Realizing All-Climate Li-S Batteries by Using a Porous Sub-Nano Aromatic Framework

Lithium-sulfur (Li-S) batteries with high energy density are currently receiving enormous attention. However, their redox kinetics at low temperature is extremely tardy, and polysulfides shuttling is serious at high temperature, which severely hinders the implementation of wide-temperature Li-S batteries. Herein, we propose an all-climate Li-S battery based on an ether-based electrolyte by using a porous sub-nano aromatic framework (SAF) modified separator. It's demonstrated that the fully conjugated SAF-3 with a small pore size (0.97 nm) and narrow band gap (1.72 eV) could efficiently block the polysulfides shuttling at elevated temperature and boost the polysulfides conversion at low temperature. Consequently, the SAF-3 modified cells work well in a wide temperature ranging from -40 to 60 degrees C. Furthermore, when operated at room temperature, the modified cell exhibits 90 % capacity retention over 100 cycles under high-sulfur loading (5.0 mg cm(-2)) and lean electrolyte (5 mu L mg(-1)).

Automated summary

In this study, an all-climate lithium-sulfur (Li-S) battery is proposed using an ether-based electrolyte and a modified separator with a porous sub-nano aromatic framework (SAF-3). The SAF-3 effectively blocks polysulfides shuttling at high temperatures and enhances polysulfides conversion at low temperatures. The modified cells exhibit good performance in a wide temperature range (-40 to 60 degrees C) and retain 90% capacity after 100 cycles under high-sulfur loading and lean electrolyte conditions at room temperature.