Battery sheet, back contact cell and photovoltaic module

Abstract

The application discloses a battery piece, a back contact battery and a photovoltaic module. On the one hand, by ensuring that the positive fine grid passes through the positive wiring area and is directly connected with the positive solder strip or the main grid, while being disconnected in the corresponding negative wiring area; similarly, the negative fine grid passes through the negative wiring area and is directly connected with the negative solder strip or the main grid, while being disconnected in the corresponding positive wiring area, the shortest and optimal current transmission path is realized, the possibility of false welding is significantly reduced, the need for additional conductive glue is eliminated, the manufacturing process is simplified, the production cost is reduced, and the risk of battery piece warping caused by multi-step processing is reduced. On the other hand, the design that the end of the positive insulating glue and the end of the negative insulating glue overlap or are flush in the second direction ensures that there is sufficient insulating isolation between adjacent fine grids of different polarities, effectively prevents short circuit problems that may occur during welding or rework, and improves the overall reliability and stability of the battery piece.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a solar cell, a back contact cell, and a photovoltaic module. Background Technology

[0002] A back contact cell (BC cell) is a special solar cell design where all electrodes are located on the back side of the cell, with no electrodes on the light-facing side. This design not only minimizes front-side shading and improves light absorption efficiency but also optimizes the overall aesthetics and integration of the cell. However, because the positive and negative electrodes are arranged on the same side in an interdigitated back contact (IBC) configuration, special care must be taken during the soldering process to avoid short circuits between the solder ribbon and the irregularly shaped grid lines.

[0003] Currently, to prevent short circuits between dissimilar grid lines caused by welding misalignment, insulating adhesive is typically printed on the main grid and the dissimilar fine grids on both sides to achieve electrical isolation. However, this method has the following problems: 1. Increased process complexity: After the insulating adhesive is printed, conductive adhesive needs to be printed and dried, which increases the processing steps, raises the cost, and may cause the battery cells to warp.

[0004] 2. Extended current transmission path: The insulating adhesive covering the main grid position means that the solder ribbon can only connect to the cell through the conductive adhesive at the PAD point, which extends the current transmission path and increases the risk of poor soldering.

[0005] 3. Potential short circuit risk: Conductive materials such as solder dross generated during soldering or rework may fall into other areas, causing the fine gates of different polarities to overlap, which may lead to short circuit faults. It is estimated that the failure rate of this type of fault is about 1%. Utility Model Content

[0006] The purpose of this application is to provide a solar cell, a back contact cell, and a photovoltaic module to improve at least one of the above-mentioned problems.

[0007] The embodiments of this application can be implemented as follows: In a first aspect, this utility model provides a battery cell, comprising: The battery cell has a positive electrode wiring area and a negative electrode wiring area extending along a first direction on its back side. The positive electrode wiring area and the negative electrode wiring area are arranged side by side along a second direction, and the first direction and the second direction are perpendicular to each other. Positive and negative electrode grids are alternately distributed along the first direction on the back of the battery cell, and both the positive and negative electrode grids extend along the second direction; wherein, the portion of the positive electrode grid that passes through the positive electrode wiring area is used to connect to the positive electrode solder strip or the positive electrode main grid, and the portion of the positive electrode grid corresponding to the negative electrode wiring area is disconnected; the portion of the negative electrode grid that passes through the negative electrode wiring area is used to connect to the negative electrode solder strip or the negative electrode main grid; A positive insulating adhesive covering the positive electrode fine grid and a negative insulating adhesive covering the negative electrode fine grid, wherein the ends of the positive electrode insulating adhesive and the ends of the negative electrode insulating adhesive overlap or are flush in the second direction.

[0008] In an optional embodiment, the distance between the positive electrode insulating adhesives located on both sides of the negative electrode wiring area is smaller than the distance between the positive electrode fine grids located on both sides of the negative electrode wiring area. The distance between the negative electrode insulating adhesives located on both sides of the positive electrode wiring area is smaller than the distance between the negative electrode fine grids located on both sides of the positive electrode wiring area.

[0009] In an optional embodiment, the distance between the positive electrode insulating adhesives located on both sides of the negative electrode wiring area is at least 0.2 mm smaller than the distance between the positive electrode fine grids located on both sides of the negative electrode wiring area; The distance between the negative electrode insulating adhesives located on both sides of the positive electrode wiring area is at least 0.2 mm smaller than the distance between the negative electrode fine grids located on both sides of the positive electrode wiring area.

[0010] In an optional embodiment, the width of both the positive electrode wiring area and the negative electrode wiring area in the second direction is 1~2mm.

[0011] In an optional embodiment, the thickness of both the positive electrode insulating adhesive and the negative electrode insulating adhesive is 20~50μm, and the width in the first direction is 10~100μm.

[0012] In an optional embodiment, the positive electrode insulating adhesive is distributed on both sides of the negative electrode wiring area in the second direction, namely a first positive electrode insulating adhesive and a second positive electrode insulating adhesive; the first positive electrode insulating adhesive is located between the positive electrode wiring area and the negative electrode wiring area, and the second positive electrode insulating adhesive is located on the side of the negative electrode wiring area away from the positive electrode wiring area; Wherein, the end of the first positive electrode insulating adhesive that is away from the negative electrode wiring area is flush with or overlaps with the negative electrode insulating adhesive.

[0013] In an optional embodiment, the negative electrode insulating adhesive is distributed on both sides of the positive electrode wiring area in the second direction, namely a first negative electrode insulating adhesive and a second negative electrode insulating adhesive; the first negative electrode insulating adhesive is located between the positive electrode wiring area and the negative electrode wiring area, and the second negative electrode insulating adhesive is located on the side of the positive electrode wiring area away from the negative electrode wiring area; Wherein, the end of the first negative electrode insulating adhesive that is away from the positive electrode wiring area is flush with or overlaps with the positive electrode insulating adhesive.

[0014] Secondly, this utility model provides a back contact battery, including a solder strip and a battery cell as described in any of the foregoing embodiments; The solder strip includes a positive solder strip and a negative solder strip. The positive solder strip is soldered on the positive wiring area, and the negative solder strip is soldered on the negative wiring area.

[0015] Thirdly, this utility model provides a back contact battery, including a solder strip and a battery cell as described in any of the foregoing embodiments; The positive wiring area is printed with a positive main grid, and the negative wiring area is printed with a negative main grid; both the positive main grid and the negative main grid have multiple PAD points; The solder strip includes a positive solder strip and a negative solder strip. The positive solder strip is welded to the PAD point on the positive main grid, and the negative solder strip is welded to the PAD point on the negative main grid.

[0016] Fourthly, this utility model provides a photovoltaic module, including the back contact battery described in the foregoing embodiments.

[0017] The beneficial effects of the embodiments of this application include, for example: On the one hand, by ensuring that the positive electrode grid passes through the positive electrode wiring area and is directly connected to the positive electrode solder strip or main grid, while disconnecting at the corresponding negative electrode wiring area; similarly, the negative electrode grid passes through the negative electrode wiring area and is directly connected to the negative electrode solder strip or main grid, while disconnecting at the corresponding positive electrode wiring area, the shortest and most optimal current transmission path is achieved, significantly reducing the possibility of poor soldering. This also eliminates the need for additional conductive adhesive, simplifies the manufacturing process, reduces production costs, and minimizes the risk of cell warping due to multi-step processing. On the other hand, the design of overlapping or flush ends of the positive and negative electrode insulating adhesives in the second direction ensures sufficient insulation between adjacent non-uniform grids, effectively preventing short circuits that may occur during welding or rework, and improving the overall reliability and stability of the cell. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a back-contact battery in the prior art; Figure 2 This is a schematic diagram of the solar cell with main busbar in this embodiment; Figure 3 This is a schematic diagram of a grid-less solar cell in this embodiment; Figure 4 for Figure 2 A schematic diagram showing the battery cells bonded to the solder ribbon; Figure 5 This is a schematic diagram of the battery cell after it has been bonded to the solder strip.

[0020] Icons: 10-Battery cell; 11-Positive wiring area; 12-Negative wiring area; 20-Main grid; 21-PAD point; 22-Positive main grid; 23-Negative main grid; 31-Positive fine grid; 32-Negative fine grid; 40-Insulating adhesive; 41-Positive insulating adhesive; 42-Negative insulating adhesive; 50-Solder ribbon; 51-Positive solder ribbon; 52-Negative solder ribbon; X-First direction; Y-Second direction. Detailed Implementation

[0021] 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.

[0022] 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. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0023] 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.

[0024] 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.

[0025] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] 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.

[0027] Currently, to avoid short circuits caused by welding the solder strip 50 misalignment and overlapping of the non-standard grid lines, insulation treatment is required for the non-standard grid lines on both sides of the main grid 20 before welding. The current treatment method is to use a printing screen to print insulating adhesive 40 on the main grid 20 and the non-standard grid lines, with a printing width of 2-10mm. The PAD points 21 of the battery containing the main grid 20 are not coated, and the grid lines of the same polarity through the cell 10 without the main grid 20 are not coated (e.g., Figure 1 The left image shows a standard 20-cell solar cell 10 with a main grid, while the right image shows a 20-cell solar cell 10 without a main grid. After printing, UV or thermal curing treatment is performed to achieve the insulation effect.

[0028] The insulation adhesive 40 is printed with a thickness of approximately 10-50µm. During the soldering stage, there is a distance between the solder strip 50 and the main grid 20 and PAD point 21, making contact soldering impossible. Therefore, it is necessary to print and coat conductive adhesive on the soldering points of the main grid 20 or the fine grids of the same polarity at the position of the main grid 20. This is not limited to conductive materials such as solder paste or conductive tape. The printing height needs to be higher than the insulation adhesive by 40-100µm. After printing, it should be cured before proceeding with the normal subsequent dicing and soldering operations.

[0029] However, this method has the following problems: 1. Increased process complexity: After the insulating adhesive 40 is printed, conductive adhesive needs to be printed and dried, which increases the processing steps, raises the cost, and may cause the battery cell 10 to warp.

[0030] 2. Extended current transmission path: The insulating adhesive 40 covers the main grid 20, so that the solder ribbon 50 can only connect to the cell 10 through the conductive adhesive at PAD point 21, which extends the current transmission path and increases the risk of poor soldering.

[0031] 3. Potential short circuit risk: Conductive materials such as solder dross generated during soldering or rework may fall into other areas, causing the fine gates of different polarities to overlap, which may lead to short circuit faults. It is estimated that the failure rate of this type of fault is about 1%.

[0032] Therefore, the inventors of this application have proposed a battery cell 10, a back contact battery, and a photovoltaic module to improve the above-mentioned problems.

[0033] The following is combined Figures 2 to 5 This application provides a detailed description of some embodiments. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0034] This embodiment discloses a battery cell 10, which includes a positive electrode fine grid 31, a negative electrode fine grid 32, a positive electrode insulating adhesive 41, and a negative electrode insulating adhesive 42.

[0035] The front side of the battery cell 10 is the light-facing side to ensure light absorption rate, aesthetics and integration. The back side of the battery cell 10 is provided with a positive electrode wiring area 11 and a negative electrode wiring area 12 that both extend along the first direction X. The positive electrode wiring area 11 and the negative electrode wiring area 12 are arranged side by side along the second direction Y, and the first direction X and the second direction Y are perpendicular. Positive electrode grid 31 and negative electrode grid 32 are alternately distributed along the first direction X on the back of the battery cell 10, and both the positive electrode grid 31 and the negative electrode grid 32 extend along the second direction Y; wherein, the part of the positive electrode grid 31 that passes through the positive electrode wiring area 11 is used to connect the positive electrode solder ribbon 51 or the positive electrode main grid 22, and the part of the positive electrode grid 31 corresponding to the negative electrode wiring area 12 is disconnected; the part of the negative electrode grid 32 that passes through the negative electrode wiring area 12 is used to connect the negative electrode solder ribbon 52 or the negative electrode main grid 23; Positive electrode insulating adhesive 41 covers the positive electrode fine grid 31, and negative electrode insulating adhesive 42 covers the negative electrode fine grid 32. The ends of the positive electrode insulating adhesive 41 and the ends of the negative electrode insulating adhesive 42 overlap or are flush with each other in the second direction Y.

[0036] As described above, in this embodiment, on the one hand, by ensuring that the positive electrode fine grid 31 passes through the positive electrode wiring area 11 and is directly connected to the positive electrode solder ribbon 51 or the main grid 20, while being disconnected in the corresponding negative electrode wiring area 12; similarly, the negative electrode fine grid 32 passes through the negative electrode wiring area 12 and is directly connected to the negative electrode solder ribbon 52 or the main grid 20, while being disconnected in the corresponding positive electrode wiring area 11, the shortest and optimal current transmission path is achieved, significantly reducing the possibility of poor soldering, while eliminating the need for additional conductive adhesive, simplifying the manufacturing process, reducing production costs, and reducing the risk of cell 10 warping due to multi-step processing. On the other hand, the design of the ends of the positive electrode insulating adhesive 41 and the negative electrode insulating adhesive 42 overlapping or flush in the second direction Y ensures sufficient insulation isolation between adjacent heterogeneous fine grids, effectively preventing short circuit problems that may occur during welding or rework, and improving the overall reliability and stability of the cell 10.

[0037] Furthermore, this design can be flexibly applied to both traditional solar cells 10 with main grids 20 and novel solar cells 10 without main grids 20, exhibiting wide applicability and good compatibility, and can meet the needs of different application scenarios.

[0038] In this embodiment, the positive electrode insulating adhesive 41 is distributed on both sides of the negative electrode wiring area 12 in the second direction Y, namely the first positive electrode insulating adhesive 41 and the second positive electrode insulating adhesive 41; the first positive electrode insulating adhesive 41 is located between the positive electrode wiring area 11 and the negative electrode wiring area 12, and the second positive electrode insulating adhesive 41 is located on the side of the negative electrode wiring area 12 away from the positive electrode wiring area 11. The end of the first positive electrode insulating adhesive 41 that is away from the negative electrode wiring area 12 is flush with or overlaps with the negative electrode insulating adhesive 42.

[0039] Thus, by distributing the positive electrode insulating adhesive 41 on both sides of the negative electrode wiring area 12 (i.e., the first positive electrode insulating adhesive 41 and the second positive electrode insulating adhesive 41), sufficient insulation isolation between the dissimilar grid lines is ensured. The first positive electrode insulating adhesive 41 is located between the positive electrode wiring area 11 and the negative electrode wiring area 12, effectively preventing short circuits caused by the offset of the solder ribbon 50 during the welding process. The end of the first positive electrode insulating adhesive 41 away from the negative electrode wiring area 12 is flush with or overlaps with the negative electrode insulating adhesive 42, further enhancing the continuity and reliability of the insulation area and avoiding potential short circuit risks caused by minute displacements. Through reasonable wiring area division and insulating adhesive 40 distribution, current can be transmitted along the shortest path, reducing unnecessary current detours, lowering resistance losses, and improving the overall conversion efficiency of the battery.

[0040] The negative electrode insulating adhesive 42 is distributed on both sides of the positive electrode wiring area 11 in the second direction Y, namely the first negative electrode insulating adhesive 42 and the second negative electrode insulating adhesive 42; the first negative electrode insulating adhesive 42 is located between the positive electrode wiring area 11 and the negative electrode wiring area 12, and the second negative electrode insulating adhesive 42 is located on the side of the positive electrode wiring area 11 away from the negative electrode wiring area 12. The end of the first negative electrode insulating adhesive 42 that is away from the positive electrode wiring area 11 is flush with or overlaps with the positive electrode insulating adhesive 41.

[0041] Thus, by distributing the negative electrode insulating adhesive 42 on both sides of the positive electrode wiring area 11 (i.e., the first negative electrode insulating adhesive 42 and the second negative electrode insulating adhesive 42), sufficient insulation isolation between the dissimilar grid lines is ensured. The first negative electrode insulating adhesive 42 is located between the positive electrode wiring area 11 and the negative electrode wiring area 12, effectively preventing short circuits caused by the offset of the solder ribbon 50 during the welding process. The end of the first negative electrode insulating adhesive 42 away from the positive electrode wiring area 11 is flush with or overlaps with the positive electrode insulating adhesive 41, further enhancing the continuity and reliability of the insulation area and avoiding potential short circuit risks caused by minute displacements. In this way, through reasonable wiring area division and insulating adhesive 40 distribution, current can be transmitted along the shortest path, reducing unnecessary current detours, reducing resistance loss, and improving the overall conversion efficiency of the battery.

[0042] It is understood that this embodiment does not impose specific restrictions on the overlap width H of the positive / negative insulating adhesive 40 in the second direction Y. As long as the basic condition of "ends flush or overlapping (i.e. H≥0)" is met, a continuous and uninterrupted insulating barrier can be formed to achieve the purpose of electrical isolation.

[0043] In actual manufacturing, slight offsets may occur in the position of the fine grid due to screen printing deviations, paste flowability, or alignment errors. If the insulating adhesive 40 coverage area is only "aligned" or "equal in width" with the fine grid, insufficient insulation and partial exposure of the fine grid may occur in the edge areas.

[0044] Therefore, in this embodiment, the distance between the positive insulating adhesives 41 located on both sides of the negative wiring area 12 is smaller than the distance between the positive fine grids 31 located on both sides of the negative wiring area 12; that is, the printing start point of the positive insulating adhesive 41 extends beyond the endpoint of the positive fine grid 31. Similarly, the distance between the negative insulating adhesives 42 located on both sides of the positive wiring area 11 is smaller than the distance between the negative fine grids 32 located on both sides of the positive wiring area 11; that is, the printing start point of the negative insulating adhesive 42 extends beyond the endpoint of the negative fine grid 32. In this way, the insulating adhesive 40 can completely wrap and cover the end of the fine grid near the main grid 20 / solder strip 50, preventing the fine grid from being exposed.

[0045] Optionally, the distance between the positive insulating adhesives 41 located on both sides of the negative wiring area 12 is at least 0.2 mm smaller than the distance between the positive fine grids 31 located on both sides of the negative wiring area 12; that is, the printing start point of the positive insulating adhesive 41 extends beyond the end point of the positive fine grid 31 by at least 0.1 mm. Similarly, the distance between the negative insulating adhesives 42 located on both sides of the positive wiring area 11 is at least 0.2 mm smaller than the distance between the negative fine grids 32 located on both sides of the positive wiring area 11; that is, the printing start point of the negative insulating adhesive 42 extends beyond the end point of the negative fine grid 32 by at least 0.1 mm. This saves on the amount of insulating adhesive 40 used, reduces costs, and prevents it from intruding into the soldering area and affecting the reliable connection between the solder strip 50 and the main grid 20.

[0046] The width of the positive electrode wiring area 11 and the negative electrode wiring area 12 in the second direction Y is 1~2mm to accommodate the current 0.5~1.5~mm solder strip 50, ensuring that the reserved width of the wiring area is greater than the width of the solder strip 50, eliminating the need to print conductive adhesive pads to increase the welding contact points, and ensuring reliable welding between the solder strip 50 and the battery cell 10.

[0047] The thickness of both the positive electrode insulating adhesive 41 and the negative electrode insulating adhesive 42 is 20~50μm, and the width in the first direction X is 10~100μm.

[0048] Thus, an insulating adhesive 40 thickness of ≥20μm ensures sufficient dielectric strength, effectively blocking leakage current between the positive and negative electrodes; it covers minor steps, particles, or surface unevenness that may occur during screen printing or etching; and it is less prone to being crushed or broken during subsequent welding processes (such as infrared heating or lamination), maintaining insulation integrity. A thickness of ≤50μm avoids stress accumulation in the film layer caused by excessive thickness, preventing warping or microcracks in the cell 10; it also does not affect the contact height difference between the solder ribbon 50 and the main grid 20 / PAD point 21, facilitating reliable welding; moreover, it reduces material usage, lowers material costs, shortens UV or thermal curing time, and increases production cycle time.

[0049] The insulating adhesive 40 has a width of ≥10μm in the first direction X, which is sufficient to completely cover the fine grid itself and provide a certain lateral protection margin; it tolerates slight widening or edge burrs of the fine grid during the printing process; and it prevents the insulating adhesive 40 from not completely covering the conductor due to insufficient width, thus forming an "edge leakage" path. A width of ≥100μm can avoid over-expansion, reduce interference with the welding space of the solder ribbon 50, and ensure direct contact between the solder ribbon 50 and the electrode; at the same time, it saves the amount of insulating adhesive 40 used, reduces material costs, is beneficial for high-density interdigitated structure design, and improves battery efficiency.

[0050] In addition, the insulating adhesive 40, with its sufficient thickness (20–50 μm) and width (10–100 μm), can form a three-dimensional, high-voltage-resistant insulating wall. Even if conductive foreign objects such as solder dross or solder balls are generated during component welding or rework, this insulating layer can effectively prevent them from forming a bridge between the positive and negative fine grids 32. At the same time, it reduces short-circuit failures caused by contamination or operational errors, significantly reducing the related defect rate from the current approximately 1%.

[0051] This embodiment also discloses a back contact battery, which can be a battery with a main grid 20 or a battery without a main grid 20. For a battery without a main grid 20, it includes a solder ribbon 50 and the battery cell 10 of the above embodiment. The solder ribbon 50 includes a positive electrode solder ribbon 51 and a negative electrode solder ribbon 52. The positive electrode solder ribbon 51 is soldered on the positive electrode wiring area 11, and the negative electrode solder ribbon 52 is soldered on the negative electrode wiring area 12.

[0052] For cells containing the main busbar 20, the components include the solder ribbon 50, the main busbar 20, and the aforementioned cell 10. The positive wiring area 11 is printed with a positive main grid 22, and the negative wiring area 12 is printed with a negative main grid 23; both the positive main grid 22 and the negative main grid 23 have multiple PAD points 21; The solder strip 50 includes a positive solder strip 51 and a negative solder strip 52. The positive solder strip 51 is welded to the PAD point 21 on the positive main grid 22, and the negative solder strip 52 is welded to the PAD point 21 on the negative main grid 23.

[0053] In addition, this embodiment also discloses a photovoltaic module, which includes the back contact battery of the above embodiment.

[0054] Finally, it should be noted that in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0055] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized in that, include: The battery cell has a positive electrode wiring area (11) and a negative electrode wiring area (12) extending along a first direction (X) on its back side. The positive electrode wiring area (11) and the negative electrode wiring area (12) are arranged side by side along a second direction (Y). The first direction (X) and the second direction (Y) are perpendicular. A positive electrode grid (31) and a negative electrode grid (32) are alternately distributed along the first direction (X) on the back of the battery cell. Both the positive electrode grid (31) and the negative electrode grid (32) extend along the second direction (Y). The portion of the positive electrode grid (31) that passes through the positive electrode wiring area (11) is used to connect the positive electrode solder strip (51) or the positive electrode main grid (22). The portion of the positive electrode grid (31) that corresponds to the negative electrode wiring area (12) is disconnected. The portion of the negative electrode grid (32) that passes through the negative electrode wiring area (12) is used to connect the negative electrode solder strip (52) or the negative electrode main grid (23). Positive insulating adhesive (41) covering the positive electrode grid (31) and negative insulating adhesive (42) covering the negative electrode grid (32), wherein the ends of the positive electrode insulating adhesive (41) and the ends of the negative electrode insulating adhesive (42) overlap or are flush in the second direction (Y).

2. The battery cell according to claim 1, characterized in that, The distance between the positive electrode insulating adhesive (41) located on both sides of the negative electrode wiring area (12) is smaller than the distance between the positive electrode fine grid (31) located on both sides of the negative electrode wiring area (12); The distance between the negative electrode insulating adhesive (42) located on both sides of the positive electrode wiring area (11) is smaller than the distance between the negative electrode fine grid (32) located on both sides of the positive electrode wiring area (11).

3. The battery cell according to claim 2, characterized in that, The distance between the positive electrode insulating adhesive (41) located on both sides of the negative electrode wiring area (12) is at least 0.2 mm smaller than the distance between the positive electrode fine grid (31) located on both sides of the negative electrode wiring area (12); The distance between the negative electrode insulating adhesive (42) located on both sides of the positive electrode wiring area (11) is at least 0.2 mm smaller than the distance between the negative electrode fine grid (32) located on both sides of the positive electrode wiring area (11).

4. The battery cell according to claim 1, characterized in that, The width of both the positive electrode wiring area (11) and the negative electrode wiring area (12) in the second direction (Y) is 1~2mm.

5. The battery cell according to claim 1, characterized in that, The thickness of both the positive electrode insulating adhesive (41) and the negative electrode insulating adhesive (42) is 20~50μm, and the width in the first direction (X) is 10~100μm.

6. The battery cell according to claim 1, characterized in that, The positive electrode insulating adhesive (41) is distributed on both sides of the negative electrode wiring area (12) in the second direction (Y), namely the first positive electrode insulating adhesive (41) and the second positive electrode insulating adhesive (41); the first positive electrode insulating adhesive (41) is located between the positive electrode wiring area (11) and the negative electrode wiring area (12), and the second positive electrode insulating adhesive (41) is located on the side of the negative electrode wiring area (12) away from the positive electrode wiring area (11); Wherein, the end of the first positive electrode insulating adhesive (41) away from the negative electrode wiring area (12) is flush with or overlaps with the negative electrode insulating adhesive (42).

7. The battery cell according to claim 1, characterized in that, The negative electrode insulating adhesive (42) is distributed on both sides of the positive electrode wiring area (11) in the second direction (Y), namely the first negative electrode insulating adhesive (42) and the second negative electrode insulating adhesive (42); the first negative electrode insulating adhesive (42) is located between the positive electrode wiring area (11) and the negative electrode wiring area (12), and the second negative electrode insulating adhesive (42) is located on the side of the positive electrode wiring area (11) away from the negative electrode wiring area (12); Wherein, the end of the first negative electrode insulating adhesive (42) away from the positive electrode wiring area (11) is flush with or overlaps with the positive electrode insulating adhesive (41).

8. A back-contact battery, characterized in that, Includes solder strip (50) and the battery cell as described in any one of claims 1-7; The solder strip (50) includes a positive solder strip (51) and a negative solder strip (52). The positive solder strip (51) is soldered on the positive wiring area (11), and the negative solder strip (52) is soldered on the negative wiring area (12).

9. A back-contact battery, characterized in that, Includes solder strip (50) and the battery cell as described in any one of claims 1-7; The positive wiring area (11) is printed with a positive main grid (22), and the negative wiring area (12) is printed with a negative main grid (23); both the positive main grid (22) and the negative main grid (23) have multiple PAD points (21). The solder strip (50) includes a positive solder strip (51) and a negative solder strip (52). The positive solder strip (51) is welded to the PAD point (21) on the positive main grid (22), and the negative solder strip (52) is welded to the PAD point (21) on the negative main grid (23).

10. A photovoltaic module, characterized in that, Includes the back contact battery as described in claim 8 or 9.

Images