A flexible nanostructured sulphur–carbon nanotube cathode with high rate performance for Li-S batteries

Abstract

We report the template-directed synthesis of sulphur–carbon nanotubes and their use to form a membrane that is binder-free, highly conductive and flexible. This nanostructured membrane is used as a self-supporting cathode without metal current-collectors for Li-S batteries. The membrane cathode has a high electrical conductivity and renders a long life of sulphur of over 100 charge–discharge cycles. High discharge capacity of sulphur was attained at 712 mA h g_sulphur⁻¹ (23 wt% S) and 520 mA h g_sulphur⁻¹ (50 wt% S) at a high current density (6 A g_sulphur⁻¹). The overall capacity of the flexible cathode correspondingly reaches 163 mA h g⁻¹ (23 wt% S) and 260 mA h g⁻¹ (50 wt% S). These results demonstrate the great potential of this nanostructured flexible membrane as a cathode for Li-S batteries with fast charge–discharge performance and long life.