A New Metallic In3O4 Sheet as an Anode Material for Sodium-Ion Batteries

Topological state of matter and high-performance electrode materials have attracted considerable attention all over the world. Here we combine these two by exploring the possibility of using In-O compound sheets for sodium-ion battery (SIB) anode materials. We report a novel In3O4 sheet and explore its geometric structure, stability, electronic structure, and properties as anode materials for energy storage through first-principles swarm structural search. The predicted In3O4 sheet exhibits great stability, metallic feature, and excellent electrode performance. The adsorption of Na atoms on 2 x 2 In3O4 supercell is exothermic, which ensures stability and safety in practical applications. The competitive Na capacity, acceptable diffusion energy barrier, and low open-circuit voltage of In3O4 sheet result in good rate capacity under operating conditions. We hope that our work will provide new insights into the studies on both anode materials for SIBs and quasi-two-dimensional metal oxides.