Li[LiyMn2-y]O-4 (y = 0.03, 0.07, 0.14) spinel powders were prepared from aqueous solutions of LiOH .H2O and Mn(CH3COO)(2). 4H(2)O, which is a simpler and cheaper method than any other solution-based synthesis. The spinels thus prepared exhibited excellent capacity retention in the voltage range of 2.4-3.4 V in spite of the cooperative Jahn-Teller distortion. The cyclability in the 4 V range (3.3-4.3 V) was improved as the lithium content on the octahedral site increased while the reversible capacity was sacrificed. Cycling over the whole 2.4-4.3 V range indicates that charging in the 4 V range introduces an irreversible change that causes capacity fading in the 3 V range, but not in the 4 V range.