阅读说明：本技术 用于太阳能电池封装的高性能pvb胶膜及其制备方法 (High-performance PVB (polyvinyl butyral) adhesive film for packaging solar cell and preparation method thereof ) 是由 齐锴亮 于 2019-12-16 设计创作，主要内容包括：本发明属于太阳能材料技术领域。一种用于太阳能电池封装的高性能PVB胶膜,包括以下组分：PVB树脂粉、有机溶剂、增塑剂、增韧剂、有机光谱转换材料A、有机光谱转换材料B、极性基团接枝改性剂、链状硅烷剂、抗静电剂、抗氧剂、紫外光稳定剂和抗黄变剂；其中,所述PVB树脂粉的PVB聚合度为900-2500,缩醛化程度大于80%,残余羟基含量小于20%,游离酸小于0.05%。本发明高性能PVB胶膜,具有光谱转换功能、透光率高、阻隔水汽效果好、附着力强、耐候性好、在恶劣环境当中稳定性好。该高性能PVB胶膜的制备方法,操作简单、稳定性和一致性好、成本较低,适于大规模生成产。(The invention belongs to the technical field of solar materials. A high-performance PVB adhesive film for packaging a solar cell comprises the following components: PVB resin powder, an organic solvent, a plasticizer, a toughening agent, an organic spectrum conversion material A, an organic spectrum conversion material B, a polar group grafting modifier, a chain silane agent, an antistatic agent, an antioxidant, an ultraviolet light stabilizer and an anti-yellowing agent; the PVB polymerization degree of the PVB resin powder is 900-2500, the acetalization degree is more than 80%, the residual hydroxyl content is less than 20%, and the free acid content is less than 0.05%. The high-performance PVB adhesive film disclosed by the invention has a spectrum conversion function, high light transmittance, good water vapor blocking effect, strong adhesive force, good weather resistance and good stability in a severe environment. The preparation method of the high-performance PVB adhesive film is simple to operate, good in stability and consistency, low in cost and suitable for large-scale production.)

1. A high-performance PVB adhesive film for packaging a solar cell is characterized by comprising the following components in parts by weight:

100 portions and 110 portions of PVB resin powder,

100 portions and 350 portions of organic solvent,

15-30 parts of a plasticizer, namely,

6-14 parts of a toughening agent,

4-10 parts of an organic spectrum conversion material A,

3-6 parts of an organic spectrum conversion material B,

1-5 parts of polar group grafting modifier,

1-3 parts of a chain-like silane agent,

0.5 to 2.5 portions of antistatic agent,

0.1 to 1 portion of antioxidant,

0.05 to 0.3 portion of ultraviolet light stabilizer,

0.05-0.3 part of anti-yellowing agent;

the PVB polymerization degree of the PVB resin powder is 900-2500, the acetalization degree is more than 80%, the residual hydroxyl content is less than 20%, and the free acid content is less than 0.05%.

2. The high performance PVB adhesive film for solar cell encapsulation according to claim 1, wherein said organic solvent is at least one of ethanol, isopropanol, toluene, xylene, DBE, triethylene glycol diisocaprylate, methyl acetate, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, cyclohexanone, dichloromethane, chloroform.

3. The high performance PVB adhesive film for solar cell encapsulation according to claim 1, wherein the organic spectrum converting material A is tetranuclear cyclopentadienyl rare earth sulfide [ (Cp ] S₂Ln)₂(THF)(μ-S)](Ln = Yb (1) Er (2) Gd (1)) or dinuclear cyclopentadienyl rare earth persulfides [ Cp₂Ln(THF)]₂(mu- η 2: η 2-S2) (Ln = Yb (1) Er (2) Gd (1)) or a guanidinium rare earth compound [ (Me)₃Si)₂NC(NCy)₂]₂LnCp (Ln = Yb (1) Er (2) Gd (1)) or tetra-coordinated rare earth metal amine-based complex [ (Me)₃Si)₂]₃Ln(μ-Cl)Li(THF)₃(Ln=Yb(1)Er(2)Gd(1))。

4. The high-performance PVB adhesive film for solar cell encapsulation according to claim 1, wherein the organic spectrum conversion material isThe material B is polystyrene PS- (MOBA) with methoxybenzoic acid₃PS- (MOBA) for ligand synthesis₃W (III) rare earth organic complex and/or PS- (BA) polystyrene benzoate₃PS- (BA) for ligand synthesis₃-W (III) rare earth organic complex, wherein W is Dy³⁺-Yb³⁺/Pr³⁺-Yb³⁺/Tb³⁺-Yb³⁺A rare earth ion pair.

5. The high performance PVB adhesive film for solar cell encapsulation according to claim 1, wherein said plasticizer is at least one of tributyl citrate, dibutyl phthalate, diethyl phthalate, diethylene glycol butyl ether acetate, triethylene glycol caprylic decanoate, triethylene glycol diheptanoate, triethylene glycol triethyl ester, and sebacic ester.

6. The high performance PVB adhesive film for solar cell encapsulation according to claim 1, wherein said chain silane agent is at least one of poly bis (diethylamino) silane, polymethylsiloxane, and polydimethylsiloxane.

7. The high-performance PVB adhesive film for packaging a solar cell according to claim 1, wherein the polar group grafting modifier is at least one of a polyvinyl alcohol grafted maleic anhydride copolymer, a polyvinyl alcohol grafted sulfonic acid copolymer, a polyvinyl alcohol grafted acrylic acid copolymer and a polyvinyl alcohol grafted methacrylic acid copolymer.

8. The high performance PVB adhesive film for solar cell encapsulation according to claim 1, wherein said uv stabilizer is at least one of bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate, bis (1-octyloxy-2, 2,6, 6-tetramethyl-4-piperidyl) sebacate, 3, 5-di-tert-butyl-4-alkyl-benzoic acid hexadecyl ester, bis-2, 2,6, 6-tetramethylpiperidinol sebacate.

9. The high performance PVB adhesive film for solar cell encapsulation according to claim 1, wherein said anti-yellowing agent is at least one of dimethyl succinate-4-hydroxy-2, 2,6, 6-tetramethyl-4-piperidinol, lauryl 3, 3-thiopropionate, 4- [ (4, 6-dioctylthio-1, 3, 5-triazin-2-yl) amino ] -2, 6-di-tert-butylphenol.

10. A method for preparing a high-performance PVB adhesive film for solar cell encapsulation according to any one of claims 1-9, comprising the steps of:

s1, adding PVB resin powder into an organic solvent, and stirring at a constant temperature of 50-60 ℃ and a stirring speed of 30-180r/min until the PVB resin powder is completely dissolved to prepare a mixed solution;

s2, transferring the mixed solution into a polytetrafluoroethylene cup, adding 10-15 zirconia balls with the diameter of 1-5mm, adding a plasticizer, a flexibilizer, an organic spectrum conversion material A, an organic spectrum conversion material B, a polar group graft modifier, a chain silane agent, an antistatic agent, an antioxidant, an ultraviolet light stabilizer and an anti-yellowing agent, stirring by adopting a non-contact planetary vacuum, and stirring at a vacuum degree of-0.095 MPa, a revolution speed of 30-120 r/min and a revolution-rotation speed ratio of 1: 1-2, stirring for 10-30min at low speed, wherein the revolution speed is 300-: 1-3, dispersing and stirring at a high speed until the components are uniformly mixed to prepare PVB adhesive film slurry;

s3, carrying out tape casting on the PVB adhesive film slurry on a tape casting forming machine to obtain a PVB wet film;

and S4, drying the PVB wet film at the temperature of 50-100 ℃ for 60-180s to form a film, and cooling and shaping to obtain the high-performance PVB adhesive film.

Technical Field

The invention belongs to the technical field of solar materials, and relates to a high-performance PVB adhesive film for packaging a solar cell and a preparation method thereof.

Background

Solar energy has the advantages of safety, reliability, no noise, no pollution, reproducibility, wide coverage and the like, and is the most important new energy at present. The solar cell is a semiconductor device with photoelectric conversion characteristics, has the function of converting solar energy into electric energy, and comprises a photovoltaic module, a glass cover plate, an encapsulation adhesive film and a back plate material. The spectral composition of sunlight covers the band from ultraviolet to far infrared, and as the wavelength increases, the photon energy of sunlight decreases. Sunlight irradiates a solar cell semiconductor, which can be really absorbed by a solar cell to generate photoelectric conversion of only 380-1200nm visible light and near-infrared light, part of energy of ultraviolet light is used for exciting to generate hole-electron pairs, and the rest of energy is lost in a lattice heat mode; the far infrared ray cannot excite to generate a hole-electron pair due to low energy, and the energy of the far infrared ray cannot be utilized by the solar cell and is lost. Meanwhile, the back plate of the traditional crystalline silicon solar cell module has certain water permeability, and water vapor penetrating through the back plate can decompose and separate out acetic acid from EVA (ethylene vinyl acetate copolymer) resin serving as an encapsulating film material, so that electrochemical corrosion is caused inside the solar cell module, and the probability of PID attenuation and snail line generation is increased. In recent years, a double-glass photovoltaic cell module is researched and developed to solve the problem, the double-glass photovoltaic cell module is a photovoltaic cell module which is formed by combining two pieces of glass (front plate glass and back plate glass) and a solar cell piece, wherein the cell pieces are connected in series and in parallel by leads and collected to lead terminals, and the double-glass photovoltaic cell module is suitable for application occasions with harsh climatic environments, such as photovoltaic power stations at seasides, water sides and areas with higher humidity. However, the current EVA adhesive film for the solar cell packaging adhesive film cannot meet the requirements of being applied to a double-glass photovoltaic cell assembly and a thin-film solar cell due to the defects of easy water absorption, hydrolysis, aging and the like.

Therefore, how to improve the conversion efficiency of the solar cell, increase the lifetime of the solar cell, and reduce the cost of the solar cell by improving the packaging material and the packaging process becomes one of the key problems. The packaging adhesive film is required to have good light transmittance to ensure the light flux incident on the photovoltaic module, and the adhesive film, the glass cover plate and the back plate film are required to have high enough bonding strength to ensure the structural stability of the solar cell module and prevent the infiltration of harmful substances. The spectrum conversion material which can absorb light with specific wavelength and emit light with other specific wavelengths is mixed in the packaging adhesive film, so that the conversion efficiency of the solar cell can be effectively improved. For example, in chinese patent CN2007103025104, an up-conversion material, a down-conversion material, and a long afterglow material are mixed in a polyethylene (polypropylene, polyvinyl chloride) base material, so that the utilization rate of sunlight is increased, the power generation time of the cell panel is prolonged, and the service life of the cell panel is prolonged. In the Chinese patent CN201010620683, a rare earth complex is doped in EVA to replace an ultraviolet light stabilizer and an absorbent in a formula, so that ultraviolet light is utilized, and the efficiency of the solar cell is improved. Chinese patent CN201110021649.8 discloses a solar cell having high photoelectric conversion efficiency with excellent productivity by mixing a phosphor into a sealing material sheet (EVA). Chinese patent CN201210341265.9 mixes sodium rare earth ion spectrum conversion powder with the particle size of 10-100nm into the POE of the sealing material, and the solar cell sealing adhesive film is prepared by high-temperature blending, extrusion, granulation and final forming.

The EVA serving as a base material of the packaging material has poor ultraviolet and damp-heat aging resistance, and is easy to degrade and yellow after being exposed to ultraviolet rays and water vapor for a long time, so that the conversion efficiency of the solar cell is reduced; 2. the spectrum conversion material is a rare earth doped inorganic substance, and is not uniformly mixed with organic substances, and the particles of the spectrum conversion material are bonded, so that the light transmittance of the packaging adhesive film is reduced, and the performance is unstable. The technical development requirements of the dual-glass photovoltaic cell assembly industry can not be well met.

Disclosure of Invention

The invention aims to solve the technical problem of providing a high-performance PVB adhesive film for packaging a solar cell, which has a spectrum conversion function, high light transmittance, good water vapor blocking effect, strong adhesive force, good weather resistance and good stability in a severe environment.

The technical scheme of the invention is as follows:

a high-performance PVB adhesive film for packaging a solar cell comprises the following components in parts by weight:

100 portions and 110 portions of PVB resin powder,

100 portions and 300 portions of organic solvent,

15-30 parts of a plasticizer, namely,

6-14 parts of a toughening agent,

4-10 parts of an organic spectrum conversion material A,

3-6 parts of an organic spectrum conversion material B,

1-5 parts of polar group grafting modifier,

1-3 parts of a chain-like silane agent,

0.5 to 2.5 portions of antistatic agent,

0.1 to 1 portion of antioxidant,

0.05 to 0.3 portion of ultraviolet light stabilizer,

0.05-0.3 part of anti-yellowing agent;

the PVB polymerization degree of the PVB resin powder is 900-2500, the acetalization degree is more than 80%, the residual hydroxyl content is less than 20%, and the free acid content is less than 0.05%. The light-transmitting and light-blocking composite material has good light-transmitting performance, gas-blocking performance, bonding performance, weather resistance, low-temperature resistance and flexibility.

Further, the organic solvent is at least one of ethanol, isopropanol, toluene, xylene, DBE, triethylene glycol diisocaprylate, methyl acetate, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, cyclohexanone, dichloromethane and chloroform, and preferably a mixed organic solvent consisting of 60% of isopropanol and 40% of triethylene glycol diisocaprylate.

Further, the organic spectrum conversion material A is tetranuclear cyclopentadienyl rare earth sulfide [ (Cp)₂Ln)₂(THF)(μ-S)](Ln = Yb (1) Er (2) Gd (1)) or dinuclear cyclopentadienyl rare earth persulfides [ Cp₂Ln(THF)]₂(mu- η 2: η 2-S2) (Ln = Yb (1) Er (2) Gd (1)) or a guanidinium rare earth compound [ (Me)₃Si)₂NC(NCy)₂]₂LnCp (Ln = Yb (1) Er (2) Gd (1)) or tetra-coordinated rare earth metal amine-based complex [ (Me)₃Si)₂]₃Ln(μ-Cl)Li(THF)₃(Ln=Yb(1)Er(2)Gd(1))。

The organic spectrum converting material a may be added to the PVB resin by chemical bonding. The material utilizes metastable nature of rare earth elementsThe state energy level characteristic can absorb a plurality of long-wave radiation with low energy under the excitation of the middle and far infrared long-wave light, and the long-wave radiation is converted into near infrared emission at the optimal response wave band of 900-1100 nm of the solar cell after photon summation. Doped with ion Gd³⁺The introduction of (2) greatly improves the luminous intensity of the complex.

Further, the organic spectrum conversion material B is polystyrene PS- (MOBA) which is methoxybenzoic acid₃PS- (MOBA) for ligand synthesis₃W (III) rare earth organic complex and/or PS- (BA) polystyrene benzoate₃PS- (BA) for ligand synthesis₃-W (III) rare earth organic complex, wherein W is Dy³⁺-Yb³⁺/Pr³⁺-Yb³⁺/Tb³⁺-Yb³⁺A rare earth ion pair.

The organic spectrum conversion material B is a near-infrared down-conversion luminescent material with self reactivity, can absorb visible light with weak response of a silicon-based solar cell and positioned before 500 nm, and passes through Dy³⁺/Pr³⁺/Tb³⁺To Yb³⁺The energy transfer process of (1) is converted into near infrared emission at the optimum response band of the solar cell of 900-1100 nm.

Further, the plasticizer is at least one of tributyl citrate, dibutyl phthalate, diethyl phthalate, diethylene glycol butyl ether acetate, triethylene glycol caprylic decanoate, triethylene glycol diheptanoate, triethylene glycol triethyl ester and sebacic ester.

Further, the toughening agent is at least one of France Achima toughening agents AX8900, EBA35BA40, EA6200 and 8921A.

Further, the chain silane agent is at least one of poly bis (diethylamino) silane, polymethylsiloxane, and polydimethylsiloxane. In the high-temperature drying and pressurizing processes, the chain-shaped silane agent and free hydroxyl-OH in PVB are combined to form-Si-OH groups in a product, and form hydrogen bonds with the-OH groups in PVB resin R', so that the chain-shaped silane agent can be quickly adsorbed on the surfaces of a battery piece and glass to form firm chemical bonds, and a stable and closed combination structure can be formed among the battery piece, the PVB adhesive film and the glass through the chemical bonds.

Further, the polar group grafting modifier is at least one of a polyvinyl alcohol grafted maleic anhydride copolymer, a polyvinyl alcohol grafted sulfonic acid copolymer, a polyvinyl alcohol grafted acrylic acid copolymer and a polyvinyl alcohol grafted methacrylic acid copolymer.

Further, the antistatic agent is at least one of nonionic antistatic agents ethoxylated alkyl amine, ethoxylated lauric amine, glycerol monostearate, Clariant antistatic agent Hostapur SAS93 and Germany Basf antistatic agent P-22.

Further, the antioxidant is at least one of antioxidants 1135, 1010, 245, 1726, B215, B501W and B900 of BASF corporation in Germany, preferably 1135 or B501W.

Further, the ultraviolet light stabilizer is at least one of bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate, bis (1-octyloxy-2, 2,6, 6-tetramethyl-4-piperidyl) sebacate, 3, 5-di-tert-butyl-4-alkyl-benzoic acid hexadecyl ester and bis-2, 2,6, 6-tetramethylpiperidyl sebacate.

Further, the anti-yellowing agent is at least one of dimethyl succinate-4-hydroxy-2, 2,6, 6-tetramethyl-4-piperidinol, 3-thiopropionic acid lauryl ester and 4- [ (4, 6-dioctylthio-1, 3, 5-triazin-2-yl) amino ] -2, 6-di-tert-butylphenol.

The preparation method of the high-performance PVB adhesive film for packaging the solar cell comprises the following steps:

s1, adding PVB resin powder into an organic solvent, and stirring at a constant temperature of 50-60 ℃ and a stirring speed of 30-180r/min until the PVB resin powder is completely dissolved to prepare a mixed solution;

s2, transferring the mixed solution into a polytetrafluoroethylene cup, adding 10-15 zirconia balls with the diameter of 1-5mm, adding a plasticizer, a flexibilizer, an organic spectrum conversion material A, an organic spectrum conversion material B, a polar group graft modifier, a chain silane agent, an antistatic agent, an antioxidant, an ultraviolet light stabilizer and an anti-yellowing agent, stirring by adopting a non-contact planetary vacuum, and stirring at a vacuum degree of-0.095 MPa, a revolution speed of 30-120 r/min and a revolution-rotation speed ratio of 1: 1-2, stirring for 10-30min at low speed, wherein the revolution speed is 300-: 1-3, dispersing and stirring at a high speed until the components are uniformly mixed to prepare PVB adhesive film slurry;

s3, carrying out tape casting on the PVB adhesive film slurry on a tape casting forming machine to prepare a PVB wet film, and controlling the thickness of the PVB adhesive film through technological parameters such as the speed of a tape casting machine, the height of a scraper and the like;

and S4, drying the PVB wet film at the temperature of 50-100 ℃ for 60-180s to form a film, and cooling and shaping to obtain the high-performance PVB adhesive film.

The invention has the following beneficial effects:

the organic spectrum conversion material A and the organic spectrum conversion material B which are both the spectrum conversion materials capable of absorbing light with specific wavelength and emitting light with other specific wavelength are selected, so that the conversion efficiency of the solar cell can be effectively improved, partial ultraviolet rays can be absorbed, and the harm of the ultraviolet rays to a PVB adhesive film is reduced.

The chain-like silane agent and the polar group grafting modifier selected by the invention can improve the sealing strength between the PVB adhesive film and the materials such as a battery piece, glass, a backlight plate and the like, are tightly attached, enhance the sealing performance, the water vapor resistance and the weather resistance of the solar battery component and have good stability in severe environment.

The plasticizer and the toughening agent selected by the invention can improve the vitrification temperature of the PVB adhesive film, improve the flexibility and the rheological property of the PVB adhesive film during heating and pressurizing, can enable the PVB adhesive film to be tightly attached to a battery piece, glass, a backlight plate and the like in the packaging process of a solar battery component, and can effectively protect a battery chip from being damaged due to good impact resistance and cold and hot impact resistance of the PVB adhesive film in the using process.

The antioxidant, the ultraviolet light stabilizer and the anti-yellowing agent selected by the invention can improve the durability and the ultraviolet light aging resistance of the PVB adhesive film.

The preparation method adopts a non-contact planetary vacuum stirring process to prepare PVB film slurry according to two steps of low-speed dispersion stirring and high-speed dispersion stirring, no external substance enters and volatilizes from the inside to the outside in a closed vacuum environment, the matching degree of each component and the formula is high, the proportion is accurate, the components are uniformly dispersed in a slurry system, and the consistency is good; the high-performance PVB adhesive film for packaging the solar cell is prepared by adopting the tape-casting forming process, has the advantages of simple operation, good stability and lower cost, and is suitable for large-scale production.

Detailed Description

The present invention will be described in detail with reference to examples, which are only preferred embodiments of the present invention and are not intended to limit the present invention.

The following is a formula table (unit: parts) of 3 examples of the high performance PVB adhesive film for solar cell encapsulation of the present invention.

The preparation method of the high-performance PVB adhesive film for packaging the solar cell comprises the following steps:

s1, adding PVB resin powder into an organic solvent, and stirring at a constant temperature of 50-60 ℃ and a stirring speed of 30-180r/min until the PVB resin powder is completely dissolved to prepare a mixed solution;

s2, transferring the mixed solution into a polytetrafluoroethylene cup, adding 10-15 zirconia balls with the diameter of 1-5mm, adding a plasticizer, a flexibilizer, an organic spectrum conversion material A, an organic spectrum conversion material B, a polar group graft modifier, a chain silane agent, an antistatic agent, an antioxidant, an ultraviolet light stabilizer and an anti-yellowing agent, stirring by adopting a non-contact planetary vacuum, and stirring at a vacuum degree of-0.095 MPa, a revolution speed of 30-120 r/min and a revolution-rotation speed ratio of 1: 1-2, stirring for 10-30min at low speed, wherein the revolution speed is 300-: 1-3, dispersing and stirring at a high speed until the components are uniformly mixed to prepare PVB adhesive film slurry;

s3, carrying out tape casting on the PVB adhesive film slurry on a tape casting forming machine to prepare a PVB wet film, and controlling the thickness of the PVB adhesive film through technological parameters such as the speed of a tape casting machine, the height of a scraper and the like;

and S4, drying the PVB wet film at the temperature of 50-100 ℃ for 60-180s to form a film, and cooling and shaping to obtain the high-performance PVB adhesive film.

The high-performance PVB adhesive films for solar cell encapsulation of the present invention, examples 1-3 and comparative example 1 (a commonly commercially available PVB adhesive film for solar cell encapsulation) were tested for various properties:

(1) and (3) testing light transmittance: taking a PVB adhesive film block with the thickness of 400 mm multiplied by 400 mm, superposing the PET film/the PVB adhesive film/the PET film, putting the PET film/the PVB adhesive film/the PET film into a die press which is preheated to 160 ℃, wherein the pressure is 1Mpa at the beginning, the pressure is increased to 3Mpa after 1 minute, and the curing time is 25 minutes. After completion of curing, the film was cooled to room temperature, and the surface of the film was peeled off, followed by cutting into 7cm × 4 cm pieces with a blade. Measuring three groups of light transmittance values under the wavelengths of lambda =555nm, 700 nm and 900 nm according to the requirements of GB2410-80, wherein the light transmittance of an adhesive film is% = (T555+ T700 + T900)/3 multiplied by 100%;

(2) ultraviolet aging resistance test: taking a PVB adhesive film block with the thickness of 400 mm multiplied by 400 mm, superposing the PET film/the PVB adhesive film/the PET film, putting the PET film/the PVB adhesive film/the PET film into a die press which is preheated to 160 ℃, wherein the pressure is 1Mpa at the beginning, the pressure is increased to 3Mpa after 1 minute, and the curing time is 25 minutes. After the curing is finished, cooling to room temperature, stripping off the PET film on the surface, cutting into clean sample pieces of 7cm multiplied by 4 cm by a knife, placing the sample in an ultraviolet aging test box, carrying out ultraviolet aging performance test for 1000 hours according to the GB/T14522-;

(3) the peeling force test of the PVB adhesive film and the glass is in accordance with the GB/T2790 test standard;

(4) the ultraviolet aging yellowing index test rate of the PVB adhesive film is in accordance with the test standard of IEC61215/IEC 61730;

(5) the double 85 aging yellowing index test rate of the PVB adhesive film is in accordance with the IEC61215/IEC61730 test standard;

(6) testing the photoelectric conversion efficiency of the cell, namely packaging a PVB adhesive film, the cell, glass and other components into a double-glass solar cell, and measuring the solar cell by using a CHI660A type electrochemical workstation produced by Shanghai Chenghua company to obtain the optimal working current I mp and the optimal working voltage I mp; i sc represents short circuit photocurrent density; voc represents an open circuit voltage; pmax represents the maximum power), the optimal working current and the optimal working voltage of the battery are obtained according to a current-voltage curve, and the photoelectric conversion rate of the solar battery is calculated according to the following formula:

wherein H is the photoelectric conversion rate of the solar cell

Pin is the incident power of sunlight, milliwatt/square centimeter;

i mp is the optimal working current, milliampere/square centimeter;

vmp is the optimum operating voltage, volts.

The test results are shown in the following table.

Therefore, the PVB adhesive film disclosed by the invention is high in light transmittance, good in adhesion with glass, good in ultraviolet aging yellowing resistance and damp-heat aging yellowing resistance, and capable of effectively improving the photoelectric conversion rate of a solar cell.

The high-performance PVB adhesive film for packaging the solar cell has a spectrum conversion function, high light transmittance, good water vapor blocking effect, strong adhesive force, good weather resistance and good stability in severe environment. The preparation method of the high-performance PVB adhesive film is simple to operate, good in stability and consistency, low in cost and suitable for large-scale production.