Lightweight flexible photovoltaic module

Abstract

This invention discloses a lightweight solar cell and a lightweight flexible photovoltaic module. The lightweight solar cell includes ultra-thin tempered glass, a first backsheet, and the solar cell itself. The ultra-thin tempered glass is disposed on the light-facing side of the solar cell and bonded to it with an adhesive film. The first backsheet is bonded to the back-facing side of the solar cell with an adhesive film. Solder strips are respectively provided on the light-facing and back-facing sides of the solar cell. The lightweight flexible photovoltaic module provided by this invention has the advantages of combining flexibility and structural strength.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and in particular to lightweight solar cells and lightweight flexible photovoltaic modules that combine flexibility and structural strength. Background Technology

[0002] Currently, lightweight photovoltaic modules face the challenge of low mechanical strength in the front panel. Some manufacturers use ultra-thin tempered glass as the front panel, but tempering large areas of thin glass is difficult, limiting the module area, increasing production costs, and its poor flexibility makes it unsuitable for curved roof installations. While fully flexible organic films can meet the requirements for lightweight and flexible front panels, their impact resistance and abrasion resistance are poor. Long-term exposure to the outdoors makes them prone to scratches and aging, failing to provide reliable physical protection for the internal solar cells. Furthermore, their light transmittance is lower than that of glass, affecting the module's photoelectric conversion efficiency. Summary of the Invention

[0003] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0004] The flexibility and mechanical strength of photovoltaic modules cannot be balanced at the same time.

[0005] The present invention aims to at least partially solve one of the technical problems in the related art.

[0006] Therefore, embodiments of the present invention propose a lightweight battery cell, comprising ultra-thin tempered glass, a first back film, and a battery cell. The ultra-thin tempered glass is arranged on the light-facing side of the battery cell and bonded to it with an adhesive film. The first back film is bonded to the back-light-facing side of the battery cell with an adhesive film. Solder strips are respectively provided on the light-facing side and the back-light-facing side of the battery cell.

[0007] The embodiments of the present invention have the advantages and technical effects of balancing flexibility and structural strength.

[0008] In some embodiments, the surface of the ultra-thin tempered glass adjacent to the battery cell is coated with an anti-reflective coating to form an anti-reflective film to increase light transmittance.

[0009] In some embodiments, the thickness of the ultrathin tempered glass is 0.8-1.6 mm. In some embodiments, one end of the solder ribbon protrudes from the edge of the battery cell to connect with the solder ribbon of an adjacent battery cell. The protruding ends of the solder ribbons on the light-facing side and the solder ribbons on the back-light-facing side of the battery cell are staggered at the edge of the battery cell and partially overlap with the protruding ends of the solder ribbons of adjacent battery cells on the same side.

[0010] In some embodiments, the protrusion length of the solder strip is 0.5-6 mm.

[0011] In some embodiments, the length and width of the ultrathin tempered glass are both 0.1-0.25 mm longer than the length and width of the battery cell.

[0012] An embodiment of the present invention provides a lightweight flexible photovoltaic module, comprising a plurality of lightweight solar cells arranged at intervals in a first direction. The lightweight solar cells are connected to any adjacent solar cells via solder ribbons. A front film covers the ultra-thin tempered glass of the plurality of lightweight solar cells, and a second back film covers the first back film of the plurality of lightweight solar cells. The front film and the second back film have deformation zones between the lightweight solar cells and adjacent lightweight solar cells, and the thickness of the front film and the second back film decreases in the deformation zones. In some embodiments, the spacing between the lightweight battery cells and adjacent lightweight battery cells is 2-10 mm.

[0013] In some embodiments, the front film, the first back film, and the second back film are PET or PVDF films.

[0014] In some embodiments, the thickness of the deformable region is 1 / 3 to 1 / 2 of that of the non-deformable region.

[0015] This application offers the following advantages: By coating with an anti-reflective coating solution to form an anti-reflective film, the reflection loss of light on the glass surface is effectively reduced, improving the photoelectric conversion efficiency of the solar cells. The thickness is limited to 0.8-1.6mm, reducing the overall weight of the solar cells while ensuring sufficient structural strength and impact resistance of the glass, providing reliable protection for the solar cells. Connecting adjacent solar cells is achieved by using solder ribbons protruding from the cell edges, providing a reliable overlap carrier for series and parallel cell connections, ensuring welding contact area and connection strength, while avoiding interference and short circuits at the protruding ends of the solder ribbons, adapting to the bending requirements of subsequent flexible modules. The limited length of the solder ribbon protrusion ensures an effective overlap length with the solder ribbons of adjacent solar cells, avoiding incomplete connections and excessive contact resistance. The glass forms a small protective covering around the edges of the solar cells, effectively preventing damage from collisions and friction, ensuring the structural integrity and power generation performance of the solar cells. This embodiment limits the spacing between lightweight solar cells to 2-10mm, providing ample bending and deformation space for the deformation zones of the front and second back films, ensuring the flexibility and adaptability of the module. It also avoids excessive spacing that reduces the number of solar cells per unit area, balancing module power generation efficiency and preventing adjacent cells from being crushed and damaged. This design also accommodates the solder ribbon connection, avoiding stress concentration or material waste, and facilitates processing of the deformation zone. PET or PVDF films are selected, combining lightweight and high toughness to reduce the overall weight of the module and meet the bending and stretching requirements of the deformation zone. The limited thickness of the deformation zone gives the film layer excellent bending and stretching toughness, ensuring more even stress distribution during bending and preventing film tearing. It retains sufficient structural strength and wear resistance, allowing for a natural transition between the deformation and non-deformation zones and avoiding stress concentration. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a lightweight battery cell according to an embodiment of the present invention.

[0017] Figure 2 This is a structural schematic diagram of a lightweight flexible photovoltaic module according to an embodiment of the present invention.

[0018] Reference numerals: 1. Ultra-thin tempered glass; 2. Battery cell; 3. Adhesive film; 4. Welding ribbon; 5. First back film; 6. Front film; 7. Second back film; 8. Deformation zone. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] An embodiment of the present invention provides a lightweight battery cell 2, comprising an ultra-thin tempered glass 1, a first back film 5 and a battery cell 2. The ultra-thin tempered glass 1 is arranged on the light-facing side of the battery cell 2 and bonded to it by an adhesive film 3. The first back film 5 is bonded to the back-light side of the battery cell 2 by the adhesive film 3. Solder strips 4 are respectively provided on the light-facing side and the back-light side of the battery cell 2.

[0021] Ultra-thin tempered glass 1 replaces the heavy cover plate, ensuring the impact and wear resistance of the solar cell 2 on the light-facing side while reducing the overall weight of the solar cell 2, making it suitable for lightweight photovoltaic applications. The encapsulating film 3 ensures tight bonding between layers, preventing moisture and impurities from entering the solar cell 2 and avoiding corrosion that could affect its power generation performance. Solder ribbons 4 are provided on both the light-facing and backlighting sides, allowing circuits to be led out from both sides of the solar cell 2, facilitating series and parallel connections between the lightweight solar cell 2 and adjacent solar cells 2. The ultra-thin tempered glass 1 can be made of high-toughness glass prepared using a chemical tempering process. The encapsulating film 3 is made of high-transmittance, aging-resistant EVA or POE film 3, with a transmittance of not less than 92%, ensuring light penetration while improving the weather resistance of the bonding between layers, preventing delamination and yellowing problems after long-term use. The solder ribbons 4 can be made of low-resistance tin-plated copper.

[0022] The embodiments of the present invention have the advantages and technical effects of balancing flexibility and structural strength.

[0023] In some embodiments, the ultrathin tempered glass 1 is coated with an anti-reflective coating liquid on the side surface adjacent to the battery cell 2 to form an anti-reflective film to increase light transmittance.

[0024] Specifically, the anti-reflective coating liquid forms an anti-reflective film at the light propagation interface between the glass and the solar cell 2, creating an optical matching layer. This reduces light reflection loss on the glass surface, allowing more incident light to pass through the glass layer and be absorbed and utilized by the solar cell 2, thereby improving the photoelectric conversion efficiency of the solar cell 2. The coated film should be tightly bonded to the glass surface, not easily peeled off, and maintain its anti-reflective effect over a long period. The film is placed on the side of the glass facing the solar cell 2 to avoid wear and corrosion from the external environment, extending the service life of the anti-reflective film. This achieves increased light transmittance without increasing the overall thickness and weight of the solar cell 2. The anti-reflective film also reduces light reflection at the interface between the glass and the adhesive film 3, reducing energy loss caused by light refraction and optimizing the light reception effect of the solar cell 2.

[0025] In some embodiments, the thickness of the ultrathin tempered glass 1 is 0.8-1.6 mm.

[0026] Specifically, this thickness range avoids the heaviness of traditional photovoltaic cover glass, reducing the overall weight of the solar cell 2, while ensuring that the ultra-thin tempered glass 1 has sufficient structural strength and impact resistance to withstand minor external impacts, sand and gravel friction, and other damage to the light-facing side of the solar cell 2, providing reliable protection for the solar cell 2. Tempered glass within this thickness range has good light transmittance, preventing excessive light attenuation due to glass thickness, ensuring that incident light can efficiently reach the light-receiving surface of the solar cell 2. The tempered glass, the interlayer film 3, and the solar cell 2 can form a good bond, avoiding loose interlayer adhesion and easy delamination caused by excessive glass thickness.

[0027] In some embodiments, one end of the solder ribbon 4 protrudes from the edge of the battery cell 2 to connect with the solder ribbon 4 of the adjacent battery cell 2. The protruding ends of the solder ribbon 4 on the light-facing side and the solder ribbon 4 on the backlight side of the battery cell 2 are staggered at the edge of the battery cell 2 and partially overlap with the protruding ends of the solder ribbon 4 of the adjacent battery cell 2 on the same side.

[0028] Specifically, one end of the welding strip 4 protrudes from the edge of the solar cell 2, providing a carrier for overlapping connection of the welding strips 4 of adjacent solar cells 2. No additional connecting components are required, simplifying the connection structure between solar cells 2, ensuring stable and efficient current transmission between adjacent solar cells 2, and avoiding power generation efficiency loss due to unreliable connection.

[0029] The protruding ends of the solder ribbons 4 on the light-facing and back-light-facing sides of the solar cell 2 are staggered. This avoids interference and squeezing between the protruding ends of the solder ribbons 4 on both sides at the edge of the solar cell 2, preventing deformation or damage to the solder ribbons 4 due to interference. It also prevents short circuits caused by contact between the solder ribbons 4 on both sides of the same solar cell 2, ensuring the circuit safety of the solar cell 2. Furthermore, the protruding ends of the solder ribbons 4 on the same side of both the light-facing and back-light-facing sides are partially overlapped with those of adjacent solar cells 2. This ensures sufficient overlap contact area between the solder ribbons 4 of adjacent solar cells 2, guaranteeing the strength of the weld and preventing issues such as incomplete connections or detachment. This improves the stability of the connection between solar cells 2, adapts to the bending and deformation requirements of flexible photovoltaic modules, and prevents the solder ribbons 4 from breaking due to concentrated stress during module bending.

[0030] In some embodiments, the protrusion length of the solder strip 4 is 0.5-6 mm.

[0031] Specifically, the target length range ensures that the protruding end of the welding ribbon 4 forms a sufficient overlap contact area with the welding ribbon 4 of the adjacent cell 2, forming an effective overlap. This avoids problems such as incomplete welding or excessive contact resistance due to insufficient overlap length, ensuring stable and efficient current transmission between adjacent cells 2. It also controls the exposed length of the welding ribbon 4, preventing excessive friction, compression, or even puncture of the membrane layer and adhesive film 3 of the module during bending and deformation due to excessive protrusion of the welding ribbon 4, which would damage the sealing and structural integrity of the module and reduce the consumption of welding ribbon 4.

[0032] In some embodiments, the length and width of the ultra-thin tempered glass 1 are both 0.1-0.25 mm longer than the length and width of the battery cell 2.

[0033] Specifically, the slightly larger size of the ultra-thin tempered glass 1 allows it to form a tiny edge covering the light-facing side of the battery cell 2, protecting the edges of the battery cell 2 and preventing damage such as chipping or cracking due to minor collisions or friction during transportation, assembly, or use. This ensures the structural integrity of the battery cell 2. At the same time, the tiny extension of 0.1-0.25mm does not cause redundancy in the tempered glass, has little impact on the overall volume and weight of the battery cell 2, and does not affect the adhesion between the tempered glass and the film 3 and the battery cell 2. This prevents gaps caused by excessive glass extension, which could lead to weak interlayer adhesion and the entry of moisture and impurities, thus ensuring sealing performance. The tiny extension also does not reduce the light transmission efficiency of the tempered glass, ensuring that incident light can reach the light-receiving surface of the battery cell 2 to the maximum extent.

[0034] An embodiment of the present invention provides a lightweight flexible photovoltaic module, comprising a plurality of lightweight solar cells 2, the plurality of lightweight solar cells 2 being arranged at intervals in a first direction, the lightweight solar cells 2 being connected to any adjacent solar cells 2 via solder ribbons 4, a front film 6 covering the ultra-thin tempered glass 1 of the plurality of lightweight solar cells 2, and a second back film 7 covering the first back film 5 of the plurality of lightweight solar cells 2, the front film 6 and the second back film 7 having a deformation zone between the lightweight solar cells 2 and adjacent lightweight solar cells 2, the thickness of the front film 6 and the second back film 7 decreasing in the deformation zone.

[0035] The lightweight flexible photovoltaic modules have lightweight solar cells 2 arranged at intervals in the first direction and connected by welding ribbons 4. This ensures the stability of current transmission between the solar cells 2, provides space for flexible deformation of the module, and prevents the solar cells 2 from being squeezed or damaged during bending. A front film 6 completely covers the ultra-thin tempered glass 1 of all lightweight solar cells 2, and a second back film 7 completely covers the first back film 5 of all lightweight solar cells 2, forming a sealed protective structure that blocks external moisture, dust, impurities, etc., from entering the module, protecting the solar cells 2 and welding ribbons 4 from corrosion and wear, and extending the module's lifespan. The front film 6 improves the light transmittance of the module on the light-facing side, while the second back film 7 enhances the insulation and weather resistance of the module on the back-facing side. The thinned deformation zone has better bending toughness and tensile properties, allowing the module to adapt to curved mounting surfaces. The deformation zone does not affect the structural stability and sealing of the solar cell 2 area. Optionally, the deformation zone can be wrinkled to improve bending performance and avoid film tearing caused by simple thinning.

[0036] In some embodiments, the spacing between the lightweight battery cell 2 and the adjacent lightweight battery cell 2 is 2-10 mm.

[0037] Specifically, this spacing provides ample bending and deformation space for the deformation zones of the front film 6 and the second back film 7, ensuring that the deformation zones can perform bending and stretching actions. This allows the module to have good flexibility and adaptability, meeting the bending requirements of curved mounting surfaces, while avoiding a reduction in the number of solar cells 2 per unit area due to excessive spacing, thus ensuring the overall power generation of the module. A reasonable spacing also prevents adjacent solar cells 2 from being squeezed or collided with each other during module bending, transportation, and use, preventing damage and cracking of the solar cells 2 and ensuring the structural integrity and power generation performance of the solar cells 2. This spacing facilitates the processing of the front film 6 and the second back film 7 in the deformation zones.

[0038] In some embodiments, the front film 6, the first back film 5, and the second back film 7 are PET or PVDF films.

[0039] Specifically, the front film 6, the first back film 5, and the second back film 7 are made of PET or PVDF film, both of which are lightweight and highly tough, reducing the overall weight of the module and ensuring good bending performance. They are suitable for bending and stretching in the module's deformation zone, preventing tearing or damage due to module deformation. PET film has high light transmittance, good insulation, and processability. When used as the front film 6, it ensures efficient light transmission, improving the module's photoelectric conversion efficiency. When used as the back film, it forms reliable insulation protection, preventing potential leakage. PVDF film has excellent weather resistance, corrosion resistance, and UV resistance, resisting the erosion of complex environments such as high outdoor temperatures, high humidity, and strong UV radiation, extending the film's lifespan and providing stable protection for the solar cells 2 and the welding ribbons 4. Both PET and PVDF films have good adhesive compatibility, forming a tight bond with the adhesive film 3, ensuring a seal and preventing moisture and impurities from entering the module.

[0040] In some embodiments, the thickness of the deformable region is 1 / 3 to 1 / 2 of that of the non-deformable region.

[0041] Specifically, the thickness of the deformable zone is limited to 1 / 3 to 1 / 2 of that of the non-deformable zone, balancing component flexibility and structural stability. This allows the membrane layer in the deformable zone to possess excellent bending and tensile toughness, adapting to the deformation requirements of irregular curved mounting surfaces. The thinned membrane layer experiences more uniform stress during bending, preventing tearing and cracking due to excessive rigidity. By not excessively thinning the membrane layer in the deformable zone, sufficient structural strength and wear resistance are preserved, preventing damage from minor friction or impacts during transportation and use. This ensures a natural transition at the connection between the deformable and non-deformable zones, avoiding stress concentration due to excessive thickness differences and improving the overall structural integrity of the membrane layer. The thickness variation between the deformable and non-deformable zones can form an approximately V-shaped groove.

[0042] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0046] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0047] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A lightweight battery cell, characterized in that, include: The battery comprises ultra-thin tempered glass, a first back film, and a battery cell. The ultra-thin tempered glass is arranged on the light-facing side of the battery cell and bonded to it with an adhesive film. The first back film is bonded to the back-light-facing side of the battery cell with an adhesive film. Solder strips are respectively provided on the light-facing side and the back-light-facing side of the battery cell.

2. The lightweight battery cell according to claim 1, characterized in that, The ultra-thin tempered glass is coated with an anti-reflective coating solution on the side of the glass adjacent to the battery cell to form an anti-reflective film and increase light transmittance.

3. The lightweight battery cell according to claim 1, characterized in that, The thickness of the ultra-thin tempered glass is 0.8-1.6 mm.

4. The lightweight battery cell according to claim 1, characterized in that, One end of the solder strip protrudes from the edge of the battery cell to connect with the solder strip of the adjacent battery cell. The protruding ends of the solder strips on the light-facing side and the backlight-facing side of the battery cell are staggered at the edge of the battery cell and partially overlap with the protruding ends of the solder strips of the adjacent battery cell on the same side.

5. The lightweight battery cell according to claim 1, characterized in that, The protrusion length of the welding strip is 0.5-6mm.

6. The lightweight battery cell according to claim 1, characterized in that, The length and width of the ultra-thin tempered glass are both 0.1-0.25 mm longer than the length and width of the battery cell.

7. A lightweight flexible photovoltaic module, comprising a plurality of lightweight solar cells as described in any one of claims 1-6, characterized in that, Multiple lightweight battery cells are spaced apart in a first direction. The lightweight battery cells are connected to any connected battery cells by solder ribbons. A front film covers the ultra-thin tempered glass of the multiple lightweight battery cells. A second back film covers the first back film of the multiple lightweight battery cells. The front film and the second back film have deformation zones between the lightweight battery cells and adjacent lightweight battery cells. The thickness of the front film and the second back film decreases in the deformation zones.

8. The lightweight flexible photovoltaic module according to claim 7, characterized in that, The spacing between the lightweight battery cells and adjacent lightweight battery cells is 2-10 mm.

9. The lightweight flexible photovoltaic module according to claim 7, characterized in that, The front film, the first back film, and the second back film are PET or PVDF films.

10. The lightweight flexible photovoltaic module according to claim 7, characterized in that, The thickness of the deformable zone is 1 / 3 to 1 / 2 of that of the non-deformable zone.

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