Hollow SnO2@carbon core–shell spheres stabilized on reduced graphene oxide for high-performance sodium-ion batteries

Abstract

Sodium ion batteries are rapidly emerging as attractive and cost-effective devices in applications such as smart grids and large-scale energy storage. However, the large size of the sodium ion and its tendency to form NaC₁₈₆ during electrochemical intercalation with carbon anodes necessitate the design of architectures which can accommodate the spatial requirements without sacrificing essential functional properties like good conductivity and high surface area. In this manuscript, we report the synthesis of three-dimensional, mesoporous, nano SnO₂ cores encapsulated in carbon shells anchored on reduced graphene oxide (SnO₂@C-rGO) by a simple microwave induced catalytic transformation of diazonium functionalized graphene oxide. The electrochemical results reveal that our SnO₂@C-rGO anodes have excellent electrochemical performance including high-capacity (493.12 mA h g⁻¹), good capacity retention and large coulombic efficiency (96.2% after 150 cycles).