Electron-rich hybrid matrix to enhance molybdenum oxide-based anode performance for Lithium-Ion batteries

Abstract

Although MoO2-based electrodes have been intensively studied as potential candidate anodes for lithium-ion batteries (LIBs) based on their high theoretical capacity (840 mAh g-1 and 5447 mAh cm-3), common issues such as severe volume variation, electrical conductivity loss, and low ionic conductivity, are prevalent. In this study, we demonstrate enhanced Li-ion kinetics and electrical conductivity of MoO2-based anodes with ternary MoO2-Cu-C composite materials. The MoO2-Cu-C was synthesized via two-step high energy ball milling where Mo and CuO are milled, followed by the secondary milling with C. With the introduction of the Cu-C hybrid matrix in MoO2 nanoparticles via the element transfer method using mechanochemical reactions, the sluggish Liion diffusion and unstable cycling behavior were significantly improved. The inactive Cu-C matrix contributes to the increase in electrical and ionic conductivity and mechanical stability of active MoO2 during cycling, as characterized by various electrochemical analyses and ex situ analysis techniques. Hence, the MoO2-Cu-C anode delivered promising cycling performance (674 mAh g-1 (at 0.1 A g-1) and 520 mAh g-1 (at 0.5 A g-1), respectively, after 100 cycles) and high-rate property (73% retention at 5 A g-1 as comparison with the specific capacity at 0.1 A g-1). The MoO2-Cu-C electrode is a propitious next-generation anode for LIBs.