Constructing NiS2/NiSe2 heteroboxes with phase boundaries for Sodium-Ion batteries.

Abstract Reasonable design and synthesis of anode materials with high capacity, excellent rate capability and good cycling stability is vital for the pragmatic application of sodium-ion batteries (SIBs). Transition metal chalcogenides possess immense potential on account of their distinguished redox reversibility and high theoretical specific capacity. Herein, the hollow metal sulfide/metal selenide (NiS2/NiSe2) heteroboxes with rich phase boundaries have been manufactured as anode for SIBs. The lattice distortion and charge redistribution at the phase boundary of the as-prepared NiS2/NiSe2 heteroboxes can expose more active sites, which is profitable to the adsorption of Na+ and accelerate the sodium storage kinetics process, and the unique hollow porous structure is conducive to buffering the volume expansion and can facilitate the penetration of electrolyte during the repeated Na+ de-intercalation process. By virtue of these advantages, the NiS2/NiSe2 heteroboxes delivers a good rate capability, where the average capacity at 10 A g-1 in comparison with 0.1 A g-1 is 64.3%. Otherwise, it exhibits an ultralong reversible capacity of 292 mA h g-1 after 2000 cycles at 10 A g-1 with only 0.0125% average capacity decay per cycle. The rational construction of phase boundary with unique structure in this article has guiding significance for the manufacture of progressive SIBs anode materials.