Fixed-bed assisted synthesis SnO2/SnS2/CNTs composite for enhanced sodium storage performance

The present study investigates the possibility to introduce the H2S capture process within the preparation of anode material for sodium ion batteries (SIBs). The H2S capture ability of SnO2/CNTs was firstly explored via a fixed-bed assisted sulfurization process: the SnO2/CNTs nanocomposite could be successfully used for the H2S removal. Meanwhile, the produced SnO2/SnS2/CNTs composite obtained after sulfurization process was directly used as active anode material for SIBs and showed enhanced electrochemical performance. Structural and compositional characterizations of the as-prepared materials were systematically investigated by XRD, SEM, TEM and TGA. Results reveal that the SnO2/CNTs composite have a comparable H2S capture ability respect to previously reported materials. Thanks to the plate-like structure of SnS2 coupled with SnO2 particles, the optimized SnO2/SnS2/CNTs material displayed an outstanding reversible specific capacity of 543 mAh g−1 under a current density of 50 mA g−1; this is much higher than the original SnO2/CNTs electrode. Further studies with electrochemical impedance spectroscopy revealed that the SnO2/SnS2/CNTs composite allowed for an enhanced sodium diffusion coefficient and increased charge transfer ability.