Unveiling Hierarchical Zinc-Vanadium Oxide Composite Microflakes as Anode Material for Lithium-Ion Batteries

Abstract

Developing unique electroactive materials is essential for meeting the escalating exigency of high-performance lithium-ion batteries (LIBs). Various vanadate-based transition metal oxides have recently attracted much interest as anode materials because they can deliver good capacity and excellent cycling stability and enable shields to adapt to the volume variations during lithium insertion/deinsertion. Herein, novel two-dimensional porous vanadium oxide (V2O5)/zinc vanadium oxide (ZnV2O6) composite flake-like architectures (VO/ZVO CFAs) with rock-textured surface morphology were prepared via a facile and ecobenign silicone oil bath-assisted wet-chemical technique, followed by annealing treatment. The possible formation mechanism is explained. When examined as an anode for LIBs, the VO/ZVO CFA-400 (annealed at 400°C) electrode showed superior reversibility with good rate performance compared to the other prepared electrodes. The VO/ZVO CFA-400 electrode exhibited a higher specific capacity of 844 mAh/g at 100 mA/g after 150 cycles, whereas 645 and 743 mAh/g remained for the VO/ZVO CFA-300 and VO/ZVO CFA-500 electrodes, respectively. Interestingly, the VO/ZVO CFA-400 electrode delivered an excellent reversible capacity of 1146 mAh/g after 600 cycles at 500 mA/g. Moreover, when operating at the high current densities of 1000 and 2000 mA/g, the VO/ZVO CFA-400 electrode revealed good reversible capacities of 497 and 340 mAh/g over 500 cycles, respectively. The excellent electrochemical performance of VO/ZVO CFAs might be ascribed to unique morphological structures and the significant number of porous sites constructed from strongly interconnected tiny nanoparticles.