Chitosan modulated engineer tin dioxide nanoparticles well dispersed by reduced graphene oxide for high and stable lithium-ion storage

Abstract

Tin based materials are widely investigated as a potential anode material for lithium-ion batteries. Effectively dispersing SnO2 nanocrystals in carbonaceous supporting skeleton using simplified methods is both promising and challenging. In this work, water soluble chitosan (CS) chains are employed to modulate the redox coprecipitation reaction between stannous chloride (SnCl2) and few-layered graphene oxide (GO), where the excessive restacking of the corresponding reduced graphene oxide sheets (RGO) has been effectively inhibited and the grain size of the in-situ formed SnO2 nanoparticles have been significantly controlled. In particular, the CS molecules are gradually detached from the RGO sheets with the GO deoxygenation process, leaving only a small quantity of CS remnants in the intermediate SnO2@CS@RGO sample. The final SnO2/CSC/RGO sample with significantly improved microstructure is synthesized after a simple thermal treatment, which delivers a high specific capacity of 842.9 mAh g−1 at 1000 mA·g−1 for 1000 cycles in half cells and a specific capacity of 410.5 mAh g−1 at 200 mA·g−1 for 100 cycles in full cells. The reasons for the good lithium-ion storage performances for the SnO2/CSC/RGO composite have been studied.