Improved cycling stability of lithium–sulphur batteries by enhancing the retention of active material with a sandwiched hydrothermally treated graphite film

Abstract

A new lithium–sulphur battery with a hydrothermally treated graphite film sandwiched between the separator and the sulphur cathode shows increased capacity, enhanced cycling stability and improved coulombic efficiency. After 50 cycles, a high capacity of 631 mA h g⁻¹ is maintained, compared to 203 mA h g⁻¹ for the Li–S battery with conventional configuration. Moreover, the coulombic efficiency is increased to near 100% from around 94%. This improved electrochemical performance could be attributed to the new cell configuration, because the graphite film greatly retains the active material by alleviating the polysulphide shuttling problem and providing extra reaction sites for sulphur species.