Electrochemical elucidation of Co0.5M0.5V2O4 (M = Fe or Zn) nanocomposite anode materials for Li-ion storage

Abstract

This work proposes spinel Co_0.5M_0.5V₂O₄ (M = Fe or Zn) nanocomposites as novel anode materials for Li-ion storage. Their electronic properties are predicted through theoretical analysis. The equal ratio of binary metal mixed V–O matrix spinel compounds actively improved the cyclic and rate capacities. The Co_0.5Zn_0.5V₂O₄ (CZVO) composite exhibits higher cyclic and rate capacities than the bare CoV₂O₄ (CVO) and Co_0.5Fe_0.5V₂O₄ (CFVO) samples. The CZVO sample demonstrates a higher reversible discharge capacity of 434 mA h g⁻¹ over 100 cycles at a current density of 200 mA g⁻¹. However, it has showed a higher rate capacity (129 mA h g⁻¹ at 5 A g⁻¹) than the other prepared samples (40 mA h g⁻¹ for bare CVO and 99 mA h g⁻¹ for CFVO at 5 A g⁻¹). The CZVO sample delivers superior electrochemical performance due to the conductivity improvements and a high order of the Co²⁺/Co³⁺ oxidation ratio. Thus, this report offers potential anode materials as an approach to improve binary metal mixed oxides for high-performance lithium storage applications in future.