Recently, Zhejiang Xin'an Chemical Group announced that its independently developed "high transmittance, UV resistant organic silicon photovoltaic film" has passed T Ü V Rheinland certification, surpassing imported products in terms of performance, marking the complete independence and controllability of China's photovoltaic industry in the field of key auxiliary materials. The adhesive film has received orders from top companies such as Longi Green Energy and Tongwei Shares, and is expected to replace imports of over 300 million square meters by 2024.


Technological breakthrough: solving the problems of UV aging and laminated bubbles
Photovoltaic film is the core material for encapsulating solar cells, which needs to maintain stability for 25 years in an environment of -40 ℃ to 85 ℃. Traditional EVA film is prone to decomposition under UV irradiation, resulting in a power attenuation of over 10% in battery cells; Although imported organic silicone film has strong weather resistance, its light transmittance is less than 90%, and bubbles are easily generated during lamination, which affects the yield of components.


Xin'an Chemical took 5 years of research and development, and through molecular structure design, introduced phenyl copolymer units into the siloxane main chain, which increased the transmittance of the adhesive film to 92% (90% for imported products). At the same time, the amount of ultraviolet absorber was reduced from 3% to 1.5%, and the cost was reduced by 20%. After aging for 5000 hours in an environment of 85 ℃ and 85% humidity, our adhesive film had a yellowing index (Δ YI) of only 1.2, which is better than the imported product (1.5), and the laminated bubble rate decreased from 5% to 0.3%. ”The Chief Scientist of Xin'an Chemical stated.


Customer verification: Longi Green Energy mass production import, efficiency increased by 0.3%
The technical director of Longi Green Energy pointed out that the increase in light transmittance of Xin'an adhesive film by 2 percentage points is equivalent to a 0.3% increase in component efficiency. Calculated based on the installed capacity of a single GW, it can generate an additional 3 million kWh of electricity per year and increase revenue by 1.5 million yuan. ”At present, Xin'an Chemical has built a photovoltaic film production line with an annual output of 500 million square meters, which can meet 30% of the domestic market demand and export to emerging markets such as India and Brazil.


Policy support: Industrial chain security receives national strategic support
According to the National Development and Reform Commission's "Several Measures to Promote the Healthy Development of the Photovoltaic Industry Chain", it is necessary to achieve 100% localization of photovoltaic auxiliary materials by 2025. The Xin'an Chemical project has been listed as a key project for new materials in the 14th Five Year Plan period, receiving a subsidy of 200 million yuan from the central government for the construction of a 100 ton pilot platform and the development of next-generation products such as special adhesive films for perovskite batteries.


The organic silicon adhesive film is just the starting point. We will develop 'bottleneck' materials around the entire photovoltaic industry chain, "said the chairman of Xin'an Chemical. The company is collaborating with the Institute of Chemistry of the Chinese Academy of Sciences to develop a" self-healing organic silicon conductive adhesive, "which is expected to solve the problem of high cost of low-temperature silver paste in heterojunction cells (HJT) and promote a further reduction of 0.05 yuan in photovoltaic electricity costs.


Industry perspective:
The localization of photovoltaic film is a microcosm of China's transformation from a 'manufacturing powerhouse' to a 'materials powerhouse'. "The Secretary General of the China Photovoltaic Industry Association stated that with breakthroughs in materials such as organosilicon and polyolefins, the global competitiveness of China's photovoltaic industry will be further consolidated, and it is expected that the export value of modules will exceed 50 billion US dollars by 2025.