Cobalt-nickel bimetallic sulfide (NiS₂/CoS₂) based dual-carbon framework for super sodium ion storage

Design hybrid metal sulfides-based anode materials is one of the most effective approaches to improve the performance of sodium-ion batteries (SIBs). However, owing to the huge volume expansion, the capacity of sulfide-based anode will decay significantly after repeated charge/discharge processes. Herein, we reported the successful demonstration of anode material based on concaved NiS₂@CoS₂ nanocube (NCSC) via a chemical etching strategy, which was derived from etching and sulfidation of Ni-Co coordination polymers (NiCoCP) precursor. The obtained NCSC anode materials deliver a high specific sodium storage capacity of 848 mAh g^-1 at 0.1 A g^-1 and a stable cyclability of 572 mAh g^-1 at 5 A g^-1 after 830 cycles. This special etching strategy exploit a novel way for the design and preparation of high-performance anode materials for SIBs.