A nanocomposite of tin dioxide octahedral nanocrystals exposed to high-energy facets anchored onto graphene sheets for high performance lithium-ion batteries

Abstract

The synthesis of nanocrystals with high-energy facets is an important and challenging research topic. In this work, we develop a facile hydrothermal method to synthesize a nanocomposite of SnO₂ octahedral nanocrystals (ONCs) exposed to high-energy {332} facets on graphene sheets (GS) as an advanced anode material for high performance lithium-ion batteries (LIBs). Electrochemical characterization of SnO₂ ONCs/GS nanocomposite shows that it exhibits much enhanced Li-battery performance compared with a nanocomposite of SnO₂ nanoparticles (NPs) exposed to stable facets on GS. The as-prepared SnO₂ ONCs/GS nanocomposite has a reversible discharge capacity of as high as 844 mA h g⁻¹ after 50 cycles at a current density of 100 mA h g⁻¹. Even at a higher current density of 5000 mA g⁻¹, the discharge capacity of the SnO₂ ONCs/GS nanocomposite is still as high as approximately 555 mA h g⁻¹, indicating good rate capability. These excellent results are attributed to the exposure of SnO₂ ONCs to high-energy facets, and the rational growth of the SnO₂ ONCs on GS. It is believed that the SnO₂ ONCs/GS nanocomposite hold great promise for applications in high performance LIBs.