Qingdao Energy Development Develops High Security Flame Retardant Biomass Lithium Battery Batteries

Under the support of the Chinese Academy of Sciences “Hundred Talents Program”, the Ministry of Science and Technology “863” major energy storage battery project, the Shandong Province Jieqing Fund and the Qingdao Key Laboratory, the Bionic Energy and Energy Storage System of the Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences After more than three years of scientific research, the team has made breakthroughs in the field of power lithium ion battery separators, and successfully developed power lithium battery separators with high-security flame-retardant biomass composite materials with independent intellectual property rights, and achieved pilot production scale. .

The diaphragm is a key component of the power lithium-ion battery. It plays an important role in blocking the positive and negative electron conductivity in the battery, allowing ions to freely pass through to achieve ion conduction, and it also affects the battery capacity, cycle life, and safety performance. At present, the mainstream products of commercial lithium ion battery separators are mechanically stretched polyethylene (PE), polypropylene (PP) microporous films, and polypropylene/polyethylene/polypropylene (PP/PE/PP) three-layer micropores. Composite membrane, core technology monopolized by foreign large companies. Commercial polyolefin separators have poor porosity, transverse tensile strength, liquid retention, and thermal stability, and cannot fully meet the requirements of rapid battery charge and discharge, and there are great safety risks.

Cellulose is derived from natural plants, has good thermal stability, is rich in production, low in price, and green and sustainable. It is a biomass polymer material with great added value and development prospects. Qingdao Energy uses biomass-cellulose as raw material, adopts melt-blown-wet process coupling technology with independent intellectual property rights, researches and develops related production and processing equipment, and develops high-security low-cost biomass composite separators. The separator has good electrolyte wettability, heat resistance, and flame retardancy, and its battery rate and cycle performance are far superior to commercial polyolefin separators.

Domestic experts highly praised the biomass composite diaphragm developed by the team and considered it as a new material system and process method. The successful development of this type of product will fill domestic gaps and provide important technical support for the development of the "blue economy" in Shandong Province and the "blue silicon valley" in Qingdao. According to the team leader Cui Guanglei's researcher, before the end of the year, the self-developed equipment will be improved and the process optimization will be completed. It is expected that an annual production capacity of 300,000 square meters will be formed next year.