Electrochemical properties of a monolayer electrode assembled with metal oxide core-shell submicron spheres as lithium-ion battery anodes

Abstract

In this work, we propose a novel electrode system as anodes for lithium-ion batteries (LIBs) using a monolayer electrode assembled with core-shell type transition metal oxide submicron spheres. The monodisperse Fe2O3 and Fe3O4/TiO2 submicron spheres were synthesized by the templating method using pH-responsive polymer particles and sol-gel processes for the coating of a TiO2 shell. This 2D monolayer structure can be directly employed as the binder-free electrodes without any need for conductive materials like super-P or carbon black. To prepare the monolayer electrodes, the monolayer of Fe2O3 and Fe3O4/TiO2 submicron spheres assembled on the PDMS sheet were fixed with the thin PVA film and moved on the copper foil for heat treatment under an argon atmosphere. These monolayer electrodes exhibit a low irreversible capacity at the first cycle and outstanding capacity retention even at high current rates due to the good structural stability by the ordered monolayer structure.