Flexible solar cell based on multi-module splicing

Abstract

The invention provides a flexible solar cell based on multi-module splicing, the flexible solar cell is composed of a plurality of modules, each module comprises a cell assembly and a substrate, the cell assembly is pasted on the substrate, the substrate comprises a circuit layer, a first covering layer and a second covering layer, the first covering layer and the second covering layer are used for clamping the circuit layer, the circuit layer is divided into a plurality of groups of cables, and the cables are connected with the first covering layer and the second covering layer. Each group of cables comprises a positive cable and a negative cable, a positive bonding pad is arranged at the position, close to one end, of the positive cable, a negative bonding pad is arranged at the position, close to the opposite end, of the negative cable, and butt joint bonding pads are arranged at the two ends of the positive cable and the two ends of the negative cable respectively. The positive output end and the negative output end of the battery assembly are connected with the positive electrode bonding pad and the negative electrode bonding pad respectively, and the butt joint bonding pad and the connecting areas arranged on the two sides of the butt joint bonding pad are used for electrical butt joint and mechanical butt joint between substrates of adjacent modules respectively. By adopting the module design of the same configuration, batch manufacturing is facilitated, the manufacturing cost is low, the structure is reliable, and the stability is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular to a flexible solar cell based on multi-module splicing. BACKGROUND

[0002] The coiled flexible solar wing has the advantages of high weight-to-power ratio and small storage volume, and has been widely used in the field of spaceflight. However, the solar blanket of the coiled flexible solar wing usually has a large size. Limited by the current manufacturing technology and equipment level, the solar blanket of the coiled flexible solar wing cannot be manufactured integrally at one time, and multiple small-size solar panels need to be manufactured first, and then the multiple solar panels are connected mechanically and electrically to form a large-size solar blanket. A common method is to paste multiple small-size solar panels to a large-size grid cloth or film material to realize mechanical connection, and then use a long cable to electrically connect each solar panel. This connection method has a complex manufacturing process and low production efficiency. SUMMARY

[0003] The present application provides a flexible solar cell based on multi-module splicing, which is composed of multiple modules, each module including a cell assembly and a substrate, the cell assembly being pasted on the substrate, the substrate including a circuit layer and first and second cover layers clamping the circuit layer, the circuit layer being divided into a plurality of groups of cable lines, each group of cable lines including one positive cable line and one negative cable line, a positive pad being provided at a proximal end of the positive cable line, a negative pad being provided at a distal end of the negative cable line, a butt pad being provided at each end of the positive and negative cable lines, a connection area being provided on the first and second cover layers on both sides of the butt pad, the positive and negative output terminals of the cell assembly being connected to the positive and negative pads respectively, the butt pad being used for electrical butt joint between the substrates of adjacent modules, and the connection area being used for mechanical butt joint between the substrates of adjacent modules.

[0004] Optionally, the connection area provided on the outer side of the butt pad is an outer connection area, and the connection area provided on the inner side of the butt pad is an inner connection area, the outer connection area being aligned with and bonded to the inner connection area of the adjacent substrate, and the inner connection area being aligned with and bonded to the outer connection area of the adjacent substrate.

[0005] Optionally, a stress-relief bend is provided at each end of the positive and negative cable lines, and the butt pad is provided at the end of the stress-relief bend.

[0006] Optionally, the butt pad at the left end is aligned with and welded to the butt pad at the right end of the adjacent substrate.

[0007] Optionally, the positive and negative pads are formed by etching the first cover layer.

[0008] Optionally, the butt joint pad is formed by etching the first cover layer and the second cover layer.

[0009] Optionally, the first butt joint pad on the adjacent first substrate is formed by etching the first cover layer, and the second butt joint pad on the adjacent second substrate is formed by etching the second cover layer.

[0010] Optionally, the butt joint pad is subjected to pressure and heating treatment by a welding pressure head after butt joint of the adjacent substrates.

[0011] Optionally, the connecting area is subjected to pressure and heating treatment by an adhesive pressure head after butt joint of the adjacent substrates.

[0012] Optionally, the welding pressure head and the adhesive pressure head simultaneously perform welding and adhesion, and the pressure and temperature of the welding pressure head and the adhesive pressure head are independently controlled respectively.

[0013] The flexible solar cell based on multi-module splicing provided by the application is convenient for batch manufacturing and has low manufacturing cost by adopting modules of the same configuration. The circuit layer arranged in the substrate is used to realize power transmission of the solar cell, and no additional transmission cable is needed, so that the solar cell has simple structure, light weight, and is thinner and easier to wind and store. The connecting area arranged on both sides of the butt joint pad can prevent the circuit connection from being subjected to tension, thereby ensuring the reliability of the welding point. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0015] Figure 1 is a structural diagram of the flexible solar cell based on multi-module splicing provided by the application.

[0016] Figure 2 is a vertical sectional view of one module in the flexible solar cell based on multi-module splicing provided by the application.

[0017] Figure 3 is a vertical sectional view of the structure of the substrate in one embodiment of the application.

[0018] Figure 4 is a top view of the structure of the substrate in the embodiment of the application.

[0019] Figure 5 is a vertical sectional view of the structure of one module in the application.

[0020] Figure 6 This is a top view illustrating the structure of one of the modules in this invention.

[0021] Figure 7 This is a schematic top view of a cable with a stress-reducing bend in one of the modules of this invention; Figure 8 This is a schematic vertical cross-sectional view of the substrate structure according to another embodiment of the present invention.

[0022] Figure 9 This is a partial structural diagram of the welding and bonding between two adjacent modules in this invention; Figure 10 This is a partial structural diagram of welding between two adjacent modules using a welding pressure head in this invention; Figure 11 This is a partial structural diagram of the present invention, showing how two adjacent modules are simultaneously welded using a welding head and bonded using an adhesive head. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] This invention provides a flexible solar cell based on multi-module splicing, such as... Figure 1 As shown, the flexible solar cell consists of multiple modules, each module including a battery assembly 1 and a substrate 2. The battery assembly 1 is attached to the substrate 2. The substrate 2 includes a circuit layer 21 and a first cover layer 22a and a second cover layer 22b that clamp the circuit layer 21. The circuit layer 21 is divided into several groups of cables, each group of cables including one positive cable 211a and one negative cable 211b. A positive electrode pad 2112a is provided near the end of the positive cable 211a, and a negative electrode pad 2112a is provided near the other end of the negative cable 211b. A negative electrode pad 2112b is provided at the end, and a mating pad 2111 is provided at both ends of the positive and negative cables 211a and 211b, respectively. Connection areas (i.e., outer connection area 221 and inner connection area 222) are provided on the first cover layer and the second cover layer on both sides of the mating pad 2111, respectively. The positive and negative output terminals of the battery assembly 1 are connected to the positive electrode pad 2112a and the negative electrode pad 2112b, respectively. The mating pad 2111 is used for electrical connection between the substrates of adjacent modules, and the connection area is used for mechanical connection between the substrates of adjacent modules.

[0025] This invention enables the mass production of flexible solar cells through a universal modular design, which greatly reduces manufacturing costs. Furthermore, by placing the circuit layer within the substrate, it enables the transmission of electrical energy generated by the solar cells without the need for additional transmission cables. Moreover, the flexible solar cells proposed in this invention are thinner than existing ones, making them easier to roll up and store, and are particularly suitable for use on satellites.

[0026] like Figure 1 As shown, when splicing between substrates (i.e., between modules), the left and right ends of two flexible solar panel modules are stacked one on top of the other. The outer connection area 221 of the right end of the first flexible solar panel module and the inner connection area 222 of the left end of the second flexible solar panel module are aligned and bonded together. The inner connection area 222 of the right end of the first flexible solar panel module and the outer connection area 221 of the left end of the second flexible solar panel module are aligned and bonded together. The mating pads 2111 of the right end of the first flexible solar panel module and the mating pads 2111 of the left end of the second flexible solar panel module are aligned and welded together.

[0027] Similarly, the third flexible substrate solar panel module and the second flexible solar panel module are spliced ​​together using the same method until all the flexible substrate solar panel modules are spliced ​​together into a complete flexible substrate solar cell (or solar blanket). The bonding of the outer and inner connection areas provides the mechanical connection of the solar blanket, enabling it to withstand tension. The welding between the mating pads provides the electrical connection of the solar blanket, connecting the positive or negative cables of all flexible solar panels into a single cable. This allows all solar cell modules located on the same set of cables (including one positive cable and one negative cable) to be connected in parallel to the spacecraft's power system.

[0028] like Figure 2 As shown, the circuit layer 21 is made of a metal foil with a specific pattern, and the first cover layer 22a and the second cover layer 22b are insulating film materials. The circuit layer 21 and the cover layers 22a and 22b, as well as the first cover layer 22a and the second cover layer 22b, are bonded together with adhesive. Through this innovative design, the substrate 2 is a flexible circuit board, facilitating the winding and storage of solar cells, and the relatively fixed circuit layers contribute to the stability and reliability of the circuit connections.

[0029] As one implementation method, such as Figure 3As shown, the outer connection area 221 is disposed on the outer side of the mating pad 2111, and the inner connection area 222 is disposed on the inner side of the mating pad 2111. The outer connection area 221 is used to align and bond with the inner connection area 222 of the adjacent substrate, and the inner connection area 222 is used to align and bond with the outer connection area 221 of the adjacent substrate. The relative positional relationship between the alignment and connection of the substrates and the adjacent substrates is as follows: Figure 1 As shown in the figure, the solder joints, which achieve circuit connection by setting external connection areas and internal connection areas on both sides of the mating pads, are mechanical connection points on both sides. When the flexible solar cell is wound, opened, or tensioned, the solder joints are protected by mechanical connection points on both sides, so that the solder joints are not affected by tension forces, and the solder joints have high reliability.

[0030] like Figure 4 As shown, the circuit layer 21 is divided into several groups of parallel, elongated cables 211. Each group of cables includes one positive cable 211a and one negative cable 211b. On the surfaces of the cover layers 22a and 22b on both sides of the mating pads 2111, outer connection areas 221 and inner connection areas 222 are respectively provided along a direction perpendicular to the cable 211. A positive electrode pad 2112a is located inside the inner connection area 222 on the positive cable 211a, and a negative electrode pad 2112b is located inside the inner connection area 222 on the negative cable 211b. The outer connection areas 221 and inner connection areas 222 are areas reserved at designated locations on the cover layers 22a and 22b for subsequent connection with adjacent modules; therefore, no special processing or treatment is required on the cover layers 22a and 22b in these areas. The outer connection areas 221 and inner connection areas 222 can be elongated connection areas with adhesive strength.

[0031] like Figure 5 As shown, the solar cell module 1 is bonded to the substrate 2 by adhesive 3. The area of ​​adhesive 3 applied to the first cover film is slightly smaller than the area of ​​the solar cell module to ensure a firm bond between the solar cell module 1 and the substrate 2, while minimizing excess adhesive 3 overflow. Figure 6 As shown, the positive output terminal 11a of the solar cell module 1 is soldered to the positive electrode pad 2112a of the positive cable 211a, and the negative output terminal 211b of the solar cell module 1 is soldered to the negative electrode pad 2112b of the negative cable 11b. This module structure, consisting of the cell module 1 and the substrate 2, is simple, has no long cables, and offers high electrical connection reliability.

[0032] To further improve the reliability of circuit connections, such as Figure 7 As shown, stress-reducing bends are respectively set next to the pads at both ends of the positive and negative cables, and the butt pads 2111 are located at the ends of the stress-reducing bends. The stress-reducing bends can be L-shaped or U-shaped. Figure 7In the middle, the positive cable 211a adopts an L-shaped stress-reducing bend, while the negative cable 211b adopts a U-shaped stress-reducing bend.

[0033] In this invention, the solder pad refers to the area where the first and second cover layers 22a and 22b are etched to expose the cable 211, allowing subsequent soldering to be performed on this exposed area (i.e., the solder pad). As one embodiment, such as... Figure 3 As shown, the positive electrode pad 2112a and the negative cable 211b only require etching of the first cover layer 22a, while the mating pad 2111 can etch both the first cover layer 22a and the second cover layer 22b. In this embodiment, each module is the same, and the modules are electrically and mechanically connected through the mating pad 2111 and the connection area on the substrate 2, respectively. As another embodiment, such as Figure 8 As shown, only one cover layer is etched at the mating pad 2111 of the flexible solar panel. Specifically, in the flexible solar panel assembled from modules into a solar blanket, the odd-numbered flexible solar panels only have the first cover layer 22a etched at the mating pad 2111, while the even-numbered flexible solar panels only have the second cover layer 22b etched at the mating pad 2111. This implementation reduces the etching process by half, but it requires distinguishing which modules are odd-numbered and which are even-numbered among all the flexible solar panels to be assembled into a solar blanket.

[0034] like Figure 9 As shown, when adjacent substrates are spliced, the welding between the mating pads 2111 is done by soldering flux 5, and the connection between the connection areas can be done by adhesive 4 to ensure that the electrical and mechanical connections between the modules are not hollow.

[0035] To further ensure the stability and reliability of the electrical connection, after aligning the mating pads of the two modules, as follows: Figure 10 As shown, a welding pressure head 6 applies pressure to the mating pads 2111, causing the mating pads 2111 of the two flexible solar panels to come into contact and be directly welded. Specific welding methods include resistance welding, ultrasonic welding, and thermocompression welding. Further, as... Figure 11 As shown, while the welding head 6 is welding the pad 2111, two bonding heads 7 can be used to apply pressure to the outer connection area 221 and the inner connection area 222 respectively to achieve bonding between adjacent substrates.

[0036] Furthermore, the welding head 6 and the bonding head 7 can heat the pressure area while applying pressure, thereby improving the welding or bonding process.

[0037] In a specific embodiment, the welding head 6 and the bonding head 7 are each mounted on an independent pressure control device, thereby enabling the simultaneous application of different pressures to the butt welding pad 2111, the outer connection area 221, and the inner connection area 222. The pressure control device can be a spring or a servo system with force feedback function.

[0038] In a specific implementation, the welding head 6 and the bonding head 7 are each equipped with an independent heating system, so as to simultaneously heat the butt pad 2111, the outer connection area 221, and the inner connection area 222 at different temperatures, thereby adapting to different welding and bonding processes.

[0039] This invention employs independent welding and bonding heads to apply pressure and heat to the butt pads and connection area, respectively. Furthermore, the pressure and temperature of both the welding and bonding heads can be individually controlled. Mechanical connection (bonding) and electrical connection (welding) can be achieved simultaneously in a single process step (heating and pressurization), thereby improving production efficiency.

[0040] The flexible solar cell based on multi-module splicing provided by this invention is easy to mass-produce and has low manufacturing cost by adopting a modular design with the same configuration. The circuit layer set in the substrate realizes the power transmission of the solar cell, eliminating the need for additional transmission cables. This makes the solar cell structure simple, lightweight, thinner, and easier to roll up and store. By setting connection areas on both sides of the mating pads, the circuit connection can be free from tension, thereby ensuring the reliability of the solder joint.

[0041] The device embodiments described above are merely illustrative. Those skilled in the art can understand and implement them without any inventive effort.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flexible solar cell based on multi-module splicing, characterized in that, Composed of multiple modules, each module includes a battery assembly and a substrate. The battery assembly is attached to the substrate. The substrate includes a circuit layer and a first cover layer and a second cover layer that hold the circuit layer. The circuit layer is divided into several groups of cables, each group of cables including one positive cable and one negative cable. A positive electrode pad is provided near one end of the positive cable, and a negative electrode pad is provided near the opposite end of the negative cable. Butt pads are provided at both ends of the positive and negative cables. Connection areas are provided on the first cover layer and the second cover layer on both sides of the butt pads. The positive and negative output terminals of the battery assembly are connected to the positive electrode pad and the negative electrode pad, respectively. The butt pads are used for electrical connection between the substrates of adjacent modules, and the connection areas are used for mechanical connection between the substrates of adjacent modules.

2. The flexible solar cell according to claim 1, characterized in that, The connection area set on the outside of the mating pad is called the outer connection area, and the connection area set on the inside of the mating pad is called the inner connection area. The outer connection area is aligned and bonded to the inner connection area of ​​the adjacent substrate, and the inner connection area is aligned and bonded to the outer connection area of ​​the adjacent substrate.

3. The flexible solar cell according to claim 1, characterized in that, Stress-reducing bends are set at both ends of the positive and negative cables, and the butt welding pads are set at the ends of the stress-reducing bends.

4. The flexible solar cell according to claim 1, characterized in that, The mating pad on the left end is aligned with and soldered to the mating pad on the right end of the adjacent substrate.

5. The flexible solar cell according to claim 1, characterized in that, The positive electrode pad and the negative electrode pad are formed by etching the first cover layer.

6. The flexible solar cell according to claim 1, characterized in that, The mating pads are formed by etching the first and second cover layers.

7. The flexible solar cell according to claim 1, characterized in that, The first mating pads on the adjacent first substrate are formed by etching the first cover layer, and the second mating pads on the adjacent second substrate are formed by etching the second cover layer.

8. The flexible solar cell according to claim 1, characterized in that, The mating pads are subjected to pressure and heat treatment by a welding head after adjacent substrates are mated.

9. The flexible solar cell according to claim 1 or 8, characterized in that, The connection area is subjected to pressure and heating treatment by an adhesive pressure head after adjacent substrates are joined.

10. The flexible solar cell according to claim 9, characterized in that, The welding head and the bonding head perform welding and bonding simultaneously, and the pressure and temperature of the welding head and the bonding head are controlled independently.

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