Flexible photovoltaic material
Through the film preparation technology combining polyolefin elastomer and ultra-clean polypropylene, the problems of flexibility, weather resistance and transmittance of traditional flexible photovoltaic materials have been solved, and the power generation efficiency and reliability of photovoltaic modules have been improved.
Patent Information
- Application Number
- CN202511079151.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-02
- Publication Date
- 2025-10-10
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Traditional flexible photovoltaic materials are prone to UV aging, which can lead to a decrease in transmittance during long-term use, and are prone to brittle cracking at low temperatures. It is difficult to simultaneously meet the comprehensive requirements of flexibility, weather resistance and high transmittance, affecting the power generation efficiency and reliability of flexible photovoltaic modules.
The film is made of polyolefin elastomer and ultra-clean polypropylene. Through cross-linking process, plasma treatment and corona treatment technology, the flexibility and light transmittance of the material are improved, and the weather resistance of the material is improved.
The flexibility of flexible photovoltaic materials in low-temperature environments and the maintenance of light transmittance during long-term use are achieved, which expands the scope of application, reduces construction difficulty, and improves the loading and unloading efficiency of photovoltaic materials.
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of photovoltaic materials, and particularly relates to a flexible photovoltaic material. BACKGROUND
[0002] The flexible solar cell is a kind of thin film battery, which is advanced in technology, excellent in performance, low in cost and widely used. One of the main application scenarios is building integrated photovoltaics, that is, integrated on the roof, outer wall and window.
[0003] As the core component of the new generation of photovoltaic technology, the flexibility of the flexible photovoltaic material directly determines the application feasibility in the scenarios such as curved building and wearable device. In the related technology, the flexible photovoltaic adhesive film is prepared by using single polyolefin material or ordinary polypropylene base material. Although the single polyolefin material has a certain flexibility, it is easy to cause the light transmittance to decrease due to ultraviolet aging (the light transmittance is usually lower than 70% after 3000 hours of ultraviolet aging) in long-term use. The ordinary polypropylene base material has a low-temperature brittleness problem, and is easy to crack when the bending radius is greater than 50mm in the environment of -20℃. In addition, the impurity content of the ordinary polypropylene base material is high (ash content > 0.01%), which can cause the light transmittance loss of the adhesive film to be more than 15%.
[0004] The above problems make it difficult for the traditional adhesive film to simultaneously meet the comprehensive requirements of flexibility (bending radius ≤ 30mm), weather resistance (light transmittance ≥ 80% after ultraviolet aging) and high light transmittance (initial light transmittance ≥ 85%) of the flexible photovoltaic material, thereby restricting the long-term power generation efficiency and reliability of the flexible photovoltaic module.
[0005] The disclosure of the above background art content is only used to assist in understanding the concept and technical solutions of the present application, and it does not necessarily belong to the prior art of the present patent application. In the absence of explicit evidence that the above content has been disclosed on the filing date of the present patent application, the above background art should not be used to evaluate the novelty and inventiveness of the present application. SUMMARY
[0006] The present application provides a flexible photovoltaic material, which can improve the long-term power generation efficiency and reliability of the flexible photovoltaic module.
[0007] To achieve the above object, the embodiments of the present application disclose the following technical solutions:
[0008] A flexible photovoltaic material is composed of an adhesive film, and the adhesive film is prepared from a polyolefin elastomer and an ultra-clean polypropylene.
[0009] In some possible embodiments, the thickness of the adhesive film is 0.3-0.5 millimeters.
[0010] In some possible embodiments, the light transmittance of the adhesive film is greater than or equal to 85% by subjecting POE and ultra-clean polypropylene to a cross-linking process.
[0011] In some possible embodiments, the flexible photovoltaic material is subjected to flow casting during the preparation process.
[0012] In some possible embodiments, the surface of the adherend is activated by optimizing the cross-linking process and using plasma treatment and corona treatment techniques.
[0013] In some possible embodiments, the cross-linking process uses a silane cross-linking method, and the specific steps are as follows:
[0014] a) uniformly mix POE resin particles, ultra-clean polypropylene resin particles, a silane coupling agent, dicumyl peroxide (DCP) in an amount of 0.01-0.5% of the total mass of POE and ultra-clean polypropylene, and dibutyltin dilaurate in an amount of 0.01-0.2% of the total mass of POE and ultra-clean polypropylene at room temperature in a high-speed mixer to prepare a premix;
[0015] b) feed the premix obtained in step a) into a twin-screw extruder for melt grafting reaction, and set the temperature of each section of the extruder as follows: 160-180°C for the feeding section, 180-220°C for the melting section, 200-240°C for the homogenizing section / mixing section, and 200-220°C for the die head; and set the screw rotation speed at 100-300 rpm;
[0016] c) water-cool and pelletize the extrudate to prepare silane grafted masterbatch particles;
[0017] d) uniformly mix the silane grafted masterbatch particles prepared in step c) with 0.1-1 parts by weight of maleic anhydride grafted polypropylene;
[0018] e) prepare an adhesive film by flow casting process from the mixture in step d);
[0019] f) allow the adhesive film obtained in step e) to stand for cross-linking at a temperature of 20-30°C and a relative humidity of 50-80% for 2-4 days, so that the cross-linking degree of the adhesive film reaches ≥60%.
[0020] In some possible embodiments, the amount of the silane coupling agent is 0.5-3% of the total mass of POE and ultra-clean polypropylene, and 0.1-1% of a degradation inhibitor is added to inhibit the degradation of PP.
[0021] In some possible embodiments, the plasma treatment uses a radio frequency plasma device, the treatment gas is argon / oxygen mixed gas with a volume ratio of 3:1, the power is 200-300 W, the treatment time is 60-180 seconds, and the contact angle of the surface after treatment is ≤30°.
[0022] In some possible embodiments, the corona treatment device adopts a high-frequency high-voltage power supply, the treatment voltage is 10-30 kV, the frequency is 20-50 kHz, the treatment speed is 1-5 meters per minute, and the peeling strength of the adhesive film from the glass after treatment is ≥15 N / 15 mm, which is still ≥8 N / 15 mm after 1000 hours of wet heat aging.
[0023] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:
[0024] The flexible photovoltaic material adhesive film is prepared by using polyolefin elastomer and ultra-clean polypropylene. The polyolefin elastomer has good flexibility, which can improve the brittleness of traditional materials in low temperature environment, thereby improving the flexibility of the flexible photovoltaic material. The impurity content of the ultra-clean polypropylene is low, which can reduce the shielding and scattering of impurities to light, and help to improve the light transmittance of the adhesive film. The polyolefin elastomer and the ultra-clean polypropylene are used in combination, which can play the synergistic effect of the two materials, avoid the shortcomings of single material in weather resistance, and make the adhesive film not prone to performance degradation due to aging in the long-term use process, thereby meeting the requirements of flexibility, weather resistance and light transmittance of the flexible photovoltaic material at the same time, and solving the problem that the three are difficult to be considered in the traditional technology.
[0025] In addition, the application range of the flexible photovoltaic cell panel can be expanded, which can be directly attached to the surface of carriers such as buildings, vehicles, glass, aircraft, etc. Secondly, due to the high adhesion, the construction difficulty is greatly reduced, and the loading and unloading efficiency of the photovoltaic material is improved. DETAILED DESCRIPTION
[0026] Reference will now be made in detail to the present application. While the application will be described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the application to these specific embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents, which can be included within the spirit and scope of the application as defined by the claims. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application can be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present application.
[0027] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
[0028] Summary of the application; Flexible solar cells are a kind of thin-film cells, advanced technology, excellent performance, low cost, wide application. One of the main application scenarios is building integrated photovoltaics, that is, integrated on the roof, outer wall, window.
[0029] As the core component of the new generation of photovoltaic technology, the flexibility of flexible photovoltaic material directly determines the application feasibility in curved building, wearable device and other scenarios. In the related technology, the flexible photovoltaic adhesive film is prepared by using single polyolefin material or ordinary polypropylene base. Although the single polyolefin material has certain flexibility, it is easy to cause the light transmittance to decrease due to ultraviolet aging (the light transmittance is usually less than 70% after 3000 hours of ultraviolet aging) in long-term use; the ordinary polypropylene base has low-temperature brittleness problem, and is easy to crack when the bending radius is greater than 50mm in -20℃ environment, and the impurity content (ash content>0.01%) is high, which can cause the light transmittance loss of the adhesive film to be more than 15%.
[0030] The above problems cause the traditional adhesive film to be difficult to simultaneously meet the comprehensive requirements of flexibility (bending radius≤30mm), weather resistance (light transmittance≥80% after ultraviolet aging) and high light transmittance (initial light transmittance≥85%) of the flexible photovoltaic material, which restricts the long-term power generation efficiency and reliability of the flexible photovoltaic module.
[0031] In view of the above technical problems, the embodiments of the present application provide a flexible photovoltaic material, which is composed of an adhesive film, and the adhesive film is prepared from a polyolefin elastomer and an ultra-clean polypropylene.
[0032] For example, the polyolefin elastomer adopts BetoppTM-PV series products (such as PV7045 or PV7200) of Borealis, the density is 0.872±0.002g / cm³, the melt index (190℃ / 2.16kg) is 5-14g / 10min, the light transmittance is >91%, the volume resistivity is >10¹ 6 Ω·cm. The resin has a narrow molecular weight distribution (Mw / Mn=2.0-2.5) and a high ethylene content (>80mol%), which ensures low-temperature flexibility.
[0033] The ultra-clean polypropylene is selected from an electrical grade polypropylene with an ash content of ≤20ppm, an isotacticity of ≥98%, a mass average molecular weight of 35-42.5 million, a molecular weight distribution of 8-10.5, and a melt index (230℃ / 2.16kg) of 3-4.5g / 10min. Preferably, HC300BF of Nordic Chemical or equivalent domestic resin is used, and the metal impurities are removed by a multi-stage extraction process.
[0034] Preferably, in some embodiments, the thickness of the adhesive film is 0.3-0.5mm.
[0035] Preferably, in some embodiments, the light transmittance of the adhesive film is greater than or equal to 85% by subjecting POE and ultra-clean polypropylene to a crosslinking process.
[0036] Preferably, in some embodiments, the flexible photovoltaic material is subjected to flow casting during the preparation process.
[0037] Preferably, in some embodiments, the surface of the adherend is activated by optimizing the crosslinking process, using plasma treatment and corona treatment technology.
[0038] Preferably, in some embodiments, the crosslinking process uses a silane crosslinking method, and the specific steps are as follows:
[0039] a) uniformly mix POE resin particles, ultra-clean polypropylene resin particles, silane coupling agent, and dicumyl peroxide (DCP) in a high-speed mixer at room temperature, with the amount of dicumyl peroxide (DCP) being 0.01-0.5% of the total mass of POE and ultra-clean polypropylene, and the amount of dibutyltin dilaurate being 0.01-0.2% of the total mass of POE and ultra-clean polypropylene, to prepare a premix;
[0040] b) melt grafting reaction of the premix obtained in step a) in a twin-screw extruder, with the temperature of each section of the extruder being set as follows: 160-180°C for the feeding section, 180-220°C for the melting section, 200-240°C for the homogenizing section / mixing section, and 200-220°C for the die head; and the screw rotation speed being 100-300 rpm;
[0041] c) water cooling and granulation of the extrudate to prepare silane grafted masterbatch particles;
[0042] Specifically, after water bath cooling (water temperature 25±2°C) of the extrudate, the masterbatch particles with a length of 3-5 mm are cut by a rotary granulator (model QLG-200), and the water content is controlled to be ≤0.05% (determined by Karl Fischer moisture meter).
[0043] d) uniformly mix the silane grafted masterbatch particles prepared in step c) with 0.1-1 parts by weight of maleic anhydride grafted polypropylene; specifically, the silane grafted masterbatch particles and maleic anhydride grafted polypropylene (PP-g-MAH) are put into a high-speed mixer (rotation speed 300 rpm) at a mass ratio of 100:0.1-100:1, and mixed for 5 minutes to make the PP-g-MAH uniformly coated on the surface of the masterbatch particles.
[0044] e) prepare an adhesive film by flow casting process of the mixture in step d);
[0045] Specifically, the mixture is fed into a casting molding machine (model LY-1200, die width 1200 mm), the die temperature is set to 200-220°C, the melt is extruded through the die slit (width 0.3-0.5 mm), and the film is quickly formed on a cooling roller (temperature 20±2°C) to obtain a film with uniform thickness. The film thickness is monitored in real time by an online thickness gauge (model Beta LaserMike 3400), and the thickness deviation is required to be ≤±5%.
[0046] f) The film obtained in step e) is placed in a constant temperature and humidity box (model BINDER KBWF 240) at a temperature of 20-30°C and a relative humidity of 50-80% for 2-4 days to crosslink the film to a crosslinking degree of ≥60%.
[0047] Specifically, the film is placed in a constant temperature and humidity box (model BINDER KBWF 240) at a temperature of 20-30°C and a relative humidity of 50-80% for 2-4 days to crosslink the film. The crosslinking degree is detected by a gel fraction test (ASTM D2765 standard), and the gel fraction is required to be ≥60%. The test method is as follows: 5 g of film sample is extracted with xylene under reflux conditions for 8 hours, dried and weighed, and the gel fraction is calculated.
[0048] Preferably, in some embodiments, the amount of silane coupling agent is 0.5-3% of the total mass of POE and ultra-clean polypropylene, and 0.1-1% of a degradation inhibitor is added to inhibit PP degradation.
[0049] Preferably, in some embodiments, the plasma treatment uses a radio frequency plasma device, the treatment gas is argon / oxygen mixed gas with a volume ratio of 3:1, the power is 200-300 W, the treatment time is 60-180 seconds, and the surface contact angle after treatment is ≤30°.
[0050] Preferably, in some embodiments, the corona treatment device uses a high-frequency high-voltage power supply, the treatment voltage is 10-30 kV, the frequency is 20-50 kHz, the treatment speed is 1-5 meters / minute, the peel strength of the film from glass after treatment is ≥15 N / 15 mm, and the peel strength after 1000 hours of wet heat aging is still ≥8 N / 15 mm.
[0051] It should be noted that the application scenario one of the embodiments of the present application is to be pasted on the glass outer facade, and the generated electric energy can be stored in the storage battery through the reverse control all-in-one machine.
[0052] The application scenario two of the embodiments of the present application is to be embedded in double-layer glass, and the generated electric energy can be stored in the storage battery through the reverse control all-in-one machine.
[0053] The application scenario three of the embodiments of the present application is to be pasted on the roof and outer facade of a house, and the generated electric energy can be stored in the storage battery through the reverse control all-in-one machine.
[0054] The application scenario four of the embodiment of the application is that the solar energy generated is stored in the storage battery of the vehicle through the light energy controller.
[0055] The application scenario four of the embodiment of the application is that the solar energy generated is stored in the storage battery of the vehicle through the light energy controller.
[0056] The application scenario five of the embodiment of the application is that the solar energy generated is stored in the storage battery of the vehicle through the light energy controller.
[0057] Example 1
[0058] Material ratio: POE 8150 (70%), super-clean PP (ash content ≤10 ppm, 30%), A-171 silane coupling agent (1.5%), antioxidant 1010 (0.3%), DCP (0.1%), DBTDL (0.05%), PP-g-MAH (0.5%).
[0059] Preparation process: double-screw extruder L / D = 30:1, screw speed 200 rpm, and the temperature of each section is set according to the above gradient. The thickness of the cast film is 0.4 mm, and the crosslinking condition is 25℃, 65% RH, 3 days.
[0060] Performance test: initial light transmittance 88%, light transmittance 82% after ultraviolet aging for 3000 hours, no cracking at a bending radius of 25 mm at-20℃, and peel strength 9.2 N / 15 mm after humid heat aging for 1000 hours.
[0061] Example 2
[0062] Material ratio: POE Engage 8407 (60%), super-clean PP (ash content ≤15 ppm, 40%), A-151 silane coupling agent (2.0%), antioxidant 168 (0.5%), DCP (0.2%), DBTDL (0.1%), PP-g-MAH (1.0%).
[0063] Preparation process: double-screw extruder L / D = 28:1, screw speed 150 rpm, cast thickness 0.3 mm, and crosslinking condition 30℃, 80% RH, 2 days.
[0064] Performance test: initial light transmittance 86%, light transmittance 81% after ultraviolet aging for 3000 hours, no cracking at a bending radius of 28 mm at-20℃, and peel strength 8.5 N / 15 mm after humid heat aging for 1000 hours.
[0065] Comparative Example 1
[0066] Using traditional EVA adhesive film (thickness 0.5mm), the test results are: light transmittance 68% after 3000 hours of ultraviolet aging, cracking when the bending radius is 50mm at-20℃, initial light transmittance 83%.
[0067] Comparative Example 2
[0068] Using ordinary PP adhesive film (ash content 0.02%), the test results are: initial light transmittance 72%, light transmittance 65% after 3000 hours of ultraviolet aging, cracking when the bending radius is 55mm at-20℃.
[0069] It can be seen by comparison that the flexible photovoltaic adhesive film of the present application is significantly superior to the prior art in flexibility, weather resistance and light transmittance, meets the stringent requirements of building integrated photovoltaic on materials, and has a broad application prospect.
[0070] It should be finally pointed out that: the above examples are only used to illustrate the technical solutions of the present application but not to limit it; although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalents, without departing from the spirit of the technical solutions of the present application, which should be covered in the technical solution range of the present application claimed.
Claims
1. A flexible photovoltaic material, characterized in that: The flexible photovoltaic material is composed of an adhesive film, and the adhesive film is prepared from polyolefin elastomer and ultra-clean polypropylene.
2. The flexible photovoltaic material according to claim 1, characterized in that: The thickness of the adhesive film is 0.3-0.5 mm.
3. The flexible photovoltaic material according to claim 1, characterized in that: The light transmittance of the adhesive film is greater than or equal to 85% by performing a cross-linking process on POE and ultra-clean polypropylene.
4. The flexible photovoltaic material according to claim 1, characterized in that: The flexible photovoltaic material is formed by tape casting during the preparation process.
5. The flexible photovoltaic material according to claim 1, characterized in that: The surface of the adherend is activated by optimizing the cross-linking process and using plasma treatment and corona treatment technology.
6. The flexible photovoltaic material according to claim 3, characterized in that: The cross-linking process adopts silane cross-linking method, and the specific steps are: a) POE resin particles, ultra-clean polypropylene resin particles, a silane coupling agent, dicumyl peroxide (DCP) in an amount of 0.01-0.5% of the total mass of POE and ultra-clean polypropylene, and dibutyltin dilaurate in an amount of 0.01-0.2% of the total mass of POE and ultra-clean polypropylene are mixed in a high-speed mixer at room temperature to prepare a premix; b) feeding the premix obtained in step a) into a twin-screw extruder for melt grafting reaction, wherein the temperatures of each section of the extruder are set as follows: feeding section 160-180° C., melting section 180-220° C., homogenizing section / mixing section 200-240° C., and die head 200-220° C.; and the screw speed is 100-300 rpm; c) water cooling and pelletizing the extrudate to obtain silane grafted masterbatch particles; d) uniformly mixing the silane grafted masterbatch particles obtained in step c) with 0.1-1 parts by weight of maleic anhydride grafted polypropylene; e) forming a film from the mixture obtained in step d) by tape casting; f) crosslinking the film obtained in step e) at a temperature of 20-30° C. and a relative humidity of 50-80% for 2-4 days, so that the crosslinking degree of the film reaches ≥60%.
7. The flexible photovoltaic material according to claim 6, characterized in that: The amount of the silane coupling agent is 0.5-3% of the total mass of POE and ultra-clean polypropylene, and 0.1-1% of a degradation inhibitor is added to inhibit PP degradation.
8. The flexible photovoltaic material according to claim 5, characterized in that: The plasma treatment uses radio frequency plasma equipment, the treatment gas is argon / oxygen mixed gas, the volume ratio is 3:1, the power is 200-300W, the treatment time is 60-180 seconds, and the surface contact angle after treatment is ≤30°.
9. The flexible photovoltaic material according to claim 5, characterized in that: The corona treatment equipment adopts a high-frequency high-voltage power supply with a treatment voltage of 10-30 kV, a frequency of 20-50 kHz, and a treatment speed of 1-5 m / min. After treatment, the peel strength between the film and the glass is ≥15 N / 15 mm, and is still ≥8 N / 15 mm after 1000 hours of wet heat aging.