Synthesis of the SnO2@C@GN hollow porous microspheres with superior cyclability for Li-ion batteries

Abstract

SnO2@C@GN hollow porous microspheres (marked as HPS-SnO2@C@GN) are synthesized by a simple two-steps method in this work. SnO2 hollow porous microspheres are prepared from annealing and selective leaching of Cu2SnS3 hollow microspheres first, and then the SnO2 microspheres are coated with dual carbon layer from the polydopamine and graphene using a so-called “capsulation” strategy. HPS-SnO2@C@GN has a hollow interior and porous carbon layer on the outside which make the composites have super conductivity and the ability to withstand the large volume expansion upon the lithiation process. HPS-SnO2@C@GN, as an anode material for Li-ion batteries, exhibit a high reversible capacity of 882 mAh g−1 after 70 cycles at a current density of 0.2 A g−1 and remain 535 mAh g−1 after 200 cycles at a high current density of 2.0 A g−1.