A hydrophilic separator for high performance lithium sulfur batteries

Abstract

Rechargeable lithium sulfur batteries have been regarded as one of the most promising power source systems for next generation EVs or HEVs. However, the low utilization of active materials, rapid capacity degradation, and poor rate capability seriously restrict their large-scale applications in commercial markets. Herein, a novel strategy, using a hydrophilic separator which is prepared by auto-oxidization and self-polymerization of a dopamine monomer onto the surface of conventional hydrophobic separators, is reported to improve the electrochemical performance of Li–S batteries. The cells with the hydrophilic separator show significantly enhanced cycle performance. At a rate of 0.2 C, the battery demonstrates an initial capacity of 1271 mA h g⁻¹, and the capacity can still remain at 1020.3 mA h g⁻¹ after 30 cycles, which improves 77% compared with the cells using conventional separators.