Heterojunction solar cell and solar cell module

Abstract

The heterojunction solar cell comprises a cell piece, metal gates and sinking grooves, the metal gates are arranged on the upper surface and the lower surface of the cell piece respectively, the upper surface and the lower surface of the cell piece are each provided with a plurality of sinking grooves, and the sinking grooves are located in gaps of the metal gates; and the sinking groove is a honeycomb-shaped sinking groove. The sinking groove is designed to be in a honeycomb shape, the cross section of the bottom face of the sinking groove is in a wave shape, and protrusions of different sizes are arranged on the inner side wall of the sinking groove. According to the design, the contact area of the sinking groove and the insulation paste is increased, meanwhile, the wavy bottom surface and the protrusions provide more adhesion points, the insulation paste is effectively prevented from falling off, and it is ensured that the sinking groove is stably filled with the insulation paste.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cells, and in particular relates to a heterojunction solar cell and a solar cell assembly. Background Art

[0002] Heterojunction solar cells, with their unique advantages such as low preparation temperature, high conversion efficiency, excellent high temperature performance, small temperature coefficient and double-sided power generation, have become a research hotspot in the photovoltaic field, showing broad research prospects and huge market potential, and therefore have attracted widespread attention from the scientific research community and the industry. The electrode design of this type of battery cleverly combines a thick main grid with a fine grid, aiming to maximize the photoelectric conversion efficiency of the battery, while reducing the electrode's shading of the battery surface and reducing the cost of electrode production.

[0003] This innovative design concept is further reflected in the heterojunction solar cell without a main grid design. In this design, the welding ribbon (also known as the interconnection ribbon) replaces the function of the traditional main grid, which is responsible for collecting the current generated by the fine grid and effectively conducting it to the outside of the cell. The design and layout of the welding ribbon not only affects the current collection efficiency, but is also directly related to the overall mechanical strength of the battery component and the reliability of the electrical connection.

[0004] Ensuring that there is both a strong mechanical connection and good electrical contact between the welding ribbon and the fine grid is the key to achieving stable connection between multiple batteries and effective collection of fine grid current. However, since the contact area between the welding ribbon and the fine grid is relatively limited, it is often point contact or line contact, which can easily cause problems such as welding deviation and cold welding during the welding process, thereby affecting the firmness of the mechanical connection and the reliability of the electrical contact. These problems may not only lead to a decline in battery performance, but also affect the long-term stable operation of the battery assembly.

[0005] In addition, when assembling solar cell modules, the design of the soldering ribbon also needs to consider its layout and bends between adjacent cells. In traditional designs, the soldering ribbon forms a clear bend between adjacent cells, which not only affects the aesthetics of the battery module, but may also cause the soldering ribbon to deform easily due to the excessive length of the bend. In long-term operation, this deformation may aggravate the fatigue damage of the soldering ribbon and even cause it to break, thus affecting the overall performance and life of the battery module. Summary of the invention

[0006] The object of the present invention is to provide a heterojunction solar cell and a solar cell module to solve the above problems.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A heterojunction solar cell comprises a cell sheet, a metal grid and a sink groove, wherein the metal grid is respectively arranged on the upper and lower surfaces of the cell sheet, and the upper and lower surfaces of the cell sheet are both provided with a plurality of sink grooves, and the sink grooves are located in the gaps of the metal grid; the sink grooves are honeycomb-shaped sink grooves. Furthermore, the metal grid is in a grid shape or in a strip shape with equal intervals.

[0008] Furthermore, the depth of the sink is more than three times the thickness of the metal grid.

[0009] Furthermore, the cross section of the bottom surface of the trough is wavy; and protrusions of different sizes are arranged on the inner side wall of the trough.

[0010] Furthermore, the groove is formed by laser engraving.

[0011] Furthermore, the number of the sinks is greater than or equal to four.

[0012] Furthermore, the number of the sink grooves on the lower surface of the battery cell is less than the number of the sink grooves on the upper surface of the battery cell.

[0013] A solar cell assembly comprises a plurality of heterojunction solar cells, insulating adhesive and special-shaped welding strips; the insulating adhesive is filled in a sink, and the special-shaped welding strips are arranged on the insulating adhesive and the metal grid on the upper surface or the lower surface of the solar cell; the special-shaped welding strips of two adjacent heterojunction solar cells are not on the same surface, and the two adjacent heterojunction solar cells are connected by the special-shaped welding strips.

[0014] Furthermore, the special-shaped welding strip is an L-shaped structure, and the thickness of the short side of the L-shape is greater than the thickness of the long side.

[0015] Furthermore, an inclined surface is arranged on the short side of the L-shape of the special-shaped welding ribbon, and the inclined surfaces of two adjacent heterojunction solar cells are matched and connected to each other.

[0016] Compared with the prior art, the present invention has the following technical effects: The present invention improves the design of the sink structure and welding strip on the battery cell, aiming to improve the mechanical connection strength, electrical contact reliability and overall aesthetics of the battery and components. The first aspect: honeycomb sink design Improve the adhesion of the insulating glue: The sink is designed to be honeycomb-shaped, and the bottom cross-section is wavy, and the inner wall is provided with protrusions of different sizes. This design increases the contact area between the sink and the insulating glue, and the wavy bottom and protrusions provide more adhesion points, effectively preventing the insulating glue from falling off and ensuring that the insulating glue is firmly filled in the sink.

[0017] Enhanced mechanical connection strength: The depth of the sink is more than three times the thickness of the metal grid. This depth design allows the insulating adhesive to form a thicker adhesion layer after filling, thereby significantly enhancing the mechanical connection strength between the solder ribbon and the solar cell. When subjected to external forces, the thicker insulating adhesive layer can better disperse the stress and prevent the solder ribbon from falling off or breaking.

[0018] The second aspect: special-shaped welding strip design Improved aesthetics: The special-shaped welding ribbon adopts an L-shaped structure. This design enables the welding ribbon to form a more compact and neat arrangement when connecting adjacent solar cells, improving the overall aesthetics of the solar cell module.

[0019] Increase the contact surface: The short side of the L-shaped solder strip is thicker than the long side, and the short side is provided with an inclined surface, and the inclined surfaces of two adjacent heterojunction solar cells are matched and connected to each other. This design increases the contact area between the solder strip and the cell, making the current transfer process smoother and reducing the electrical failure problem caused by poor contact.

[0020] Enhanced connection stability: The design of the special-shaped solder strip makes the connection point bevel contact, which is more stable than traditional point contact or line contact. When subjected to external force, the bevel contact can better disperse the stress and prevent the solder strip from deformation or breakage, thereby ensuring the long-term stable operation of the battery assembly.

[0021] In summary, this technical solution effectively improves the mechanical connection strength, electrical contact reliability and overall aesthetics of heterojunction solar cells and their components through innovative honeycomb sink design and special-shaped welding strip design. These improvements not only improve the performance and life of cells and components, but also provide strong support for the further development and application of heterojunction solar cell technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the present invention.

[0023] Figure 2 It is a schematic diagram of the structure after the insulating glue is filled in the present invention.

[0024] Figure 3 This is a schematic diagram of the connection of solar cell components.

[0025] in: 1. Battery cell; 2. Metal grid; 3. Sink; 4. Special-shaped welding strip; 5. Insulating glue. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Example 1, please refer to Figure 1 A heterojunction solar cell includes a cell 1, a metal grid 2 and a sink 3, wherein the metal grid 2 is respectively arranged on the upper and lower surfaces of the cell 1, and a plurality of sinks 3 are arranged on the upper and lower surfaces of the cell 1, and the sinks 3 are located in the gaps of the metal grid 2; the sinks 3 are honeycomb-shaped sinks.

[0030] By providing honeycomb-shaped sink grooves 3 on the upper and lower surfaces of the battery cell 1 and placing metal grids 2 in the sink grooves, the contact area between the battery cell and the metal grid is effectively increased. This design not only improves the stability of the mechanical connection, but also enhances the deformation resistance of the battery assembly during the lamination process, and reduces the risk of hidden cracks in the battery cell due to stress concentration.

[0031] The design of the honeycomb-shaped sink groove 3 enables the metal grid 2 to fit more closely to the surface of the battery cell, reducing the contact resistance and improving the electrical transmission efficiency. At the same time, the presence of the sink groove also facilitates the connection between the welding strip and the metal grid, ensuring the smooth transmission of current between the battery cells, thereby improving the overall performance of the battery assembly.

[0032] Compared with the traditional main grid design, the surface of the heterojunction solar cell without the main grid design is smoother, reducing the shielding of the grid line on the cell and improving the utilization rate of light. The arrangement of the honeycomb sink 3 is both beautiful and practical, and can further improve the appearance quality of the battery assembly.

[0033] The busbar-free design reduces the amount of metal grid lines used, thereby reducing production costs. At the same time, the preparation process of the honeycomb sink 3 is relatively simple, and it is easy to achieve large-scale production, which is conducive to reducing the overall manufacturing cost of heterojunction solar cells.

[0034] Since the grid lines do not block the light, more light can reach the surface of the cell and be converted into electrical energy, thus improving the conversion efficiency of the battery. In addition, the sink design also helps improve the heat dissipation performance of the cell, further improving the working efficiency and stability of the battery.

[0035] In summary, this heterojunction solar cell design including honeycomb grooves and metal grids has shown remarkable technical effects in enhancing mechanical connection strength, improving electrical contact reliability, improving aesthetics and reducing shading, reducing production costs, and improving cell conversion efficiency. It has important practical application value and promotion prospects.

[0036] Embodiment 2, the present invention provides a heterojunction solar cell, specifically comprising: It is mainly composed of a battery cell 1, a metal grid 2 and a sink 3. The metal grid 2 is two fine meshes, which are attached to the upper and lower surfaces of the battery cell 1 to help collect and conduct current. There are several sinks 3 on the upper and lower surfaces of the battery cell 1. These sinks 3 are hidden in the gaps of the metal grid 2, and the shape is like a honeycomb, which not only increases the surface area, but also looks very beautiful.

[0037] The design of the metal grid 2 is also very distinctive. It is in a grid shape or composed of strips with equal spacing, which can ensure the smooth flow of current and make the battery cell 1 look more regular. The depth of the sink 3 is more than three times the thickness of the metal grid 2. In this way, the sink can better fix the metal grid and enhance the connection strength between them.

[0038] The cross section of the bottom surface of the sink 3 is wavy, and such a design can increase the contact area between the sink and the metal grid or the insulating glue, and improve the stability of the connection. In addition, there are some protrusions of different sizes on the inner side wall of the sink 3, which play a locking role and can further enhance the firmness of the connection.

[0039] It is worth mentioning that these sink grooves 3 are formed by laser engraving technology, with very high precision and regular shape. There are at least four such sink grooves 3 on each battery cell, and some battery cells even have more sink grooves on the upper surface than on the lower surface. Such a design can better meet different current collection requirements.

[0040] Embodiment 3, a solar cell module: This solar cell assembly is composed of a plurality of the above-mentioned heterojunction solar cells, insulating glue 5 and shaped solder strips 4. The insulating glue 5 is cleverly filled in the sink 3, which can not only fix the metal grid 2 but also play an insulating role. The shaped solder strips 4 are like a bridge connecting the cells. They are set on the insulating glue 5 and the metal grid 3 on the upper or lower surface of the cell 1. In particular, the shaped solder strips 4 of two adjacent heterojunction solar cells are not on the same surface. They are cleverly connected together through the shaped solder strips 4 to form a complete circuit.

[0041] The design of the special-shaped welding ribbon 4 is L-shaped, and the thickness of the short side is thicker than the long side, which can ensure the strength of welding and save materials. In addition, the L-shaped short side of the special-shaped welding ribbon 4 is also provided with an inclined surface, and the inclined surfaces of two adjacent heterojunction solar cells can be matched and connected to each other, making the connection of the entire component more compact and stable.

[0042] Such a design not only improves the conversion efficiency of solar cells, but also enhances the mechanical strength and connection stability of the module, making the entire solar cell module more durable and reliable.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heterojunction solar cell, characterized in that: The invention comprises a battery cell (1), a metal grid (2) and a sink groove (3), wherein the metal grid (2) is respectively arranged on the upper and lower surfaces of the battery cell (1), and the upper and lower surfaces of the battery cell (1) are both provided with a plurality of sink grooves (3), and the sink grooves (3) are located in the gaps of the metal grid (2); the sink grooves (3) are honeycomb-shaped sink grooves.

2. A heterojunction solar cell according to claim 1, characterized in that: The metal grid (2) is in the form of a grid or strips with equal spacing.

3. A heterojunction solar cell according to claim 1, characterized in that: The depth of the sink groove (3) is more than three times the thickness of the metal grid (2).

4. The heterojunction solar cell according to claim 1, characterized in that: The cross section of the bottom surface of the trough (3) is wave-shaped; and protrusions of different sizes are arranged on the inner side wall of the trough (3).

5. The heterojunction solar cell according to claim 1, characterized in that: The groove (3) is formed by laser engraving.

6. The heterojunction solar cell according to claim 1, characterized in that: The number of the sinks (3) is greater than or equal to four.

7. A heterojunction solar cell according to claim (1), characterized in that: The number of the sink grooves on the lower surface of the battery cell (1) is less than the number of the sink grooves on the upper surface of the battery cell (1).

8. A solar cell module, characterized in that: The invention comprises a plurality of heterojunction solar cells according to any one of claims 1 to 7, an insulating adhesive (5) and a special-shaped welding ribbon (4); the insulating adhesive (5) is filled in a sink (3), and the special-shaped welding ribbon (4) is arranged on the insulating adhesive (5) and the metal grid (3) on the upper surface or the lower surface of the battery cell (1); the special-shaped welding ribbons (4) of two adjacent heterojunction solar cells are not on the same surface, and the two adjacent heterojunction solar cells are connected via the special-shaped welding ribbon (4).

9. A solar cell assembly according to claim 8, characterized in that: The special-shaped welding strip (4) is an L-shaped structure, and the thickness of the short side of the L-shape is greater than the thickness of the long side.

10. A solar cell assembly according to claim 9, characterized in that: The L-shaped short side of the special-shaped welding strip (4) is provided with an inclined surface, and the inclined surfaces of two adjacent heterojunction solar cells are matched and connected to each other.

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