2D MoSi2N4 as electrode material of Li-air battery — A DFT study

Li-air batteries are one of the most promising next-generation batteries. The development of 2D layered materials enriches the materials for Li-air batteries. In this work, a DFT study of the configuration and energetics of Li atoms on 2D MoSi2N4 is presented. We propose 2D MoSi2N4 as a suitable material for both anode and cathode materials of Li-air batteries. The high Li ion conductivity of 2D MoSi2N4 brings advantages for it to be an anode, and the low barrier for Li2O2 growth on 2D MoSi2N4 brings advantages for it to be a cathode material. The maximum capacity of Li-loaded MoSi2N4 is predicted to be 129 mAh/g. For Li-loaded MoSi2N4, the anode potential is stable (~ -0.2 V relative to Li bulk) in a wide range of Li loading (Li% = 12 ~ 75%). As the cathode, the open-circuit cathode potential is stable (~ 2.8 V relative to Li bulk) during the growth of Li2O2 slab. Our work reveals the possibility of 2D MAX phases (M is transition metal, A is Al or Si, and X is C, N, or both) as metal-air battery materials. Graphical Abstract MoSi2N4 as electrode material of Li-air battery.