3D porous SnO2/MXene as a superior anode material for Li-ion and Na-ion battery

In this paper, we synthesized the SnO2/MXene composite with unique three-dimensional (3D) porous framework by removing of polystyrene (PS) nanospheres as sacrificial templates. The SnO2 nanopaticles are evenly anchored in MXene nanosheets by electrostatic self-assembly. The composite demonstrates plenty of hierarchical pores and a greatly enlarged interfacial area, which can facilitate the permeation of electrolyte and provide more active sites for Li+/Na+ intercalation. The conductive porous structure can also promote the fast transport of electrons and ions, and maintain the structural stability of eletrode in the cycling. The SnO2/MXene composite shows increased reversible capacities and excellent cycling stability for dual storage of both Li+ and Na+. As anode material for lithium ion storage, it has long-life cycling performance of 373.7 mAh/g after 1400 cycles at 5 A/g, superior than most reported SnO2/carbide composites. For sodium ion storage, the conposite also shows a increased capacity of 236.8 mAh/g at 0.4 A/g after 100 cycles. This study provides a design strategy for preparing anode materials of advanced battery system with promising electrochemical performance.