Stretchable flexible braided photovoltaic array and preparation method thereof

Abstract

The invention relates to a stretchable flexible woven photovoltaic array and a preparation method thereof, and belongs to the technical field of photovoltaic.The stretchable flexible woven photovoltaic array is characterized in that a plurality of stretchable strip-shaped battery units are woven to form the array; the strip-shaped battery unit comprises a strip-shaped substrate circuit and a plurality of photovoltaic devices, and the strip-shaped substrate circuit is an FPCB circuit and comprises a flexible substrate and a conductive layer; the strip-shaped battery unit is of an island bridge structure, the island bridge structure is a photovoltaic device bonding pad, and a photovoltaic device is welded on the photovoltaic device bonding pad; and the bridge type structure is a bistable paper-cut structure formed by cutting the strip-shaped substrate circuit into gaps. According to the method, the design efficiency of the photovoltaic array is improved through programmable parameterization design, the designed photovoltaic array can be prevented from stress damage in deformation, the substrate is endowed with high ductility and rapid deformation recovery capability, the effective working area reaches 100%, and the tensile property, the photoelectric conversion efficiency and the stability of the flexible photovoltaic array are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of photovoltaic technology, and particularly relates to a stretchable flexible woven photovoltaic array and a preparation method thereof. Background Art

[0002] Photovoltaic power generation is a technology that directly converts light energy into electrical energy by using the photovoltaic effect at the semiconductor interface, and is widely used in various power generation fields. Due to its low cost and high stability, photovoltaics have been widely used in energy supply at present. Under sufficient sunlight irradiation, a photovoltaic system can provide a stable power supply and achieve complete independent power supply without relying on any other energy sources.

[0003] Currently, various wearable devices are developing rapidly, but there is a lack of self-powered technologies that can provide long-term and stable power supply for wearable devices. Since wearable devices need to be installed on the surfaces of various flexible organisms for a long time, there are requirements for the flexibility, stretchability, and weight of the devices. Photovoltaic technology relies on solar power generation, and its sustainability has great advantages among various self-powered technologies. Since traditional silicon solar cells exhibit brittleness and poor mechanical strength and cannot be bent or folded, they cannot meet the wearing requirements. Therefore, it is necessary to develop flexible solar cells.

[0004] Currently, there are two main ideas for flexible photovoltaics: (1) Material innovation: Developing flexible optoelectronic materials for processing and manufacturing, such as perovskite solar cells, organic solar cells, etc. Although such solar cells exhibit good flexibility, there are problems in terms of stability, cost, processing complexity, and material cleaning performance, and it is difficult to achieve practical applications.

[0005] (2) Structural innovation: Improving the stretching and bending properties of traditional rigid structures by combining traditional rigid solar cells with flexible substrates and special mechanical structures such as paper-cutting, origami structures, island-bridge structures, and corrugated structures. This idea is mostly based on traditional silicon-based solar cells, with low cost, high conversion efficiency, and high stability. Very ideal commercial applications have been achieved at present.

[0006] For example, the invention patent with the publication number CN119031810A discloses a flexible stretchable photovoltaic module and a manufacturing method thereof. The component includes a polyimide film flexible substrate and a photovoltaic device. A circuit is processed on the substrate, and at the same time, slits are cut to divide the flexible substrate into specific unit paper-cutting structures, and the devices are connected through the circuit to form an array. The flexible performance of the original rigid battery is optimized by the flexibility of the substrate and the stretchability of the cutting structure. However, the stretching rate of this component is low and the effective working area of the device decreases.

[0007] For another example, a stretchable solar cell array and its manufacturing method are disclosed in the invention patent with the publication number CN118039717A. The components of this assembly from bottom to top are: an elastic substrate (1), an electrospun fiber layer (2), a liquid metal circuit (5), and a solar cell (3). The liquid metal circuit (5) forms a loop and connects the solar cell (3) through the electrospun fiber film unit (21) in the electrospun fiber layer (2). However, the manufacturing materials of this assembly are relatively expensive, the liquid metal circuit has risks of stability and leakage, and the effective working area of the device is relatively low.

[0008] Therefore, more efficient and durable photovoltaic designs are needed to meet the requirements of flexible devices, ensuring the long-term stable operation and service life of the equipment. Summary of the Invention

[0009] The purpose of the present invention is to provide a stretchable flexible woven photovoltaic assembly and its manufacturing method, which can improve the mechanical properties of the flexible photovoltaic array, and significantly enhance the stretching performance and photoelectric conversion efficiency of the flexible photovoltaic array.

[0010] To achieve the purpose of the present invention, the following technical solutions are provided: A stretchable flexible woven photovoltaic array is formed by weaving a plurality of strip-shaped battery units into an array. The strip-shaped battery unit includes a strip-shaped substrate circuit and a plurality of photovoltaic devices. The strip-shaped substrate circuit is an FPCB circuit, which includes a flexible substrate and a conductive layer.

[0011] By means of weaving, the present invention weaves the flexible substrate circuit FPCB and a plurality of photovoltaic devices into an array, solving the technical problem that traditional rigid photovoltaic assemblies are difficult to adapt to dynamic curved surfaces and high-stretching scenarios; and the weaving layout forms a distributed circuit network, which not only improves the energy collection efficiency, but also reduces the impact of local fracture on the overall performance through redundant design, significantly increasing the effective working area of the photovoltaic array.

[0012] Preferably, the strip-shaped battery unit has an island-bridge structure. The island structure is a photovoltaic device pad, and a photovoltaic device is welded above the photovoltaic device pad; the bridge structure is a bistable paper-cut structure formed by cutting the strip-shaped substrate circuit into slits.

[0013] Based on the island-bridge structure, the present invention fixes the photovoltaic device through solder paste on the rigid island-shaped pad, ensuring that the photovoltaic array is protected from stress damage during deformation. The bridge-shaped bistable paper-cut structure formed by cutting endows the substrate with high ductility and rapid deformation recovery ability through a controllable folding or unfolding mechanism; the topological optimization of the bridge-shaped bistable paper-cut structure further disperses the strain and enhances the cyclic durability, providing a reliable and continuous energy supply solution for applications such as wearable devices and flexible robots.

[0014] Preferably, the ratio of the length of the bridge-shaped part to the length of the island-shaped structure is 1.

[0015] The elongation rate of the overall woven circuit is related to the length ratio of the island-shaped structure that does not undergo stretching and the bridge-shaped bistable structure that bears the main tensile deformation. Selecting the above length ratio can ensure that the photovoltaic array is free from stress damage during deformation, endow the substrate with high ductility and rapid deformation recovery ability, significantly improve the mechanical strength of the flexible photovoltaic array and realize the lightweight of the photovoltaic array.

[0016] Preferably, the ratio of the thickness of the deformation end to the thickness of the fixed end of the bistable paper-cut structure is 1.

[0017] By regulating the thickness ratio of the deformation end to the fixed end, multi-dimensional optimization is achieved: the deformation end preferentially undergoes elastic deformation to absorb external strain and disperse stress, while the fixed end remains rigid to stably support the functional unit and avoid device damage; the stiffness gradient formed by the thickness difference can reduce the critical energy barrier of bistable switching, improve the deformation response speed and controllability; at the same time, the optimization of the strain distribution significantly reduces the stress concentration at the joints, delays the crack propagation, and enhances the cyclic durability of the photovoltaic array; in addition, the fixed end adapts to the mechanical stability requirements of the photovoltaic array, and the ultra-thin design of the deformation end is compatible with high elongation rate, balancing protection and stretchability in a limited space, and finally realizing efficient energy transfer and long-term reliable operation under complex curved surfaces or dynamic morphological surfaces.

[0018] Preferably, the ratio of the width to the length of the slit in the bistable paper-cut structure is 0.15.

[0019] The aspect ratio within the above range can guide the strain to be evenly distributed along the serpentine path, avoid local stress concentration, thereby delaying crack propagation and enhancing cyclic durability; at the same time, by extending the bending path of the slit, the bistable paper-cut structure is allowed to achieve ultra-high elongation rate through a controllable folding or unfolding mechanism during stretching while maintaining the stability of bistable switching; in addition, it can also balance the structural stiffness and flexibility, and preferably a larger one is selected within the allowable processing accuracy to obtain higher tensile properties.

[0020] Preferably, the weaving method includes one or more of biaxial weaving and triaxial weaving.

[0021] By selecting the weaving method, a stretchable flexible woven photovoltaic array is formed, which together with the appropriate bridge-island width ratio and island-bridge structure achieves 100% effective working area.

[0022] Preferably, the flexible substrate is a polyimide film flexible substrate.

[0023] Preferably, the photovoltaic device is an IBC solar cell unit, with the front side being the light absorption area and the back side being provided with an integer number of sets of interleaved positive electrode areas and negative electrode areas.

[0024] More preferably, the size of the IBC solar cell unit is smaller than that of the island-shaped structure.

[0025] By pasting a tape mask with a specific shape to control the weldable areas of the electrodes, the weldable areas of the positive and negative electrodes are arranged on both sides and connected to the pads on the substrate circuit; in coordination with the size of the photovoltaic device to ensure that the coverage rate after weaving reaches 100%, significantly increasing the effective working area of the photovoltaic array.

[0026] External pads are led out at both ends of the stretchable strip-shaped battery unit for connection to an external circuit.

[0027] Preferably, external pads are provided at both ends of each strip-shaped battery unit for series and parallel connection of the strip-shaped battery units through welding wires or pluggable interfaces to form a flexible woven photovoltaic array.

[0028] The stretchable strip-shaped battery units are connected in parallel, which can reduce the voltage loss in the overall circuit.

[0029] More preferably, the voltage and current parameters of the stretchable flexible woven photovoltaic array are in a proportional relationship with the number of stretchable strip-shaped battery units and the photovoltaic devices.

[0030] The voltage of each photovoltaic device is U and the current is I. The number of photovoltaic devices in a single stretchable strip-shaped battery unit is n. The current of each stretchable strip-shaped battery unit is I and the voltage is nU. The magnitude of the current I of a single photovoltaic device is positively correlated with the area of the photovoltaic device, and the current of a single photovoltaic device can be adjusted by changing the size of the photovoltaic device. The magnitude of the voltage of a single photovoltaic device is related to the performance parameters of the IBC battery itself used. Therefore, the electrical parameters of the flexible woven photovoltaic array can be adjusted by setting the number of stretchable strip-shaped battery units and the size and number of the photovoltaic devices they carry.

[0031] Preferably, there are specific wire traces in the strip-shaped substrate circuit, and the wire is a copper wire.

[0032] The present invention also provides a preparation method for a programmable stretchable flexible woven photovoltaic array, including the following steps: (1) Drawing the target surface of the stretchable flexible woven photovoltaic array; (2) Determining the weaving array parameters according to the current and voltage parameters, dividing the target surface according to the weaving array parameters to obtain the positions of the island-bridge structures, and connecting the positions of the island-bridge structures into warp and weft lines to obtain different design schemes of the flexible woven photovoltaic array; (3) Based on different design schemes of flexible woven photovoltaic arrays, construct an array mechanical grid model, conduct mechanical model analysis on the model, and optimize the woven array parameters; (4) Provide a flexible substrate, determine the island-bridge structure on the flexible substrate according to the woven array parameters to form strip-shaped battery units, and weave the strip-shaped battery units into a stretchable flexible woven photovoltaic array by means of weaving.

[0033] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention combines the island-bridge structure and the bistable paper-cut structure to form a stretchable strip-shaped battery unit, ensuring that the photovoltaic array is free from stress damage during deformation, and endowing the substrate with high ductility and rapid deformation recovery ability, improving the stretching performance of the circuit while ensuring the circuit stability.

[0034] (2) The parallel connection of photovoltaic devices combines with the woven layout to form a distributed circuit network. The structure is compact, which can ensure 100% coverage. And the photovoltaic devices based on IBC solar cells not only improve the energy collection efficiency, but also reduce the influence of local fracture on the overall performance through redundant design, significantly increasing the photoelectric conversion efficiency of the photovoltaic array.

[0035] (3) The external shape parameters such as the size, shape, and density of the woven structure, as well as the electrical parameters such as the voltage and current of the overall woven circuit, can be programmably parametrically designed by adjusting the external shape parameters of the strip, the number of unit parameters, and the total number of strips, etc., greatly improving the design efficiency of the photovoltaic array. Finally, the designed woven flexible photovoltaic array has excellent stretching performance and bending performance, and can be attached and adapted to a variety of complex surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of the stretchable flexible woven photovoltaic array provided in this embodiment.

[0037] Figure 2 It is a schematic structural diagram of the woven circuit structures of two specifications provided in this embodiment.

[0038] Figure 3 It is a schematic structural diagram of the stretchable FPCB circuit provided in this embodiment.

[0039] Figure 4 It is a stretching schematic diagram of a single stretchable strip-shaped battery unit provided in this embodiment.

[0040] Figure 5 It is a stretching schematic diagram of the bistable paper-cut structure unit provided in this embodiment, where Figure 5 (a) in it is the first stable form of the bistable paper-cut structure unit, Figure 5 (b) in it is the second stable form of the bistable paper-cut structure unit.

[0041] Figure 6 Schematic diagram of relevant structural parameters of the bistable paper-cutting structure provided in this embodiment.

[0042] Figure 7 Stress-strain curve of a single stretchable strip-shaped battery cell under the optimal parameters provided in this embodiment.

[0043] Figure 8 Schematic diagram of the photovoltaic device provided in this embodiment.

[0044] Figure 9 Schematic diagram of the series connection of the stretchable flexible woven photovoltaic array provided in this embodiment.

[0045] Figure 10 Schematic diagram of the stretchable flexible woven photovoltaic array under bending provided in this embodiment.

[0046] Figure 11 Schematic diagram of the stretchable flexible woven photovoltaic array under tension provided in this embodiment.

[0047] Figure 12 Schematic diagram of the stretchable flexible woven photovoltaic array under bending and tension provided in this embodiment.

[0048] Figure 13 Schematic diagram of the programmable target surface structure provided in this embodiment.

[0049] Figure 14 Schematic diagram of the programmable design topological structure provided in this embodiment, where Figure 14 (a) in it is a 4×5 woven array of programming design, Figure 14 (b) in it is a 7×9 woven array of programming design.

[0050] Figure 15 Schematic diagram of the programmable design mechanical optimization provided in this embodiment.

[0051] Figure 16 Schematic diagram of the result of the finally optimized mechanical model provided in this embodiment.

[0052] In the figure, 1 and 2 are stretchable strip-shaped substrate circuits; 11 are photovoltaic devices; 111 is the non-electrode region of the IBC cell; 112 is the negative electrode region of the IBC cell; 113 is the positive electrode region of the IBC cell; 114 is a polyimide tape mask; 12 is an FPCB circuit; 121 is an external pad; 122 is an island structure; 123 is a bistable paper-cut structure; 1231 is a bistable paper-cut slit unit; 124 is a photovoltaic device pad; 2 and 3 are stretchable strip-shaped substrate circuits; 3 is a series external circuit; 4 is an array mechanical grid model; 41 is an initial boundary; 42 is a target boundary; 43 is an internal grid point; 44 is an internal grid edge. Detailed implementation manners

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Usually, the components of the embodiments of the present invention described and shown in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but only represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0054] As Figure 1 shown, it is a schematic diagram of a 5×5 stretchable flexible woven photovoltaic array provided in this embodiment, including 5 strips of 2-unit strip-shaped stretchable woven circuits (1) and 5 strips of 3-unit strip-shaped stretchable woven circuits (2).

[0055] As Figure 2 shown, it is a schematic diagram of two specifications of woven structures in this example. Each woven circuit includes an FPCB circuit (12) and a photovoltaic device (11) welded thereto.

[0056] As Figure 3 shown, it is a schematic diagram of the structure of the FPCB circuit in this example. The overall circuit outline is in an island-bridge structure. Among them, the island structure part bears the photovoltaic device (11), and a photovoltaic device pad (124) is provided for soldering with solder paste. The bridge part cuts the overall circuit outer frame into slits of a specific shape to form a bistable paper-cut structure (123), and the internal circuit is designed into a special snake-shaped structure along the shape of the slits.

[0057] As Figure 4As shown, it is a stretching schematic diagram of a single woven circuit in this example. During the stretching process of the overall woven photovoltaic array, the bistable paper-cutting structure (123) in the bridge structure part deforms and opens, while the island structure part (122) basically does not deform. Therefore, the overall woven circuit realizes large-range stretching through the bistable paper-cutting structure, and at the same time, the island structure part carrying the photovoltaic device basically does not deform, ensuring that the photovoltaic device (11) carried will not be damaged due to deformation stress during the stretching process.

[0058] In this example, the stretching rate of the overall woven photovoltaic array circuit is related to the length ratio of the island structure without stretching and the bridge-type bistable structure carrying the main stretching deformation. The length of the bridge is , and the length of the island is . The definition of the bridge-island ratio is: .

[0059] As Figure 5 shown is the stretching schematic diagram of the bistable paper-cutting structure unit (123). Figure 5 (a) is its first stable form, Figure 5 (b) is its second stable form. The stretching process of the bistable paper-cutting structure mainly occurs when the bistable paper-cutting gap unit (1231) deforms under the axial tensile force F, and the gap opens and the two gap edges parallel transform into an approximately symmetric shape of the two gaps. During the whole process, the overall shape transitions from the first stable state to the second stable state and finally reaches the second stable state to achieve large-deformation stretching.

[0060] As Figure 6 shown is the schematic diagram of the relevant structure parameters of the bistable paper-cutting structure in this example. The thickness of the deformation end (1232) of the bistable paper-cutting gap unit is , and the thickness of the fixed end (1233) of the bistable paper-cutting gap unit is . The definition of the thickness ratio is: .

[0061] The length of the bistable paper-cutting gap unit (1231) is , and the width of the bistable paper-cutting unit (123) is . The definition of the width-length ratio is: .

[0062] The stretching rate of the woven photovoltaic array circuit is related to these three parameters: the bridge-island ratio, the thickness ratio, and the width-length ratio. The stretching rate increases with the increase of , and the stretching increase rate decreases with the increase of . It is preferred that is an island-bridge structure of 1. At this time, the stretching increase rate is the largest, and the maximum stretching benefit can be obtained to realize the lightweight of the photovoltaic device. The stretching rate of the woven photovoltaic array circuit increases with decreases with the increase of , and higher tensile properties can be obtained. The tensile rate of the woven photovoltaic array circuit increases with the increase of , and under the condition that the processing accuracy permits, a larger can obtain higher tensile properties.

[0063] The processing accuracy in this example is 0.03 mm. From the Figure 7 results, it can be seen that in the actual test of this example, a polyimide film with a thickness of 75 μm is used, is 1, is 1, is 0.15, the stress-strain curve of the woven circuit is measured, and the maximum tensile rate can reach more than 100%.

[0064] As Figure 8 shown, the photovoltaic device (11) used in this example. This device is based on a specific cell of an IBC solar cell. The front side of this cell is a light absorption surface, and the back side is a non-electrode region (111), a negative electrode region (112), and a positive electrode region (113) arranged in sequence. By pasting a polyimide tape mask (112) with a specific shape to control the weldable area of the electrodes, the weldable areas of the positive and negative electrodes are arranged on both sides and connected to the pads on the circuit. The size of the battery is preferably equal to the size of the island part (122) to ensure that the coverage rate after weaving can reach 100%. Other types of batteries that can ensure the size and single-sided connection of the electrodes can be used, such as gallium arsenide batteries. All photovoltaic device units are connected in parallel in a single stretchable strip-shaped cell unit ( Figure 3 ), and pads (121) are led out at both ends for connection to an external circuit, which can reduce the voltage loss of the overall circuit.

[0065] In this example, the overall photovoltaic array is woven by the most classic "one-up-one-down" biaxial weaving method in warp and weft weaving. The island structure part (122) carrying the photovoltaic device is placed on the bridge structure part (123), and an overall stretchable flexible woven photovoltaic array is formed. When ensuring that the bridge-island length ratio is 1 and the length and width of the island unit are the same, an effective working area of 100% can be achieved, significantly improving the photoelectric conversion efficiency.

[0066] In addition, the voltage of each photovoltaic device is U, the current is I, the number of photovoltaic devices in a single stretchable strip-shaped battery unit is n, the current of each stretchable strip-shaped battery unit is I, and the voltage is nU. The magnitude of the current I of a single photovoltaic device is positively correlated with the area of the photovoltaic device, and the current of a single photovoltaic device can be adjusted by changing the size of the photovoltaic device. The magnitude of the voltage of a single photovoltaic device is related to the performance parameters of the IBC battery itself used. Therefore, the electrical parameters of the flexible woven photovoltaic array can be adjusted by setting the number of stretchable strip-shaped battery units and the size and number of the photovoltaic devices they carry.

[0067] In this example, the size of the battery unit used is 4.85 mm × 4.85 mm, the voltage is 0.6 V, and the current is 90 mA. The voltage of the 2-unit woven circuit is 0.6 V, and the current is 180 mA; the voltage of the 3-unit woven circuit is 0.6 V, and the current is 360 mA. As Figure 9 shown, all the stretchable strip-shaped battery unit woven strips are connected in series, and the voltage of the obtained woven photovoltaic array is 6 V, and the current is 180 mA. Specifically, as Figure 9 shown, since there are lead-out endpoints (121) at both ends of each woven strip, two identical circuits (3) can be obtained at this time. When a part of the woven circuit fails, the spare circuit trace can work, and the stability performance of the woven photovoltaic array has great advantages. The woven photovoltaic array has good flexibility and stretchability. As Figure 10 、 Figure 11 and Figure 12 shown are schematic diagrams of the circuit under bending, stretching, and combined deformation.

[0068] The present invention also provides a preparation method of a programmable stretchable flexible woven photovoltaic array. As Figure 13 - Figure 15 shown, the present invention can achieve the programmability of the circuit topology through the warp and weft weaving process. On complex curved surfaces or dynamically deformed surfaces, the geometric shape and mechanical requirements of the target surface can be dynamically adapted by adjusting the spatial arrangement density of the woven strips and the node connection method. Through the grasshopper plug-in in the rhino software, the topological analysis and design of the curved surface can be realized to obtain different schemes, and then the kangaroo software is used to evaluate and optimize different schemes to obtain the optimal weaving scheme. By providing a flexible substrate, the island-bridge structure and the bistable paper-cut structure are determined on the flexible substrate according to the weaving array parameters to form stretchable strip-shaped battery units, and the stretchable strip-shaped battery units are woven into a stretchable flexible woven photovoltaic array by weaving.

[0069] Specifically, as Figure 13As shown in the figure, draw the target surface in Rhino, determine the corresponding weaving array parameters n×m according to the required circuit current and voltage parameters, divide the target surface according to the parameters of n×m to obtain the positions of the island-bridge structures of the weaving array, and connect the nodes into warp and weft lines to obtain the target weaving array. As Figure 14 Figure (a) shows a 4×5 weaving array. As Figure 14 Figure (b) shows a 7×9 weaving array. Taking the peripheral series circuit as an example, the voltage of the component in Figure 14(a) is 5.4 V and the current is 360 mA; the voltage of the component in Figure 14(b) is 9.6 V and the current is 630 mA. When n and m are not equal, the voltages and currents of the warp and weft weaving strips are not equal. Due to the characteristic of taking the smaller value for the parallel voltage and the series current, there are design losses in the circuit. Therefore, the parameter form of n×n is preferred.

[0070] Next, as Figure 15 shown in the figure, it is a schematic diagram of the array mechanical mesh model (4) established in Kangaroo. Among them, the internal grid points (43) represent the island part (122), and the internal grid edges (44) represent the bridge part (123). In this example, the stress situation of an 8×8 weaving array attached to a hemispherical plane with a diameter of 45 mm is simulated. Among them, the external rectangular frame (41) is the initial boundary of the weaving circuit, and the circle (42) inscribed in the rectangular outer frame is the circuit boundary after attachment. Apply edge constraints, linear damping constraints on the grid edges, and tension during the attachment process to this model. The ratio of the edge damping of the grid lines to the applied tension constraint should be consistent with the elastic modulus of the material and the ratio of the maximum tensile force to ensure the reliability of the mechanical model prediction. As Figure 16 shown in the figure, it is the result of the finally optimized mechanical model. According to the form of the mechanical model, change the damping of different grid lines so that the overall surface presents a smoother shape, and the deformation amount is consistent with the actual numerical value of the structure. Based on the optimized weaving array parameters, design a stretchable flexible weaving photovoltaic array.

[0071] In addition, the terms "upper", "lower", "inner", "outer", "front", and "rear" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Unless otherwise specifically stated, the relative steps, numerical expressions, and values of the components and steps described in these embodiments do not limit the scope of the present invention.

[0072] Of course, the above are only specific embodiments of the present invention and do not limit the scope of implementation of the present invention. Any equivalent changes or modifications made according to the structures, features, and principles described in the scope of the patent application of the present invention should be included in the scope of the patent application of the present invention.

[0073] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present invention, used to illustrate the technical solutions of the present invention, rather than limiting it. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the technical field of the present invention can still modify the technical solutions described in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims described.

Claims

1. A stretchable flexible woven photovoltaic array, characterized in that, An array is formed by weaving a number of strip-shaped battery units; The strip-shaped battery unit includes a strip-shaped base circuit and a number of photovoltaic devices. The strip-shaped base circuit is an FPCB circuit, including a flexible base and a conductive layer.

2. The flexible woven photovoltaic array according to claim 1, wherein The strip-shaped battery unit is an island-bridge structure. The island structure is a photovoltaic device pad, and a photovoltaic device is welded on the upper part of the photovoltaic device pad; the bridge structure is a bistable paper-cut structure formed by cutting the strip-shaped base circuit into slits.

3. The flexible woven photovoltaic array according to claim 1, wherein The weaving method includes one or more of biaxial weaving and triaxial weaving.

4. The flexible woven photovoltaic array according to claim 1, wherein, The flexible base is a polyimide film flexible base.

5. The flexible woven photovoltaic array according to claim 1, wherein, The photovoltaic devices are connected in parallel to the strip-shaped base circuit through the photovoltaic device pads.

6. The flexible woven photovoltaic array according to claim 5, wherein The photovoltaic device is an IBC solar cell unit, with a light absorption area on the front and an integer group of alternately arranged positive electrode areas and negative electrode areas on the back.

7. The flexible woven photovoltaic array according to claim 6, wherein, The size of the IBC solar cell unit is smaller than that of the island structure.

8. The flexible woven photovoltaic array according to claim 1, wherein External pads are provided at both ends of each strip-shaped battery unit for the strip-shaped battery units to be connected in series and parallel through welding wires or pluggable interfaces to form a flexible woven photovoltaic array.

9. The flexible woven photovoltaic array according to claim 8, wherein The voltage and current parameters of the flexible woven photovoltaic array are in a proportional relationship with the number of strip-shaped battery units and the photovoltaic devices.

10. A preparation method of a programmable stretchable flexible woven photovoltaic array, characterized in that, It includes the following steps: (1) Draw the target surface of the stretchable flexible woven photovoltaic array; (2) Determine the weaving array parameters according to the current and voltage parameters, divide the target surface according to the weaving array parameters to obtain the positions of the island-bridge structures, and connect the positions of the island-bridge structures into warp and weft to obtain different design schemes of the flexible woven photovoltaic array; (3) Based on different design schemes of the flexible woven photovoltaic array, construct an array mechanical grid model to analyze the mechanical model of the model and optimize the weaving array parameters; (4) Provide a flexible base, determine the island-bridge structures on the flexible base according to the weaving array parameters to form strip-shaped battery units, and weave the strip-shaped battery units into a stretchable flexible woven photovoltaic array by weaving.

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