Local structure and lithium-proton ion exchange in Li1.33−x/3CoxMn1.67−2x/3O4 spinels

Lithium manganate spinels with the formula Li1+xMn2−xO4 undergo lithium↔proton ion exchange to form a protonated λ-MnO2-type phase. The Li1+xMn2−xO4 phases are metastable, and preparation at temperatures in excess of 400 °C results in phase separation. By partially substituting the manganese with cobalt, single-phase spinels of formula Li1.33−x/3CoxMn1.67−2x/3O4 (0