Thermodynamic Equilibrium-Guided Design of High-Performance Fe2VO4 Anode Materials for Lithium-Ion Batteries

Transition-metal oxides are of significant interest due to their excellent theoretical specific capacity. However, during the ion intercalation and deintercalation process, these materials often exhibit poor cycling stability due to volumetric expansion. To enhance the cycling stability of these materials, extensive experimentation is required to optimize their structural stability, highlighting the urgent need for methods that can reduce experimentation while achieving the desired results. In this study, FactSage software was employed for thermodynamic calculations to methodically investigate the impacts of carbon content, sintering temperature, and sintering environment on the Fe-V phase equilibrium, and the optimal conditions for synthesizing Fe2VO4 were proposed, greatly reducing the experimentations. The proposed Fe2VO4 anode material exhibited a competitive reversible capacity of 1147.7 mAh g(-1) after 500 cycles at 0.5 A g(-1) and 852.7 mAh g(-1) after 600 cycles at 1 A g(-1). Furthermore, when operando characterizations and multiple electrochemical research strategies were combined, the pseudocapacitance, ion diffusion reaction, and corresponding phase transition mechanism of Fe2VO4 anode material were revealed, confirming the Li+ storage mechanism of Fe2VO4 anode materials. This study demonstrates that designing materials through thermodynamic calculations can provide new theoretical guidance and strategies for the development of high-performance electrode materials.