Nano sulfurized polyacrylonitrile cathode for high performance solid-state lithium–sulfur batteries

For all-solid-state lithium-sulfur batteries, the volume expansion effects of the sulfur cathode would cause the capacity decay, resulting in reducing the efficiency of the cell. In this work, nano-spherical sulfide polyacrylonitrile (NS-SPAN) is prepared with a uniform diameter of around 150 nm. While Li4(BH4)3I as solid-state electrolyte effectively inhibits the growth of lithium dendrites and enhances the cycling performance. Then, NS-SPAN as the cathode is matched with Li4(BH4)3I solid-state electrolyte to assemble the all-solid-state lithium-sulfur battery. At a current density of 0.2 mAcm−2 at 100 °C, the voltage of the Li–Li cell is able to maintain stable after 250 h cycling. After 150 cycles at 0.1 C, the lithium-sulfur battery still has a discharge capacity of 878.5 mAh g−1, with the coulombic efficiency of 99%.