Dissolution of Mn into an electrolyte from LiMn2O4 in Li ion cell is researched recently. To study an influence of the dissolved manganese species on performance of negative electrode, electrochemical behavior of graphite was investigated in LiClO4 solution containing Mn2+ by dissolving Mn(ClO4)(2). During charging, manganese ions were firstly electroreduced on the electrode, followed by Li intercalation into graphite. Mn deposition was confirmed after charge-discharge test, furthermore, the reversible capacity of lithium intercalation was decreased. The results were compared to those in a cobalt additive electrolyte.