For Li i , a configuration with a Li-Li dumbbell split between neighbouring 12d sites is around 0.07 eV lower than a lone Li + i on the 12d site (see Figure ). The preference for Li-Li dumbbell configuration was reported for the parent spinel compound LMO. The Madelung potentials for Li + in the T d 8c crystal site are around -9.54 V, whereas those in the interstitial 4a and 12d are -6.84 V and -6.40 V respectively. Neutral Li 0 i gives an electron polaron on a neighbouring Mn (giving Mn 3+ ) beside the Li-Li dumbbell.