SnS2/Co3S4 Hollow Nanocubes Anchored on S‐Doped Graphene for Ultrafast and Stable Na‐Ion Storage

Abstract SnS2 has been widely studied as an anode material for sodium‐ion batteries (SIBs) based on the high theoretical capacity and layered structure. Unfortunately, rapid capacity decay associated with volume variation during cycling limits practical application. Herein, SnS2/Co3S4 hollow nanocubes anchored on S‐doped graphene are synthesized for the first time via coprecipitation and hydrothermal methods. When applied as the anode for SIBs, the sample delivers a distinguished charge specific capacity of 1141.8 mAh g−1 and there is no significant capacity decay (0.1 A g−1 for 50 cycles). When the rate is increased to 0.5 A g−1, it presents 845.7 mAh g−1 after cycling 100 times. Furthermore, the composite also exhibits an ultrafast sodium storage capability where 392.9 mAh g−1 can be obtained at 10 A g−1 and the charging time is less than 3 min. The outstanding electrochemical properties can be ascribed to the enhancement of conductivity for the addition of S‐doped graphene and the existence of p–n junctions in the SnS2/Co3S4 heterostructure. Moreover, the presence of mesopores between nanosheets can alleviate volume expansion during cycling as well as being beneficial for the migration of Na+.