LAUSR

Abstract Utilizing copper coordination compound as Cu, S, N and C sources, nano-sized Cu9S5 coated with N, S co-doped carbon (NSC) has been prepared via one-step calcination. The uniform nanosize Cu9S5 were well coated by NSC with the thickness of about 4 nm. The Cu9S5/NSC composite as a new anode for sodium-ion battery shows high reversible charge specific capacity of 412.0 mAh g−1 at 100 mA g−1 and good capacity retention after 200 cycles, which is attributed to the encapsulated structure and strong binding interaction between Cu9S5 and NSC (bridge bonds of C-S-Cu and C-O-Cu).