At -30°C, SEMCORP Group Successfully Developed a High Specific Energy Battery Semi-solid Electrolyte Composite Separator

Technological innovation drives future development. Recently, it was learned from the research institute of SEMCORP that the company has developed a new type of separator product for battery cells used in new energy vehicles, 3C products, and energy storage among other areas—the semi-solid electrolyte composite separator. After repeated experimental verifications, this product has shown outstanding low-temperature discharge performance compared to conventional separator products in the industry. Especially in ultra-low temperature environments of -30°C, it can still increase the discharge capacity retention rate of the finished battery cell by more than 10%. Moreover, its cell puncture test pass rate is also higher than that of conventional separators, which is of great significance in improving the safety performance of batteries.

 Low-Temperature Performance Test Charts at Different Temperatures

Cell Puncture Test Temperature Rise Curve

Cell Puncture Test Voltage Curve

For this product, a special team from the research institute of SEMCORP Group, after years of technical tackling and in collaboration with both internal and external partners as well as upstream and downstream, has successfully developed. Its room-temperature ionic conductivity is between 1-10 millisiemens per centimeter (mS/cm).

In terms of performance, not only is its low-temperature performance outstanding, but the resistance of the cell after use is significantly reduced compared to conventional separators. Furthermore, in a 1C/1C charge/discharge rate cycle test conducted 1000 times, it was found that cells using this composite separator have a higher cycle capacity retention rate even when the electrolyte retention amount is 30% less compared to conventional separators.

Cycle Capacity Comparison Chart

In recent years, SEMCORP Group has been committed to the research and development and industrialization of high-end lithium battery separator new materials, focusing on improving the quality of lithium battery separator products and cutting-edge technology. In 2022, the R&D investment reached 724 million yuan, continuously attracting global industry-leading talents. In 2021, SEMCORP, together with Beijing WELION and TIANMULAKE, established a joint venture company in Liyang, Changzhou, Jiangsu—Jiangsu Sanhe, to research, produce, and sell semi-solid electrolyte coating separators and various high-end coating separators used in semi-solid batteries. The first phase of the project's plant has been basically completed, and the installation and commissioning of 2 high-performance coating film production lines have begun trial production.

Aerial View of Jiangsu Sanhe Base

Looking forward, SEMCORP Group will base itself on the development of the national new energy industry, adhere to the path of independent innovation-driven development, and fully implement the company's "1139" project goals, striving to become a world-class material research and development production enterprise.