The intercalation compound Li(Mn0.9Co0.1)O2 as a positive electrode for rechargeable lithium batteries

By replacing only 10% of the Mn by Co in the layered lithium intercalation compound LiMnO2 the amount of lithium that can be removed and reinserted is increased by 50% corresponding to an increase in the ability to store charge from 130 to 200 mA h g–1 at 100 µ A cm–2 and rendering this low cost/toxicity material of potential interest as a positive electrode in rechargeable lithium batteries; furthermore the cooperative Jahn–Teller distortion due to localised high spin Mn3+(3d4) in LiMnO2 appears to be suppressed for Lix(Mn0.9Co0.1)O2; x<0.9 (80% Mn3+ assuming Co3+).