Yuan Botao, Liu Jipeng, Dong Liwei, Chen Dongjiang, Zhong Shijie, Liang Yifang, Liu Yuanpeng, Ji Yuanpeng, Wu Xiaoqiang, Kong Qingquan, Han Jiecai, He Weidong
National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, and, Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin, 150080, China.
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China.
Small. 2022 Jun;18(23):e2107664. doi: 10.1002/smll.202107664. Epub 2022 May 8.
Incorporation of ceramic materials into separators has been frequently applied in both research and industry to improve the overall high-temperature performances of lithium ion batteries. However, inorganic ceramic particles tend to form aggregation in separators and even fall off in the separator matrix due to the inferior combination between ceramic particles and polymer matrix, giving rise to a decrease in separator porosity and thus the degradation of battery performances. Herein, a single-layer core-shell architecture is designed to reinforce the polymer matrix through encircling Al O particles by poly(vinylidene fluoride) with strong inter-molecular interaction. The 3D-reinforced microstructure effectively improves pore distribution and thermal stability to resist the dimensional deformation at high temperatures, thus giving rise to a high Coulombic efficiency of 99.16% and 87.5% capacity retention after 500 cycles at 80 °C for LiFePO /Li batteries. In particular, the excellent performances of the proposed separator microstructure are confirmed with a thickness value of commercial separators. This work provides a promising strategy to fabricate a core-shell structural composite separator for stable lithium ion batteries at high temperatures.
