High-performance prelithiated Si-S full cell enabled by trifluorobenzene modified diluted high-concentration electrolyte

Silicon-sulfur (Si-S) full cells show significant potential in energy storage due to their high theoretical energy density compared to commercial lithium-ion batteries. Nevertheless, a majority of electrolytes reported for Si-S full cells still cannot meet the requirements of stable long-duration cycling. Herein, we report a high-areal-capacity Si-S full cell consisted with prelithiated SiO, thick Li2S-Se0.05S0.95@pPAN electrode and a trifluorobenzene (F3B) modified and diluted high-concentration electrolytes. This novel electrolyte can effectively mitigate the volume expansion of the prelithiated SiO anode and enhance the utilization of active S in the cathode, showing excellent compatibility with electrodes. The assembled Si-S full cell using modified electrolyte displays remarkable cyclability over 100 cycles at 0.1C, exhibiting higher capacity retention (54.0% vs. 17.5%) than the pristine electrolyte without F3B. More importantly, a full cell with a thick sulfur cathode (16 mg/cm2) exhibits a superior initial areal capacity of 8.34 mAh/cm2 and high-capacity retention of 52% after 80 cycles, even at a lean electrolyte condition (2 μL/mg). This work provides guidance for the achievement of high-performance Si-S full cells under lean electrolytes.