Manganese Carbodiimide Nanoparticles Modified with N-Doping Carbon: A Bifunctional Cathode Electrocatalyst for Aprotic Li-O2 Battery

We develop a facile method to prepare a hierarchical mesoporous nanocomposite of manganese carbodiimide nanoparticles modified with N-doping carbon materials (MnNCN/NC). The nanocomposite is endowed with superior performance in Li-O-2 battery because of the synergistic reaction between nanosized manganese carbodiimide and N-doping carbon materials. Evaluated as the electrocatalyst, the MnNCN/NC nanocomposite delivers high specific capacity of 9960 mA h g(-1) with a discharge plateau of ca. 2.7 V, higher than those of bulk MnNCN/NC and NC individually. The MnNCN/NC nanocomposite also exhibits a lower overpotential in battery operation. Compared to the bulk-MnNCN/NC and NC electrodes, a superior cycling stability of 100 cycles is obtained based on the electrode with the electrocatalyst of MnNCN/NC nanocomposites. Combining the experimental research studies and the density functional theory calculations, it can be observed that the superior electrochemical performance resulted from the high electrocatalytic activity {Mn-N-6} moieties and the high conductivity of N-doping carbon material substrates, which could facilitate the mass transfer and electronic kinetics for the battery reactions. It also provides a new method of the manganese carbodiimide preparation and a new insight for the application of metal carbodiimide.