Photovoltaic module

Abstract

The utility model provides a kind of photovoltaic module belongs to photovoltaic technical field.The photovoltaic module includes front encapsulation structure, cell unit and back encapsulation structure which are sequentially laminated;Wherein, front encapsulation structure includes transparent front plate layer and first encapsulation adhesive film layer which are sequentially arranged from top to bottom;Transparent front plate layer includes first weather-resistant flame-retardant coating, substrate layer and second weather-resistant flame-retardant coating which are sequentially arranged from top to bottom, and the thickness of transparent front plate layer is 300~800μm.Based on the combination structure of transparent front plate layer, it helps to improve the effects of ultraviolet resistance, moisture resistance and heat resistance of the module, and improve the flame-retardant performance of photovoltaic module.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a photovoltaic module. Background Technology

[0002] With the development and widespread application of solar cell technology, photovoltaic power generation has become one of the more competitive energy forms. Solar cells convert light energy into electrical energy through the photoelectric effect or photochemical effect. Based on different cell structures, solar cells can be divided into various types, such as emitter and back passivated (PERC) cells, tunnel oxide passivated contact (TOPCon) cells, and heterojunction with intrinsic thin-layer (HJT) cells.

[0003] Photovoltaic modules encapsulate multiple solar cells connected in series or parallel, converting light energy into electrical energy through the photoelectric effect or photochemical effect. In related technologies, photovoltaic modules often use double-layered or single-layered glass as a protective encapsulation layer on the front side. To achieve better protection, the glass used is relatively thick, resulting in a heavier module. Furthermore, the glass material is relatively fragile, potentially offering limited protection to the solar cells inside the module during subsequent use. Utility Model Content

[0004] In view of this, in order to at least partially solve the aforementioned technical problems, this utility model provides a photovoltaic module.

[0005] According to one embodiment of the present invention, a photovoltaic module is provided, comprising a front encapsulation structure, a battery cell, and a back encapsulation structure stacked sequentially; wherein, the front encapsulation structure comprises a transparent front panel layer and a first encapsulation film layer arranged sequentially from top to bottom; the transparent front panel layer comprises a first weather-resistant and flame-retardant coating, a substrate layer, and a second weather-resistant and flame-retardant coating arranged sequentially from top to bottom, and the thickness of the transparent front panel layer is 300~800μm.

[0006] In some illustrative embodiments, the thickness of the first weather-resistant and flame-retardant coating is 15~50μm, the thickness of the substrate layer is 275~720μm, and the thickness of the second weather-resistant and flame-retardant coating is 10~30μm.

[0007] In some illustrative embodiments, the light transmittance of the transparent front panel layer is >85%.

[0008] In some illustrative embodiments, the light transmittance of the first encapsulating film layer is >88%, and the basis weight of the first encapsulating film layer is 300~900 g / m².2 .

[0009] In some illustrative embodiments, the first encapsulating film layer includes a first flame-retardant film layer, a fiber layer, and a second flame-retardant film layer arranged sequentially from top to bottom, and the thickness of the first encapsulating film layer is 240~1100μm.

[0010] In some illustrative embodiments, the thickness of the first flame-retardant adhesive film layer is 100~450μm, the thickness of the fiber layer is 40~200μm, and the thickness of the second flame-retardant adhesive film layer is 100~450μm.

[0011] In some illustrative embodiments, the fiber layer comprises at least one of glass fiber mat or glass fiber cloth; the basis weight of the fiber layer is 100~400 g / m². 2 .

[0012] In some illustrative embodiments, the substrate layer is chlorinated polyvinyl chloride; the first weather-resistant flame-retardant coating and / or the second weather-resistant flame-retardant coating is a mixed coating of phosphorus-nitrogen flame retardant and polyester resin.

[0013] In some illustrative embodiments, the back-side encapsulation structure includes a second encapsulating film layer and a photovoltaic backsheet; the thickness of the second encapsulating film layer is 300~950μm, the thickness of the photovoltaic backsheet is 300~800μm, and the photovoltaic backsheet is made of chlorinated polyvinyl chloride.

[0014] In some illustrative embodiments, the battery cell includes multiple battery strings, each battery string including multiple solar cells, the solar cells being selected from any one of back contact solar cells, heterojunction solar cells, and tunnel oxide passivated contact cells.

[0015] According to the photovoltaic module provided in the above embodiments of this utility model, the double-sided coating of the transparent front panel provides good protection for the substrate layer, resisting ultraviolet radiation, rainwater erosion, wind and sand abrasion, etc. The sandwich structure formed by the upper and lower coatings of the transparent front panel and the intermediate substrate layer helps reduce yellowing, embrittlement, and cracking of the substrate layer, extending the service life of the photovoltaic module and improving the stability of its power generation efficiency. The double-sided coating of the transparent front panel provides additional fire protection for the photovoltaic module, meeting its safety requirements. The aforementioned thicker transparent front panel helps provide good mechanical strength and impact resistance, while also considering the cost requirements of the materials used, reducing the weight of the module, and lowering the difficulty and cost of installation. Attached Figure Description

[0016] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the present invention with reference to the accompanying drawings.

[0017] Figure 1A cross-sectional schematic diagram of a photovoltaic module according to an embodiment of the present invention is shown.

[0018] In the accompanying drawings, the meanings of the reference numerals are as follows:

[0019] 1. Front-facing packaging structure;

[0020] 11. Transparent front panel layer;

[0021] 111. First weather-resistant and flame-retardant coating;

[0022] 112. Substrate layer;

[0023] 113. Second weather-resistant and flame-retardant coating;

[0024] 12. First encapsulating film layer;

[0025] 121. First flame-retardant adhesive film layer;

[0026] 122. Fiber layer;

[0027] 123. Second flame-retardant adhesive film layer;

[0028] 2. Battery unit;

[0029] 3. Backside packaging structure;

[0030] 31. Second encapsulating film layer;

[0031] 32. Photovoltaic backsheet. Detailed Implementation

[0032] The embodiments of the present invention will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, numerous specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the present invention.

[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The term "comprising" as used herein indicates the presence of features, steps, or operations, but does not exclude the presence or addition of one or more other features.

[0034] When using expressions such as "at least one of A, B or C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B or C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B, and C, etc.).

[0035] In this invention, the relative position between two components (e.g., a membrane or region), referred to as "above," "on," or "above," can mean that the two components are in direct contact or that they are not in direct contact. Similarly, the relative position between two components, referred to as "below," "under," or "below," can mean that the two components are in direct contact or that they are not in direct contact. For example, when one component (e.g., a membrane or region) is referred to as "on another component," it can be directly on the other component, or there may be other components between them. On the other hand, when a component is referred to as "directly on another component," there are no components between them. Furthermore, when one component is referred to as "on another component," the two have a vertical relationship in the planar view, and this component can be above or below the other component, thus this vertical relationship depends on the orientation of the device.

[0036] Related technologies attempt to increase the mechanical strength of the battery string by increasing the thickness of the glass on its surface. However, this makes the module too heavy, and the glass has limited impact resistance, making it difficult to maintain the stability of the module.

[0037] To address the aforementioned issues, an attempt was made to cover the battery string surface with polyethylene terephthalate (PET) film material; however, its impact resistance and hail resistance are poor. Furthermore, such components may pose certain safety hazards, especially for building rooftops.

[0038] In realizing the concept of this utility model, it was discovered that by placing a weather-resistant and flame-retardant coating on both sides of the substrate layer in the front-side encapsulation structure, the module's resistance to ultraviolet radiation, moisture, and heat is enhanced, and its fire resistance is significantly improved. Simultaneously, the thicker transparent front panel provides better mechanical strength and impact resistance, thereby improving the structural stability of the module.

[0039] Specifically, according to one embodiment of the present invention, a photovoltaic module is provided. Figure 1 A cross-sectional schematic diagram of a photovoltaic module according to an embodiment of the present invention is shown. The thickness of each layered structure is for illustrative purposes only and does not represent the actual dimensions.

[0040] like Figure 1 As shown, the photovoltaic module of this application includes a front encapsulation structure 1, a battery cell 2 and a back encapsulation structure 3 stacked in sequence.

[0041] The front-side encapsulation structure 1 includes a transparent front panel layer 11 and a first encapsulating film layer 12 arranged sequentially from top to bottom. The transparent front panel layer is located on the front of the battery cell 2, serving a protective function and having high light transmittance, reducing adverse effects on light collection efficiency. The first encapsulating film layer 12 is used to adhere the transparent front panel layer 11 to the battery cell 2, serving an adhesive and fixing function.

[0042] Furthermore, the transparent front panel layer 11 includes a first weather-resistant and flame-retardant coating 111, a substrate layer 112, and a second weather-resistant and flame-retardant coating 113, arranged sequentially from top to bottom. The first weather-resistant and flame-retardant coating 111 is located on the upper surface of the substrate layer 112 and is directly exposed to the environment, providing initial protection against ultraviolet radiation, environmental pollution, or corrosion. The second weather-resistant and flame-retardant coating 113 is located on the lower surface of the substrate layer 112 and further protects the substrate from potential contamination or moisture penetration from the battery cell 2 and encapsulation materials. The substrate layer 112, for example, uses a polymer sheet to provide mechanical support strength and rigidity for the transparent front panel layer 11, forming a support structure for the component and resisting external impacts.

[0043] According to embodiments of this invention, the transparent front panel layer 11 provides a protective structure for the module, while the use of the substrate layer 112 significantly reduces the weight of the module, lowering installation difficulty and cost. Furthermore, the three-layer sandwich structure improves the peel strength, UV resistance, moisture resistance, and heat resistance of the transparent front panel layer 11, maintaining module stability and high power generation. Additionally, the flame-retardant properties of the weather-resistant and flame-retardant coatings on the upper and lower surfaces of the substrate layer 112 provide excellent fire resistance, reducing the possibility of safety hazards.

[0044] Similarly, the back-side encapsulation structure also serves to protect battery cell 2.

[0045] In some embodiments, the thickness of the transparent front panel layer 11 is 300~800μm. This setting can reduce costs while providing good mechanical strength, maintaining a light weight, and taking into account good fire resistance and impact resistance. If the thickness of the transparent front panel layer 11 is too large, the cost will increase and may affect the transmittance of incident light, thus negatively impacting the light utilization rate of the battery cell 2; if the thickness of the transparent front panel layer 11 is too small, it is difficult to provide sufficient protection, and the improvement in fire resistance and impact resistance is limited.

[0046] Optionally, the thickness of the transparent front panel layer 11 may be, for example, 300μm, 400μm, 500μm, 600μm, 700μm or 800μm, or a range consisting of any two of the above values.

[0047] It should be noted that, unless otherwise specified, “thickness” generally refers to the dimension along the direction perpendicular to the surface of battery cell 2.

[0048] In some embodiments, the substrate layer 112 is chlorinated polyvinyl chloride (PVC). Chlorinated PVC has flame-retardant properties, with a flame retardancy rating of V-0. V-0 rating means that when chlorinated PVC is burned with a standardized flame (such as a methane flame), it self-extinguishes within 10 seconds. Combining the substrate layer 112 with the aforementioned weather-resistant and flame-retardant coating can significantly improve the fire resistance of photovoltaic modules, especially when installed on building rooftops, further reducing the possibility of safety hazards.

[0049] It should be noted that chlorinated polyvinyl chloride (PVC) can be understood as being prepared by chlorinating polyvinyl chloride resin. For example, chlorine gas can be introduced into the PVC resin in a solution or fluidized bed to carry out a chlorination reaction by heating or photoinitiation, thereby increasing the chlorine atom content on the PVC molecular chain.

[0050] Alternatively, the chlorine content of chlorinated polyvinyl chloride may be 65-70%.

[0051] In some embodiments, the first weather-resistant flame-retardant coating 111 and / or the second weather-resistant flame-retardant coating 113 are mixed coatings of phosphorus-nitrogen flame retardants and polyester resins. Polyester resins possess good chemical stability, and as the base carrier of the mixed coating, they provide uniform dispersion of the phosphorus-nitrogen flame retardants, maintaining the functional stability of the first weather-resistant flame-retardant coating 111 and / or the second weather-resistant flame-retardant coating 113. The addition of phosphorus-nitrogen flame retardants helps to enhance flame-retardant properties.

[0052] It is understood that the present invention may be a first weather-resistant and flame-retardant coating 111 that is a mixed coating of the aforementioned materials; or a second weather-resistant and flame-retardant coating 112 that is a mixed coating of the aforementioned materials; or both the first weather-resistant and flame-retardant coating 111 and the second weather-resistant and flame-retardant coating 112 may be a mixed coating of the aforementioned materials.

[0053] Preferably, both the first weather-resistant and flame-retardant coating 111 and the second weather-resistant and flame-retardant coating 112 are composite coatings of the aforementioned materials. This configuration further enhances the fire-retardant performance.

[0054] In some implementations, the phosphorus-nitrogen flame retardant accounts for 5-10% by mass in the hybrid coating. This setting allows for the provision of flame retardant effects while avoiding negative impacts on the overall weather resistance of the hybrid coating.

[0055] Optionally, the mass percentage of phosphorus-nitrogen flame retardant in the mixed coating may be, for example, 5%, 6%, 7%, 8%, 9% or 10%, or a range consisting of any two of the above values.

[0056] In some embodiments, the phosphorus-nitrogen flame retardant is selected from at least one of melamine, ammonium polyphosphate, and phosphazene. The aforementioned phosphorus-nitrogen flame retardants can provide good flame retardant properties.

[0057] Optionally, the phosphorus-nitrogen flame retardants used in the first weather-resistant flame retardant coating 111 and the second weather-resistant flame retardant coating 112 may be the same or different, and this utility model does not impose any particular limitation on this.

[0058] In some embodiments, battery cell 2 includes multiple battery strings, each battery string including multiple solar cells, the solar cells being selected from any one of back contact solar cells (BC cells), heterojunction solar cells (HJT cells), and tunnel oxide passivated contact cells (TOPCon cells).

[0059] Furthermore, the back contact battery can be a traditional IBC battery (interdigitated back contact battery), or a TBC battery (TOPCon back contact battery), an HBC battery (heterojunction back contact battery), or a hybrid battery (i.e., the PN passivation is made of different passivation materials, such as a combination of polycrystalline silicon passivation and amorphous / microcrystalline passivation).

[0060] The aforementioned solar cell includes a cell body, which includes at least a substrate and a doped layer on the substrate. The substrate is a rectangular or square structure and may have four corners, which may include chamfers or not.

[0061] The aforementioned HJT battery body has a first surface and a second surface arranged opposite to each other. The first surface can be a light-receiving surface, and the second surface can be a backlighting surface. The doped layer includes n-doped regions and p-doped regions. The p-doped regions are located on the first surface, and the n-doped regions are located on the second surface. The two can also be interchanged as needed, without particular limitation here.

[0062] The aforementioned TOPCon battery body has a first surface and a second surface arranged opposite to each other. The first surface can be a light-receiving surface, and the second surface can be a backlighting surface. The doped layer includes n-doped regions and p-doped regions. The p-doped regions are located on the first surface, and the n-doped regions are located within the second surface. The two can also be interchanged as needed, without particular limitation here.

[0063] The aforementioned IBC battery body includes alternating n-doped regions and p-doped regions disposed on a substrate along a first direction to form an interdigitated doped structure. Electrode structures spaced apart from each other are disposed in the n-doped regions and the p-doped regions, respectively.

[0064] The aforementioned TBC cell body includes a tunneling oxide layer disposed on a substrate, and n-doped and p-doped regions formed by doped polycrystalline silicon layers. The TOPCon structure formed by the stacked tunneling oxide layer and doped polycrystalline silicon layers provides higher carrier lifetime and lower surface recombination compared to IBC cells, thus improving the photoelectric conversion efficiency of TBC cells.

[0065] The aforementioned HBC battery comprises n-doped and p-doped regions on a substrate to form a heterojunction structure. The n-doped regions include, but are not limited to, microcrystalline silicon or amorphous silicon (to provide electrons), while the p-doped regions may also use microcrystalline silicon or amorphous silicon (e.g., using boron as a dopant to provide holes). HBC batteries help improve carrier lifetime and reduce surface recombination. Furthermore, a transparent conductive oxide layer (TCO) can be formed between the surfaces of the n-doped and p-doped regions and the electrodes. This facilitates carrier collection in the doped regions and also provides some anti-reflection effect.

[0066] The battery body of the aforementioned hybrid battery can adopt a layer structure similar to that of an IBC battery or a TBC battery, and on this basis, a corresponding passivation layer structure can be configured, such as a combination of at least two of polycrystalline silicon passivation, amorphous silicon passivation, and microcrystalline silicon passivation.

[0067] The materials used in the aforementioned n-doped and p-doped regions can each independently include one or more semiconductor materials such as monocrystalline silicon, amorphous silicon, polycrystalline silicon, or microcrystalline silicon. n-type doping is achieved by introducing donor impurities, such as group VA elements like phosphorus (P), arsenic (As), or antimony (Sb), into the aforementioned semiconductor materials; p-type doping is achieved by introducing acceptor impurities, such as group IIIA elements like boron (B), aluminum (Al), or gallium (Ga), into the aforementioned semiconductor materials.

[0068] In photovoltaic modules, the electrical connection lines of adjacent preceding solar cells have opposite polarities to the electrical connection lines of connected following cells, in order to achieve current transmission.

[0069] Since the specific structure of the solar cell is not the focus of this invention, it will not be described in detail here.

[0070] In some embodiments, the thickness of the first weather-resistant and flame-retardant coating 111 is 15-50 μm. This provides sufficient protection while maintaining good light transmittance. If the thickness is too thin, it is difficult to form continuous protection, resulting in poor absorption of ultraviolet rays; if the thickness is too thick, although it can improve the protection to some extent, it will lead to increased costs and negatively affect light transmittance.

[0071] Optionally, the thickness of the first weather-resistant and flame-retardant coating 111 can be 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm, or a range consisting of any two of the above values.

[0072] In some embodiments, the thickness of the substrate layer 112 is 275~720μm. This setting balances the requirements of mechanical strength, lightweight, and light transmittance. If the thickness is too thin, it is difficult to provide good impact resistance; if the thickness is too thick, the weight will be high, increasing the cost and negatively impacting the light transmittance.

[0073] Optionally, the thickness of the substrate layer 112 can be 275μm, 300μm, 350μm, 400μm, 450μm, 500μm, 550μm, 600μm, 650μm, 700μm, 710μm or 720μm, or a range consisting of any two of the above values.

[0074] In some embodiments, the thickness of the second weather-resistant and flame-retardant coating 113 is 10~30 μm. This provides adhesion and auxiliary protection, improving the peel strength of the transparent front panel layer 11. It should be noted that the second weather-resistant and flame-retardant coating 113 is suitable for providing adhesion, and its thickness can be adjusted to be thinner than the first weather-resistant and flame-retardant coating 111 as needed.

[0075] Optionally, the thickness of the second weather-resistant and flame-retardant coating 113 can be 10μm, 15μm, 20μm, 25μm or 30μm, or a range consisting of any two of the above values.

[0076] In some embodiments, the transmittance of the transparent front panel 11 is >85%. It is understood that, as the core structure of a photovoltaic module, the cell unit 1 needs to absorb a significant amount of incident light to convert it into photocurrent, thereby achieving photovoltaic power generation. Maintaining the transmittance of the transparent front panel 11 within the aforementioned range helps to reduce the negative impact on incident light while ensuring mechanical strength.

[0077] Optionally, the light transmittance of the transparent front panel layer 11 may be, for example, 86%, 88%, 90%, 92%, 94%, 96%, etc., or a range consisting of any two of the above values.

[0078] In some embodiments, the light transmittance of the first encapsulating film layer 12 is >88%. Similarly, this arrangement can reduce the negative impact on the light absorption effect of the photovoltaic module.

[0079] Optionally, the light transmittance of the first encapsulating film layer 12 may be, for example, 89%, 90%, 91%, 92%, 94%, 96%, or a range consisting of any two of the above values.

[0080] In some embodiments, the basis weight of the first encapsulating film layer 12 is 300~900 g / m². 2 This design can absorb the impact energy of severe weather conditions, such as hail, reducing the risk of microcracks in battery cell 2.

[0081] Optionally, the basis weight of the first encapsulating film layer 12 can be, for example, 300 g / m². 2 400g / m 2 500g / m 2 600g / m 2 700g / m 2 800g / m 2 Or 900g / m 2 etc., or a range consisting of any two of the above values.

[0082] In some embodiments, the first encapsulating film layer 12 includes a first flame-retardant film layer 121, a fiber layer 122, and a second flame-retardant film layer 123, arranged sequentially from top to bottom. The thickness of the first encapsulating film layer 12 is 240~1100μm. This arrangement enhances the flame-retardant effect through the first and second flame-retardant film layers 121 and 123, and strengthens the impact resistance of the component through the fiber layer 122.

[0083] In some embodiments, the thickness of the first encapsulating film layer 12 is 240~1100μm. This setting provides sufficient adhesion and further improves the impact resistance of the module. If the thickness is too thin, the effect on improving the impact resistance of the module is limited; if the thickness is too thick, it will negatively affect the light transmittance and thus the photoelectric conversion efficiency of the module.

[0084] Optionally, the thickness of the first encapsulating film layer 12 can be, for example, 240μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm, 1000μm or 1100μm, or a range consisting of any two of the above values.

[0085] In some embodiments, the thickness of the first flame-retardant adhesive film layer 121 is 100~450 μm. This arrangement provides interfacial adhesion and stress buffering. If the thickness is too thin, the adhesive ability is limited; if the thickness is too thick, it has an adverse effect on light transmission.

[0086] Optionally, the thickness of the first flame-retardant adhesive film layer 121 can be, for example, 100μm, 150μm, 200μm, 250μm, 260μm, 280μm, 300μm, 350μm, 400μm or 450μm, or a range consisting of any two of the above values.

[0087] In some embodiments, the thickness of the fiber layer 122 is 40~200 μm. This arrangement provides the component with impact resistance, resulting in better hail resistance and reducing adverse effects on light transmittance.

[0088] Optionally, the thickness of the fiber layer 122 can be, for example, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm or 200 μm, or a range consisting of any two of the above values.

[0089] In some embodiments, the thickness of the second flame-retardant adhesive film layer 123 is 100~450μm. Similar to the first flame-retardant adhesive film layer 121, it provides better interfacial adhesion and stress buffering. If the thickness is too thin, the adhesion is limited; if the thickness is too thick, it has an adverse effect on light transmission.

[0090] Optionally, the thickness of the second flame-retardant adhesive film layer 123 may be, for example, 100μm, 150μm, 200μm, 250μm, 260μm, 280μm, 300μm, 350μm, 400μm or 450μm, or a range consisting of any two of the above values.

[0091] It should be noted that the thickness of the first flame-retardant adhesive film layer 121 and the second flame-retardant adhesive film layer 123 can be the same or different, and can be set according to actual needs. This utility model does not make any special limitation in this regard.

[0092] In some embodiments, the fiber layer 122 includes at least one of fiberglass mat or fiberglass cloth. Fiberglass mat has good flexibility but lower strength than fiberglass cloth, making it suitable for curved components; fiberglass cloth has good strength but lower flexibility than fiberglass mat, making it suitable for planar components. Different materials for the fiber layer 122 can be selected according to different application scenarios, and this invention does not impose any particular limitations.

[0093] In some embodiments, the basis weight of the fiber layer 122 is 100~400 g / m².2 This configuration further enhances the impact resistance of the components. Too low a basis weight offers limited improvement in impact resistance; too high a basis weight results in poor adhesion of the flame-retardant adhesive layer, potentially leading to delamination.

[0094] Optionally, the basis weight of the fiber layer 122 can be, for example, 100 g / m². 2 200g / m 2 300g / m 2 Or 400g / m 2 etc., or a range consisting of any two of the above values.

[0095] In some embodiments, the first flame-retardant adhesive film layer 121 and / or the second flame-retardant adhesive film layer 123 are a mixed coating of phosphorus-nitrogen flame retardant and an adhesive film. The adhesive film may be selected from at least one of ethylene-vinyl acetate copolymer (EVA), ethylene-octene copolymer (POE), and vinyl acetate-olefin-vinyl acetate copolymer (EPE). The adhesive film has good chemical stability, and as a base carrier for the mixed coating, it can provide uniform dispersion of the phosphorus-nitrogen flame retardant, maintaining the functional stability of the first flame-retardant adhesive film layer 121 and / or the second flame-retardant adhesive film layer 123. The addition of the phosphorus-nitrogen flame retardant helps to enhance the flame-retardant performance.

[0096] In some embodiments, the basis weight of the adhesive film is 300~900g / m². This setting provides more uniform protection for the battery cell 2, enhancing the module's moisture resistance and microcrack resistance.

[0097] In some embodiments, the back-side encapsulation structure 3 includes a second encapsulating film layer 31 and a photovoltaic backsheet 32. This configuration enhances the protective effect on the back of the photovoltaic module. It is understood that the material composition of the second encapsulating film layer 31 can be the same as that of the first flame-retardant film layer 121, and will not be described in detail here.

[0098] It should be noted that the second encapsulating film layer 31 in the back-side encapsulation structure 3 can be made of different materials depending on the type of battery string. For example, in a module composed of bifacial cells, the second encapsulating film layer 31 on the back can be made of a transparent material to increase the incident efficiency of light on the back side. In a module composed of back-contact cells, either a transparent or non-transparent material can be used, without particular limitation.

[0099] In some embodiments, the thickness of the second encapsulating film layer 31 is 300~950μm. This configuration allows the photovoltaic backsheet 32 ​​to be tightly bonded to the battery cell 2.

[0100] Optionally, the thickness of the second encapsulating film layer 31 may be, for example, 300μm, 400μm, 480μm, 500μm, 600μm, 700μm, 800μm, 900μm or 950μm, or a range consisting of any two of the above values.

[0101] In some embodiments, the thickness of the photovoltaic backsheet 32 ​​is 300~800μm. This configuration enhances the protective effect of the photovoltaic backsheet 32.

[0102] Optionally, the thickness of the photovoltaic backsheet 32 ​​may be, for example, 300μm, 400μm, 500μm, 600μm, 700μm, 750μm, or 800μm, 900μm, or 950μm, or a range consisting of any two of the above values.

[0103] In some embodiments, the photovoltaic backsheet 32 ​​is made of chlorinated polyvinyl chloride. The same material as the substrate layer 112 provides good fire resistance for both the front encapsulation structure 1 and the back encapsulation structure 3.

[0104] In some embodiments, the present invention may be laminated with other thin films and / or coatings on the surface of the transparent front panel layer 11 and / or the photovoltaic back panel 32 as needed.

[0105] In some embodiments, it is understood that chlorinated polyvinyl chloride can be used as a substrate layer 112 and fixed to the upper surface of the battery cell 2 through the first encapsulation film layer 12, or it can be laminated with other materials to the upper surface of the battery cell 2. This utility model does not make any particular limitation.

[0106] In some implementations, the above-mentioned multi-layered structures can be bonded together by hot pressing with a laminator to form a photovoltaic module.

[0107] This invention utilizes a combination of different layered structures to achieve photovoltaic modules with both good fire resistance and impact resistance, meeting the requirements for fire protection and hail resistance. Furthermore, the photovoltaic modules of this invention are lightweight yet possess high mechanical strength, a stable structure, and a long service life, allowing for direct application to the roofs of old factories, corrugated steel structures, and other buildings, thus broadening the application scenarios for photovoltaic modules.

[0108] In one specific embodiment, a transparent front panel layer, a first encapsulating film layer, a battery cell, a second encapsulating film layer, and a photovoltaic backsheet are integrally laminated and formed from top to bottom using a laminator with heating and vacuuming. Specifically, the transparent front panel layer comprises, from top to bottom, a first weather-resistant and flame-retardant coating, a chlorinated polyvinyl chloride (PVC) vinyl material layer, and a second weather-resistant and flame-retardant coating. The first weather-resistant and flame-retardant coating has a thickness of 25 μm, the chlorinated PVC vinyl material layer has a thickness of 710 μm, and the second weather-resistant and flame-retardant coating has a thickness of 15 μm. The overall thickness of the transparent front panel layer is 750 μm, and the light transmittance is 88%. Both weather-resistant and flame-retardant coatings are hybrid coatings formed by mixing 10% melamine by mass into polyester resin. The first encapsulating film layer has a basis weight of 700 g / m³. 2 The light transmittance is 89%, and the overall thickness is 600μm. The first encapsulation film layer, from top to bottom, consists of a first flame-retardant film layer, a glass fiber layer, and a second flame-retardant film layer. Both the first and second flame-retardant film layers are 260μm thick and are formed by mixing melamine into POE to create a mixed film layer. The melamine mass fraction is 10%. The glass fiber layer uses a basis weight of 200g / m². 2 The fiberglass cloth has a fiberglass layer thickness of 80 μm. The second encapsulating film layer has a thickness of 480 μm. Similarly, melamine is mixed into the POE to form a mixed encapsulating film layer, with a melamine mass fraction of 10%. The POE has a basis weight of 450 g / m³. 2 The photovoltaic backsheet layer is 750μm thick and made of chlorinated polyvinyl chloride sheet. According to the IEC61730-2 fire resistance test standard, the photovoltaic module obtained by using this embodiment can achieve a CLASS A fire resistance rating; while most conventional flexible modules currently have a CLASS C fire resistance rating. The photovoltaic module of this invention significantly improves the fire safety of the module and broadens its application scenarios.

[0109] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A photovoltaic module, characterized in that, It includes a front packaging structure, a battery cell, and a back packaging structure that are stacked in sequence. The front-side encapsulation structure includes a transparent front panel layer and a first encapsulation film layer arranged sequentially from top to bottom; The transparent front panel layer includes a first weather-resistant and flame-retardant coating, a substrate layer, and a second weather-resistant and flame-retardant coating arranged sequentially from top to bottom, and the thickness of the transparent front panel layer is 300~800μm.

2. The photovoltaic module according to claim 1, characterized in that, The thickness of the first weather-resistant and flame-retardant coating is 15~50μm, the thickness of the substrate layer is 275~720μm, and the thickness of the second weather-resistant and flame-retardant coating is 10~30μm.

3. The photovoltaic module according to claim 1, characterized in that, The light transmittance of the transparent front panel is >85%.

4. The photovoltaic module according to claim 1, characterized in that, The light transmittance of the first encapsulating film layer is >88%, and the basis weight of the first encapsulating film layer is 300~900 g / m². 2 .

5. The photovoltaic module according to claim 4, characterized in that, The first encapsulation film layer includes a first flame-retardant film layer, a fiber layer, and a second flame-retardant film layer arranged sequentially from top to bottom, and the thickness of the first encapsulation film layer is 240~1100μm.

6. The photovoltaic module according to claim 5, characterized in that, The thickness of the first flame-retardant adhesive film layer is 100~450μm, the thickness of the fiber layer is 40~200μm, and the thickness of the second flame-retardant adhesive film layer is 100~450μm.

7. The photovoltaic module according to claim 6, characterized in that, The fiber layer includes at least one of glass fiber mat or glass fiber cloth; The basis weight of the fiber layer is 100~400 g / m². 2 .

8. The photovoltaic module according to claim 1, characterized in that, The substrate layer is chlorinated polyvinyl chloride; The first weather-resistant and flame-retardant coating and / or the second weather-resistant and flame-retardant coating are a mixture of phosphorus-nitrogen flame retardant and polyester resin.

9. The photovoltaic module according to claim 1, characterized in that, The back-side encapsulation structure includes a second encapsulation film layer and a photovoltaic backsheet; The thickness of the second encapsulating film layer is 300~950μm, the thickness of the photovoltaic backsheet is 300~800μm, and the photovoltaic backsheet is chlorinated polyvinyl chloride.

10. The photovoltaic module according to any one of claims 1 to 9, characterized in that, The battery cell includes multiple battery strings, and each battery string includes multiple solar cells. The solar cells are selected from any one of back contact solar cells, heterojunction solar cells, and tunnel oxide passivated contact cells.

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