Ni0.6Fe0.4S2/rGO Heterogenous Nanocubes Anode for Stable and Efficient Na/K-Ion Storage

Rational design of electrode materials with cycle stability and high reversible capacity is crucial to the commercial applications of sodium/potassium ion batteries (SIBs/PIBs) in the future. Developing a high-efficiency anode for SIBs and PIBs, which is formed from the heterogenous Ni-Fe bimetallic nanocube composite selenide grown on graphene (Ni0.6Fe0.4Se2/rGO, abbreviated as NFSG). The Ni0.6Fe0.4S2 nanocubes of about 200 nm in which uniformly grown on rGO can provide larger specific surface, broader redox potential, and the stable microchannels to elevate the diffusion rate of Na/K-ion charge transfer. Utilized as a anode for SIBs, the NFSG electrode exhibits the rate capacity of 366.9 mAh g(-1) at 5.0 A g(-1) and the longevity of 82.3% circulating over 1000 cycles. For PIBs, NFSG electrode displays the capacities of 335.6 mAh g(-1) at 0.05 A g(-1) and 108.1 mAh g(-1) at 2.0 A g(-1) and an outstanding cyclic performance with retained capacity of 260.9 mAh g(-1) (0.1 A g(-1)) after 100 cycles.