Surface‐Confined SnS2@C@rGO as High‐Performance Anode Materials for Sodium‐ and Potassium‐Ion Batteries

Abstract Potassium‐ (PIBs) and sodium‐ion batteries (SIBs) are emerging as promising alternatives to lithium‐ion batteries owing to the low cost and abundance of K and Na resources. However, the large radius of K+ and Na+ lead to sluggish kinetics and relatively large volume variations. Herein, a surface‐confined strategy is developed to restrain SnS2 in self‐generated hierarchically porous carbon networks with an in situ reduced graphene oxide (rGO) shell (SnS2@C@rGO). The as‐prepared SnS2@C@rGO electrode delivers high reversible capacity (721.9 mAh g−1 at 0.05 A g−1) and superior rate capability (397.4 mAh g−1 at 2.0 A g−1) as the anode material of SIB. Furthermore, a reversible capacity of 499.4 mAh g−1 (0.05 A g−1) and a cycling stability with 298.1 mAh g−1 after 500 cycles at a current density of 0.5 A g−1 were achieved in PIBs, surpassing most of the reported non‐carbonaceous anode materials. Additionally, the electrochemical reactions between SnS2 and K+ were investigated and elucidated.