Foldable portable double-sided semi-flexible photovoltaic module structure

Abstract

The utility model discloses a foldable portable double-sided semi-flexible photovoltaic module structure, belongs to the technical field of solar photovoltaic, and aims to solve the problems that a photovoltaic module is poor in impact resistance, easy to warp, only capable of single-sided power generation, and low in power generation efficiency, and comprises a back film, and a first black EVA (Ethylene Vinyl Acetate) strip is arranged above the back film; two sides of the top surface of the first black EVA strip are respectively and fixedly provided with four mutually clamped PCB edge strips, two sides of the top surface of the first black EVA strip are respectively connected with a rear anti-impact layer, the rear anti-impact layers are correspondingly positioned in the four PCB edge strips, the top surfaces of the rear anti-impact layers are connected with a second packaging film, the top surface of the second packaging film is connected with a battery piece, a front anti-impact layer is arranged above the battery piece, and the front anti-impact layer is arranged above the battery piece. The top surface of the front anti-impact layer is connected with a second black EVA strip; according to the utility model, the front shock-resistant layer, the rear shock-resistant layer, the front film and the rear film are arranged, so that the mechanical shock-resistant protection capability of the battery piece is improved, and meanwhile, the photovoltaic module is not easy to warp and is more portable.

Description

Technical Field

[0001] The utility model belongs to the technical field of solar photovoltaics, and in particular relates to a foldable and portable double-sided semi-flexible photovoltaic component structure. Background Art

[0002] Traditional single-glass crystalline silicon solar photovoltaic modules use ultra-clear tempered glass for their front covers, providing excellent protection against mechanical impact and moisture intrusion. However, its rigidity, fragility, and heavy weight limit its use in certain scenarios, such as foldable or portable photovoltaic charging applications. These portable photovoltaic products require high module conversion efficiency, portability, mechanical impact resistance, and low cost. To improve module conversion efficiency and control costs, crystalline silicon cells such as PERC, IBC, HJT, and TOPCon are used. To achieve the portability of these photovoltaic modules, they typically require a foldable form factor. Furthermore, given the vast majority of mechanical impacts in these applications, strengthening the impact-resistant layer on the back of the module is more effective. One solution involves using a thin fluoropolymer film, such as polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), or ethylene-tetrafluoroethylene (ETFE), as the front film 14 of the module. Multilayer polyethylene terephthalate (PET) sheets are placed in front of and / or behind the solar cells 7 as the front and rear impact-resistant layers 5 of the module. These layers are then laminated using encapsulant materials such as polyethylene vinyl acetate (EVA) and polyolefin elastomer (POE), along with films such as polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and ethylene-tetrafluoroethylene (ETFE). Another solution involves using a thicker transparent PET sheet as the back impact-resistant layer. However, this approach encounters material supply and technical challenges: photovoltaic transparent PET films or sheets are modified by adding additives such as nucleating agents, light stabilizers, UV absorbers, and hydrolysis inhibitors, and undergo surface treatment or coating to improve weather resistance and adhesion to EVA or POE. Its thickness ranges from 30μm to 350μm, which is insufficient to provide sufficient bending stiffness and impact resistance for such components. Furthermore, even if transparent PET sheets meeting the required bending stiffness and impact resistance were available, and after the aforementioned modification and surface treatment, residual stresses generated by differences in the thermal expansion coefficients of the component layers can lead to high residual stresses during natural cooling after lamination, which can cause component warping and collapse.

[0003] Existing photovoltaic modules have poor impact resistance during use, making them susceptible to damage from impact, warping, and only capable of single-sided power generation, resulting in low power generation efficiency.

[0004] Therefore, a foldable and portable double-sided semi-flexible photovoltaic module structure is needed to solve the problems of poor impact resistance, easy warping, and only single-sided power generation in the existing technology, resulting in low power generation efficiency. Utility Model Content

[0005] The purpose of the present invention is to provide a foldable and portable double-sided semi-flexible photovoltaic module structure to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a foldable and portable double-sided semi-flexible photovoltaic module structure, comprising a back film, a first black EVA strip is arranged above the back film, four mutually engaged PCB edge strips are fixed on both sides of the top surface of the first black EVA strip, a rear impact-resistant layer is connected to both sides of the top surface of the first black EVA strip, the rear impact-resistant layer is correspondingly located in the four PCB edge strips, the top surface of the rear impact-resistant layer is connected to a second packaging film, the top surface of the second packaging film is connected to a battery cell, a front impact-resistant layer is arranged above the battery cell, the top surface of the front impact-resistant layer is connected to a second black EVA strip, the top surface of the second black EVA strip is connected to a fourth packaging film, and the top surface of the fourth packaging film is connected to the front film.

[0007] It should be noted in the solution that the top surface of the back film is connected to the first packaging film, and the top surface of the first packaging film is connected to the bottom surface of the first black EVA strip.

[0008] It is further worth mentioning that busbars are connected to both sides of the top surface of the battery cell, and braided copper strips are fixed to the adjacent ends of the two busbars.

[0009] It should be further explained that the top surfaces of the PCB edge strips, the first black EVA strips, the battery cells, the busbars and the braided copper strips are connected with a third packaging film, and the bottom surface of the front impact-resistant layer is connected with the top surface of the third packaging film.

[0010] As a preferred embodiment, the front film is a polyvinylidene fluoride film.

[0011] As a preferred embodiment, the backing film is a tetrafluoroethylene-hexafluoroethylene-vinylidene fluoride copolymer film.

[0012] Compared with the prior art, the foldable and portable double-sided semi-flexible photovoltaic module structure provided by the present invention has at least the following beneficial effects:

[0013] (1) By setting the front anti-impact layer, the rear anti-impact layer, the front film and the rear mold, the mechanical impact protection capability of the cell is improved, and the photovoltaic module is not easy to warp and is more lightweight.

[0014] (2) By arranging the battery cell, the front film, the back film, the first black EVA strip and the second black EVA strip, the photovoltaic module can generate electricity on both sides, thereby increasing the unit area of the product and making the power generation efficiency higher.

[0015] (3) By selecting materials for the back film, the first packaging film, the first black EVA strip, the PCB edge strip, the rear impact-resistant layer, the second packaging film, the third packaging film, the front impact-resistant layer, the second black EVA strip, the fourth packaging layer and the front film, the production cost of the photovoltaic module can be reduced.

[0016] (4) By providing the first packaging film, the second packaging film, the third packaging film and the fourth packaging film, the entire photovoltaic module can be easily folded, thereby improving the portability of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the interlayer structure of the utility model before overall lamination;

[0018] Figure 2 This is a schematic diagram of the overall planar structure of the utility model;

[0019] Figure 3 This is a schematic diagram of the planar structure of the PCB edge strip assembly of the utility model;

[0020] Figure 4 This is a schematic diagram of the planar structure of the PCB edge strip of the utility model.

[0021] In the picture:

[0022] 1. Back film; 2. First packaging film; 3. First black EVA strip; 4. PCB edge strip; 5. Rear impact-resistant layer; 6. Second packaging film; 7. Solar cell; 8. Busbar; 9. Braided copper tape; 10. Third packaging film; 11. Front impact-resistant layer; 12. Second black EVA strip; 13. Fourth packaging film; 14. Front film. DETAILED DESCRIPTION

[0023] See also Figure 1-4The utility model provides a foldable and portable double-sided semi-flexible photovoltaic module structure, including a back film 1, a first black EVA strip 3 is arranged above the back film 1, four mutually engaged PCB edge strips 4 are fixed on both sides of the top surface of the first black EVA strip 3, and rear impact-resistant layers 5 are connected on both sides of the top surface of the first black EVA strip 3, and the rear impact-resistant layers 5 are correspondingly located in the four PCB edge strips 4, the top surface of the rear impact-resistant layer 5 is connected to a second packaging film 6, the top surface of the second packaging film 6 is connected to a battery cell 7, a front impact-resistant layer 11 is arranged above the battery cell 7, the top surface of the front impact-resistant layer 11 is connected to a second black EVA strip 12, the top surface of the second black EVA strip 12 is connected to a fourth packaging film 13, and the top surface of the fourth packaging film 13 is connected to a front film 14.

[0024] The front film 14 can be selected from fluorine-containing polymer films, such as polyvinylidene fluoride film, ethylene-tetrafluoroethylene copolymer film, ethylene-chlorotrifluoroethylene copolymer film, polyvinyl fluoride film, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer film, tetrafluoroethylene-hexafluoropropylene copolymer film, and polychlorotrifluoroethylene film.

[0025] The fourth packaging film 13 is a thermoplastic or thermosetting polymer elastomer film layer with an elastic modulus between 30 and 70 MPa and a glass transition temperature between -60°C and -30°C, preferably thermoplastic polyolefin, with an elastic modulus of approximately 30 MPa and a thickness of approximately 0.5 mm; polyethylene vinyl acetate, polyolefin elastomer, etc. may be selected.

[0026] The front impact-resistant layer 11 is made of a material with an elastic modulus of 2 to 10 GPa, preferably a weather-resistant biaxially oriented polyethylene terephthalate substrate with an elastic modulus of about 9 GPa and a thickness of about 270 μm, and is surface-coated or surface-treated to improve the bonding strength with the third packaging film 10 .

[0027] The second packaging film 6 is a thermoplastic or thermosetting polymer elastomer film layer with an elastic modulus between 30 and 70 MPa and a glass transition temperature between -60°C and -30°C, preferably polyethylene vinyl acetate, with an elastic modulus of approximately 65 MPa and a thickness of approximately 0.25 mm; thermoplastic polyolefins, polyolefin elastomers, etc. may be selected.

[0028] The rear impact-resistant layer 5 is made of a material with an elastic modulus of 2 to 10 GPa, preferably a weather-resistant biaxially oriented polyethylene terephthalate substrate with an elastic modulus of about 4 GPa and a thickness of about 270 μm, and is surface-coated or surface-treated to improve the bonding strength with the second packaging film 6 .

[0029] The first black EVA strip 3 and the second black EVA strip 12 have an elastic modulus of about 65 MPa and a thickness of 0.45 mm.

[0030] Furthermore, the top surface of the back film 1 is connected to the first packaging film 2 , and the top surface of the first packaging film 2 is connected to the bottom surface of the first black EVA strip 3 .

[0031] The first packaging film 2 is provided to improve the packaging between the back film 1 and the first black EVA strip 3 .

[0032] The first packaging film 2 is a thermoplastic or thermosetting polymer elastomer film layer with an elastic modulus between 30 and 70 MPa and a glass transition temperature between -60°C and -30°C, preferably polyethylene vinyl acetate, with an elastic modulus of approximately 65 MPa and a thickness of approximately 0.25 mm; thermoplastic polyolefins, polyolefin elastomers, etc. may be selected.

[0033] Furthermore, bus bars 8 are connected to both sides of the top surface of the battery cell 7 , and braided copper strips 9 are fixed to the adjacent ends of the two bus bars 8 .

[0034] The busbars 8 and braided copper strips 9 are provided to form a circuit system with the solar cells 7 to manufacture a photovoltaic module.

[0035] The busbar 8 and the braided copper strip 9 are welded to the battery cell 7 to form a circuit system. The battery cell 7 includes but is not limited to battery technology products such as PERC, IBC, TOPCON, and HJT.

[0036] Furthermore, the top surfaces of the PCB edge strip 4 , the first black EVA strip 3 , the battery cell 7 , the busbar 8 and the braided copper strip 9 are connected with a third packaging film 10 , and the bottom surface of the front impact-resistant layer 11 is connected to the top surface of the third packaging film 10 .

[0037] The third packaging film 10 is provided so that the front impact-resistant layer 11 can be connected to the PCB edge strip 4 , the first black EVA strip 3 , the battery cell 7 , the busbar 8 and the braided copper strip 9 .

[0038] The third packaging film 10 is a thermoplastic or thermosetting polymer elastomer film layer with an elastic modulus between 30 and 70 MPa and a glass transition temperature between -60°C and -30°C. Polyethylene vinyl acetate, polyolefin elastomer, etc. are optional. Preferably, the film is thermoplastic polyolefin with an elastic modulus of approximately 30 MPa and a thickness of approximately 0.5 mm.

[0039] Furthermore, the front film 14 is a polyvinylidene fluoride film.

[0040] The front film 14 is provided to improve the impact resistance of the entire photovoltaic module.

[0041] Furthermore, the back film 1 is a tetrafluoroethylene-hexafluoroethylene-vinylidene fluoride copolymer film.

[0042] The back film 1 can be selected from fluorine-containing polymer films, such as polyvinylidene fluoride film, ethylene-tetrafluoroethylene copolymer film, ethylene-chlorotrifluoroethylene copolymer film, polyvinyl fluoride film, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer film, tetrafluoroethylene-hexafluoropropylene copolymer film, and polychlorotrifluoroethylene film.

[0043] By providing the back film 1, the impact resistance of the entire photovoltaic module can be improved.

[0044] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A foldable and portable double-sided semi-flexible photovoltaic module structure, comprising a back film (1), characterized in that: A first black EVA strip (3) is provided above the back film (1); four mutually engaged PCB side strips (4) are fixed on both sides of the top surface of the first black EVA strip (3); rear impact-resistant layers (5) are connected on both sides of the top surface of the first black EVA strip (3); the rear impact-resistant layers (5) are located correspondingly within the four PCB side strips (4); the top surface of the rear impact-resistant layer (5) is connected to a second packaging film (6); the top surface of the second packaging film (6) is connected to a battery cell (7); a front impact-resistant layer (11) is provided above the battery cell (7); the top surface of the front impact-resistant layer (11) is connected to a second black EVA strip (12); the top surface of the second black EVA strip (12) is connected to a fourth packaging film (13); the top surface of the fourth packaging film (13) is connected to the front film (14).

2. The foldable and portable double-sided semi-flexible photovoltaic module structure according to claim 1, characterized in that: The top surface of the back film (1) is connected to a first packaging film (2), and the top surface of the first packaging film (2) is connected to the bottom surface of the first black EVA strip (3).

3. The foldable and portable double-sided semi-flexible photovoltaic module structure according to claim 1, characterized in that: Both sides of the top surface of the battery cell (7) are connected to bus bars (8) respectively, and braided copper strips (9) are fixed to adjacent ends of two bus bars (8).

4. The foldable and portable double-sided semi-flexible photovoltaic module structure according to claim 1, characterized in that: The top surfaces of the PCB edge strip (4), the first black EVA strip (3), the battery cell (7), the busbar (8) and the braided copper strip (9) are connected to a third packaging film (10), and the bottom surface of the front impact-resistant layer (11) is connected to the top surface of the third packaging film (10).

5. The foldable and portable double-sided semi-flexible photovoltaic module structure according to claim 1, characterized in that: The front film (14) is a polyvinylidene fluoride film.

6. The foldable and portable double-sided semi-flexible photovoltaic module structure according to claim 1, characterized in that: The back film (1) is a tetrafluoroethylene-hexafluoroethylene-vinylidene fluoride copolymer film.

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