Effect of replacing M (M=Cu, Zn) with Fe on the properties of high entropy (MgCoNiZnCu)O

Fe substitution of Cu or Zn in the high-entropy powder (MgCoNiCuZn)O was realized with a hydrothermal method. The effects of different substitution amounts on the crystal structure, product morphology and electrochemical properties of high entropy (MgCoNiCuZn)O were determined with X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEMEDS) and electrochemical methods. The results showed that when Zn was replaced by 0.05 mol of Fe at 160 ℃ for 12 h or 900 ℃ for 3 h, all of the Fe entered the high entropy rock salt structure and cooperated with Cu2+ to provide more channels for the removal/insertion of Li+, thus improving the electrochemical performance. The discharge capacity was 631.5 F/g at 0.1 A/g, and the capacity retention rate was 89% after 500 cycles.