Waste tea-based porous carbon–sulfur composite cathodes for lithium–sulfur battery

In this work, waste tea-based porous carbons were prepared by hydrothermal carbonization and then followed by the chemical activation using KOH and ZnCl 2 . As-prepared porous carbons were then used to host sulfur as composite cathodes for lithium–sulfur (LiS) battery system. The porous carbon–sulfur composite electrodes with optimized sulfur loading of 60 wt% exhibited the best electrochemical performance by delivering initial specific capacity of 1048 mAh g −1 at 0.05 C and maintained specific capacity of 627 mAh g −1 after 100 cycles. Moreover, it showed good capacity retention of 428 mAh g −1 at 0.5 C even after 100 cycles, which demonstrates its promising roles as host material for sulfur cathodes in LiS batteries.