Preparation and electrochemical performance of LixMnO2 materials by a reduction and lithiation method

The preparation of LixMnO2 materials via a novel reduction and lithiation method is reported. The effect of lithium concentration, lithiation temperature and lithiation time on the composition, structure and electrochemical performance of the resulting materials was investigated. Altering the lithiation conditions resulted in distinct materials with different lithium contents of x = 0.07, 0.12 and 0.16. XRD suggested that these materials were stabilized γ-MnO2, a swollen lithiated manganese dioxide phase, and a LiMn2O4/γ-MnO2 mixture, respectively. The materials showed superior electrochemical performance over ten cycles, in a non-aqueous coin cell containing a Li metal anode, compared to LixMnO2 materials with equivalent x, prepared by co-precipitation. In particular, the Li0.12MnO2 and Li0.16MnO2 materials showed unexpectedly high reversible capacities of 160 mAh/g at high discharge rate of 30 mA/g.