Heat-treatment effect on phase stability, cation distribution, chemical composition, and electrochemical behavior for Fe-substituted Li2MnO3

By combining coprecipitation, hydrothermal, and firing methods under various firing temperatures (500-750 degrees C), Fe-substituted Li2MnO3 (nominal formula Li(1.2)Ye(0.4)Mn(0.4)O(2)) samples were prepared. A pure O3 phase was obtained below 700 degrees C. However, a small amount of spinel ferrite-like LiFe5O8 coexisted as an impurity phase for the sample that was fired at 750 degrees C. The maximum initial and 10th discharge capacities were obtained at 600-650 degrees C because of the balance between the development of 3d cation ordering, their primary particle size, and Li content, depending on the iron valence, which is changeable between 3+ and 4+.