Mn metal batteries are rarely reported due to the lack of a stable electrolyte. Here, an N,N-dimethylformamide (DMF)-based organic electrolyte with stable Mn plating/stripping for over 500 h and high Coulombic efficiency (CE) for a Mn metal battery is presented. The battery-specifically composed of an electrolyte made of DMF and ethylenediamine (EDA), a cathode made of 3,4,9,10-perylenetetracarboxylicdiimide (PTCDI), and an anode made of Mn metal-displayed a specific capacity of 105 mA h g-1. These results indicated the effectiveness of our new method for preparing low-cost and highly stable secondary Mn ion batteries.