Defect engineering in molybdenum-based electrode materials for energy storage

Molybdenum-based materials have stepped into the spotlight as promising electrodes for energy storage systems due to their abundant valence states, low cost, and high theoretical capacity. However, the performance of conventional molybdenum-based electrode materials has been limited by slow diffusion dynamics and deficient thermodynamics. Applying defect engineering to molybdenum-based electrode materials is a viable method for overcoming these intrinsic limitations to realize superior electrochemical performance for energy storage. Herein, we systematically review recent progress in defect engineering for molybdenum-based electrode materials, including vacancy modulation, doping engineering, topochemical substitution, and amorphization. In particular, the essential optimization mechanisms of defect engineering in molybdenum-based electrode materials are presented: accelerating ion diffusion, enhancing electron transfer, adjusting potential, and maintaining structural stability. We also discuss the existing challenges and future objectives for defect engineering in molybdenum-based electrode materials to realize high-energy and high-power energy storage devices.