Preparation Of Antireflective Self-Cleaning Coating Materials For Solar Panels

Solar energy,as an important component of new energy,is an important area of the national"dual carbon"strategic goal.However,when solar panels are exposed to the atmospheric environment for a long time,surface ash pollution seriously reduces power generation efficiency.Long term cleaning is a huge challenge..Photocatalytic super hydrophilic self-cleaning antireflective coating is an effective way to solve the dust pollution.In this paper,TiO₂/SiO₂ composite solution gel method is used to prepare the coating material.Through photocatalytic degradation of organics,the surface super hydrophilic"drainage"way to achieve self-cleaning of the solar panel surface,reduce the reflection of solar light,and improve the power generation efficiency of the solar panel.The main research results are as follows:（1）To solve the problem of drying shrinkage cracking of SiO₂ gel,the factors affecting drying shrinkage of SiO₂ bulk gel were first studied.Through the screening of raw materials,selection of catalysts,regulation of sol pH,addition of toughening materials,treatment of ionic impurities and other methods,it was found that the higher the concentration of sodium silicate,the smaller the shrinkage of the gel prepared,and the higher the concentration,the faster the setting would be;pH value will affect the time of sol gel and gel strength,and the gel prepared with sulfuric acid as catalyst has the best anti shrinkage performance;Polyvinyl alcohol（PVA）can improve the toughness of gel.It is found that with the increase of PVA addition,the shrinkage of gel decreases,and the excessive PVA will lead to the decrease of light transmittance of gel block.（2）Secondly,sepiolite fiber and TiO₂ are introduced into the SiO₂ gel to form a composite coating material.It is found that the alkali metal ions in the sol will damage the integrity of the SiO₂ film coating,and the coating method and drying environment will affect the film structure.Sepiolite fiber can improve the toughness of the film,and improve the hydrophilicity of the film at the same time.The best effect is achieved when the addition of sepiolite fiber is 0.5%,and the addition of TiO₂ is 0.5%.The final film has an anti reflective effect in the range of 400nm～800nm,with a photocatalytic degradation rate of 98.3%and a contact angle of 4.59°.（3）Finally,process experiments were conducted on solar panels using composite coating materials,using three process methods:flat laying,rolling coating,and brushing to prepare self-cleaning films.Based on the uniformity test of the liquid film,the optimal coating process was determined to be flat laying.In order to control the thickness of the final film and ensure the transparency of the coating,PVC,PET,PC,and PP film materials were selected as coating tools to prepare self-cleaning films.The results showed that the thickness of the self-cleaning film coated with PC material film was 25.78nm,with the best self-cleaning effect and an increase in power generation of 2.3%.