Mn3N2 as a novel negative electrode material for rechargeable lithium batteries

The lithium electrochemistry of Mn3N2 thin films fabricated by magnetron sputtering has been investigated by galvanostatic cell cycling and cyclic voltammetry for the first time. The reversible capacities of Mn3N2 thin film electrodes under the discharging currents of 80 mA/g and 160 mA/g were found to be 579 mAh/g and 500 mAh/g respectively. The electrochemical reaction mechanisms involving the irreversible conversion from Mn3N2 to Mn and Li3N in the first discharging process and the reversible transformation between Mn with Li3N and Mn6N2.58 in subsequent cycles were proposed. The irreversible electrochemical reaction mechanism results in an unavoidable capacity loss and low columbic efficiency of 70% in the first cycle. The high reversible capacity, good cycle performance and low polarisation of Mn3N2 film electrode make it potential anode material for future lithium-ion batteries.