Photovoltaic encapsulation film and photovoltaic module

Abstract

The present application belongs to the field of photovoltaic technology. The present application discloses a photovoltaic encapsulation film, which includes a first film outer layer, a second film outer layer and a film inner layer; the second film outer layer is arranged on the side of the film inner layer away from the first film outer layer; the film inner layer is arranged between the first film outer layer and the second film outer layer, the film inner layer includes a barrier layer, the barrier layer includes a first barrier layer and a second barrier layer; the first barrier layer is one of an EVOH layer or a PVDC layer; the second barrier layer is arranged on at least one side of the first barrier layer, the second barrier layer is one of a PA layer, an EVOH layer or a PVDC layer; the oxygen permeability of the film inner layer is less than or equal to 100cm 3 / (m 2 ·24h·0.1MPa). The present application also discloses a photovoltaic module. The photovoltaic encapsulation film in the present application has both good water vapor barrier performance and good oxygen barrier performance, and has high reliability, so that the photovoltaic module can operate stably for a long time.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic technology, and in particular relates to a photovoltaic encapsulation film and a photovoltaic module. Background Art

[0002] With the development of society, energy shortage and environmental pollution problems have become increasingly serious. It has become a consensus that we should vigorously develop the sustainable development path of renewable energy. Among them, photovoltaic power generation technology with unique advantages has been rapidly developed.

[0003] Photovoltaic encapsulation film is an important encapsulation material in photovoltaic modules. Photovoltaic modules are often used in some harsh environments, so photovoltaic encapsulation film is required to have certain water-blocking and corrosion-resistant effects to ensure that photovoltaic modules can operate stably and long-term.

[0004] Water vapor and oxygen in the atmosphere can penetrate into the photovoltaic module and corrode the grid lines of the cell, affecting the power generation efficiency of the photovoltaic module, especially the N-type TOPCon cell single-glass module. However, the high barrier performance of photovoltaic encapsulation film in related technologies usually only focuses on the barrier to water vapor, while ignoring the impact of oxygen penetration on photovoltaic modules. Summary of the invention

[0005] The embodiment of the present application provides a photovoltaic encapsulation film, which has both excellent water vapor barrier performance and oxygen barrier performance and has high reliability, so that the photovoltaic module can operate stably for a long time.

[0006] The embodiment of the present application provides a photovoltaic encapsulation film, which includes a first film outer layer, a second film outer layer and a film inner layer; the second film outer layer is arranged on one side of the first film outer layer; the film inner layer, the film inner layer is arranged between the first film outer layer and the second film outer layer, the film inner layer includes a barrier layer, the barrier layer includes a first barrier layer and a second barrier layer; the first barrier layer is one of an EVOH layer or a PVDC layer; the second barrier layer is arranged on at least one side of the first barrier layer, the second barrier layer is one of a PA layer, an EVOH layer or a PVDC layer; the oxygen permeability of the film inner layer is less than or equal to 100cm 3 / (m 2 ·24h·0.1MPa).

[0007] Furthermore, the inner layer of the adhesive film also includes a support layer, and the support layer is arranged on at least one side of the barrier layer.

[0008] Furthermore, the support layer includes a first support layer and a second support layer, the first support layer is arranged on one side of the barrier layer, and the second support layer is arranged on the side of the barrier layer away from the first support layer; the first support layer is one of a PP layer, a PE layer or a CPE type film layer; the second support layer is one of a PP layer, a PE layer or a CPE type film layer.

[0009] Furthermore, the inner layer of the adhesive film also includes a bonding layer, and the bonding layer is arranged between the supporting layer and the barrier layer.

[0010] Furthermore, the inner layer of the adhesive film also includes a protective layer, and the protective layer is arranged on at least one side of the barrier layer.

[0011] Furthermore, the inner layer of the adhesive film also includes an adhesive layer, and the adhesive layer is arranged between the protective layer and the barrier layer.

[0012] Furthermore, the barrier layer further includes a third barrier layer, and the third barrier layer is disposed on at least one side of the first barrier layer and / or at least one side of the second barrier layer.

[0013] Furthermore, the thickness of the inner layer of the adhesive film is 10 μm to 180 μm.

[0014] Furthermore, the outer layer of the first adhesive film is one of an EVA layer or a POE layer, and the weight of the outer layer of the first adhesive film is 100g / m 2 ~300g / m 2 The outer layer of the second film is one of an EVA layer or a POE layer, and the weight of the outer layer of the second film is 100g / m 2 ~300g / m 2 .

[0015] The present application also provides a photovoltaic module, which includes a front substrate, a front packaging film, a battery layer, a rear packaging film and a rear substrate stacked in sequence; at least one of the front packaging film or the rear packaging film is selected from the above-mentioned photovoltaic packaging film.

[0016] The photovoltaic encapsulation film in the present application has multiple barrier layers, which can better block water vapor and oxygen, have high reliability, and enable the photovoltaic module to operate stably for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the cross-sectional structure of a photovoltaic encapsulation film in one embodiment of the present application;

[0018] Figure 2 This is a schematic diagram of the cross-sectional structure of the inner layer of the adhesive film in the first embodiment of the present application;

[0019] Figure 3 This is a schematic diagram of the cross-sectional structure of the inner layer of the adhesive film in the second embodiment of the present application;

[0020] Figure 4 This is a schematic diagram of the cross-sectional structure of the inner layer of the adhesive film in the third embodiment of the present application;

[0021] Figure 5 This is a schematic diagram of the cross-sectional structure of the inner layer of the adhesive film in the fourth embodiment of the present application;

[0022] Figure 6 This is a schematic diagram of the cross-sectional structure of a photovoltaic module in one embodiment of the present application;

[0023] Figure 7 It is a power attenuation diagram of the comparative example and the embodiment after accelerated aging under 105°C-95%RH conditions.

[0024] In the figure: photovoltaic encapsulation film 100, first film outer layer 11, second film outer layer 12, film inner layer 13, barrier layer 131, first barrier layer 1311, second barrier layer 1312, third barrier layer 1313, support layer 132, first support layer 1321, second support layer 1322, adhesive layer 133, protective layer 134; photovoltaic module 200, front substrate 21, front encapsulation film 22, battery cell layer 23, rear encapsulation film 24, rear substrate 25. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the specific implementation manner of the present application will be clearly and completely described below in conjunction with the drawings in the implementation manner of the present application.

[0026] Water vapor and oxygen in the atmosphere will penetrate into the interior of photovoltaic modules and corrode the grid lines of the cell cells, affecting the power generation efficiency of the photovoltaic modules. However, the high barrier performance of photovoltaic encapsulation films in related technologies usually only focuses on the barrier to water vapor, while ignoring the impact of oxygen on photovoltaic modules. On the one hand, since water vapor is more likely to penetrate into the interior of photovoltaic modules and corrode the grid lines of the cell cells than oxygen, people pay more attention to the water barrier performance of photovoltaic encapsulation films; on the other hand, for the high oxygen barrier materials in the prior art, their water barrier performance is poor and they have certain hygroscopicity, which makes it difficult to meet the higher water barrier requirements of photovoltaic encapsulation films. In order to solve this problem, the present invention provides a photovoltaic encapsulation film with good water barrier performance and oxygen barrier performance.

[0027] The present application embodiment provides a Figure 1 The photovoltaic encapsulation film 100 shown in the figure comprises a first film outer layer 11, a second film outer layer 12 and a film inner layer 13. The second film outer layer 12 is arranged on one side of the first film outer layer 11, and the film inner layer 13 is arranged between the first film outer layer 11 and the second film outer layer 12. Figure 2As shown, the inner layer 13 of the film includes a barrier layer 131, and the barrier layer 131 includes a first barrier layer 1311 and a second barrier layer 1312. The first barrier layer 1311 is a high barrier layer 131, which has excellent oxygen barrier properties and can improve the oxygen barrier properties of the photovoltaic encapsulation film 100. Although the first barrier layer 1311 has good oxygen barrier properties, only setting a single first barrier layer 1311 cannot meet the water barrier and weather resistance required by the photovoltaic encapsulation film 100. Therefore, a second barrier layer 1312 is also provided on at least one side of the first barrier layer 1311. The second barrier layer 1312 has certain oxygen barrier and water barrier properties, which can assist the first barrier layer 1311 in blocking oxygen and improve the water barrier properties of the inner layer 13 of the film. Through the mutual cooperation of the first barrier layer 1311 and the second barrier layer 1312, the oxygen permeability of the inner layer 13 of the film can be made less than or equal to 100cm 3 / (m 2 ·24h·0.1MPa) to prevent oxygen from penetrating into the interior of the photovoltaic module. The first film outer layer 11 and the second film outer layer 12 have good encapsulation performance and good bonding performance with other interfaces. The first film outer layer 11 and the second film outer layer 12 can also provide certain water-blocking and aging-resistant properties, can protect the film inner layer 13 and improve the weather resistance and stability of the photovoltaic encapsulation film 100. The photovoltaic encapsulation film 100 in the embodiment of the present application can have good water-blocking and oxygen-blocking properties by setting the first film outer layer 11, the second film outer layer 12 and the film inner layer 13.

[0028] As an optional implementation, Figure 3 As shown, the second barrier layer 1312 is disposed on both sides of the first barrier layer 1311. The sandwich structure formed by the first barrier layer 1311 and the second barrier layer 1312 can further improve the oxygen and water barrier properties of the film inner layer 13, and improve the reliability of the photovoltaic encapsulation film 100.

[0029] As an optional embodiment, the first barrier layer 1311 includes at least one of an EVOH layer or a PVDC layer. The EVOH layer is an ethylene-vinyl alcohol copolymer layer, and the PVDC layer is a polyvinylidene chloride layer. The EVOH layer and the PVDC layer have high transparency and high light transmittance, and can be applied to the photovoltaic encapsulation film 100. The EVOH layer and the PVDC layer have good oxygen barrier properties, which can make the inner layer 13 of the film have good oxygen barrier properties. The EVOH layer has a higher oxygen barrier rate, better thermal stability and processing performance; the PVDC layer has better water barrier ability than the EVOH layer. During production, a suitable first barrier layer 131 can be selected according to the use environment and requirements.

[0030] As an optional embodiment, the second barrier layer 1312 is one of a PA layer, an EVOH layer, or a PVDC layer. The PA layer, the EVOH layer, or the PVDC layer has certain oxygen barrier properties and water vapor barrier properties, and can protect the first barrier layer 1311 while further improving the oxygen barrier and water barrier properties of the film inner layer 13. It should be noted that the material selected for the first barrier layer 1311 and the material selected for the second barrier layer 1312 can be the same or different.

[0031] As an optional implementation, Figure 3 As shown, the inner film layer 13 further includes a support layer 132, and the support layer 132 is disposed on at least one side of the barrier layer 131. The support layer 132 has good physical and mechanical properties and can support and protect the inner film layer 13. The support layer 132 can also provide a certain heat sealing performance, improve the interlayer bonding force between the inner film layer 13 and the first film outer layer 11 and the second film outer layer 12, and improve the packaging performance of the photovoltaic packaging film 100.

[0032] As an optional implementation, Figure 3 As shown, the support layer 132 includes a first support layer 1321 and a second support layer 1322, the first support layer 1321 is arranged on one side of the barrier layer 131, and the second support layer 1322 is arranged on the side of the barrier layer 131 away from the first support layer 1321. Providing support layers 132 on both sides of the barrier layer 131 can better protect the barrier layer 131 located in the middle, and improve the reliability of the photovoltaic encapsulation film 100. Providing support layers 132 on both sides of the barrier layer 131 does not require distinguishing between the front and back during use, making the use of the photovoltaic encapsulation film 100 more convenient.

[0033] As an optional embodiment, the first support layer 1321 is one of a PP layer, a PE layer or a CPE type film layer, and the second support layer 1322 is one of a PP layer, a PE layer or a CPE type film layer. The PP layer, the PE layer and the CPE type film layer have good mechanical properties and can support and protect the first barrier layer 1311 and the second barrier layer 1312. The PP layer, the PE layer and the CPE type film layer have good processing properties and are convenient for the production and processing of the photovoltaic encapsulation film 100.

[0034] As an optional implementation, Figure 3As shown, the adhesive film inner layer 13 further includes an adhesive layer 133, and the adhesive layer 133 is disposed between the support layer 132 and the barrier layer 131. The adhesive layer 133 can bond the support layer 132 and the barrier layer 131. For example, the PP layer, PE layer, and CPE type film layer have better support and protection capabilities, but have poor affinity with the barrier layer 131. When the support layer 132 adopts the PP layer, PE layer, and CPE type film layer, the two layers with poor affinity can be firmly bonded together through the adhesive layer 133, thereby improving the structural stability of the adhesive film inner layer 13.

[0035] As an optional implementation, the adhesive layer 133 may be a conventional adhesive resin layer (TIE layer). The adhesive resin has good adhesive properties and can improve the structural stability of the adhesive film inner layer 13.

[0036] As an optional implementation, Figure 4 As shown, the film inner layer 13 further includes a protective layer 134, which is disposed on at least one side of the barrier layer 131. The protective layer 134 can protect the barrier layer 131, making the barrier layer 131 less susceptible to damage, thereby increasing the service life of the film inner layer 13 and further improving the oxygen barrier capability.

[0037] As an optional embodiment, when the inner layer 13 of the adhesive film is provided with a protective layer 134 and a support layer 132, the protective layer 134 is provided on the side of the support layer 132 away from the barrier layer 131. The wear resistance and breakdown resistance of the protective layer 134 are better than those of the support layer 132. Being provided on the outer layer can make the mechanical properties of the inner layer 13 of the adhesive film better and the reliability higher.

[0038] As an optional implementation, an adhesive layer 133 may be provided between the protective layer 134 and the barrier layer 131 , and between the protective layer 134 and the support layer 132 , so as to make the structure of the inner layer 13 of the adhesive film more stable.

[0039] As an optional embodiment, the protective layer 134 includes a PA layer. The PA layer is a multilayer composite structure whose main polymer material is polyamide. The PA layer has good mechanical properties, wear resistance and breakdown resistance, and can better protect the first barrier layer 1311 and the second barrier layer 1312. The PA layer also has certain barrier properties, which can further improve the oxygen barrier and water vapor barrier properties of the inner layer 13 of the film. The protective layer 134 can use the same PA layer as the second barrier layer 1312, or a PA layer different from the second barrier layer 1312. For example, the second barrier layer 1312 uses nylon MXD6 with better barrier properties, and the protective layer 134 uses conventional nylon 66.

[0040] As an optional implementation, Figure 5As shown, the barrier layer 131 further includes a third barrier layer 1313, which is disposed on at least one side of the first barrier layer 1311 and / or at least one side of the second barrier layer 1312. The third barrier layer 1313 can further improve the water and oxygen barrier capabilities of the film inner layer 13, so that the photovoltaic encapsulation film 100 can better protect the solar cells.

[0041] As an optional embodiment, the third barrier layer 1313 includes a PVDC layer. The PVDC layer has good oxygen barrier properties and certain water vapor barrier properties, and can assist the first barrier layer 1311 and the second barrier layer 1312 to improve the water vapor barrier properties and oxygen barrier properties of the film inner layer 13.

[0042] As an optional implementation, the thickness of the film inner layer 13 is 10 μm to 180 μm. Under this thickness, the film inner layer 13 has good water and oxygen barrier properties, and the photovoltaic encapsulation film 100 is thinner as a whole, meeting the requirements of thin photovoltaic modules.

[0043] As an optional embodiment, the first film outer layer 11 is one of an EVA layer or a POE layer, and the second film outer layer 12 is one of an EVA layer or a POE layer. EVA is an ethylene-vinyl acetate copolymer, and the EVA layer has high transparency, excellent UV aging resistance and excellent wet heat aging resistance, extremely low shrinkage, and high volume resistivity. EVA also has high adhesion ability, can be applied to various interfaces, and can better bond the film inner layer 13 to the photovoltaic substrate or battery cell. POE is a polyolefin elastomer, and the POE layer has excellent toughness and good processability, has no unsaturated double bonds in the molecular structure, and has excellent aging resistance.

[0044] As an optional embodiment, the weight of the first film outer layer 11 is 100 g / m 2 ~300g / m 2 The weight of the second film outer layer 12 is 100 g / m 2 ~300g / m 2 The increase in the gram weight of the first film outer layer 11 and the second film outer layer 12 can improve the aging resistance and packaging properties of the photovoltaic encapsulation film 100. However, the gram weight of the first film outer layer 11 and the second film outer layer 12 should not be too high. The increase in gram weight will also increase the thickness of the photovoltaic encapsulation film 100, which does not meet the requirements of lightness and thinness. The gram weight of the first film outer layer 11 is 100g / m 2 ~300g / m 2 The weight of the second film outer layer 12 is 100 g / m 2 ~300g / m 2Within this gram weight range, the first film outer layer 11 and the second film outer layer 12 are relatively light and thin, and have good packaging performance, and the photovoltaic packaging film 100 has better weather resistance and aging resistance.

[0045] It should be noted that the EVOH layer, PVDC layer, PA layer, PP layer, PE layer, CPE film layer, EVA layer and POE layer involved in the present application are all single-layer or multi-layer composite structures formed by their respective main polymer materials. For example, the PA layer is a single-layer or multi-layer composite structure whose main polymer material is PA, and the EVA layer is a single-layer or multi-layer composite structure whose main polymer material is EVA, and the same is true for other layers.

[0046] The present application also provides a method such as Figure 6 The photovoltaic module 200 shown in the figure comprises a front substrate 21, a front encapsulation film 22, a cell layer 23, a rear encapsulation film 24 and a rear substrate 25 stacked in sequence. At least one of the front encapsulation film 22 or the rear encapsulation film 24 is the above-mentioned photovoltaic encapsulation film 100. The photovoltaic encapsulation film 100 in the present application has good water vapor barrier performance and oxygen barrier performance, and can better protect the cell layer 23. The cell can be selected from N-type TOPCon cell, HJT cell, BC cell or P-type PERC cell.

[0047] The present application is further described below in conjunction with the examples, but the protection scope of the present application is not limited to the examples. A photovoltaic encapsulation film is prepared according to the following Table 1.

[0048] Table 1: Photovoltaic encapsulation films

[0049]

[0050]

[0051] Table 1: Photovoltaic encapsulation films (continued)

[0052]

[0053] The encapsulation film in Table 1 is used for encapsulation, and the encapsulation structure of the photovoltaic module is shown in Table 2 and Table 3.

[0054] Table 2: Examples 1-4

[0055]

[0056]

[0057] Table 3: Examples 6-8 and Comparative Examples 1-2

[0058]

[0059] 1. Performance test:

[0060] The above embodiments and comparative examples were subjected to performance tests.

[0061] Oxygen transmission rate: Use an oxygen transmission rate tester (model: OX-TRAN 2 / 12OTR) to test the oxygen transmission rate of the photovoltaic encapsulation film, refer to the ASTM D3985 standard test method, and the test temperature is 23°C.

[0062] Water vapor transmission rate: The water vapor transmission rate of the photovoltaic encapsulation film was tested using a water vapor transmission rate tester (model: AQUATRAN3 / 38H), referring to the ASTM F1249 standard test method, and the test conditions were: 37.8°C, 90% RH.

[0063] The thickness of the inner layer of the test composite film and the gram weight of the first / second outer layer of the film are shown in Table 1.

[0064] Power attenuation: The power of the photovoltaic module is tested before and after accelerated aging at 105℃-95%RH, and the power attenuation is calculated.

[0065] 2. Performance test results:

[0066] The performance test results of photovoltaic encapsulation films S1-S4 and conventional films D1-D2 are shown in Table 4 below.

[0067] Table 4: Oxygen permeability and water vapor permeability

[0068]

[0069]

[0070] From the relevant data in Table 4, it can be seen that the oxygen permeability and water vapor permeability of photovoltaic encapsulation film S1, photovoltaic encapsulation film S2 and photovoltaic encapsulation film S4 are better than those of conventional film D2, and the water vapor barrier performance is better, and the oxygen barrier performance is much better than that of conventional film D2. Compared with conventional film D1, photovoltaic encapsulation film S3 has lower oxygen permeability and water vapor permeability, and its oxygen and water barrier properties are significantly improved.

[0071] The power attenuation curves before and after aging of the comparative example and the embodiment are as follows: Figure 7 shown.

[0072] Figure 7 The power attenuation diagram of the comparative example and the embodiment before and after accelerated aging under 105℃-95%RH conditions. Figure 7It can be seen from the relevant data that after an aging time of 240h, the power attenuation of Examples 2, 3 and 7 is significantly reduced compared to that of Comparative Example 1, and the corrosion resistance of the photovoltaic modules is relatively strong. The power attenuation of Examples 5, 6 and 8 is significantly reduced compared to that of Comparative Example 2, and the corrosion resistance of the photovoltaic modules is relatively strong. It can be seen that the inner layer of the film can improve the barrier properties of the photovoltaic encapsulation film. The rear encapsulation film of Examples 1 and 4 adopts the photovoltaic encapsulation film in this application, but the improvement is smaller than that of Comparative Examples 1 and 2. This is because the battery cell used in this test is an N-type TOPCon battery, and the side of the battery cell close to the front substrate is more sensitive to oxygen and is more susceptible to oxygen corrosion.

[0073] In summary, the photovoltaic encapsulation film in the present application has good oxygen barrier capability and water vapor barrier capability, which can better protect the battery cells, prevent the battery cells from being corroded, and improve the reliability and service life of the photovoltaic module.

[0074] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. A photovoltaic encapsulation film, characterized in that: include: First film outer layer; A second adhesive film outer layer, the second adhesive film outer layer is arranged on one side of the first adhesive film outer layer; An adhesive film inner layer, the adhesive film inner layer is arranged between the first adhesive film outer layer and the second adhesive film outer layer, the adhesive film inner layer includes a barrier layer, and the barrier layer includes a first barrier layer and a second barrier layer; The first barrier layer is one of an EVOH layer or a PVDC layer; The second barrier layer is disposed on at least one side of the first barrier layer, and the second barrier layer is one of a PA layer, an EVOH layer, or a PVDC layer; The oxygen permeability of the inner layer of the film is less than or equal to 100 cm 3 / (m 2 ·24h·0.1MPa).

2. The photovoltaic encapsulation film according to claim 1, characterized in that: The inner layer of the adhesive film further comprises a supporting layer, and the supporting layer is arranged on at least one side of the barrier layer.

3. The photovoltaic encapsulation film according to claim 2, characterized in that: The support layer comprises a first support layer and a second support layer, wherein the first support layer is arranged on one side of the barrier layer, and the second support layer is arranged on a side of the barrier layer away from the first support layer; The first support layer is one of a PP layer, a PE layer or a CPE type film layer; The second supporting layer is one of a PP layer, a PE layer or a CPE type film layer.

4. The photovoltaic encapsulation film according to claim 2, characterized in that: The inner layer of the adhesive film further comprises a bonding layer, and the bonding layer is arranged between the supporting layer and the barrier layer.

5. The photovoltaic encapsulation film according to claim 1, characterized in that: The inner layer of the adhesive film further comprises a protective layer, and the protective layer is arranged on at least one side of the barrier layer.

6. The photovoltaic encapsulation film according to claim 5, characterized in that: The inner layer of the adhesive film further comprises a bonding layer, and the bonding layer is arranged between the protective layer and the barrier layer.

7. The photovoltaic encapsulation film according to claim 1, characterized in that: The barrier layer further includes a third barrier layer, and the third barrier layer is disposed on at least one side of the first barrier layer and / or at least one side of the second barrier layer.

8. The photovoltaic encapsulation film according to claim 1, characterized in that: The thickness of the inner layer of the adhesive film is 10 μm to 180 μm.

9. The photovoltaic encapsulation film according to claim 1, characterized in that: The first film outer layer is one of an EVA layer or a POE layer, and the weight of the first film outer layer is 100g / m 2 ~300g / m 2 ; The second film outer layer is one of an EVA layer or a POE layer, and the weight of the second film outer layer is 100g / m 2 ~300g / m 2 .

10. A photovoltaic module, characterized in that: The photovoltaic module comprises a front substrate, a front packaging film, a battery layer, a rear packaging film and a rear substrate stacked in sequence; At least one of the front layer encapsulation film or the back layer encapsulation film is selected from the photovoltaic encapsulation film according to any one of claims 1 to 9.

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