Lithium-ion batteries based on overlithiated LiMn2O4

The irreversible capacity loss at the carbon anode in the C/LiMn ₂O₄ cell can be compensated for with the use of the excess Li, x, in Li_1+xMn₂O₄, where x is chosen to be equal to the irreversible capacity. The authors have found a convenient method to prepare Li_1+xMn₂O₄ for any value of x, where 0<x<1. The overlithiated materials are two-phase systems consisting of cubic LiMn₂O₄ and tetragonal Li₂Mn₂O₄. The second Li in Li₂ Mn₂O₄ can be extracted fully at ~3 V without affecting the rechargeability of the Li in the cubic phase between 3.8 and 4.2 V, versus Li⁺/Li. The capacity and rechargeability of Li(graphite)/Li_1+xMn₂O₄ Li-ion cells is discussed