Tunable oxygen vacancies in MoO3 lattice with improved electrochemical performance for Li-ion battery thin film cathode

MoO3 is a kind of promising cathode material for lithium-ion batteries (LIBs), owing to its high specific capacity (279 mA h g−1) and layered structure. However, low electrical conductivity and sluggish reaction kinetics results in poor rate and Li-ions storage capability. The introduction of oxygen vacancies (OVs) can promote Li+ diffusion, and produce great electrical conductivity. Here, we report a strategy to synergize the merits of OVs by pulsed laser deposition (PLD) by adjusting oxygen partial pressures (2~20 Pa). The appropriate OVs concentration not only significantly approves electrochemical performance but also increases pseudocapacitance contribution. The Li-ion diffusion coefficient of MoO3−x is remarkably improved by one or two orders of magnitude compared with that of MoO3. Therefore, this facile and efficient strategy on OVs could afford a reference for other metal oxides for high-performance electrode materials.