Alkali ions pre-intercalation and reduced graphene coating of MnO2 for high-capacity Li-ion battery

Abstract

MnO2 is considered to be a prospective material for lithium-ion batteries anode. However, in practical applications, MnO2 has shortcomings such as low conductivity, large volume change and high charge transfer resistance, which seriously hinder its commercial application. In this work, MnO2 are preintercalated with various alkali cations (Na+, or NH4+) and coating with reduced graphene oxide through electrodeposition which designed for LIBs to improve its electrochemical behavior and understand the effect of cations and coating. It demonstrates that alkali cations can affect the growth morphology and electrochemical performance of MnO2, and graphene can improve electrical conductivity. Due to the advantages of its structure, MnO2&NH4+@rGO shows high capacity, rate performance (640 mAh g-1) and a long lifetime in lithium-ion batteries.