Supported SnS2 nanosheet array as binder-free anode for sodium ion batteries

Transition-metal sulfides have been generally identified as one of the promising anode candidates for sodium ion batteries yet still suffer from serious capacity decay. Herein, we carry out a simple and effective hydrothermal method for preparation of vertically aligned SnS2 nanosheets grown on carbon cloth as binder-free anode for sodium ion batteries. Specifically, the self-standing anode material displays excellent electrochemical properties including high specific capacity, outstanding rate capability, and long cycle stability. The large discharge capacity of 1039.9 mA h g−1 at 0.2 A g−1 is achieved. Even at much high current density of 2 A g−1, the reversible capacity can reach 673.4 mA h g−1 after 400 cycles. Meanwhile, this anode material can also withstand various current densities ranging from 0.1 to 2 A g−1 and exhibits good capacity recovery ability. Electrochemical kinetic analysis suggests that the mechanical flexibility between SnS2 nanosheets and carbon cloth conductive substrate could well maintain the structural integrality, thus providing favorable transport kinetics for both electrons and sodium ions during repeated battery operation.