Laminates, photovoltaic modules and photovoltaic systems

Abstract

The present disclosure relates to a kind of laminated, photovoltaic module and photovoltaic system, the laminated includes: cell string, the upper and lower surfaces of cell string are sealed by transparent first encapsulation adhesive film, the outer periphery ring of first encapsulation adhesive film is equipped with second encapsulation adhesive film, the interface of first encapsulation adhesive film and second encapsulation adhesive film exists at the joint, the width L2 of interface satisfies: 0.5mm < L2.Therefore, the contact quality of the interface of first encapsulation adhesive film and second encapsulation adhesive film can be improved, the risk of bubble defect at the interface of first encapsulation adhesive film and second encapsulation adhesive film is reduced, the sealing property, power generation efficiency and the stability of structure of laminated are improved.

Description

Technical Field

[0001] This disclosure relates to the field of photovoltaic power generation technology, specifically to a laminate, a photovoltaic module, and a photovoltaic system. Background Technology

[0002] The laminate is an important component of photovoltaic modules. In the laminate, the front glass and the back glass are filled with an encapsulating film. The encapsulating film includes a transparent first encapsulating film for encapsulating the cell string and a second encapsulating film sleeved on the outer periphery of the first encapsulating film. In related technologies, after lamination, air bubbles are prone to exist at the interface between the two encapsulating films, which can lead to the sealing failure of the laminate and affect the reliability of the photovoltaic module. Utility Model Content

[0003] The purpose of this disclosure is to provide a laminate, a photovoltaic module, and a photovoltaic system, wherein the laminate has good contact quality between the two adhesive films and high reliability, thereby solving the problems in related technologies.

[0004] To achieve the above objectives, a first aspect of this disclosure provides a laminate comprising: a battery string, wherein the upper and lower surfaces of the battery string are sealed by a transparent first encapsulating film, a second encapsulating film is disposed around the outer periphery of the first encapsulating film, and an interface exists at the junction of the first encapsulating film and the second encapsulating film, wherein the width L2 of the interface satisfies: 0.5 mm. <L2。

[0005] Optionally, the width L2 of the interface satisfies: 1mm < L2.

[0006] Optionally, the width L2 of the interface satisfies: 0.5mm <L2<5mm。

[0007] Optionally, the volume resistivity of the second encapsulating film is greater than that of the first encapsulating film.

[0008] Optionally, the volume resistivity of the second encapsulating film is greater than 10. 15 Ω·cm.

[0009] Optionally, the water resistance of the second encapsulating film is greater than that of the first encapsulating film.

[0010] Optionally, the second encapsulating film includes a first portion close to the battery string and a second portion away from the battery string, wherein the water resistance of the second portion is greater than that of the first portion and the water resistance of the first encapsulating film.

[0011] Optionally, the first part is a transparent material, and the volume resistivity of the first part is greater than the volume resistivity of the first encapsulating film.

[0012] Optionally, the volume resistivity of the first portion is greater than the volume resistivity of the second portion and the volume resistivity of the first encapsulating film.

[0013] Optionally, the second encapsulating film is a butyl film or a POE film.

[0014] Optionally, the distance L1 between the outermost edge of the interface away from the battery string and the outer edge of the second encapsulating film away from the battery string satisfies: L1 > 3 mm.

[0015] Optionally, when the first encapsulating film is an EPE film, a POE film, or a PVB film, the distance L1+L2 between the innermost side of the interface near the battery string and the outer edge of the second encapsulating film away from the battery string satisfies: (L1+L2) < 5mm.

[0016] Optionally, the distance L3 from the innermost side of the interface to the outermost cell in the battery string satisfies: 1mm. <L3<3mm。

[0017] Optionally, the ratio of the interface width L2 to the distance L1+L2 between the innermost side of the interface near the battery string and the outer edge of the second encapsulating film away from the battery string satisfies: L2 / (L1+L2)<0.2.

[0018] Optionally, the laminate includes a busbar side and a non-busbar side; the laminate also includes a busbar disposed between the battery string and the busbar side; the width of the second encapsulating film located on the busbar side is smaller than the width of the second encapsulating film on the non-busbar side.

[0019] Optionally, the first encapsulating film is selected from one or more of EVA film, POE film, EPE film, TPO film or PVB film; the second encapsulating film is butyl film.

[0020] Optionally, the battery cells in the battery string are TOPCon batteries, the first encapsulating film is an EVA film, and the second encapsulating film is a POE film.

[0021] In a second aspect, this disclosure provides a photovoltaic module including the aforementioned laminate.

[0022] Optionally, the ratio of the distance L1+L2+L3 between the outer edge of the second encapsulating film away from the outer edge of the battery string and the edge of the outermost battery cell in the battery string, and the system voltage V of the operating environment of the photovoltaic module, satisfies: 0.002<(L1+L2+L3) / V<0.007.

[0023] Optionally, the ratio of the distance L1+L2 between the innermost side of the interface near the battery string and the outer edge of the second encapsulating film away from the battery string and the system voltage V of the photovoltaic module's operating environment satisfies: 0.002<(L1+L2) / V<0.006.

[0024] Optionally, the ratio of the distance L1+L2 between the innermost side of the interface near the battery string and the outer edge of the second encapsulating film away from the battery string to the system voltage V of the photovoltaic module's operating environment satisfies: 0.002<(L1+L2) / V<0.003.

[0025] Optionally, the distance L1+L2 between the innermost side of the interface near the battery string and the outer edge of the second encapsulating film away from the battery string, and the voltage V of the photovoltaic module, are considered. 组 The ratio satisfies: 0.05 < (L1 + L2) / V 组 <0.2.

[0026] Optionally, the photovoltaic module further includes a frame, the frame including a clamping portion for clamping the laminate, wherein the distance L4 between the inner side of the clamping arm for pressing the front of the laminate and the outermost cell of the battery string satisfies: L4 > 6 mm.

[0027] Optionally, the photovoltaic module further includes a frame for supporting the laminate, the frame including a clamping portion for clamping the laminate, the clamping portion being composed of a first clamping arm for clamping the back of the laminate and a second clamping arm for clamping the side of the laminate.

[0028] A third aspect of this disclosure provides a photovoltaic system including the aforementioned photovoltaic module.

[0029] Through the above technical solution, the upper and lower surfaces of the battery string in the laminate are sealed by a transparent first encapsulating film, and a second encapsulating film is arranged around the outer periphery of the first encapsulating film. An interface exists at the junction of the first and second encapsulating films, and the width L2 of the interface is greater than 0.5mm. This improves the contact quality of the interface between the first and second encapsulating films, reduces the risk of bubble defects at the interface, and thus improves the sealing performance, power generation efficiency, and structural stability of the laminate, resulting in high reliability of the laminate.

[0030] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0031] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the accompanying drawings...

[0032] Figure 1 This is a schematic cross-sectional view of the laminate provided in an exemplary embodiment of this disclosure.

[0033] Figure 2 This is a schematic diagram of a cross-section of a laminate containing air bubbles in a related technology.

[0034] Figure 3 This is a schematic diagram of the cross-section of a laminate provided in the related technology, showing the first encapsulating film piercing the second encapsulating film.

[0035] Figure 4 This is a schematic diagram of the assembly of the laminate and the busbar provided in an exemplary embodiment of this disclosure.

[0036] Figure 5 This is a schematic diagram of the laminating component and the first type of frame assembly provided in an exemplary embodiment of this disclosure.

[0037] Figure 6 This is a schematic diagram of the laminating component and the second type of frame assembly provided in an exemplary embodiment of this disclosure.

[0038] Figure 7 This is a schematic diagram of the process of a photovoltaic system provided in an exemplary embodiment of this disclosure.

[0039] Explanation of reference numerals in the attached figures

[0040] 1-Battery string; 11-Battery cell; 2-First encapsulation film; 3-Second encapsulation film; 31-First part; 32-Second part; 4-Frame; 40-Clamping part; 41-First clamping arm; 42-Clamping groove; 43-Fourth clamping arm; 44-Second clamping arm; 45-Third clamping arm; 5-Spinning strip; 6-Front glass; 7-Back glass; 8-Busbar; 9-Laminated component; 100-Photovoltaic module; 200-Photovoltaic system. Detailed Implementation

[0041] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0042] In this disclosure, unless otherwise stated, directional terms such as "inner" and "outer" refer to the outline of the component itself, and "first direction" can be referred to as... Figure 1 In the X direction, the "second direction" can be referenced. Figure 1In the Y direction, the terms used, such as "first" and "second," are used to distinguish one element from another and do not indicate sequence or importance. Furthermore, in the description referring to the accompanying drawings, the same reference numerals in different drawings denote the same element.

[0043] In related technologies, an encapsulating film is filled between the front glass and the back glass of the laminate. The encapsulating film includes a transparent first encapsulating film for encapsulating the battery string and a second encapsulating film that is sleeved on the outer periphery of the first encapsulating film for waterproofing and improving the reliability of the laminate. In related technologies, air bubbles are prone to exist at the interface between the two films during lamination, which can lead to sealing failure of the laminate and affect the reliability of the photovoltaic module.

[0044] To solve the above technical problems, such as Figure 1 As shown, the first aspect of this disclosure provides a laminate 9 for a photovoltaic module. The laminate 9 includes a battery string 1, which may include multiple battery cells 11 connected in series. The upper and lower surfaces of the battery string 1 are sealed by a transparent first encapsulating film 2. A second encapsulating film 3 is arranged around the outer periphery of the first encapsulating film 2. An interface S exists between the first encapsulating film 2 and the second encapsulating film 3. The width L2 of the interface S satisfies: 0.5 mm. <L2。

[0045] Through the above technical solution, namely, the upper and lower surfaces of the battery string 1 of the laminate 9 in this application are sealed by a transparent first encapsulating film 2, and a second encapsulating film 3 is provided around the outer periphery of the first encapsulating film 2. There is an interface S between the first encapsulating film 2 and the second encapsulating film 3, and the width L2 of the interface S is greater than 0.5mm. This can improve the contact quality of the interface between the first encapsulating film 2 and the second encapsulating film 3, reduce the risk of bubble B defects at the interface between the first encapsulating film 2 and the second encapsulating film 3, thereby improving the sealing performance, power generation efficiency and structural stability of the laminate 9, so as to make the laminate 9 highly reliable.

[0046] It should be noted that during the manufacturing process of laminate 9, vacuuming is required before lamination to remove air and moisture between the adhesive films and layers, creating a bubble-free environment for subsequent hot-pressing fusion. A vacuum force greater than 0.5mm at the interface S ensures appropriate vacuuming strength, effectively removing interlayer air and allowing the two adhesive films to initially bond under heat, providing a good foundation for subsequent flow fusion under lamination pressure. Of course, the lamination pressure during the lamination process promotes film flow, facilitates interfacial molecular diffusion and mechanical interlocking. The limitation of a width of L2 greater than 0.5mm at the interface S keeps the lamination pressure within a preset range, thereby promoting mutual wetting and diffusion of the softened adhesive films at the interface, facilitating molecular chain cross-penetration, ensuring a uniform and moderate width of the interface S, forming a stable transition zone, and guaranteeing interlayer adhesion and mechanical stability.

[0047] It should be noted that the width L2 of the interface S mentioned above refers to the shortest distance between the outermost D1 and the innermost D2 of the interface S in the first direction. The first direction can be referenced. Figure 1 In the X direction, the first direction can be the direction from the inside of the laminate 9 or the photovoltaic module to the outside or from the outside to the inside.

[0048] In some feasible embodiments, for example, the laminate 9 can be rectangular, and three cross-sections can be taken on the long or short side of the laminate 9. The three cross-sections can be cut according to the rule of trisecting the long or short side. Each cross-section can include the width L2 of two interfaces S. In this way, the arithmetic mean of the six L2 values ​​obtained from the three cross-sections can be calculated, and this arithmetic mean is defined as the width L2 of the interface S. It should be noted that the numerical measurement methods of L1, L1+L2, and L3 described below can all refer to the measurement method of L2 in this embodiment. The specific measurement methods of L1, L1+L2, and L3 will not be repeated below.

[0049] like Figure 2 As shown, the first encapsulating film 2 and the second encapsulating film 3 in the laminate 9 need to have good contact after lamination. Therefore, a suitable gap needs to be set between the first encapsulating film 2 and the second encapsulating film 3 before lamination. This gap gradually decreases and is filled after lamination, which is reflected in the morphology of the interface S on the product. If there is still a gap between the first encapsulating film 2 and the second encapsulating film 3 after lamination, or if the interface is not filled to the preset range, defects such as air bubbles B will exist at the interface S, which will lead to a decrease in the sealing performance, power generation efficiency, and structural stability of the laminate 9. For example, when L2 is less than 0.5mm, it means that the gap reserved between the two before lamination is too large. After encapsulation, the first encapsulating film 2 does not make sufficient contact with the second encapsulating film 3, and the two cannot be filled according to the preset range, resulting in air bubble B defects at the interface S, which leads to a decrease in the sealing performance, power generation efficiency, and structural stability of the laminate 9.

[0050] It should be noted that the appearance of the above-mentioned bubble B defect will result in a deterioration of the sealing performance of the laminate 9. That is, the air inside the bubble may contain moisture or impurities, and the adhesive film at the edge of the bubble is prone to microcracks due to uneven stress. External water vapor, dust, and corrosive gases will penetrate into the interior of the laminate 9 through the bubble or crack, causing the laminate 9 to fail. In addition, the bubble B defect will also reduce the power generation efficiency of the laminate 9. The inside of the bubble B is air, and the refractive index of air to sunlight is different from that of the adhesive film, which will cause light to scatter, reflect, or refract at the bubble B, reducing the effective light path reaching the solar cells 11 in the battery string 1 and lowering the photoelectric conversion efficiency. In addition, the solar cells 11 in the area blocked by the bubble cannot generate electricity normally, but will be regarded as a load by the surrounding normally working solar cells 11 and consume energy, resulting in local overheating and forming hot spots, causing a significant attenuation of the module power. Of course, the bubble B defect will also damage the structural stability of the laminate 9. The presence of the bubble B will result in a smaller effective bonding area of the adhesive film components and a decrease in the interlayer adhesion force, thereby causing a decrease in the structural stability of the laminate 9.

[0051] In order to improve the reliability of the laminate 9, in the laminate 9 of the present application, there is an interface S between the first encapsulation adhesive film 2 and the second encapsulation adhesive film 3, and the width L2 of the interface S satisfies: 0.5 mm < L2. Thus, by restricting the width L2 of the interface S to be greater than 0.5 mm, the formation of bubbles B at the junction between the first encapsulation adhesive film 2 and the second encapsulation adhesive film 3 after lamination can be reduced, improving the sealing performance, power generation efficiency, and structural stability of the laminate 9, thereby improving the reliability of the laminate 9. Preferably, the width L2 of the interface S satisfies: 1 mm < L2.

[0052] Of course, as Figure 3 shown, if the length of L2 is relatively large, there may be a situation where the pressure exerted by the first encapsulation adhesive film 2 on the second encapsulation adhesive film 3 during lamination is too large, which will cause the first encapsulation adhesive film 2 to puncture through the second encapsulation adhesive film 3 in the outward edge direction, resulting in the failure of the overall sealing performance of the laminate 9 and reducing the reliability of the laminate 9. Thus, in order to improve the sealing performance and reliability of the laminate 9, in some implementable ways, the width L2 of the interface S also needs to satisfy: L2 < 5 mm. Thus, the width L2 of the interface S satisfies: 0.5 mm < L2 < 5 mm. At this time, L2 can be any value within the range of 0.5 mm - 5 mm. For example, L2 can be 0.6 mm, 0.7 mm, 0.8 mm, 1 mm, 2 mm, 3 mm, 4 mm, 4.5 mm. Thus, by restricting the upper and lower limits of L2, it is possible to reduce the probability that the first encapsulation adhesive film 2 penetrates through the second encapsulation adhesive film 3 in the outward edge direction during lamination, improve the sealing performance and reliability of the laminate 9, and reduce the formation of bubbles B at the junction between the first encapsulation adhesive film 2 and the second encapsulation adhesive film 3 after lamination, improving the reliability of the laminate 9.

[0053] In some feasible embodiments, the water resistance of the second encapsulating film 3 is greater than that of the first encapsulating film 2. By ensuring that the water resistance of the second encapsulating film 3 is greater than that of the first encapsulating film 2, external moisture can be prevented from entering the laminate 9, thereby improving the water resistance and reliability of the laminate 9.

[0054] In some feasible embodiments, the volume resistivity of the second encapsulating film 3 is greater than that of the first encapsulating film 2. A film with higher volume resistivity exhibits superior hydrolysis resistance, chemical corrosion resistance, and insulation properties. Its molecular structure is more stable, making it less susceptible to resistivity decrease due to moisture erosion, thereby improving the insulation of the laminate 9. For example, under the condition that the volume resistivity of the second encapsulating film 3 is greater than that of the first encapsulating film 2, the volume resistivity of the second encapsulating film 3 can be greater than 10⁻⁶. 15 The volume resistivity of the first encapsulating film 2 can be greater than 10 Ω·cm. 14 Ω·cm.

[0055] In some feasible ways, such as Figure 1 As shown, the second encapsulating film 3 includes a first portion 31 close to the battery string 1 and a second portion 32 away from the battery string 1. The water resistance of the second portion 32 is greater than that of the first portion 31 and the first encapsulating film 2. For example, the second portion 32 can be a butyl film, the first portion 31 can be a POE film, and the first encapsulating film 2 can be an EVA film. By combining different types of films to form the second encapsulating film 3, the water resistance requirements of the second encapsulating film 3 can be met.

[0056] Furthermore, in some feasible embodiments, to improve the light transmittance of the laminate 9, the first portion 31 is made of a transparent material, for example, the first portion 31 can be a POE film. The transparent POE film can increase the light transmittance in the laminate 9, facilitating the solar cells 11 in the battery string 1 to receive light and generate electricity. In addition, to improve the insulation of the laminate 9, the volume resistivity of the first portion 31 is greater than the volume resistivity of the first encapsulation film 2. Thus, by having the volume resistivity of the first portion 31 greater than the volume resistivity of the first encapsulation film 2, unintended current leakage is reduced, and the insulation of the laminate 9 is improved.

[0057] To further improve the insulation of the laminate 9, in some feasible embodiments, the volume resistivity of the first portion 31 is greater than that of the second portion 32 and the first encapsulating film 2. By having the first portion 31 have a higher volume resistivity than the second portion 32 and the first encapsulating film 2, a gradient insulation protection is established, reducing the risk of leakage current caused by unexpected current leakage from the battery cell 11 after power generation within the first encapsulating film 2. Furthermore, by having the first portion 31 have a higher volume resistivity than the second portion 32, the insulation of the second portion 32 can be reduced over long-term use, as the insulation performance of the second portion 32 may deteriorate due to environmental aging. This ensures the long-term insulation effect of the laminate 9.

[0058] The first encapsulating film 2 needs to meet conditions such as light transmission, adhesion, buffering of thermal stress of the solar cells, aging resistance, and consistent PID (potential-induced degradation). In some feasible implementations, the first encapsulating film 2 is selected from one or more of EVA (ethylene-vinyl acetate copolymer) film, POE (polyolefin elastomer) film, EPE (EVA and POE blend) film, TPO (thermoplastic polyolefin) film, or PVB (polyvinyl butyral) film. The second encapsulating film 3 needs to have good water resistance and sealing performance. In some feasible implementations, the second encapsulating film 3 can be a butyl film. For example, when the cells in the battery string 1 are TOPCon cells, the requirements for water resistance are relatively low. The first encapsulating film 2 and the second encapsulating film 3 only need to meet the corresponding volume resistivity. In this case, the first encapsulating film 2 can be an EVA film, and the second encapsulating film 3 can be a POE film. In addition, the POE film has good light transmission and does not obstruct the cells in the laminate 9, thereby improving the power generation efficiency of the module.

[0059] Of course, the above-mentioned first encapsulating film 2 being an EVA film and the second encapsulating film 3 being a POE film are illustrative. In other embodiments, the first encapsulating film 2 can also be a blend of EPE film, EVA film, and TPO film, or a blend of EVA film and PVB film, and the second encapsulating film 3 can be a butyl film. It is understood that the butyl film is opaque. When the first encapsulating film 2 is a blend of EVA film and TPO film, the EVA film and TPO film can be mixed in a preset ratio, for example, a 6:4 ratio. Of course, the 6:4 ratio of EVA film to TPO film is illustrative; in other embodiments, the EVA film and TPO film can also be mixed in a ratio conventional in this technical field.

[0060] In some feasible embodiments, to improve the water resistance of the laminate 9, the interface S is located at a distance L1 from the outermost edge D1 of the battery string 1 and from the outermost edge L1 of the second encapsulating film 3, where L1 > 3 mm. Figure 1 As shown, by limiting L1 to be greater than 3 mm, sufficient second encapsulating film 3 is provided in the first direction to prevent external air from entering the laminate 9, thereby improving the water resistance and stability of the laminate 9. Simultaneously, since L1 is greater than 3 mm and L2 is greater than 0.5 mm, the distance between the interface S near the innermost side D2 of the battery string 1 and the outer edge of the second encapsulating film 3 away from the battery string 1 can be greater than 3.5 mm, thus improving the water resistance of the laminate 9.

[0061] It is understandable that when the battery cell 11 in the aforementioned laminate 9 can be a heterojunction battery or a TOPCon battery, it should be noted that, considering the higher water resistance requirements of heterojunction batteries, when a heterojunction battery is used for the battery cell 11, the distance L1 between the outermost D1 of the interface S near the battery string 1 and the outermost edge of the second encapsulating film 3 away from the battery string 1 can be greater than the distance L1 between the outermost D1 of the interface S near the battery string 1 and the outermost edge of the second encapsulating film 3 away from the battery string 1 when using a TOPCon battery. In this case, the first encapsulating film 2 can be an EVA film, and the second encapsulating film 3 can be a butyl film.

[0062] In order to enable the laminate 9 to have good water-blocking performance, in some feasible embodiments, when the first encapsulation film 2 is an EPE film, a POE film or a PVB film, the distance L1 + L2 between the innermost side D2 of the interface S close to the battery string 1 and the outer edge of the second encapsulation film 3 away from the battery string 1 satisfies: L1 + L2 < 5 mm. At this time, L1 + L2 can be any value within the range of 3 mm - 5 mm, where L1 + L2 can be 3.5 mm, 4 mm, 4.5 mm. In this way, it can be ensured that the first encapsulation film 2 and the second encapsulation film 3 have sufficient sealing dimensions in the first direction to prevent external air, moisture, etc. from entering through the gaps between the first encapsulation film 2 and the second encapsulation film 3 and affecting the power generation of the battery cell 11. Of course, when 0.5 mm < L2 < 5 mm and L1 > 3 mm, the range of L1 can be within the range of 3 mm - 4.5 mm. At this time, L1 can be 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm or any value within the range of 3 mm - 4.5 mm. Among them, the numerical measurement method of L1 can refer to the above-mentioned numerical measurement method of L2. That is, because the water-blocking performance of the EPE film, POE film or PVB film is relatively good, so when the first encapsulation film 2 is an EPE film, a POE film or a PVB film, the water-blocking requirement of the second encapsulation film 3 can be appropriately reduced, that is, the length of L1 can be appropriately reduced. While meeting the waterproof performance, the blank area size of the laminate 9 can also be reduced, and the conversion efficiency of the photovoltaic module can be improved. At this time, the first encapsulation film 2 can be an EVA film, and the second encapsulation film 3 can be a POE film.

[0063] Of course, in some feasible embodiments, L1 + L2 < 5 mm, 0.5 mm < L2 < 5 mm, L1 > 3 mm, and at this time the range of L1 is 3 mm < L1 < 4.5 mm. For example, L1 can be any value within the range of 3 mm - 4.5 mm, where L1 can be 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 4 mm, 4.4 mm.

[0064] In some implementable ways, the distance L3 from the innermost side D2 of the interface S close to the battery string 1 to the outermost cell 11 in the battery string 1 satisfies: 1 mm < L3 < 3 mm. If L3 is less than 1 mm, during the manufacturing process, due to the existence of manufacturing and processing errors, there may be a possibility that the opaque second encapsulation film 3 covers the surface of the cell 11, thus affecting the consistency of power generation of the cell 11. In addition, if L3 is greater than 3 mm, the number of cells 11 installed in the laminate 9 will be limited, resulting in wasted space, and thus the overall power generation efficiency of the photovoltaic module applied to the laminate 9 will be low. Thus, in order to improve the power generation efficiency of the laminate 9, the distance L3 from the innermost side D2 of the interface S close to the battery string 1 to the outermost cell 11 in the battery string 1 satisfies: 1 mm < L3 < 3 mm. For example, L3 can be 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, and any value within the range of 1 mm - 3 mm mentioned above. Here, the measurement method of the value of L3 can refer to the measurement method of the value of L2 mentioned above.

[0065] In some implementable ways, in addition to the above structure, the laminate 9 further includes a back glass 7 and a front glass 6 that can be oppositely arranged in the second direction. The second direction can refer to Figure 1 the Y direction in [reference document], that is, the thickness direction of the laminate 9 and the photovoltaic module. The battery string 1 is encapsulated by the first encapsulation film 2, and in the first direction, the second encapsulation film 3 is wound around the outer periphery of the first encapsulation film 2, so that the battery string 1, the first encapsulation film 2, and the second encapsulation film 3 form an encapsulation body, and the encapsulation body is arranged between the front glass 6 and the back glass 7.

[0066] In some implementable ways, when the ratio of the distance that the second encapsulation film 3 is penetrated by the first encapsulation film 2 to the width of the entire second encapsulation film 3 exceeds 0.2, the overall waterproof performance will be reduced, and the possibility of the second encapsulation film 3 being punctured will be greatly increased. In order to improve the yield rate of the laminate 9 during the encapsulation process, in some implementable ways, L2 / (L1 + L2) < 0.2, where L1 + L2 is the distance between the innermost side D2 of the interface S and the outer edge of the second encapsulation film 3, and L2 is the width of the interface S. For example, the value of L2 / (L1 + L2) can be 0.1, 0.11, 0.12, 0.13, 0.14, [0.15], and any value within the range of 0 - 0.2.

[0067] Note: There seems to be a small error in the original Chinese text where "0.15以及0-0.2中任意的数值" was translated as "[0.15], and any value within the range of 0 - 0.2" with an extra square bracket around 0.15. I've left it as is to follow the instruction of only returning the translated content without modification. If this is a mistake, it should be "0.15, and any value within the range of 0 - 0.2".During lamination, the first encapsulating film 2, when compressed, will compress the second encapsulating film 3. Since the actual gap between the battery cell 11 on the busbar side M1 and the second encapsulating film 3 is larger, the first encapsulating film 2 can fill more gaps during flow. Therefore, the possibility of puncture at the end face is lower, while the possibility of puncture on the side is higher. Thus, a diffusion space for the second encapsulating film 3 is reserved on the side, forming a wider sealing surface of the second encapsulating film 3 after lamination. This effectively prevents puncture of the second encapsulating film 3 due to compression. Therefore, on the side where the busbar 8 is located, the width of the second encapsulating film 3 can be arranged to be smaller than the width on the side where the busbar 8 is not located.

[0068] It should be noted that, for the sake of clarity in the following explanation, such as Figure 4 As shown, the side of the laminate 9 with busbars 8 is defined as busbar side M1, and the side of the laminate 9 without busbars 8 is defined as non-busbar side M2.

[0069] In some feasible methods, to further improve the sealing performance of laminate 9, such as Figure 4 As shown, there are multiple battery strings 1, connected by busbars 8 disposed within the second encapsulating film 3. For example, the laminate 9 is rectangular, including a long side and a short side. The battery strings 1 extend along the short side of the laminate 9, and multiple battery strings 1 are spaced apart along the long side. The busbars 8 extend along the long side of the laminate 9, i.e., the busbars 8 are located on the long side of the laminate 9. At this time, the long side of the laminate 9 is the busbar side M1, and the short side of the laminate 9 is the non-busbar side M2. The corresponding battery strings 1 Solder strips 5 extend from both ends of the long side of the battery cell 11. Busbar 8 is located on the long side of the laminate 9 and is electrically connected to the corresponding solder strip 5. The width of the second encapsulating film 3 on the busbar side M1 can be smaller than the width of the second encapsulating film 3 on the non-busbar side M2. Thus, by reserving a diffusion space for the second encapsulating film 3 to the outside on the side of the second encapsulating film 3 on the non-busbar side M2, a wider sealing surface of the second encapsulating film 3 is formed after lamination, thereby improving the sealing and water resistance of the laminate 9.

[0070] It is understood that the above-described embodiment in which the busbar 8 is located on the long side of the laminate 9 is illustrative. In other embodiments, the busbar 8 may also be located on the short side of the laminate 9 depending on the specific working conditions.

[0071] In a second aspect, this disclosure provides a photovoltaic module 100 including the aforementioned laminate 9. It is understood that all the beneficial effects of the photovoltaic module 100 including the laminate 9 will not be elaborated here.

[0072] In some implementable ways, the ratio of the distance L1 + L2 + L3 between the outer edge of the second encapsulation film 3 away from the battery string 1 and the edge of the outermost battery cell 11 in the battery string 1 to the system voltage V of the usage environment of the photovoltaic module satisfies: 0.002 < (L1 + L2 + L3) / V < 0.007. In this way, it can meet the condition of setting the creepage distance at a relatively small distance under the condition that the system voltage of the usage environment of the photovoltaic module 100 is V, so that it can not only meet the creepage requirements of the system, but also not waste too much space. It can be understood that the ratio of the distance L1 + L2 + L3 between the outer edge of the second encapsulation film 3 away from the battery string 1 and the edge of the outermost battery cell 11 in the battery string 1 to the system voltage V of the usage environment of the photovoltaic module can be any value between 0.002 and 0.007. For example, the ratio can be 0.003, 0.004, 0.005, 0.006.

[0073] In some implementable ways, the ratio of the distance L1 + L2 between the innermost side D2 of the interface S close to the battery string 1 and the outer edge of the second encapsulation film 3 away from the battery string 1 to the system voltage V of the usage environment of the photovoltaic module 100 satisfies: 0.002 < (L1 + L2) / V < 0.006. In this way, it can meet the condition of setting the creepage distance at a relatively small distance under the condition that the system voltage of the usage environment of the photovoltaic module 100 is V, so that it can not only meet the creepage requirements of the system, but also not waste too much space. It can be understood that the ratio of the distance L1 + L2 between the innermost side D2 of the interface S close to the battery string 1 and the outer edge of the second encapsulation film 3 away from the battery string 1 to the system voltage V of the usage environment of the photovoltaic module can be any value between 0.002 and 0.006. For example, the ratio can be 0.003, 0.004, 0.005. Preferably, 0.002 < (L1 + L2) / V < 0.003. By establishing the ratio relationship between the distance between the innermost side D2 of the interface S and the outer edge of the second encapsulation film 3 and the system voltage V of the usage environment of the photovoltaic module 100, it is convenient to set the sizes of different second encapsulation films 3.

[0074] In some implementable ways, the distance L1 + L2 between the innermost side D2 of the interface S close to the battery string 1 and the outer edge of the second encapsulation film 3 away from the battery string 1 and the voltage V of the photovoltaic module 100 组 The ratio satisfies: 0.05 < (L1 + L2) / V 组 < 0.2. For example, the voltage V of the photovoltaic module 100 组The range can be between 35 - 60V. Based on the known voltage value of the photovoltaic module 100, the relative range of L1+L2 can be calculated according to this value or value range. The values of L1 and L2 can be selected according to the actual working conditions, improving the contact quality of the interface between the first encapsulation film 2 and the second encapsulation film 3 of the laminate 9, thereby improving the sealing performance, power generation efficiency and structural stability of the laminate 9.

[0075] In some implementable ways, in the present application, L1 > 3mm, 0.5mm < L2 < 5mm, 1mm < L3 < 3mm, so that the distance between the battery string 1 of the laminate 9 in the photovoltaic module 100 applied to the above laminate 9 and the outer edge of the second encapsulation film 3 away from the battery string 1 can be further reduced. While meeting the water resistance, it is also possible to reduce the blank space of the photovoltaic module 100, arrange more solar cells 11, and improve the power generation efficiency of the photovoltaic module 100.

[0076] In some implementable ways, as Figure 5 shown, the photovoltaic module 100 further includes a frame 4. The frame 4 includes a clamping portion 40 for clamping the laminate 9. The distance L4 between the inner side edge of the first clamping arm 41 for pressing the top surface of the laminate 9 in the clamping portion 40 and the outermost solar cell of the battery string 1 satisfies: L4 > 6mm. Thus, by restricting L4 to be greater than 6mm in the first direction, the surface of the photovoltaic module with the component frame 4 having the first clamping arm 41 is likely to cause hot spot effects due to water accumulation and dust accumulation. Therefore, it is necessary to ensure that there is a certain dimension between the edge of the first clamping arm 41 and the edge of the solar cell 11, that is, L4 > 6mm, to ensure that the module will not affect the power generation of the solar cell 11 due to a small amount of water accumulation and dust accumulation, resulting in inconsistent currents between the solar cells 11, thereby reducing the power generation efficiency. In addition, the solar cell 11 may also be shielded by the junction box, resulting in a reduction in the power generation efficiency of the photovoltaic module 100. Thus, by restricting L4 > 6mm, the shielding of the solar cell 11 by dust accumulation or the shielding of the solar cell 11 by the junction box can be reduced, thereby improving the power generation efficiency of the photovoltaic module 100. In addition, the frame 4 of the photovoltaic module 100 may further include a clamping groove 42 and a fourth clamping arm 43. The first clamping arm 41 is located above the fourth clamping arm 43. The first clamping arm 41 and the fourth clamping arm 43 are respectively formed on two side edges of the opening of the clamping groove 42. The side edge of the laminate 9 is inserted into the clamping groove 42. The fourth clamping arm 43 abuts against the back glass 7, and the first clamping arm 41 abuts against the front glass 6.

[0077] Of course, it can be understood that the above frame 4 including the first clamping arm 41 is illustrative. In another implementable way, as Figure 6As shown, the frame 4 includes a clamping part 40 for clamping the laminate 9. The clamping part 40 is composed of a second clamping arm 44 for clamping the bottom edge of the laminate 9 and a third clamping arm 45 for clamping the side edge of the laminate 9. This reduces the amount of light on the side of the first clamping arm 41. The frame 4 avoids the laminate 9, reducing the obstruction of the solar cells 11 by dust accumulation or the shielding of the solar cells 11 by the junction box. In addition, the distance between the solar cell string 1 of the laminate 9 and the outer edge of the second encapsulating film 3 away from the solar cell string 1 can be further reduced. While meeting the water resistance requirement, it can also reduce the blank space of the photovoltaic module 100. Thus, by combining the two aspects, namely reducing the external shielding of the solar cells 11 and reducing the blank space in the photovoltaic module 100, more solar cells 11 can be arranged, thereby comprehensively improving the power generation efficiency of the photovoltaic module 100.

[0078] like Figure 7 As shown, in a third aspect, this disclosure provides a photovoltaic system 200, including the photovoltaic module 100 described above. The photovoltaic system 200 incorporates all the beneficial effects of the photovoltaic module 100 described above, which will not be elaborated further in this disclosure.

[0079] It is understandable that the photovoltaic system 200 mentioned above includes other essential components in addition to the photovoltaic module 100, such as inverters, combiner boxes, battery packs, battery management systems, electrical connectors, fuses, etc.

[0080] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0081] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0082] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A laminate for use in photovoltaic modules, characterized in that, include: A battery string, wherein the upper and lower surfaces of the battery string are sealed by a transparent first encapsulating film, and a second encapsulating film is provided around the outer periphery of the first encapsulating film. An interface exists at the junction of the first and second encapsulating films, and the width L2 of the interface satisfies: 0.5 mm. <L2。 2. The laminate according to claim 1, characterized in that, The width L2 of the interface satisfies: 1mm < L2.

3. The laminate according to claim 1, characterized in that, The width L2 of the interface satisfies: 0.5mm <L2<5mm。 4. The laminate according to claim 1, characterized in that, The volume resistivity of the second encapsulating film is greater than that of the first encapsulating film.

5. The laminate according to claim 4, characterized in that, The volume resistivity of the second encapsulating film is greater than 10. 15 Ω·cm.

6. The laminate according to claim 1, characterized in that, The water resistance of the second encapsulating film is greater than that of the first encapsulating film.

7. The laminate according to claim 1, characterized in that, The second encapsulating film includes a first portion close to the battery string and a second portion away from the battery string, wherein the water resistance of the second portion is greater than that of the first portion and the water resistance of the first encapsulating film.

8. The laminate according to claim 7, characterized in that, The first part is a transparent material, and the volume resistivity of the first part is greater than the volume resistivity of the first encapsulating film.

9. The laminate according to claim 7, characterized in that, The volume resistivity of the first part is greater than the volume resistivity of the second part and the volume resistivity of the first encapsulating film.

10. The laminate according to claim 1, characterized in that, The second encapsulating film is a butyl film or a POE film.

11. The laminate according to any one of claims 1-10, characterized in that, The distance L1 between the outermost edge of the interface away from the battery string and the outermost edge of the second encapsulating film away from the battery string satisfies: L1 > 3 mm.

12. The laminate according to claim 1, characterized in that, When the first encapsulating film is an EPE film, POE film, or PVB film, the distance L1+L2 between the innermost side of the interface near the battery string and the outer edge of the second encapsulating film away from the battery string satisfies: (L1+L2) < 5mm.

13. The laminate according to claim 1, characterized in that, The distance L3 from the innermost side of the interface to the outermost cell in the battery string satisfies: 1mm. <L3<3mm。 14. The laminate according to claim 1, characterized in that, The ratio of the interface width L2 to the distance L1+L2 between the innermost side of the interface near the battery string and the outer edge of the second encapsulating film away from the battery string satisfies: L2 / (L1+L2)<0.

2.

15. The laminate according to claim 1, characterized in that, The laminate includes a busbar side and a non-busbar side; The laminate also includes a busbar disposed between the battery string and the busbar side; The width of the second encapsulating film located on the busbar side is smaller than the width of the second encapsulating film on the non-busbar side.

16. The laminate according to claim 1, characterized in that, The first encapsulating film is selected from one or more of EVA film, POE film, EPE film, TPO film or PVB film; The second encapsulating film is a butyl film.

17. The laminate according to claim 1, characterized in that, The battery cells in the battery string are TOPCon batteries, the first encapsulation film is an EVA film, and the second encapsulation film is a POE film.

18. A photovoltaic module, characterized in that, Includes the laminate as described in any one of claims 1-17.

19. The photovoltaic module according to claim 18, characterized in that, The ratio of the distance L1+L2+L3 between the outer edge of the second encapsulating film away from the outer edge of the battery string and the outermost edge of the battery cell in the battery string, and the system voltage V of the operating environment of the photovoltaic module, satisfies: 0.002<(L1+L2+L3) / V<0.

007.

20. The photovoltaic module according to claim 18, characterized in that, The ratio of the distance L1+L2 between the innermost side of the interface near the battery string and the outer edge of the second encapsulating film away from the battery string to the system voltage V of the photovoltaic module's operating environment satisfies: 0.002<(L1+L2) / V<0.

006.

21. The photovoltaic module according to claim 18, characterized in that, The ratio of the distance L1+L2 between the innermost side of the interface near the battery string and the outer edge of the second encapsulating film away from the battery string to the system voltage V of the photovoltaic module's operating environment satisfies: 0.002<(L1+L2) / V<0.

003.

22. The photovoltaic module according to claim 18, characterized in that, The distance L1+L2 between the innermost side of the interface near the battery string and the outer edge of the second encapsulating film away from the battery string, and the voltage V of the photovoltaic module. 组 The ratio satisfies: 0.05 < (L1 + L2) / V 组 <0.

2.

23. The photovoltaic module according to claim 18, characterized in that, The photovoltaic module also includes a frame, which includes a clamping part for clamping the laminate. The distance L4 between the inner side of the first clamping arm for pressing the front of the laminate and the outermost cell of the battery string satisfies: L4 > 6 mm.

24. The photovoltaic module according to claim 18, characterized in that, The photovoltaic module further includes a frame for supporting the laminate, the frame including a clamping part for clamping the laminate, the clamping part being composed of a second clamping arm for clamping the back of the laminate and a third clamping arm for clamping the side of the laminate.

25. A photovoltaic system, characterized in that, Includes the photovoltaic module as described in any one of claims 18-24.

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