Columnar assembly and successive heating of colloidal 2D nanomaterials on graphene as an efficient strategy for new anode materials in lithium ion batteries: The case of In ₂S ₃ nanoplates

This study shows that heat-treatment of colloidal inorganic nanoplates with columnar assembly under argon is a good strategy for development of anode materials. The heating of colloidal In ₂S ₃ nanoplates under argon resulted in the formation of film-like materials through interconnection of plates in a side by side manner. When the columnarly assembled colloidal In ₂S ₃ plates were heated at 400 °C under argon for 2 hours on graphene, more efficient anode materials with smaller diameters were obtained. Interestingly, the heat-treated columnarly assembled In ₂S ₃ plates on graphene had a layered structure, which was attributed to the possible existence of carbon materials between plates formed by the heat-treatment of surfactants under argon. The resultant graphene-In ₂S ₃ composites showed enhanced discharge capacities, up to 716-837 mA h g ^-1, as well as excellent stabilities. In addition, the materials showed promising coulombic efficiencies and rate performances. We believe that, based on the strategy in this work, diverse graphene-inorganic nanomaterial composites with a layered structure can be prepared and applied as new anode materials in lithium ion batteries.