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

¹ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, China
² College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu, 610225, China

^* Corresponding email.zixuanfang@uestc.edu.cn
^** Corresponding email.mwu@uestc.edu.cn

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.