Nitrogen-Doped Nanoporous Graphenic Carbon: An Efficient Conducting Support for O₂ Cathode

Herein, we synthesize a nanoporous N-doped graphenic carbon with high surface area and a higher graphenization/graphitic degree by further developing the metallothermic reduction of gaseous CO₂ by adding N₂ into the gas flow. The N-doped nanoporous carbon is composed of both a highly porous graphenic and non-graphitic matrix and homogeneously dispersed ordered graphitic nanodomains, which constitute a very unique composite carbon structure. The resulting N-doped graphenic carbon exhibits much more favorable reactivity as a carbon conducting support in the O₂ cathode of Li-O₂ batteries, increasing the specific capacity of the GC electrode from 5300 to 9600 mAh g⁻¹. The N-doped carbon also exhibits lower overpotentials during initial cycling for the charging process as well as an enhanced cycling performance compared to the undoped carbon. These results demonstrate that N-doping has a strong correlation with the enhanced performance of O₂ cathode of Li-O₂ batteries.