Electrochemical properties of layered Li–Cr–Mn oxides prepared at high temperature

The LixMn0.91CryO4+δ material having α-NaFeO2 structure was prepared by a solution method. This material was calcined at 900 °C to improve its structural stability. The high firing temperature also leads to materials having relatively high crystallinity that is beneficial for good capacity retention. Indeed, the layered Li3.07Mn0.91Cr1.06O5.37 not only shows relatively good cycle performance but also exhibits an excellent discharge capacity of 191 mA h/g in the first cycle. Cyclic voltammetry and AC impedance spectroscopy were also employed to characterize the reversibility and reactions of lithium insertion and extraction in LixMn0.91CryO4+δ electrodes.