Facile synthesis of porous TiO2/SnO2 nanocomposite as lithium ion battery anode with enhanced cycling stability via nanoconfinement effect

Abstract

SnO2 is a potential anode material with high theoretical capacity for lithium-ion batteries (LIBs), however, its applications have been limited by the severe volume expansion during charging-discharging process. In this work, an inverse opal TiO2/SnO2 composite with an interconnect network nanostructure was designed to confine SnO2 nanoparticles in the porous TiO2. Due to this nanoconfinement structure, the volume expansion in the process was effectively alleviated, therefore the safety performance and cycling stability of the battery were effectively improved. At the same time, with a large number of microporous structures in the framework, the appearance of pseudocapacitance improves the rate performance and reversible capacity. In terms of electrochemical kinetics, its framework provides the connected path for charge migration, effectively reducing the charge transfer impedance, meanwhile, quantities of micropores in its skeleton could provide a smoother channel for lithium ions, thus greatly improving the diffusion rate of LIBs. The design of this nanostructure provides a new idea for the research of SnO2-based anode with effectively enhanced electrochemical performance, which is promising anode for practical application.