High Performance Lithium–Sulfur Batteries with a Sustainable and Environmentally Friendly Carbon Aerogel Modified Separator

Carbon-based aerogel prepared via direct conversion of natural biomass has wide application prospects in the environment and energy field. Herein, the sustainable and environmentally friendly porous carbon aerogel is prepared through hydrothermal treatment, freeze-drying, and postpyrolysis using sweet potato as the precursor. The as-prepared carbon aerogel is used to modify the commercial separator of lithium–sulfur batteries to solve the problems of poor cycle life and low utilization rate of active substances. The carbon aerogel coating can not only suppress the shuttle effect of the polysulfide intermediates during cycling and reduce the cell resistance but also act as an upper current collector to increase the utilization rate of sulfur. The cell with carbon aerogel modified separator exhibits high electrochemical performance. The results show that the initial discharge capacity is 1216 mAh/g at 0.1 C and the reversible discharge capacity retains 431 mAh/g after 1000 cycles at 1 C with the Coulombic efficiency over 95.3%