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

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 Li-ion 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.