Cu2S@ N, S Dual‐Doped Carbon Matrix Hybrid as Superior Anode Materials for Lithium/Sodium ion Batteries

Abstract Cu 2 S is considered as a promising electrode material for lithium‐ion and sodium‐ion batteries owing to its flat charge‐discharge plateau as well as the abundant reserves. However, serious capacity fading and formation of polysulfides during electrochemical process restrict its practical application. In this work, a new type of Cu 2 S@N, S dual‐doped carbon matrix (Cu 2 S@NSCm) hybrid is synthesized through a simple in‐situ polymerization process and subsequent carbonization process. Due to the N, S dual‐doped carbon matrix, which can buffer the volume change, restrain the dissolution of polysulfide and enhance the electron conductivity during electrochemical process, the hybrid demonstrates excellent electrochemical performance. The Cu 2 S@NSCm hybrid exhibits a reversible capacity of 560.1 mAh g −1 at a current density of 1000 mA g −1 after 550 cycles when used in lithium‐ion batteries, which is among the best performance for Cu 2 S based anode materials. Moreover, a capacity of 182.3 mAh g −1 is obtained after 50 cycles when used as an anode material in sodium ion batteries, which is much better than the pure Cu 2 S.