3D Graphene Encapsulated Hollow CoSnO₃ Nanoboxes as a High Initial Coulombic Efficiency and Lithium Storage Capacity Anode

Abstract

3D Graphene sheets encapsulated amorphous hollow CoSnO₃ nanoboxes (H-CoSnO₃ @reduced graphene oxide [RGO]) are successfully fabricated by first preparing 3D graphene oxides encapsulated solid CoSn(OH)₆ nanocubes, followed by an alkaline etching process and subsequent heating treatment in Ar. The hollow CoSnO₃ nanoboxes with average particle size of 230 nm are uniformly and tightly encapsulated by RGO sheets. As an anode material for Li-ion batteries, H-CoSnO₃ @RGO displays high initial Coulombic efficiency of 87.1% and large reversible capacity of 1919 mA h g^-1 after 500 cycles at the current density of 500 mA g^-1 . Moreover, excellent rate capability (1250, 1188, 1141, 1115, 1086, 952, 736, and 528 mA h g^-1 at 100, 200, 300, 400, 500, 1000, 2000, and 5000 mA g^-1 , respectively) is acquired. The reasons for excellent lithium storage properties of H-CoSnO₃ @RGO are discussed in detail.