim 6, characterized in that, The first, second, third, and fourth battery cells each have two chamfers on their two long sides.
9. The back contact battery assembly as claimed in claim 1, characterized in that, The first battery string includes two first sub-battery strings of equal length, and the polarities of the two first sub-battery strings are symmetrically arranged along the center point in the second direction; the second battery string includes two second sub-battery strings of equal length, and the polarities of the two second sub-battery strings are symmetrically arranged along the center point in the second direction.
10. The back contact battery assembly as claimed in claim 1, characterized in that, The first and second battery cells are electrically connected by a first solder strip, the third and fourth battery cells are electrically connected by a second solder strip, and the first and second battery strings are electrically connected by a busbar.