Improving Na+ transport kinetics and Na+ storage of hierarchical rhenium-nickel sulfide (ReS2@NiS2) hollow architecture by assembling layered 2D-3D heterostructures

Abstract

Abstract Mixed metal sulfides have been widely used as anode material of sodium-ion batteries (SIBs) because of their excellent conductivity and sodium ion storage performance. Herein, ReS2@NiS2 heterostructures have been triumphantly designed and prepared through anchoring ReS2 nanosheet arrays on the surface of NiS2 hollow nanosphere. Specifically, the carbon nanospheres was used as hard template to synthesize NiS2 hollow spheres as the substrate and then the ultrathin two-dimensional ReS2 nanosheet arrays were uniformly grown on the surface of NiS2. The internal hollow property provides sufficient space to relieve the volume expansion, and the outer two-dimensional nanosheet realizes the rapid electron transport and insertion/extraction of Na+. Owing to the great improvement of the transport kinetics of Na+, NiS2@ReS2 heterostructure electrode can achieve a high specific capacity of 400\u2009mA\u2009h/g at the high current density of 1 A/g and still maintain a stable cycle stability even after 220 cycles. This hard template method not only paves a new way for the design and construct binary metal sulfide heterostructure electrode materials with outstanding electrochemical performance for Na+ batteries but also open up the potential applications of anode materials of SIBs.