Mn2C monolayer: A superior anode material offering good conductivity, high storage capacity and ultrafast ion diffusion for Li-ion and Na-ion batteries

Developing superior anode materials with offering good conductivity, excellent ion diffusion ability, and high storage capacity is highly desired in current Li-/Na-ion battery (LIB/NIB) technologies. Here, we demonstrate Mn2C monolayer can serve as a such anode material with providing excellent performances on all the crucial judgments. Mn2C monolayer offers stable Li/Na adsorption and relatively low open-circuit voltages, which are desired for anode materials. Mn2C monolayer hosts excellent conductivity during Li/Na adsorption process. Mn2C monolayer shows very high specific capacities for Li (887.6 mA h g(-1)) and Na (443.6 mA h g(-1)). Remarkably, Mn2C monolayer nearly has the lowest Li/Na diffusion barrier among known 2D anode materials, which offers ultrafast ion diffusion. These results suggest Mn2C monolayer is one of the few superior LIB/NIB anode materials indentified so far.