Bouquet-Like Mn₂SnO₄ Nanocomposite Engineered with Graphene Sheets as an Advanced Lithium-Ion Battery Anode

Abstract

Volume expansion is a major challenge associated with tin oxide (SnO _x), which causes poor cyclability in lithium-ion battery anode. Bare tin dioxide (SnO₂), tin dioxide with graphene sheets (SnO₂@GS), and bouquet-like nanocomposite structure (Mn₂SnO₄@GS) are prepared via hydrothermal method followed by annealing. The obtained composite material presents a bouquet structure containing manganese and tin oxide nanoparticle network with graphene sheets. Benefiting from this porous nanostructure, in which graphene sheets provide high electronic pathways to enhance the electronic conductivity, uniformly distributed particles offer accelerated kinetic reaction with lithium ion and reduced volume deviation in the tin dioxide (SnO₂) particle during charge-discharge testing. As a consequence, ternary composite Mn₂SnO₄@GS showed a high rate performance and outstanding cyclability of anode material for lithium-ion batteries. The electrode achieved a specific capacity of about 1070 mA h g^-1 at a current density of 400 mA g^-1 after 200 cycles; meanwhile, the electrode still delivered a specific capacity of about 455 mA h g^-1 at a high current density of 2500 mA g^-1. Ternary Mn₂SnO₄@GS material could facilitate fabrication of unique structure and conductive network as advanced lithium-ion battery.