Manganese dissolution from spinel LiMn2O4 cathode material is one of the origins of a significant capacity fading with cycling for rechargeable lithium ion batteries. To suppress the manganese dissolution, the Li1+xMn2-xO4 (0 less than or equal to x less than or equal to 0.1) spinels were prepared. Their cycle performances and the amount of manganese dissolution from the spinels in charged state into an electrolyte were investigated to confirm that the manganese dissolution was suppressed in the lithium-doped spinels system. As a result, it was found that the rate of manganese dissolution decreased and the cyclability was improved with increasing doping amount of lithium in the spinel Compound due to stabilizing the spinel structure by subustituting lithium for manganese in 16d sites.