Preparation of Cation-Disordered Li₃V₂O₅ Nanorod Cathode Materials and Improvement of Their Electrochemical Stability

It is important for the further improvement of lithium-ion battery energy densities to develop high-specific-capacity cathode materials. Li₃V₂O₅ has attracted much attention due to its high specific capacity, even exceeding 240 mA·h/g. However, its low electrochemical cycling stability induced by the low Li⁺ transport dynamics and irreversible phase transition restricts the application of Li₃V₂O₅ cathode materials in lithium-ion batteries. In this paper, co-doped Li₃V₂O₅ nanorod cathode materials were prepared. The one-dimensional structure can relieve the accumulation of strain during charging and discharging process. Also, Co³⁺ doping can stabilize the structure of Li₃V₂O₅ by forming the more intense Co—O bonds. Furthermore, Co³⁺ doping expands the cell volume and ratio of V⁴⁺ in Li₃V₂O₅. These collectively result in the improved Li⁺ diffusion coefficient and cycling stability of Li₃V₂O₅. The 1% Co-doped Li₃V₂O₅ (i.e., 1%Co–LVO sample) has a specific discharge capacity of 256.43 mA·h/g at a current density of 50 mA/g and a capacity retention rate of 77.3% after 100 cycles, which is 28% greater than that of the pristine Li₃V₂O₅. 1%Co–LVO sample shows a superior capacity fading (i.e., 0.23%/cycle). This paper can provide an effective method for the preparation and performance regulation of high-energy-density lithium-ion cathode material (i.e., Li₃V₂O₅).