Rational design and synthesis of hierarchically structured SnO2 microspheres assembled from hollow porous nanoplates as superior anode materials for lithium-ion batteries

摘要

Herein,hierarchically structured SnO2 microspheres are designed and synthesized as an efficient anode material for lithium-ion batteries using hollow SnO2 nanoplates.Three-dimensionally ordered macroporous (3-DOM) SnOx-C microspheres synthesized by spray pyrolysis are transformed into hierarchically structured SnO2 microspheres by a two-step post-treatment process.Sulfidation produces hierarchically structured SrnS-SnS2-C microspheres comprising tin sulfide nanoplate and carbon building blocks.A subsequent oxidation process produces SnO2 microspheres from hollow SnO2 nanoplate building blocks,which are formed by Kirkendall diffusion.The discharge capacity of the hierarchically structured SnO2 microspheres at a current density of 5 A·g-1 for the 600th cycle is 404 mA·h·g-1.The hierarchically structured SnO2 microspheres have reversible discharge capacities of 609 and 158 mA·h·g-1 at current densities of 0.5 and 30 A·g-1,respectively.The ultrafine nanosheets contain empty voids that allow excellent lithium-ion storage performance,even at high current densities.