CN102352067B - EVA (ethylene-vinyl acetate) for enhancing efficiency of solar module - Google Patents

Abstract

The invention discloses a kind of EVA for improving the efficiency of solar modules, which is encapsulated between the glass and the battery sheet in the solar modules, that is, applied to the upper EVA adhesive film in the modules. It is made by adding new ultraviolet light absorber and other components into the vinyl resin, which has good absorption performance for ultraviolet light in the wavelength range of 345-380nm, and enhances the incident light and reflected light on the surface of the upper EVA film in the module. The reflected light on the battery sheet improves the photoelectric conversion efficiency of the battery sheet.

Description

An EVA for improving the efficiency of solar modules

technical field

The invention relates to an EVA for encapsulating solar modules, in particular to an EVA for improving the efficiency of solar modules by changing the EVA's spectral response to cells in the effective band of ultraviolet light.

Background technique

At present, the continuous use of conventional energy has brought about a series of economic and social problems such as energy shortage and environmental degradation. Generally speaking, conventional energy refers to energy that is relatively mature in technology and has been used on a large scale, while new energy usually refers Energy that has not yet been used on a large scale and is being actively researched and developed. Therefore, coal, oil, natural gas, and large and medium-sized hydropower are all regarded as conventional energy sources, and solar energy is a non-polluting green energy that is currently used on a large scale. It is the main trend in the development of solar cell components, and it is also the goal pursued by technology researchers.

The traditional EVA materials used for solar module encapsulation are ethylene-vinyl acetate, polyolefin, polyurethane, etc., all of which have high UV aging resistance, and the UV wavelength range is cut off before 380nm. High-efficiency solar cells have a very high response to photoelectric conversion efficiency in the ultraviolet band (280-400nm), and the effective wavelength range of the solar module spectrum simulator is between 345-1100nm. On the other hand, it can effectively use the light in the effective wavelength band of ultraviolet light between 345-380nm.

The interior of the solar module is equipped with EVA, cells, ribbons, and backsheets. Since the cells and ribbons are inorganic materials, direct ultraviolet light basically has no aging effect on them, because the backsheets are mostly made of polymer composites. Material composition, susceptible to photodegradation by UV light, resulting in reduced molecular weight, darker color, and lower strength. Therefore, it is necessary to prevent direct ultraviolet light aging irradiation. Therefore, how to effectively use the EVA between the glass and the battery sheet in the solar module to the ultraviolet light with a wavelength of 345-380nm to further improve the photoelectric conversion efficiency of the solar module is the invention. technical challenge.

Contents of the invention

The purpose of the present invention is to improve the efficiency of solar modules, and propose a new type of EVA adhesive film, which is applied between the glass in the solar module and the light-receiving surface of the solar cell, so as to change the spectrum of the solar cell in the effective band of the ultraviolet region by changing EVA. Response, to enhance the incident light on the EVA surface and the reflected light reflected on the glass and then reflected from the glass back to the cell, so as to further improve the photoelectric conversion efficiency of the cell.

In order to achieve the above object, the present invention proposes the following technical scheme: a kind of EVA for improving the efficiency of solar modules, characterized in that: the EVA is prepared from the following raw materials in proportions by weight:

Wherein, the ultraviolet absorber is formed by mixing 2-hydroxyl-4-methoxybenzophenone and 2-hydroxyl-4-n-octyloxybenzophenone.

The antioxidant is formed by mixing one or more of the following: tris (2,4-di-tert-butylphenyl) phosphite, distearyl pentaerythritol diphosphite, [β-(3 , 5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, β-(4-hydroxy-3,5-di-tert-butylphenyl) n-octadecyl propionate, tri(phosphite monononylbenzene and dinonylbenzene mixed ester), tris(nonylphenyl)phosphite.

The crosslinking agent is a peroxide, which is selected from 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 1,1-(diperoxyt-butyl)3 , 3,5-trimethylcyclohexane, and one or more of tert-butylperoxy 2-ethylhexyl carbonate.

The light stabilizer is selected from hindered amine bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) decanedate, bis(2,2,6,6 -Tetramethyl-4-piperidinyl) sebacate, and one or more of polysuccinic acid (4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol ester) mixed.

The maximum absorption wavelength range of 2-hydroxy-4-methoxybenzophenone in the ultraviolet light absorber is 280-340nm, and the optimum weight ratio is 0.1-0.25 parts.

The absorption wavelength range of 2-hydroxyl-4-n-octyloxybenzophenone in the ultraviolet light absorber is 270-330nm, and the optimum weight ratio is 0.1-0.25 parts.

The silane coupling agent is selected from γ-aminopropyl triethoxysilane (KH-550), γ-glycidyl etheroxypropyl trimethoxysilane, vinyl triethoxysilane, 3-aminopropyl It is formed by mixing one or more of vinyltrimethoxysilane and vinyltrimethoxysilane.

10%-50% by weight of the titanium dioxide is rutile type, and the particle diameter of the titanium dioxide is 100-400nm.

The EVA is applied on the upper layer EVA adhesive film in the solar module.

Compared with the prior art, after the upper layer EVA encapsulated in the solar module adopts the EVA proposed by the present invention, it has the following advantages:

First, it can make full use of the ultraviolet light with a wavelength between 345-380nm of the solar spectrum simulator, even if the solar cell can fully absorb the ultraviolet light with a wavelength between 345-380nm, which improves the general grade of solar cells and high-efficiency batteries The photoelectric conversion efficiency of the chip, the invention can improve the CTM (Cell to Module, packaging efficiency of the component) of the module by 0.3-1%.

Second, by adding special titanium dioxide materials, under the condition of certain EVA light transmittance, the reflection of incident light can be enhanced, thereby improving the effective light reflected from the glass surface, and further improving the photoelectric conversion efficiency of solar cells.

Description of drawings

Fig. 1 is the front view of solar module;

Fig. 2 adopts the top view of the solar module of EVA package of the present invention;

Fig. 3 is the light reuse figure after the incident light is reflected by the upper layer EVA of the present invention;

Fig. 4 is a diagram of the direction of light after the incident light is reflected by the traditional upper layer EVA.

Detailed ways

The technical solutions in the preferred embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention.

As shown in Figures 1, 2, and 3, the new EVA disclosed by the present invention for improving the efficiency of solar modules is applied between the glass and the battery sheet in the solar module, that is, the light-receiving side of the battery sheet, and the solar module is from top to bottom. The bottom includes glass 1, upper EVA film 2, battery sheet 3, lower EVA film 4 and back plate 5, in addition, the assembly also includes junction box 6, bus bar 8 welded between battery sheets 3, and coated on Border 7 around the component's perimeter. The novel EVA disclosed by the present invention is encapsulated on the light-receiving side between the glass and the battery sheet 3 , that is, the upper layer of EVA adhesive film 2 .

Specifically, the EVA disclosed by the present invention for improving the efficiency of solar modules is obtained by improving the processing formula and process in the main material ethylene-vinyl acetate, and it is made of the following raw materials in proportions by weight:

1) 100 parts of ethylene-vinyl acetate;

2) 0.5-1.2 parts of antioxidant;

3) 0.3-1.2 parts of cross-linking agent;

4) 0.05-0.20 parts of light stabilizer;

5) 0.1-0.5 parts of UV absorber;

6) 0.5-1.5 parts of silane coupling agent;

7) 0.05-1 part of titanium dioxide.

Wherein, the antioxidants are divided into hindered phenol antioxidants and phosphite lipid antioxidants, and the antioxidants are specifically formed by mixing one or more of the following: three (2,4-di tert-butylphenyl) phosphite, distearyl pentaerythritol diphosphite, [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, β-(4- Hydroxy-3,5-di-tert-butylphenyl) n-octadecyl propionate, tris(mononylbenzene and dinonylbenzene mixed ester) phosphite, tris(nonylphenyl)phosphite.

The cross-linking agent is mainly peroxides, and the cross-linking agent is specifically formed by mixing one or more of the following: 2,5-dimethyl-2,5-bis(tert-butyl peroxide oxy)hexane, 1,1-(tert-butyldiperoxy)3,3,5-trimethylcyclohexane, 2-ethylhexyl carbonate.

The light stabilizer consists of hindered amines bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) decanedate, bis(2,2,6,6-tetra Methyl-4-piperidinyl) sebacate, and one or more of polysuccinic acid (4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol ester) mixed become.

The ultraviolet absorber is formed by mixing two components of 2-hydroxyl-4-methoxybenzophenone and 2-hydroxyl-4-n-octyloxybenzophenone. The 2-hydroxyl benzophenone used in the present invention The characteristics of -4-methoxybenzophenone and 2-hydroxy-4-n-octoxybenzophenone 2 are respectively:

2-Hydroxy-4-methoxybenzophenone is a white crystalline powder with a density of 1.324g/cm3, a melting point of 62-66°C, a boiling point of 150-160°C (0.67kPa), and a temperature of 220°C (2.4kPa). Soluble in most organic solvents such as ethylene vinyl acetate, insoluble in water. The maximum absorption wavelength range of this product is 280-340nm. It has good thermal stability, and it begins to decompose when the temperature is increased to 200°C; it hardly absorbs visible light. In the present invention, its optimal dosage is 0.1-0.25 parts.

2-Hydroxy-4-n-octyloxybenzophenone is a white crystalline powder with a density of 1.160g/cm3 and a melting point of 48-49°C. It is soluble in most organic solvents such as ethylene vinyl acetate and insoluble in water. It can strongly absorb ultraviolet rays with a wavelength of 270-330nm, and can be used in various polyolefins, polyesters, ethylene vinyl acetate and other materials with low volatility. The optimal dosage in the present invention is 0.1-0.25 parts.

The silane coupling agent is a tackifier, consisting of γ-aminopropyltriethoxysilane (KH-550), γ-glycidyl etheroxypropyltrimethoxysilane, vinyltriethoxysilane, 3 -Aminopropyltrimethoxysilane), and one or more of vinyltrimethoxysilane are mixed and proportioned.

10%-50% by weight of the titanium dioxide is rutile type, and the particle diameter is between 100-400nm. White titanium dioxide powder of the present invention has 2 advantages:

1) Intrinsic absorption of ultraviolet light with a wavelength of 220-330nm; because the ultraviolet light with a wavelength of 220-330nm can strongly damage the PET layer (polymer material) of the backplane, resulting in its yellowing, Therefore, white titanium dioxide powder is used to absorb ultraviolet light with a wavelength range between 220-330nm.

2) When the light transmittance of the material is constant, the addition of titanium dioxide can enhance the reflection of incident light, thereby increasing the effective light reflected from the glass surface and further improving the photoelectric conversion efficiency of the solar cell.

As shown in Figure 3 and 4, the upper strata EVA adhesive film in the solar module adopts the reflected light direction figure of the present invention's EVA and traditional EVA respectively, as can be seen from Fig. 3, irradiates to adopt the upper strata EVA adhesive film of EVA material of the present invention The incident light is reflected from the upper layer of EVA to the glass and then reflected from the glass back to the battery sheet, while the incident light irradiated on the upper layer of EVA film made of traditional EVA material is directly scattered to the battery sheet without being reflected by the glass, thereby improving Photoelectric conversion efficiency of solar modules.

The technical contents and technical characteristics of the present invention have been disclosed above, but those skilled in the art may still make various replacements and modifications based on the teachings and disclosures of the present invention without departing from the spirit of the present invention. Therefore, the protection scope of the present invention should not be limited to The content disclosed in the embodiment should include various replacements and modifications that do not depart from the present invention, and are covered by the claims of this patent application.

Claims (8)

1. EVA who be used for to improve solar components efficient, it is characterized in that: described EVA is become by the preparation of raw material of following weight part proportioning:

Wherein, described ultraviolet absorbers is mixed by ESCALOL 567 and Octabenzone; What the weight in the described titanium dioxide was counted 10%-50% is rutile-type, and the particle diameter of titanium dioxide is 100-400nm.

2. the EVA for improving solar components efficient according to claim 1, it is characterized in that: described oxidation inhibitor is for being selected from three (2, the 4-di-tert-butyl-phenyl) phosphorous acid ester, distearyl tetramethylolmethane diphosphorous acid fat, [β-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol ester, β-(4-hydroxyl-3,5 di-tert-butyl-phenyls) the positive octadecanol ester of propionic acid, tricresyl phosphite (single nonyl benzene and dinonyl benzene mixed ester), one or more that reach in three (nonyl phenyl) phosphite mix.

3. the EVA for improving solar components efficient according to claim 2, it is characterized in that: described linking agent is superoxide, it is by being selected from 2,5-dimethyl-2, two (t-butyl peroxy) hexanes of 5-, 1,1-(two tert-butyl peroxide) 3,3,5-trimethyl-cyclohexane, one or more that reach in the t-butyl peroxy 2-ethylhexyl carbonic ether mix.

4. the EVA for improving solar components efficient according to claim 1, it is characterized in that: described photostabilizer is for being selected from hindered amines pair (1-octyloxies-2,2,6,6-tetramethyl--4-piperidyl) last of the ten Heavenly stems diester, two (2,2,6,6-tetramethyl--4-piperidyl) sebate, and poly-succinic (4 hydroxyls-2,2,6,6-tetramethyl--1 piperidines ethanol fat) one or more in mix.

5. the EVA for improving solar components efficient according to claim 1, it is characterized in that: the absorbing wavelength scope of described ESCALOL 567 is 280-340nm, its optimum weight part proportioning is 0.1-0.25 part.

6. the EVA for improving solar components efficient according to claim 1, it is characterized in that: the absorbing wavelength scope of described Octabenzone is 270-330nm, its optimum weight part proportioning is 0.1-0.25 part.

7. the EVA for improving solar components efficient according to claim 1, it is characterized in that: described silane coupling agent is for being selected from γ-aminopropyl triethoxysilane, γ-glycidyl ether oxygen propyl trimethoxy silicane, vinyltriethoxysilane, the 3-aminopropyl trimethoxysilane, and one or more mixing match in the vinyltrimethoxy silane form.

8. according to claim 1 to the described EVA for improving solar components efficient of 7 any one, it is characterized in that: described EVA is arranged in the sensitive side of solar components cell piece.

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