Superior lithium-ion storage performances of SnO2 powders consisting of hollow nanoplates

Abstract

Hierarchical structured transition metal oxides have attracted considerable attention as anode materials for lithium-ion batteries because they possess large surface area that can provide large contact area with the electrolyte and short diffusion distance for Li ions. Here, a hierarchical structured assembly of hollow SnO2 nanoplates is synthesized by one-step oxidation of SnS2 powders. The SnS2 powders comprising of dense nanoplates synthesized by the hydrothermal method transform into SnO2 powders comprising of hollow nanoplates by nanoscale Kirkendall diffusion at the oxidation temperature of 500 degrees C. After the transformation of SnS2 into SnO2 powders, the Brunauer-Emmett-Teller surface area of the powders increases from 22.8 to 82.7 m(2) g(-1). The hierarchical structured SnO2 powders show superior lithium-ion storage performances compared to SnS2 powders with the same structure. The discharge capacities of SnS2 and SnO2 powders at a current density of 1 A g(-1) for the 300th cycle are 273 and 754 mA h g(-1), respectively. The SnO2 powders show a high reversible capacity of 169 mA h g(-1) even at an extremely high current density of 30 A g(-1). The outstanding electrochemical properties of the SnO2 powders can be attributed to their unique morphological structure having hollow nanoplates and optimum crystallite size, which increases the contact area between the active materials and the electrolyte and the buffered stress caused by the volume expansion during cycling. (C) 2019 Elsevier B.V. All rights reserved.