A New CuO-Fe₂O₃ ‐Mesocarbon Microbeads Conversion Anode in a High‐Performance Lithium‐Ion Battery with a Li₁.₃₅Ni₀.₄₈Fe₀.₁Mn₁.₇₂O₄ Spinel Cathode

A ternary CuO-Fe₂O₃ ‐mesocarbon microbeads (MCMB) conversion anode was characterized and combined with a high‐voltage Li₁.₃₅Ni₀.₄₈Fe₀.₁Mn₁.₇₂O₄ spinel cathode in a lithium‐ion battery of relevant performance in terms of cycling stability and rate capability. The CuO-Fe₂O₃-MCMB composite was prepared by using high‐energy milling, a low‐cost pathway that leads to a crystalline structure and homogeneous submicrometrical morphology as revealed by XRD and electron microscopy. The anode reversibly exchanges lithium ions through the conversion reactions of CuO and Fe₂O₃ and by insertion into the MCMB carbon. Electrochemical tests, including impedance spectroscopy, revealed a conductive electrode/electrolyte interface that enabled the anode to achieve a reversible capacity value higher than 500 mAh g⁻¹ when cycled at a current of 120 mA g⁻¹. The remarkable stability of the CuO-Fe₂O₃-MCMB electrode and the suitable characteristics in terms of delivered capacity and voltage‐profile retention allowed its use in an efficient full lithium‐ion cell with a high‐voltage Li₁.₃₅Ni₀.₄₈Fe₀.₁Mn₁.₇₂O₄ cathode. The cell had a working voltage of 3.6 V and delivered a capacity of 110 mAh g_{cathode}⁻¹ with a Coulombic efficiency above 99 % after 100 cycles at 148 mA g_{cathode}⁻¹. This relevant performances, rarely achieved by lithium‐ion systems that use the conversion reaction, are the result of an excellent cell balance in terms of negative‐to‐positive ratio, favored by the anode composition and electrochemical features