The synthesis and the structural features of a mixed manganese-cobalt oxide, Mn2.2Co0.27O4 obtained at low temperature (400°C) are reported. Electrochemical lithium insertion occurs in one reduction process located around 2.8V, involving only the reduction of manganese ions in the oxide. During cycling experiments, performed with various experimental conditions, the best results show a high capacity retention, i.e. 85% of the initial specific capacity (95Ah/kg) after the 20th cycle.