Amorphous Vanadium Oxide/Molybdenum Oxide Hybrid with Three Dimensional Ordered Hierarchically Porous Structure as a High-Performance Li-Ion Battery Anode

摘要

Transition metal oxides as anode materials for lithium ion batteries (LIBs) generally suffer from significant capacity fading due to their chemical and mechanical degradations upon extended cycling. In this work, a three-dimensional (3D) ordered hierarchically porous amorphous hybrid based on vanadium oxide and molybdenum oxide (3D-OHP-a-VOx/MoOy) was first constructed and investigated as an ideal anode material for LIBs. The valence states of V and Mo in this hybrid were determined by X-ray absorption near-edge structure (XANES) measurements. The as-synthesized 3D-OHP-a-VOx/MoOy exhibits significantly improved lithium storage performance in terms of specific capacity, cycling stability, and rate capability compared to single-component a-VOx, a-MoOy, and highly crystalline VOx/MoOy hybrid (c-VOx/MoOy). The enhanced lithium storage performance of 3D-OHP-a-VOx/MoOy probably benefits from its amorphous nature, synergistic effect between a-VOx and a-MoOy, and 3D hierarchically porous structure. To the best of our knowledge, our result is the best among the as-reported molybdenum oxides and vanadium oxides for energy storage applications. This strategy in the current work offers a new perspective in designing high-performance anode materials for LIBs.