Sulfur-rich CuS1+x cathode for lithium batteries

Abstract

Copper sulfide is one of the promising cathode materials for the next-generation secondary batteries due to its high electrical conductivity and relatively high capacity. The outstanding cycling performance of sulfur-rich CuS1+x (0.58 ≤ x ≤ 0.61) cathode material obtained by one-step spray pyrolysis was demonstrated in this work. A simple approach of increasing the sulfur content up to CuS1.58 achieved ~900 mAh g−1 for 20 cycles at 0.1C. Furthermore, a small addition of carbon (5 wt%) by wet ball milling extremely enhanced discharge capacity to 1200 mAh g−1.