Photovoltaic-geomembrane with integrated composite structure and method of making same

Abstract

The application provides a photovoltaic-geotechnical membrane with an integrated composite structure and a preparation method thereof, relates to the technical field of building integrated photovoltaics, and comprises, from bottom to top, a base impermeable membrane layer, a bonding functional layer, an integrated photovoltaic power generation layer, a transparent packaging protective layer and a weather-resistant protective layer; the integrated photovoltaic power generation layer forms a whole without an independent interface with the base impermeable membrane layer through the bonding functional layer; the integrated photovoltaic power generation layer is a flexible thin-film solar cell roll with a surface activation treatment and a monolithic integrated structure, and the monolithic integrated structure comprises at least two lead-out electrodes. The photovoltaic-geotechnical membrane provided by the application realizes fusion from the material interface and the manufacturing process source, eliminates the delamination risk caused by physical lamination, has good flexibility of the composite structure, can adapt to the deformation of a hydraulic building foundation, and has high insulation and waterproof grades.

Description

Technical Field

[0001] This invention relates to the field of building-integrated photovoltaic (BIPV) materials technology, and in particular to a photovoltaic-geomembrane with an integrated composite structure and its preparation method. Background Technology

[0002] Currently, surface photovoltaic (PV) and reservoir PV projects typically employ a floating structure combined with traditional PV modules, or install PV supports separately on the dam slope. These methods present several challenges, including occupying dedicated space, impacting the project's aesthetics and operational maintenance, requiring high resistance to wind and waves, and being disconnected from the main functions of the water conservancy project.

[0003] On the other hand, geomembranes are widely used seepage-proof materials in water conservancy projects. Current technologies often use silicone structural adhesives, polyurethane sealants, butyl tape, or acrylic double-sided adhesives to physically adhere standard photovoltaic panels to the geomembrane surface, but these methods have the following fundamental drawbacks: 1. Risk of interface failure: The thermal expansion coefficients and mechanical properties of the two materials are mismatched, which can easily lead to delamination and debonding under temperature changes and water pressure, thus damaging the overall seepage prevention.

[0004] 2. Poor electrical safety and reliability: Waterproof sealing of connecting cables and connectors is difficult, and leakage, short circuits, and insulation failure are prone to occur in long-term immersion in water or humid environments.

[0005] 3. Poor durability: The stacked structure is bulky and lacks flexibility, making it difficult to adapt to foundation deformation; the multi-layer interface becomes a channel for water vapor and corrosive media to penetrate, accelerating aging.

[0006] 4. Simple physical superposition is prone to failure: It only forms macroscopic mechanical interlocking or weak van der Waals force bonding, without chemical bonding, and is extremely prone to failure under humid heat cycling.

[0007] Therefore, there is an urgent need for a design that truly integrates physical and electrical performance, making it both a high-performance waterproofing material and a reliable photovoltaic film for power generation. Summary of the Invention

[0008] The purpose of this invention is to provide a photovoltaic-geomembrane with an integrated composite structure and its preparation method. By using an adhesive functional layer, the integrated photovoltaic power generation layer and the base impermeable membrane layer are fused into a whole without independent interfaces, eliminating the risk of delamination caused by physical layering. The composite structure has good flexibility and can adapt to the deformation of hydraulic engineering foundations. Electrical connections are embedded, and it has high insulation and waterproofing levels.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a photovoltaic-geomembrane with an integrated composite structure, which, from bottom to top, comprises a base impermeable membrane layer, an adhesive functional layer, an integrated photovoltaic power generation layer, a transparent encapsulation protective layer, and a weather-resistant protective layer; The integrated photovoltaic power generation layer forms a whole without independent interfaces with the base waterproof membrane layer through the adhesive functional layer; The integrated photovoltaic power generation layer is a flexible thin-film solar cell roll with a monolithic integrated structure, which has undergone surface activation treatment on the free surface of a flexible substrate. The monolithic integrated structure includes at least two lead-out electrodes, each including a positive lead-out electrode and a negative lead-out electrode located at both ends of the flexible thin-film solar cell roll in the width direction. The positive lead-out electrode is an exposed TCO located at one end of the flexible thin-film solar cell roll in the width direction, and the negative lead-out electrode is an exposed back electrode located at the other end of the flexible thin-film solar cell roll in the width direction.

[0010] Furthermore, based on the above technical solution, the monolithic integrated structure refers to the following: the internal solar cells and interconnecting circuits of the integrated photovoltaic power generation layer are integrated during thin film deposition by means of P1-P3 laser scribing, forming an inseparable monolithic integrated structure in which the solar cells and interconnecting circuits are connected end to end and buried in the flexible thin film solar cell.

[0011] Furthermore, based on the above technical solution, a first external wire and a second external wire are respectively provided on both sides of the width direction of the integrated photovoltaic power generation layer. One end of the first external wire is electrically connected to the positive electrode by means of conductive adhesive bonding, and the other end is electrically connected to the first waterproof connector. One end of the second external wire is electrically connected to the negative electrode by means of conductive adhesive, and the other end is electrically connected to the second waterproof connector; The surface of the lead-out electrode facing away from the flexible substrate is a flat adhesive surface, and the first external wire and the second external wire are both bonded to this flat adhesive surface with conductive adhesive.

[0012] Furthermore, based on the above technical solution, the flexible thin-film solar cell roll is selected from amorphous silicon, copper indium gallium selenide, or perovskite thin-film solar cells; And / or, the flexible substrate material includes stainless steel foil or polyimide (PI); And / or, the surface activation treatment is corona treatment or plasma treatment; And / or, the thickness of the integrated photovoltaic power generation layer is 0.05-0.30 mm; And / or, the elastic modulus of the integrated photovoltaic power generation layer is 104-105 MPa.

[0013] Furthermore, based on the above technical solution, the base geomembrane layer is a toughened PVC membrane or a flexible TPO membrane; And / or, the elastic modulus of the base geomembrane layer is 10. 2 -10 3 MPa, elongation at break ≥250%; And / or, the thickness of the base geomembrane layer is 0.5-2.0 mm; And / or, the adhesive functional layer is a functional coating applied or hot-pressed onto the upper surface of the base geomembrane layer, and the material is a two-component polyurethane adhesive modified with a silane coupling agent. The modification method for two-component polyurethane adhesives modified with silane coupling agents includes the following steps: The silane coupling agent is premixed with the polyol, and then stirred for 25-35 min at 55-65℃ and vacuum -0.1~-0.05 MPa to allow the silane to alcoholyze and disperse evenly. After further cooling to 40℃, isocyanate is added, and the mixture is stirred at 50-80℃ for 5-8 h to obtain a two-component polyurethane adhesive modified with the silane coupling agent. The silane coupling agent is KH-550; Polyols include one or more of polyether diols, polyether triols, polyethylene adipate diol, and polycaprolactone diol; Isocyanates include one or more of diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, and toluene diisocyanate; The amount of silane coupling agent added is 1.0-2.0 wt% of the total mass of the two-component polyurethane adhesive modified with the pre-set silane coupling agent. The amount of isocyanate group in isocyanate is 1.1 to 1.3 times the amount of hydroxyl group in polyol; And / or, the elastic modulus of the adhesive functional layer is 500-2000 MPa.

[0014] Furthermore, based on the above technical solution, the material of the transparent encapsulation protective layer is fluorinated ethylene propylene copolymer or polyolefin elastomer; The transparent encapsulation protective layer formed by fluorinated ethylene propylene copolymer has a thickness of 50-127 μm and a light transmittance of ≥91%. The thickness of the transparent encapsulation protective layer formed by polyolefin elastomer is 300-500 μm, and the light transmittance is ≥90%. And / or, the weather-resistant protective layer is selected from fluorocarbon coatings containing benzotriazole ultraviolet absorbers, nano-silica-organosilicon hybrid coatings, or modified acrylic coatings containing triazine ultraviolet absorbers. And / or, the thickness of the weather-resistant protective layer is 5-20 μm.

[0015] The present invention also provides a method for preparing a photovoltaic-geomembrane with an integrated composite structure as described above, characterized by comprising the following steps: S1: The polymer is melted and extruded, and after shaping, a base geomembrane layer is obtained; S2: Unroll and preheat the base geomembrane layer, then apply adhesive to the base geomembrane layer to obtain an incompletely cured adhesive functional layer; S3: P4 laser scribing is performed on both sides of the edge region of the flexible thin-film solar cell roll in the width direction to form lead-out electrodes. On one side edge region, the back electrode above the flexible substrate is exposed to form a negative lead-out electrode, and on the other side edge region, the TCO above the flexible substrate is exposed to form a positive lead-out electrode. Then, the free surface of the flexible substrate and the bonding surface of the lead-out electrodes are respectively subjected to surface activation treatment. The free surface of the flexible substrate of the flexible thin-film solar cell roll is pressed onto the adhesive functional layer under tension control. After hot rolling composite, the adhesive functional layer is completely cured and combined with the flexible thin-film solar cell roll to obtain a composite integrated photovoltaic power generation layer film. S4: The transparent encapsulation protective layer is pressed onto the integrated photovoltaic power generation layer by a hot roller, and then a weather-resistant coating is applied to the surface of the transparent encapsulation protective layer. After curing, a weather-resistant protective layer is obtained. S5: The positive electrode is bonded to one end of the first external wire with conductive adhesive, and the negative electrode is bonded to one end of the second external wire with conductive adhesive to obtain a photovoltaic-geomembrane with an integrated composite structure. S6: Rewind to obtain a photovoltaic-geomembrane roll product with an integrated composite structure.

[0016] Furthermore, based on the above technical solution, in step S1, melt extrusion is carried out using a single screw extruder with a die temperature of 185-195℃; after three-roll calendering and cooling, a base geomembrane layer with a thickness of 0.5-2.0mm is formed and then wound up for later use. And / or, in step S2, the temperature for unwinding and preheating the base geomembrane layer is 60-80℃; And / or, in step S2, the thickness of the incompletely cured adhesive functional layer is 80-120 μm; And / or, step S5 further includes electrically connecting the other end of the first external wire to the first waterproof connector; and electrically connecting the other end of the second external wire to the second waterproof connector.

[0017] Furthermore, based on the above technical solution, in step S3, tension control includes: unwinding tension of 20-50N, lamination section tension of 30-80N, and rewinding tension of 40-60N. And / or, in step S3, the temperature of the hot roller is 120-150℃, the pressure is 0.15-0.25Mpa, and the linear speed is 0.8-1.5m / min; And / or, in step S3, the surface activation treatment is corona treatment or plasma treatment; wherein, Corona treatment includes: output power 2-10kW, output frequency 15-30kHz, electrode voltage 5-15kV, and treatment speed 1-20m / min; Plasma treatment includes: vacuum degree 10-100Pa, radio frequency power 100-500W, treatment gas is O2 and / or Ar and / or N2, gas flow rate 50-200sccm, and treatment time 30-180s; And / or, in step S3, the P4 laser scribing is performed using a picosecond laser with a wavelength of 1000-1100nm; And / or, in step S4, the material of the transparent encapsulation protective layer includes a polyolefin elastomer or a fluorinated ethylene propylene copolymer; The hot roller composite temperature of the polyolefin elastomer is 145-155℃, the pressure is 0.15-0.25MPa, the linear speed is 1.5-3m / min, and the cooling roller is used for rapid cooling and shaping. The hot roller bonding temperature of fluorinated ethylene propylene copolymer is 255-265℃, the pressure is 0.1-0.15MPa, and it is slowly cooled to below 50℃ for cooling and shaping. And / or, in step S4, the weather-resistant coating is selected from fluorocarbon coatings containing benzotriazole UV absorbers, nano-silica-organosilicon hybrid coatings, or modified acrylic coatings containing triazine UV absorbers. And / or, in step S4, a weather-resistant coating is applied to the surface of the transparent encapsulation protective layer using a micro-gravure coating or spraying process, and then UV-cured or heat-cured to form a weather-resistant protective layer. And / or, the width of photovoltaic-geomembrane products with integrated composite structures is 2-3m.

[0018] The present invention also provides a method for combining a photovoltaic-geomembrane with an integrated composite structure prepared by the method described above or the method described above, comprising the following steps: At least two photovoltaic-geomembrane panels are laid together: when two adjacent photovoltaic-geomembrane panels are laid together, the first waterproof connector of one photovoltaic-geomembrane panel is plugged into the second waterproof connector of the other photovoltaic-geomembrane panel to achieve electrical series connection between adjacent photovoltaic-geomembrane panels. In this system, the positive terminal of each photovoltaic-geomembrane is output to the outside through the first waterproof connector, and the negative terminal is output to the outside through the second waterproof connector. During installation, the positive and negative terminals of two adjacent photovoltaic-geomembranes are connected end to end in sequence to achieve electrical connection.

[0019] The photovoltaic-geomembrane with an integrated composite structure and its preparation method provided by this invention have at least the following beneficial effects: 1. The photovoltaic-geomembrane with an integrated composite structure provided by the present invention achieves fusion from the material interface and manufacturing process source, eliminating the risk of delamination caused by physical layering. The composite structure has good flexibility and can adapt to the deformation of hydraulic structure foundations. The electrical connection is embedded, and the insulation and waterproofing levels are high.

[0020] 2. The lead-out electrode and the embedded interconnect circuit are integrally formed from the same material, rather than being separate metal components. There is no heterogeneous material interface between the lead-out electrode and the embedded interconnect circuit, which fundamentally eliminates the stress concentration problem caused by excessive differences in material properties. Moreover, the bonding surface of the lead-out electrode is a flat thin film surface, and the conductive adhesive can be evenly coated, resulting in lower and more uniform contact resistance. In addition, since there are no heterogeneous interface gaps like those of traditional solder strips, moisture cannot penetrate along the interface capillary, laying a structural foundation for the long-term waterproof sealing and bending durability of the lead-out end.

[0021] 3. Synergistic Functions and Matched Lifespan: The materials of each layer are selected and adapted to ensure that the weather resistance, hydrolysis resistance, and UV resistance are coordinated, resulting in a consistent overall lifespan and avoiding the "weakest link" effect.

[0022] 4. Multiple benefits combined: While achieving the core function of seepage prevention in water conservancy projects, it does not require additional land for power generation, is installed on the dam surface without obstructing the water body, and does not affect the ecological environment of the reservoir, resulting in significant comprehensive benefits. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in 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 the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 A schematic diagram of a photovoltaic-geomembrane with an integrated composite structure provided by the present invention; Figure 2 This is a structural schematic diagram of the connection method between two adjacent photovoltaic-geomembrane panels provided by the present invention; legend: 1. Base layer impermeable membrane; 2. Adhesive functional layer; 3. Integrated photovoltaic power generation layer; 3a. Battery cell; 3b. Interconnection circuit; 4. Transparent encapsulation protective layer; 5. Weather-resistant protective layer; 6. Lead-out electrode; 7. First waterproof connector; 8. Second waterproof connector; 9. First external wire; 10. Second external wire. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. 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. Process parameters not specifically specified in the following embodiments are generally performed under conventional conditions.

[0026] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0027] According to a first aspect of the invention, such as Figure 1 As shown, a photovoltaic-geomembrane with an integrated composite structure is provided, which includes, from bottom to top, a base impermeable membrane layer 1, an adhesive functional layer 2, an integrated photovoltaic power generation layer 3, a transparent encapsulation protective layer 4, and a weather-resistant protective layer 5; The integrated photovoltaic power generation layer 3 forms a whole without independent interfaces with the base waterproof membrane layer 1 through the adhesive functional layer 2; The integrated photovoltaic power generation layer 3 is a flexible thin-film solar cell roll with a monolithic integrated structure, formed by surface activation treatment of the free surface of a flexible substrate.

[0028] Specifically, "no independent interface" means that during the curing process, the adhesive functional layer 2 fuses the integrated photovoltaic power generation layer 3 and the base waterproof membrane layer 1 into one unit, with no clear boundary between the three layers. The free surface of the flexible substrate refers to the side that is in contact with the adhesive functional layer 2.

[0029] Specifically, the dyne value (tested with a dyne pen) of the free surface of the flexible substrate of flexible thin-film solar cell roll is usually only 30-35 mN / m. After surface activation treatment, polar groups such as hydroxyl and carbonyl groups can be introduced into the surface, which can increase the dyne value to ≥48 mN / m or the roughness Ra to ≥0.5μm, significantly improving the wettability and chemical bonding density with the adhesive functional layer, and the peel strength can be increased from <3 N / cm to >6 N / cm.

[0030] As an optional embodiment of the present invention, the flexible thin-film solar cell roll is selected from amorphous silicon (a-Si), copper indium gallium selenide (CIGS) or perovskite thin-film solar cells; after the free surface of the flexible substrate of the flexible thin-film solar cell roll is surface activated, it is directly thermally composited with the base waterproof membrane layer 1 by hot pressing through the adhesive functional layer 2 to form an integral whole without independent interfaces. The flexible substrate is made of materials including stainless steel foil or polyimide (PI). Surface activation treatment can be either corona treatment or plasma treatment; The thickness of the integrated photovoltaic power generation layer is 0.05-0.30 mm; The elastic modulus of the integrated photovoltaic power generation layer is 104-105 MPa.

[0031] As an optional embodiment of the present invention, such as Figure 1 As shown, the monolithic integrated structure refers to the following: the battery cell 3a and the interconnecting circuit 3b inside the integrated photovoltaic power generation layer 3 are integrated during thin film deposition by laser scribing with P1-P3, forming an inseparable monolithic integrated structure in which the battery cell 3a and the interconnecting circuit 3b are connected end to end and buried in the flexible thin film solar cell.

[0032] Furthermore, P1-P3 laser scribing refers to the most crucial process in the manufacturing of thin-film solar cells. It uses a laser to scribble three grooves on the cell, replacing the welding and metal wires of traditional crystalline silicon cells, and directly forming a series circuit on the substrate.

[0033] The flexible thin-film solar cell rolls used in this invention have all undergone P1-P3 laser scribing.

[0034] Specifically, this invention employs a monolithic integrated structure formed by P1-P3 laser scribing, connecting the battery cell and the interconnect circuit end-to-end, to replace the rigid solder strip connection scheme in traditional photovoltaic modules. Compared to traditional solder strips, this invention fundamentally eliminates the stress concentration phenomenon at the solder joint caused by the rigid metal conductor (welding material) and the flexible polymer substrate during bending. At the same time, since the interconnect circuit is completely embedded, the differentiation channel for moisture to penetrate into the battery along the traditional solder strip is completely cut off, significantly improving the bending reliability and long-term weather resistance of the photovoltaic power generation layer, and achieving a synergistic improvement in flexibility and waterproofness.

[0035] As one embodiment of the present invention, such as Figure 1 As shown, the monolithic integrated structure also includes at least two lead-out electrodes 6. The lead-out electrodes 6 include a positive lead-out electrode and a negative lead-out electrode located at the two end edges of the flexible thin-film solar cell roll in the width direction. The positive lead-out electrode is an exposed TCO located at one end edge of the flexible thin-film solar cell roll in the width direction, and the negative lead-out electrode is an exposed back electrode located at the other end edge of the flexible thin-film solar cell roll in the width direction.

[0036] Specifically, the lead-out electrode 6 is obtained by the following method: P4 laser scribing is performed on both edge regions of the flexible thin-film solar cell roll in the width direction, wherein the back electrode above the flexible substrate is exposed on one edge region to form a negative lead-out electrode, and the TCO above the flexible substrate is exposed on the other edge region to form a positive lead-out electrode. The P4 laser scribing can be performed using a picosecond laser, for example, with a laser wavelength of 1000-1100nm, preferably 1064nm.

[0037] Furthermore, there are no specific limitations on the size and shape of the lead-out electrodes, as long as they can be connected to external wires.

[0038] The integrated photovoltaic power generation layer 3 has at least one external wire on each side of its width direction (each lead-out electrode 6 corresponds to one external wire): a first external wire 9 and a second external wire 10. One end of the first external wire 9 is electrically connected to the positive lead-out electrode by means of conductive adhesive, and the other end is electrically connected to the first waterproof connector 7. One end of the second external wire 10 is electrically connected to the negative electrode by means of conductive adhesive, and the other end is electrically connected to the second waterproof connector 8.

[0039] In one embodiment of the present invention, the surface of the lead electrode 6 facing away from the flexible substrate is a flat bonding surface, and the first external wire and the second external wire are both bonded to the flat bonding surface by conductive adhesive.

[0040] Specifically, since the lead-out electrode is integrally formed with the flexible substrate and the thin-film embedded interconnect circuit, and the thin-film structure of the lead-out electrode can also buffer the stress generated when the external wire is bent, the problem of film peeling and stress concentration caused by directly connecting the rigid solder strip to the fragile scribing terminal is avoided.

[0041] Furthermore, during the surface activation treatment of the free surface of the flexible substrate, the bonding surface of the lead-out electrode is also simultaneously activated. This introduces polar functional groups such as hydroxyl and carboxyl groups into the bonding surface of the lead-out electrode, transforming the conductive adhesive coated on the lead-out electrode from simple physical curing to chemical bonding and anchoring. This significantly improves the peel strength between the conductive adhesive and the lead-out electrode, ensuring the long-term stability of the contact resistance of the lead-out end under repeated bending. Moreover, the high surface energy after activation greatly improves the wettability and spreadability of the conductive adhesive on the surface of the lead-out electrode, increasing the actual conductive contact area. More importantly, the surface-activated lead-out electrode surface and the conductive adhesive form a dense, gapless interface, which can construct a terminal waterproof barrier in the lead-out electrode area, completely blocking the capillary penetration path of water vapor along the conductive medium-polymer interface.

[0042] In one optional embodiment of the present invention, the base geomembrane layer is composed of common polymer geomembranes such as toughened PVC membrane or flexible TPO (thermoplastic polyolefin synthetic resin) membrane, with an elastic modulus of 10. 2 -10 3 MPa; as the structural foundation and main seepage barrier, the thickness is preferably 0.5-2.0mm (e.g. 0.7mm, 1mm, 1.3mm, 1.5mm, 1.7mm, etc.), and the elongation at break is ≥250% to accommodate foundation deformation.

[0043] As an optional embodiment of the present invention, the adhesive functional layer is a functional coating applied to the upper surface of the base geomembrane layer by coating or hot pressing, and the material is a two-component polyurethane adhesive modified with a silane coupling agent. The modification method for two-component polyurethane adhesives modified with silane coupling agents includes the following steps: The silane coupling agent (such as KH-550 or KH-792) is premixed with polyols (such as polyether diol (N220), polyether triol (N303), polyethylene adipate diol (PEA), polycaprolactone diol (PCL) etc.); then stirred for 25-35 min at 55-65℃ and vacuum -0.1~-0.05 MPa to allow the silane to alcoholyze and disperse evenly; after further cooling to 40℃, isocyanate (such as MDI (diphenylmethane diisocyanate), PAPI (polymethylene polyphenyl polyisocyanate), TDI (toluene diisocyanate) etc.) is added, and mixed at 50-80℃ for 5-8 h to obtain a two-component polyurethane adhesive modified with the silane coupling agent.

[0044] Specifically, the silane coupling agent can react with isocyanate groups (-NCO) to form urea bonds (-NH-CO-NH-), which are embedded in the polyurethane network; the silane end hydrolyzes in the presence of moisture to form silanol (Si-OH). The two-component polyurethane adhesive modified with the silane coupling agent can significantly improve the bonding strength of the base geomembrane layer and the integrated photovoltaic power generation layer to more than 40%.

[0045] The amount of silane coupling agent added is 1.0-2.0 wt% of the total mass of the two-component polyurethane adhesive modified with the pre-set silane coupling agent. The amount of isocyanate group in isocyanate is 1.1 to 1.3 times the amount of hydroxyl group in polyol.

[0046] Specifically, the adhesive functional layer, after curing, possesses the following characteristics: High hardness: Shore A hardness of 60-80 after curing; High adhesion: It is chemically compatible with the upper photovoltaic layer material and has strong adhesion, with a peel strength ≥5N / cm; Electrical insulation: Volume resistivity ≥10 4 Ω·cm, electrical strength ≥20kV / mm, ensuring that even if the base membrane is damaged and water seeps in, the photovoltaic circuit can still maintain a high insulation resistance between the photovoltaic circuit and the water body; Stress buffering: The elastic modulus of the adhesive functional layer is 500-2000 MPa, which is between that of the base geomembrane layer (10 2 -10 3 MPa) and integrated photovoltaic power generation layer (10 4 -10 5 Between MPa), modulus gradient matching is used to eliminate interfacial stress singularities, buffer deformation stress caused by temperature cycling and foundation settlement, and prevent interlayer shear failure.

[0047] As an optional embodiment of the present invention, the transparent encapsulation protective layer is a high-transmittance, weather-resistant, and scratch-resistant polymer layer covering the integrated photovoltaic power generation layer. The material is selected from fluorinated ethylene propylene copolymer (FEP) (the transparent encapsulation protective layer formed therefrom has a thickness of 50-127μm (e.g., 80μm, 100μm, 110μm, etc.) and a light transmittance ≥91%) or polyolefin elastomer POE (the transparent encapsulation protective layer formed therefrom has a thickness of 300-500μm (e.g., 350μm, 400μm, 450μm, etc.) and a light transmittance ≥90%), used to protect the solar cells from moisture erosion and mechanical damage.

[0048] As an optional embodiment of the present invention, the weather-resistant protective layer is a thin coating containing ultraviolet absorbers and anti-hydrolysis agents located on the outermost layer, with a thickness of 5-20 μm, and is selected from fluorocarbon coatings containing benzotriazole ultraviolet absorbers, nano-silica-organosilicon hybrid coatings, or modified acrylic coatings containing triazine ultraviolet absorbers.

[0049] Specifically, the base geomembrane of this invention is made of UV-resistant high-molecular polymer geomembrane (such as toughened PVC containing hindered amine light stabilizer HALS); the adhesive functional layer is made of yellowing-resistant high-molecular polymer material (such as a two-component polyurethane adhesive modified with a silane coupling agent); the integrated photovoltaic power generation layer is made of intrinsically PID-resistant flexible thin-film solar cell roll material (such as CIGS); the transparent encapsulation protective layer is made of a polymer layer with both UV resistance and hydrolysis resistance (such as FEP); and the outermost layer is a weather-resistant protective layer, for example, made of a hybrid coating composed of benzotriazole and nano-SiO2, forming a weather-resistant gradient barrier from bottom to top.

[0050] Furthermore, the materials used in each layer are either free of easily hydrolyzable ester bonds or are modified materials resistant to hydrolysis, which ensures that the weight loss rate of each layer is ≤1% under the condition of immersion in hot water at 70℃.

[0051] According to a second aspect of the present invention, a method for preparing a photovoltaic-geomembrane with an integrated composite structure as described in the first aspect is provided, comprising the following steps: S1: The polymer is melted and extruded, and after shaping, a base geomembrane layer is obtained; S2: Unroll and preheat the base geomembrane layer, then apply a two-component polyurethane adhesive modified with a silane coupling agent onto the base geomembrane layer to obtain an incompletely cured adhesive functional layer. S3: P4 laser scribing is performed on both sides of the edge region of the flexible thin-film solar cell roll in the width direction to form lead-out electrodes. On one side edge region, the back electrode above the flexible substrate is exposed to form a negative lead-out electrode, and on the other side edge region, the TCO above the flexible substrate is exposed to form a positive lead-out electrode. Then, the free surface of the flexible substrate and the bonding surface of the lead-out electrodes are respectively subjected to surface activation treatment. The free surface of the flexible substrate of the flexible thin-film solar cell roll is pressed onto the adhesive functional layer under tension control. After hot rolling composite, the adhesive functional layer is completely cured and combined with the flexible thin-film solar cell roll to obtain a composite integrated photovoltaic power generation layer film. Specifically, the flexible thin-film solar cell roll consists of, from bottom to top, a flexible substrate, a back electrode layer, a photovoltaic layer, a transparent conductive electrode (TCO), and an encapsulation layer. The back electrode layer and TCO constitute the negative and positive electrodes of the power generation module, respectively. Lead electrodes are formed on both sides of the roll's width using P4 laser etching: on one side, the encapsulation layer is removed, exposing the upper surface of the TCO as the positive lead electrode; on the other side, the encapsulation layer, TCO, and photovoltaic layer are removed, exposing the upper surface of the back electrode as the negative lead electrode. A first external wire is bonded to the TCO surface of the positive lead electrode using conductive adhesive, and a second external wire is bonded to the back electrode surface of the negative lead electrode using conductive adhesive, thereby achieving the external electrical connection of the embedded interconnect circuit's positive and negative electrodes.

[0052] S4: The transparent encapsulation protective layer is pressed onto the integrated photovoltaic power generation layer by a hot roller, and then a weather-resistant coating is applied to the surface of the transparent encapsulation protective layer. After curing, a weather-resistant protective layer is obtained. S5: The positive electrode is bonded to one end of the first external wire with conductive adhesive, and the negative electrode is bonded to one end of the second external wire with conductive adhesive to obtain a photovoltaic-geomembrane with an integrated composite structure. S6: Rewind to obtain a photovoltaic-geomembrane roll product with an integrated composite structure.

[0053] Specifically, the two-component polyurethane adhesive modified with a silane coupling agent contains polar groups such as isocyanate groups (-NCO), urethane groups (-NH-COO-), or urea groups. For toughened PVC substrates, these polar groups can form hydrogen bonds and dipole interactions with active sites on the PVC surface. Simultaneously, the polyurethane molecular chains can swell and diffuse in the plasticizer micro-regions on the PVC surface, embedding the adhesive layer into its surface microstructure. Upon cooling, an interpenetrating network transition layer is formed in the interface region, thereby eliminating clear interface lines and achieving a strong physical bond. For flexible TPO films, the isocyanate groups (-NCO) in the adhesive can chemically react with trace amounts of unsaturated bonds or polar groups generated by oxidation on the TPO surface. At the same time, the polyurethane molecular chains physically entangle in the amorphous regions of the TPO surface, similarly forming an interpenetrating network transition layer, achieving a strong bond through both chemical and physical bonding, thus eliminating clear interface lines.

[0054] Furthermore, surface activation treatment of the flexible substrate of the flexible thin-film solar cell roll can introduce active groups such as hydroxyl (-OH) or carboxyl (-COOH). The silanol (Si-OH, derived from the hydrolysis of silane coupling agent) in the adhesive functional layer can undergo a condensation reaction with the active groups such as hydroxyl (-OH) or carboxyl (-COOH) to form Si-OC covalent bonds, thereby enabling the adhesive functional layer to achieve a strong chemical bond with the flexible thin-film solar cell roll.

[0055] As an optional embodiment of the present invention, in step S1, melt extrusion is carried out using a single screw extruder, with the die temperature being 185-195℃ (e.g., 187℃, 190℃, 193℃, etc.); after three-roll calendering and cooling, a base impermeable membrane layer with a thickness of 0.5-2.0mm (e.g., 0.7mm, 1mm, 1.3mm, 1.5mm, etc.) is formed and then wound up for later use.

[0056] As an optional embodiment of the present invention, in step S2, the temperature for unwinding and preheating the base geomembrane layer is 60-80℃ (e.g., 65℃, 70℃, 75℃, etc.). In step S2, the thickness of the incompletely cured adhesive functional layer is 80-120 μm (e.g., 90 μm, 100 μm, 110 μm, etc.).

[0057] Immediately after the adhesive is applied, the next process begins, utilizing residual heat to promote the initial reaction. Specifically, after the adhesive is applied, the residual heat (60-80℃) of the base geomembrane layer causes an addition polymerization reaction between isocyanate groups (-NCO) and polyol hydroxyl groups (-OH), generating urethane segments (-NH-COO-), which initially positions the adhesive layer and establishes a certain initial tack. Subsequently, during the hot-pressing stage, the reaction continues, with -NCO in the system reacting with hydroxyl, amino, or water vapor to form a denser cross-linked network, completing the curing process. This process ensures both thorough wetting of the adhesive layer and the substrate, achieving the final mechanical strength and environmental resistance.

[0058] As an optional embodiment of the present invention, step S3 includes tension control including: The unwinding tension is 20-50N to prevent the roll material from loosening and wrinkling; The lamination tension is 30-80N to ensure a tight fit with the uncured adhesive functional layer and to eliminate air bubbles; The winding tension is 40-60N to form a tight coil and prevent interlayer slippage.

[0059] Specifically, the lower limit of all tensions is 20N to prevent material relaxation from causing interlayer misalignment, and the upper limit of all tensions is 80N to avoid excessive stretching that could cause the flexible cell layer to break. Within the above tension limits, the tension is adjusted in real time according to the actual situation to ensure that the flexible thin-film solar cell roll is tightly adhered to the adhesive functional layer.

[0060] As an optional embodiment of the present invention, in step S3, the temperature of the hot roller is 120-150℃ (e.g., 125℃, 130℃, 140℃, 145℃, etc.), the pressure is 0.15-0.25Mpa (e.g., 0.17Mpa, 0.2Mpa, 0.23Mpa, etc.), and the linear speed is 0.8-1.5m / min (e.g., 1m / min, 1.2m / min, 1.4m / min, etc.), so as to completely cure the adhesive layer and complete the chemical bonding with the photovoltaic substrate.

[0061] As an optional embodiment of the present invention, in step S3, the P4 laser marking is performed using a picosecond laser with a wavelength of 1000-1100nm (e.g., 1050nm, 1060nm, 1070nm, etc.), preferably 1064nm.

[0062] As an optional embodiment of the present invention, in step S3, the surface activation treatment is corona treatment or plasma treatment. The corona treatment includes: output power of 2-10kW (e.g., 3kW, 5kW, 7kW, etc.), output frequency of 15-30kHz (e.g., 17kHz, 20kHz, 23kHz, 25kHz, 27kHz, etc.), electrode voltage of 5-15kV (e.g., 7kV, 10kV, 13kV, etc.), and processing speed of 1-20m / min (e.g., 5m / min, 7m / min, 13m / min, 15m / min, 17m / min, etc.). Plasma treatment includes: vacuum level of 10-100 Pa (e.g., 20 Pa, 50 Pa, 70 Pa, etc.), radio frequency power of 100-500 W (e.g., 200 W, 300 W, 400 W, etc.), treatment gas of O2, Ar, or N2, gas flow rate of 50-200 sccm (e.g., 80 sccm, 100 sccm, 130 sccm, 150 sccm, 170 sccm, etc.), and treatment time of 30-180 s (e.g., 50 s, 70 s, 100 s, 130 s, 150 s, 170 s, etc.).

[0063] Specifically, after plasma treatment, in addition to increasing the dyne value, the roughness Ra of the flexible substrate can also be increased to ≥0.5μm through high-energy ion bombardment.

[0064] As an optional embodiment of the present invention, in step S4, the material of the transparent encapsulation protective layer includes POE (polyolefin elastomer) or FEP (fluorinated ethylene propylene copolymer). The hot roller composite temperature of POE is 145-155℃ (e.g., 148℃, 150℃, 153℃, etc.), the pressure is 0.15-0.25MPa (e.g., 0.17MPa, 0.2MPa, 0.23MPa, etc.), the linear speed is 1.5-3m / min (e.g., 1.7m / min, 2m / min, 2.5m / min, etc.), and the cooling roller is used for rapid cooling and shaping. The hot roller bonding temperature of FEP is 255-265℃ (e.g., 257℃, 260℃, 263℃, etc.), and the pressure is 0.1-0.15MPa (e.g., 0.11MPa, 0.13MPa, etc.). It is then slowly cooled to below 50℃ for cooling and shaping.

[0065] As an optional embodiment of the present invention, in step S4, the weather-resistant coating is selected from fluorocarbon coatings containing benzotriazole ultraviolet absorbers, nano-silica-organosilicon hybrid coatings, or modified acrylic coatings containing triazine ultraviolet absorbers. Typically, and not specifically, fluorocarbon coatings containing benzotriazole UV absorbers include 40-50 parts of fluorocarbon resin (such as FEVE resin); 1.5-3.0 parts of benzotriazole UV absorber (such as Tinuvin 328 or UV-531); 1.0-2.0 parts of hindered amine light stabilizer (such as Tinuvin 292); 5-10 parts of nano-SiO2 sol (particle size 10-20 nm, solid content 30%); 1-2 parts of organosilane coupling agent (such as KH-560); 5-8 parts of isocyanate curing agent; and 25-50 parts of solvent (such as a mixture of xylene and butyl acetate).

[0066] In step S4, a weather-resistant coating is applied to the surface of the transparent encapsulation layer using a micro-gravure coating or spraying process, followed by UV curing (UV wavelength 365nm-395nm, UV power density 80-120mW / cm²). 2 A weather-resistant protective layer is formed by curing at a speed of 5-15 m / min or by heat curing (temperature 80-120℃, time 2-5 min).

[0067] As an optional embodiment of the present invention, step S5 further includes electrically connecting the other end of the first external wire 9 to the first waterproof connector 7. The other end of the second external wire 10 is electrically connected to the second waterproof connector 8.

[0068] As an optional embodiment of the present invention, the width of the photovoltaic-geomembrane product with an integrated composite structure is 2-3m.

[0069] According to a third aspect of the present invention, a method for combining a photovoltaic-geomembrane with an integrated composite structure prepared by a method for preparing a photovoltaic-geomembrane with an integrated composite structure as described in the first aspect or as described in the second aspect is provided, comprising the following steps: like Figure 2 As shown, at least two photovoltaic-geomembrane modules are laid together: when two adjacent photovoltaic-geomembrane modules are laid together, the first waterproof connector 7 (such as a waterproof hole plug, which connects to the positive terminal of the module) of one photovoltaic-geomembrane module is plugged into the second waterproof connector 8 (such as a waterproof pin plug, which connects to the negative terminal of the module) of the other photovoltaic-geomembrane module to achieve electrical series connection between adjacent modules; In this system, the positive terminal of each component is output to the outside through the first waterproof connector 7, and the negative terminal is output to the outside through the second waterproof connector 8. During installation, the positive and negative terminals of two adjacent photovoltaic-geomembrane components are connected end to end in sequence to achieve electrical connection.

[0070] Specifically, since each photovoltaic-geomembrane module is equipped with connectors according to a unified polarity standard at the factory (i.e., all modules are equipped with a first waterproof connector at the positive end and a second waterproof connector at the negative end), during on-site installation, it is only necessary to plug the non-standard connectors (first connector and second connector) of adjacent modules into each other to automatically achieve the correct matching of positive and negative poles. There is no need to identify the polarity on-site, which avoids the risk of reverse connection and saves on-site welding work, greatly improving the laying efficiency and connection reliability.

[0071] The present invention will be further described in detail below with reference to specific embodiments and comparative examples. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0072] Example 1 This embodiment provides a photovoltaic-geomembrane with an integrated composite structure, such as... Figure 1 As shown, from bottom to top, it includes a base impermeable membrane layer 1, an adhesive functional layer 2, an integrated photovoltaic power generation layer 3, a transparent encapsulation protective layer 4, and a weather-resistant protective layer 5; The integrated photovoltaic power generation layer 3 forms a whole without independent interfaces with the base waterproof membrane 1 through the adhesive functional layer 2; The integrated photovoltaic power generation layer 3 is a CIGS flexible thin-film solar cell roll with a flexible substrate that has undergone corona treatment and has a monolithic integrated structure (P1-P3 laser scribing has been completed). The internal solar cells 3a and interconnect circuits 3b of the integrated photovoltaic power generation layer 3 are integrated during thin film deposition by laser scribing with P1-P3, forming an inseparable monolithic integrated structure in which solar cells 3a and interconnect circuits 3b are connected end to end and buried in the flexible thin film solar cell. like Figure 1 As shown, the monolithic integrated structure also includes two lead-out electrodes 6, including a positive lead-out electrode and a negative lead-out electrode located at both ends of the flexible thin-film solar cell roll in the width direction. The positive lead-out electrode is an exposed TCO located at one end of the flexible thin-film solar cell roll in the width direction, and the negative lead-out electrode is an exposed back electrode located at the other end of the flexible thin-film solar cell roll in the width direction.

[0073] The surface of the lead-out electrode 6 facing away from the flexible substrate is a flat adhesive surface, and the first external wire 9 and the second external wire 10 are both bonded to this flat adhesive surface with conductive adhesive.

[0074] like Figure 1 As shown, the integrated photovoltaic power generation layer 3 has a first external conductor 9 and a second external conductor 10 on both sides in the width direction. One end of the first external wire 9 is electrically connected to the positive lead electrode by means of conductive adhesive, and the other end is electrically connected to the waterproof hole. One end of the second external wire 10 is electrically connected to the negative electrode by means of conductive adhesive, and the other end is electrically connected to the waterproof pin.

[0075] Among them, the base geomembrane layer 1 is a toughened PVC membrane (DuPont Elvaloy® KEE) with a thickness of 1.0 mm, an elongation at break of 258%, and an elastic modulus of 350 MPa.

[0076] The adhesive functional layer 2 is a two-component polyurethane adhesive modified with aminosilane coupling agent KH-550. The coating thickness is 0.1 mm, and after curing, the Shore hardness is A70, the electrical strength is 22 kV / mm, and the volume resistivity is ≥10. 4 Ω·cm, the elastic modulus of the adhesive functional layer is 1200MPa; The modification method of two-component polyurethane adhesive modified with aminosilane coupling agent KH-550 includes the following steps: KH-550 was pre-mixed with polyether diol (model PPG400, manufacturer: Lianhong New Materials) until uniform, and then stirred for 30 min at 60℃ and vacuum -0.08 MPa to allow silane alcoholysis and uniform dispersion. After further cooling to 40℃, diphenylmethane diisocyanate was added, and the mixture was stirred at 60℃ for 8 h to obtain a two-component polyurethane adhesive modified with silane coupling agent. The total mass of the two-component polyurethane adhesive modified with the pre-set aminosilane coupling agent KH-550 is 100 kg. The addition amount of KH-550 is 1.5 wt% of the total mass of the two-component polyurethane adhesive modified with the pre-set aminosilane coupling agent KH-550; The amount of isocyanate group in isocyanate is 1.2 times the amount of hydroxyl group in polyol.

[0077] The integrated photovoltaic power generation layer 3 has a thickness of 50 μm and an elastic modulus of 2.5 × 10⁻⁶. 4 MPa; The transparent encapsulation protective layer 4 uses DuPont Teflon® FEP film, model PV3131, with a thickness of 75μm and a light transmittance of 92%. The weather-resistant protective layer 5 is a fluorocarbon coating containing benzotriazole ultraviolet absorbers, with a thickness of 10μm; The fluorocarbon coating containing benzotriazole UV absorbers includes: 45 parts of fluorocarbon resin FEVE; 2 parts of benzotriazole UV absorber (Tinuvin 328); 1.5 parts of hindered amine light stabilizer (Tinuvin 292); 7 parts of nano-SiO2 (particle size 10-20nm, solid content 30%) sol; 1.5 parts of organosilane coupling agent (KH-560); 6 parts of isocyanate curing agent (polymethylene polyphenyl polyisocyanate, model PAPI™ 94, manufacturer Dow Chemical); and 37 parts of solvent (mixed solvent of xylene and butyl acetate).

[0078] This embodiment also provides a method for preparing a photovoltaic-geomembrane with an integrated composite structure as described above, comprising the following steps: S1: The high molecular polymer (toughened PVC) is melt-extruded using a single screw extruder at a die temperature of 190℃; after three-roll calendering and cooling, a base waterproof membrane layer with a thickness of 1.0mm is formed and then wound up for later use. S2: Unroll and preheat the base geomembrane layer to 75°C, then apply a two-component polyurethane adhesive modified with aminosilane coupling agent KH-550 onto the base geomembrane layer to obtain an incompletely cured coating adhesive functional layer with a thickness of 0.1mm. S3: Perform P4 laser scribing on both edge regions along the width direction of the CIGS flexible thin-film solar cell roll to form lead-out electrodes: In one edge region, the encapsulation layer above the roll material is removed, exposing the upper surface of the TCO as the positive electrode lead-out electrode; On the other edge region, the encapsulation layer, TCO and photovoltaic layer are removed to expose the upper surface of the back electrode as the negative electrode lead-out electrode. The free surface of the flexible substrate and the bonding surface of the two lead-out electrodes are then corona treated. The flexible thin-film solar cell roll is then pressed onto the adhesive functional layer under tension control. After hot rolling composite, the adhesive functional layer is completely cured and bonded to the flexible thin-film solar cell roll, resulting in a film material with an integrated photovoltaic power generation layer. The unwinding tension is 20-50N, the lamination tension is 30-80N, and the winding tension is 40-60N. The hot roll bonding temperature is 150℃, the pressure is 0.2MPa, the linear speed is 1.2m / min, and the peel strength at 180° is 6.2N / cm after the adhesive layer is fully cured. Picosecond laser (1064nm) was used to complete the P4 line marking; The back side (free side) of the PI substrate of CIGS flexible thin-film solar cell roll is corona treated with a dyne value ≥48mN / m; The corona treatment includes: an output power of 5kW, an output frequency of 20kHz, an electrode voltage of 10kV, and a processing speed of 5m / min.

[0079] S4: The transparent encapsulation protective layer FEP is pressed onto the integrated photovoltaic power generation layer by hot roller, and then a weather-resistant coating is applied to the surface of the transparent encapsulation protective layer. After thermosetting, a weather-resistant protective layer is obtained. The FEP layer is hot-rolled at a temperature of 255℃ and a pressure of 0.15MPa, and then slowly cooled to below 50℃ for cooling and shaping. The thermosetting temperature is 100℃ and the time is 3 minutes.

[0080] S5: Bond the positive electrode to one end of the first external wire with conductive adhesive, and connect the other end of the first external wire to the waterproof hole; bond the negative electrode to one end of the second external wire with conductive adhesive, and connect the other end of the second external wire to the waterproof needle to obtain a photovoltaic-geomembrane with an integrated composite structure.

[0081] S6: Rewinding to obtain a photovoltaic-geomembrane roll product with an integrated composite structure. The finished roll is 2m wide and weighs 2.4kg / m². 2 .

[0082] When laying and connecting two adjacent photovoltaic-geomembrane units prepared in this embodiment, the waterproof hole of one photovoltaic-geomembrane is inserted into the waterproof pin of the other photovoltaic-geomembrane to achieve electrical series connection between adjacent photovoltaic-geomembrane units.

[0083] Example 2 This embodiment provides a photovoltaic-geomembrane with an integrated composite structure, the structure of which is the same as in Embodiment 1; Among them, the base geomembrane layer 1 is a 1.5mm thick flexible TPO membrane (material model Sarnafil® TS77-18), with an elongation at break of 312% and an elastic modulus of 450MPa.

[0084] The adhesive functional layer 2 is a two-component polyurethane adhesive modified with aminosilane coupling agent KH-550, with a coating thickness of 0.12 mm. After curing, it has a Shore hardness of A75, an electrical strength of 25 kV / mm, and a volume resistivity ≥10. 4 Ω·cm, the elastic modulus of the adhesive functional layer is 1500MPa; The modification method of two-component polyurethane adhesive modified with aminosilane coupling agent KH-550 includes the following steps: KH-550 was pre-mixed with polycaprolactone diol and then stirred for 30 min at 60°C and vacuum -0.08 MPa to allow the silane to be alcoholyzed and uniformly dispersed. After further cooling to 40°C, polymethylene polyphenyl polyisocyanate was added and mixed at 60°C for 8 h to obtain a two-component polyurethane adhesive modified with a silane coupling agent. The total mass of the two-component polyurethane adhesive modified with the pre-set aminosilane coupling agent KH-550 is 100 kg. The amount of KH-550 added is 1.8 wt% of the total mass of the two-component polyurethane adhesive modified with the pre-set aminosilane coupling agent KH-550; The amount of isocyanate group in isocyanate is 1.25 times the amount of hydroxyl group in polyol.

[0085] The integrated photovoltaic power generation layer 3 is a CIGS flexible thin-film solar cell roll (P1-P3 laser marking has been completed), with a thickness of 75μm and an elastic modulus of 3×10. 4 MPa; The transparent encapsulation protective layer 4 uses POE film (model PV 8660), with a thickness of 0.35mm and a light transmittance of 91%. The weather-resistant protective layer 5 is a modified acrylic coating containing triazine ultraviolet absorbers, with a thickness of 15μm; The modified acrylic coating containing triazine UV absorbers includes: 50 parts of modified acrylic resin (model Setalux® 91757); 2.5 parts of triazine UV absorber (Tinuvin 1577); 1.5 parts of hindered amine light stabilizer (Tinuvin 292); 5 parts of nano TiO2 (particle size 20-30 nm); 3 parts of nano SiO2 (particle size 10-20 nm, solid content 30%); 0.5 parts of leveling agent (polyether modified polydimethylsiloxane, model BYK-333, manufacturer BYK Chemical); 0.3 parts of defoamer (BYK-052N); 8 parts of isocyanate curing agent (polymethylene polyphenyl polyisocyanate, model PAPI™ 94, manufacturer Dow Chemical); and 29.2 parts of solvent (mixed solvent of xylene and butyl acetate).

[0086] This embodiment also provides a method for preparing a photovoltaic-geomembrane with an integrated composite structure as described above, comprising the following steps: S1: The high molecular weight polymer (TPO) is melt-extruded using a single screw extruder at a die temperature of 200℃; after three-roll calendering and cooling, a base geomembrane layer with a thickness of 1.5mm is formed and then wound up for later use; S2: Unroll and preheat the base geomembrane layer to 80℃, then apply a two-component polyurethane adhesive modified with aminosilane coupling agent KH-550 onto the base geomembrane layer to obtain an incompletely cured coating adhesive functional layer with a thickness of 0.12mm. S3: Perform P4 laser scribing on both edge regions along the width direction of the CIGS flexible thin-film solar cell roll to form lead-out electrodes: In one edge region, the encapsulation layer above the roll material is removed, exposing the upper surface of the TCO as the positive electrode lead-out electrode; On the other edge region, the encapsulation layer, TCO and photovoltaic layer are removed to expose the upper surface of the back electrode as the negative electrode lead-out electrode. The free surface of the flexible substrate and the bonding surface of the two lead-out electrodes are then subjected to plasma treatment. The flexible thin-film solar cell roll is then pressed onto the adhesive functional layer under tension control. After hot rolling composite, the adhesive functional layer is completely cured and bonded to the flexible thin-film solar cell roll, resulting in a film material with an integrated photovoltaic power generation layer. The unwinding tension is 30-50N, the lamination tension is 40-80N, and the winding tension is 50-60N. The hot roll bonding temperature is 135℃, the pressure is 0.22MPa, the linear speed is 1.0m / min, and the 180° peel strength after the adhesive layer is fully cured is 7.5N / cm. Picosecond laser (1064nm) was used to complete the P4 line marking; The back side (free side) of the PI substrate of CIGS flexible thin-film solar cell roll is plasma treated to achieve a dyne value ≥50mN / m and a roughness Ra ≥0.5μm. The plasma treatment includes: a vacuum of 50 Pa, a radio frequency power of 300 W, a radio frequency of 13.56 MHz, and the treatment gases being O2 and Ar, with a gas flow rate of 100 sccm and a treatment time of 60 s.

[0087] S4: The transparent encapsulation protective layer POE is pressed onto the integrated photovoltaic power generation layer by hot rollers, and then a weather-resistant coating is applied to the surface of the transparent encapsulation protective layer. After UV curing, a weather-resistant protective layer is obtained. The POE layer is hot-rolled at a temperature of 150℃, a pressure of 0.20MPa, a linear speed of 2.0m / min, and then slowly cooled to below 50℃ for cooling and shaping. UV curing includes: wavelength 385nm, UV power density 100mW / cm². 2 Curing speed: 10 m / min; S5: Same as Example 1; S6: Rewinding to obtain a photovoltaic-geomembrane roll product with an integrated composite structure. The finished roll is 2.5m wide and weighs 3.2kg / m². 2 .

[0088] When laying and connecting two adjacent photovoltaic-geomembrane units prepared in this embodiment, the waterproof hole of one photovoltaic-geomembrane is inserted into the waterproof pin of the other photovoltaic-geomembrane to achieve electrical series connection between adjacent photovoltaic-geomembrane units.

[0089] Example 3 This embodiment provides a photovoltaic-geomembrane with an integrated composite structure, the structure of which is the same as in Embodiment 1; Among them, the base geomembrane layer 1 is a toughened PVC membrane (DuPont Elvaloy® KEE) with a thickness of 0.8mm, an elongation at break of 275%, and an elastic modulus of 280MPa.

[0090] Adhesive functional layer 2 (same as in Example 1); The integrated photovoltaic power generation layer 3 is a perovskite flexible thin-film solar cell roll (P1-P3 laser marking has been completed), with a thickness of 25μm and an elastic modulus of 1.5×10⁻⁶. 4 MPa; The transparent encapsulation protective layer 4 uses DuPont Teflon® FEP film, model PV3131, with a thickness of 127μm and a light transmittance of 93%. Weather-resistant protective layer 5 is a nano-silica-organic silicon hybrid coating with a thickness of 8μm; The nano-silica-organosilicon hybrid coating comprises: 40 parts of organosilicon resin (methylphenyl organosilicon resin, model SH-9601, manufacturer: Jipeng); 15 parts of nano-SiO2 sol (particle size 10-20 nm, solid content 30%); 2 parts of aminosilane coupling agent (KH-550); 1 part of epoxysilane (KH-560); 0.5 parts of titanate coupling agent (isopropyltris(dioctylpyrophosphate)); 0.5 parts of leveling agent (BYK-306); 0.1 parts of curing catalyst (dibutyltin dilaurate); and 40.9 parts of solvent (mixed solvent of xylene and butyl acetate).

[0091] This embodiment also provides a method for preparing a photovoltaic-geomembrane with an integrated composite structure as described above, comprising the following steps: S1: The high molecular polymer (toughened PVC) is melt-extruded using a single screw extruder at a die temperature of 190℃; after three-roll calendering and cooling, a base waterproof membrane layer with a thickness of 0.8mm is formed and then wound up for later use. S2: Unroll and preheat the base geomembrane layer to 65°C, then apply a two-component polyurethane adhesive modified with aminosilane coupling agent KH-550 onto the base geomembrane layer to obtain an incompletely cured coating adhesive functional layer with a thickness of 0.1mm. S3: P4 laser scribing is performed on both sides of the edge region along the width direction of the perovskite flexible thin-film solar cell roll to form lead-out electrodes: In one edge region, the encapsulation layer above the roll material is removed, exposing the upper surface of the TCO as the positive electrode lead-out electrode; On the other edge region, the encapsulation layer, TCO and photovoltaic layer are removed to expose the upper surface of the back electrode as the negative electrode lead-out electrode. The free surface of the flexible substrate and the bonding surface of the two lead-out electrodes are then corona treated. The flexible thin-film solar cell roll is then pressed onto the adhesive functional layer under tension control. After hot rolling composite, the adhesive functional layer is completely cured and bonded to the flexible thin-film solar cell roll, resulting in a film material with an integrated photovoltaic power generation layer. The unwinding tension is 25-45N, the lamination tension is 35-70N, and the winding tension is 45-65N. The hot roll bonding temperature is 140℃, the pressure is 0.18MPa, the linear speed is 1.5m / min, and the 180° peel strength after the adhesive layer is fully cured is 5.8N / cm. Picosecond laser (1064nm) was used to complete the P4 line marking; The back side of the PI substrate of the perovskite flexible thin film solar cell roll is corona treated with a dyne value ≥50mN / m; The corona treatment includes: a processing power of 6kW, an output frequency of 22kHz, an electrode voltage of 12kV, and a processing speed of 8m / min.

[0092] S4: The transparent encapsulation protective layer FEP is pressed onto the integrated photovoltaic power generation layer by hot roller, and then a weather-resistant coating is applied to the surface of the transparent encapsulation protective layer. After thermosetting, a weather-resistant protective layer is obtained. The FEP layer is hot-rolled at a temperature of 260℃ and a pressure of 0.12MPa, and then slowly cooled to below 50℃ for cooling and shaping. The thermosetting temperature is 100℃ and the time is 3 minutes.

[0093] S5: Same as Example 1; S6: Rewinding to obtain a photovoltaic-geomembrane roll product with an integrated composite structure. The finished roll is 3.0m wide and weighs 2.1kg / m². 2 .

[0094] When laying and connecting two adjacent photovoltaic-geomembrane units prepared in this embodiment, the waterproof hole of one photovoltaic-geomembrane is inserted into the waterproof pin of the other photovoltaic-geomembrane to achieve electrical series connection between adjacent photovoltaic-geomembrane units.

[0095] Comparative Example 1 The main difference between this comparative example and Example 1 is that corona treatment is not applied to the flexible substrate of the integrated photovoltaic power generation layer 3, while the remaining steps and technical parameters are the same as in Example 1.

[0096] Comparative Example 2 The main difference between this comparative example and Example 1 is that the two-component polyurethane adhesive in the adhesive functional layer 2 was not modified by the aminosilane coupling agent KH-550. The remaining steps and technical parameters are the same as in Example 1.

[0097] Performance testing Elongation at break: Elongation at break ≥250%, GB / T 1040 Determination of tensile properties of plastics.

[0098] Water resistance: Water vapor transmission rate < 0.1 g / m 2 ·d, GB / T 26253-2010 Determination of water vapor transmission rate of plastic films and sheets by infrared detector method.

[0099] Insulation: Insulation resistance (after immersion in water for 24 hours) > 100 MΩ, GB / T 3048.5 Test method for electrical properties of wires and cables, insulation resistance test.

[0100] Indivisibility (peel strength between photovoltaic power generation layer and base geomembrane layer): peel strength ≥ 5 N / cm, GB / T 2790 Adhesives 180° peel strength test method.

[0101] Weather resistance: Power decay <3% after temperature cycling (-40℃~85℃, 200 cycles), in accordance with IEC 61215-2:2021.

[0102] Series test: TC200 (-40℃~+85℃) + DH1000 (85℃ / 85%RH) is used, in accordance with IEC 61215-2:2021.

[0103] Results data Table 1 Performance data of the prepared photovoltaic-geomembrane with integrated composite structure Table 2 Performance data after series testing As can be seen from Tables 1 and 2 above, the photovoltaic-geomembrane with integrated composite structure prepared in Examples 1-3 exhibits the following after series testing: weather resistance power decay <5%; retention rate of initial peel strength after series testing ≥80%; retention rate of elongation at break of initial PVC base layer after series testing ≥75%; and insulation resistance >50 MΩ after series testing. This demonstrates that each layer ages synchronously, and there is no "short-board effect" where "failure of a single layer first leads to overall scrapping".

[0104] As can be seen from Tables 1 and 2 above, in Comparative Example 1, the flexible substrate of the integrated photovoltaic power generation layer 3 was not subjected to corona treatment, making it impossible to introduce active groups such as hydroxyl (-OH) or carboxyl (-COOH) groups onto the substrate surface. Consequently, the silanol in the adhesive functional layer could not achieve a strong bond with the flexible substrate through chemical bonding. This resulted in an initial peel strength of only 3.5 N / cm, which further decreased to 2.0 N / cm after series testing, with a retention rate of only about 57%. Insufficient peel strength led to the propagation of interfacial microcracks, causing water vapor to permeate along the interface, increasing the water vapor permeability from 0.35 g / m² to 0.58 g / m³. 2 •d, the insulation resistance decreased from 45 MΩ to 22 MΩ, the elongation at break decreased from 240% to 168% due to stress concentration, and local delamination occurred in the weather resistance (power attenuation of 12.5%). Comparative Example 1 exhibits a typical interface bottleneck effect—the interface bonding fails earlier than the base layer and the photovoltaic layer itself, and the overall performance deteriorates faster than the synchronous aging of each layer.

[0105] As can be seen from Tables 1 and 2 above, the two-component polyurethane adhesive for the adhesive functional layer in Comparative Example 2 was not modified with the aminosilane coupling agent KH-550. This resulted in a significant reduction in the number of polar groups in the adhesive functional layer, hindering the formation of hydrogen bonds and weakening dipole interactions with the base geomembrane layer. Furthermore, it prevented chemical bonding with the flexible substrate of the flexible thin-film solar cell roll, and lacked urea bond crosslinking points introduced by silane, leading to a decrease in the cohesive strength of the adhesive layer itself. This resulted in an initial peel strength of only 2.8 N / cm, decreasing to only 1.5 N / cm after series bonding, with a retention rate of approximately 54%; and a water vapor permeability as high as 0.42→0.68 g / m³. 2 •d, the insulation resistance decreased from 38 MΩ to 16 MΩ, the elongation at break decreased from 230% to 158%, and severe delamination occurred in the weather resistance (power attenuation of 15.8%). The weakest link effect was more prominent in Comparative Example 2—the adhesive layer itself became the weakest link, deteriorating first under humid heat aging and mechanical stress, leading to the rapid failure of the entire composite structure and the inability to achieve the synergistic effect of synchronous aging of each layer.

[0106] 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 or all of the technical features; and these 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 the present invention.

Claims

1. A photovoltaic-geomembrane with an integrated composite structure, characterized in that, From bottom to top, it includes a base waterproof membrane layer (1), an adhesive functional layer (2), an integrated photovoltaic power generation layer (3), a transparent encapsulation protective layer (4), and a weather-resistant protective layer (5). The integrated photovoltaic power generation layer (3) forms a whole without independent interface with the base waterproof membrane layer (1) through the adhesive functional layer (2); The integrated photovoltaic power generation layer (3) is a flexible thin-film solar cell roll with a single-piece integrated structure, which has undergone surface activation treatment on the free surface of a flexible substrate. The monolithic integrated structure includes at least two lead-out electrodes (6). The lead-out electrodes (6) include a positive lead-out electrode and a negative lead-out electrode located at both ends of the flexible thin-film solar cell roll in the width direction. The positive lead-out electrode is an exposed TCO located at one end of the flexible thin-film solar cell roll in the width direction, and the negative lead-out electrode is an exposed back electrode located at the other end of the flexible thin-film solar cell roll in the width direction.

2. The photovoltaic-geomembrane with an integrated composite structure according to claim 1, characterized in that, The monolithic integrated structure refers to the following: the battery cell (3a) and interconnect circuit (3b) inside the integrated photovoltaic power generation layer (3) are integrated during the deposition of thin film by laser scribing with P1-P3, forming an inseparable monolithic integrated structure in which the battery cell (3a) and interconnect circuit (3b) are connected end to end and buried in the flexible thin film solar cell.

3. The photovoltaic-geomembrane with an integrated composite structure according to claim 1, characterized in that, The integrated photovoltaic power generation layer (3) has a first external wire (9) and a second external wire (10) on both sides of its width direction. One end of the first external wire (9) is electrically connected to the positive electrode by means of conductive adhesive, and the other end is electrically connected to the first waterproof connector (7). One end of the second external wire (10) is electrically connected to the negative electrode by means of conductive adhesive, and the other end is electrically connected to the second waterproof connector (8); The surface of the lead-out electrode (6) facing away from the flexible substrate is a flat adhesive surface, and the first external wire (9) and the second external wire (10) are both bonded to the flat adhesive surface with conductive adhesive.

4. The photovoltaic-geomembrane with an integrated composite structure according to any one of claims 1-3, characterized in that, The flexible thin-film solar cell roll is selected from amorphous silicon, copper indium gallium selenide, or perovskite thin-film solar cells. And / or, the flexible substrate material includes stainless steel foil or polyimide (PI); And / or, the surface activation treatment is corona treatment or plasma treatment; And / or, the thickness of the integrated photovoltaic power generation layer (3) is 0.05-0.30 mm; And / or, the elastic modulus of the integrated photovoltaic power generation layer (3) is 104-105 MPa.

5. The photovoltaic-geomembrane with an integrated composite structure according to any one of claims 1-3, characterized in that, The base geomembrane layer (1) is a toughened PVC membrane or a flexible TPO membrane; And / or, the elastic modulus of the base geomembrane layer (1) is 10. 2 -10 3 MPa, elongation at break ≥250%; And / or, the thickness of the base geomembrane layer (1) is 0.5-2.0 mm; And / or, the adhesive functional layer (2) is a functional coating applied to the upper surface of the base geomembrane layer (1) by coating or hot pressing, and the material is a two-component polyurethane adhesive modified with a silane coupling agent; The modification method for two-component polyurethane adhesives modified with silane coupling agents includes the following steps: The silane coupling agent is premixed with the polyol, and then stirred for 25-35 min at 55-65℃ and vacuum -0.1~-0.05 MPa to allow the silane to alcoholyze and disperse evenly. After further cooling to 40℃, isocyanate is added, and the mixture is stirred at 50-80℃ for 5-8 h to obtain a two-component polyurethane adhesive modified with the silane coupling agent. The silane coupling agent is KH-550; Polyols include one or more of polyether diols, polyether triols, polyethylene adipate diol, and polycaprolactone diol; Isocyanates include one or more of diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, and toluene diisocyanate; The amount of silane coupling agent added is 1.0-2.0 wt% of the total mass of the two-component polyurethane adhesive modified with the pre-set silane coupling agent; The amount of isocyanate group in isocyanate is 1.1 to 1.3 times the amount of hydroxyl group in polyol; And / or, the elastic modulus of the adhesive functional layer is 500-2000 MPa.

6. The photovoltaic-geomembrane with an integrated composite structure according to any one of claims 1-3, characterized in that, The material of the transparent encapsulation protective layer (4) is fluorinated ethylene propylene copolymer or polyolefin elastomer; The transparent encapsulation protective layer (4) formed by the fluorinated ethylene propylene copolymer has a thickness of 50-127 μm and a light transmittance of ≥91%. The thickness of the transparent encapsulation protective layer (4) formed by polyolefin elastomer is 300-500 μm, and the light transmittance is ≥90%; And / or, the weather-resistant protective layer (5) is selected from fluorocarbon coatings containing benzotriazole ultraviolet absorbers, nano-silica-organosilicon hybrid coatings, or modified acrylic coatings containing triazine ultraviolet absorbers; And / or, the thickness of the weather-resistant protective layer (5) is 5-20 μm.

7. A method for preparing a photovoltaic-geomembrane with an integrated composite structure as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: The polymer is melted and extruded, and after shaping, a base geomembrane layer is obtained (1). S2: Unroll and preheat the base geomembrane layer (1), and then apply adhesive to the base geomembrane layer (1) to obtain an incompletely cured adhesive functional layer (2). S3: P4 laser scribing is performed on both sides of the edge area of ​​the flexible thin film solar cell roll in the width direction to form lead-out electrodes (6). The back electrode above the flexible substrate is exposed on one side edge area to form a negative lead-out electrode, and the TCO above the flexible substrate is exposed on the other side edge area to form a positive lead-out electrode. The free surface of the flexible substrate and the bonding surface of the lead-out electrode (6) are then surface activated. The free surface of the flexible substrate of the flexible thin film solar cell roll is pressed onto the adhesive functional layer (2) under tension control. After hot rolling composite, the adhesive functional layer (2) is completely cured and combined with the flexible thin film solar cell roll to obtain the film material of the composite integrated photovoltaic power generation layer (3). S4: Press the transparent encapsulation protective layer (4) onto the integrated photovoltaic power generation layer (3) using a hot roller, then coat the surface of the transparent encapsulation protective layer (4) with a weather-resistant coating, and obtain the weather-resistant protective layer (5) after curing. S5: Connect the positive electrode to one end of the first external wire (9) with conductive adhesive, and connect the negative electrode to one end of the second external wire (10) with conductive adhesive to obtain a photovoltaic-geomembrane with an integrated composite structure. S6: Rewind to obtain a photovoltaic-geomembrane roll product with an integrated composite structure.

8. The method for preparing a photovoltaic-geomembrane with an integrated composite structure according to claim 7, characterized in that, In step S1, melt extrusion is carried out using a single screw extruder with a die temperature of 185-195℃; after three-roll calendering and cooling, a base geomembrane layer (1) with a thickness of 0.5-2.0mm is formed and then wound up for later use; And / or, in step S2, the temperature of the unwinding preheating of the base geomembrane layer (1) is 60-80℃; And / or, in step S2, the thickness of the incompletely cured adhesive functional layer (2) is 80-120 μm; And / or, step S5 further includes electrically connecting the other end of the first external wire (9) to the first waterproof connector (7); and electrically connecting the other end of the second external wire (10) to the second waterproof connector (8).

9. The method for preparing a photovoltaic-geomembrane with an integrated composite structure according to claim 7 or 8, characterized in that, In step S3, tension control includes: unwinding tension of 20-50N, lamination section tension of 30-80N, and rewinding tension of 40-60N; And / or, in step S3, the temperature of the hot roller is 120-150℃, the pressure is 0.15-0.25Mpa, and the linear speed is 0.8-1.5m / min; And / or, in step S3, the surface activation treatment is corona treatment or plasma treatment; wherein, Corona treatment includes: output power 2-10kW, output frequency 15-30kHz, electrode voltage 5-15kV, and treatment speed 1-20m / min; Plasma treatment includes: vacuum degree 10-100Pa, radio frequency power 100-500W, treatment gas is O2 and / or Ar and / or N2, gas flow rate 50-200sccm, and treatment time 30-180s; And / or, in step S3, the P4 laser scribing is performed using a picosecond laser with a wavelength of 1000-1100nm; And / or, in step S4, the material of the transparent encapsulation protective layer (4) includes a polyolefin elastomer or a fluorinated ethylene propylene copolymer; The hot roller composite temperature of the polyolefin elastomer is 145-155℃, the pressure is 0.15-0.25MPa, the linear speed is 1.5-3m / min, and the cooling roller is used for rapid cooling and shaping. The hot roller bonding temperature of fluorinated ethylene propylene copolymer is 255-265℃, the pressure is 0.1-0.15MPa, and it is slowly cooled to below 50℃ for cooling and shaping. And / or, in step S4, the weather-resistant coating is selected from fluorocarbon coatings containing benzotriazole UV absorbers, nano-silica-organosilicon hybrid coatings, or modified acrylic coatings containing triazine UV absorbers. And / or, in step S4, a weather-resistant coating is applied to the surface of the transparent encapsulation protective layer (4) using a micro-gravure coating or spraying process, and then UV-cured or heat-cured to form a weather-resistant protective layer (5). And / or, the width of photovoltaic-geomembrane products with integrated composite structures is 2-3m.

10. A method for combining a photovoltaic-geomembrane with an integrated composite structure prepared by the preparation method of a photovoltaic-geomembrane with an integrated composite structure as described in any one of claims 3-6 or as described in any one of claims 8-9, characterized in that, Includes the following steps: At least two photovoltaic-geomembrane pieces are laid together: when two adjacent photovoltaic-geomembrane pieces are laid together, the first waterproof connector (7) of one photovoltaic-geomembrane piece is plugged into the second waterproof connector (8) of the other photovoltaic-geomembrane piece to achieve electrical series connection between adjacent photovoltaic-geomembrane pieces. In this process, the positive end of each photovoltaic-geomembrane is output to the outside through the first waterproof connector (7), and the negative end is output to the outside through the second waterproof connector (8). During installation, the positive and negative ends of two adjacent photovoltaic-geomembranes are connected end to end to achieve electrical connection.

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