Stoichiometric LiMnO[sub 2] with a Layered Structure

Changing the synthesis conditions of layered stoichiometric (O3 structure) induces differences in the charge/discharge capacity as a function of cycle number, during conversion of layered stoichiometric to spinel. Once a spinel phase has formed, such differences disappear, except for material synthesized by melt exchange. Differences in behavior between and are attributed to the former converting to spinel via a 2-phase reaction. A nanodomain structure forms on cycling but unlike nonstoichiometric or the nonstoichiometric doped materials, the domains show some evidence of growth on cycling. Ballmilling can improve the cyclability at low cycle numbers, hastening the conversion to spinel and attenuating somewhat the dip and rise in capacity in the early stages of cycling; however, ballmilling also induces greater fade at higher cycle numbers.