Graphene-Based Oxygen Reduction Reaction Catalysts for Metal Air Batteries

In the past few years, the metal air batteries developed fast due to their remarkably high theoretical energy output. So far, the oxygen reduction reaction catalysts still have been the bottleneck for high power application of metal air batteries because of their sluggish kinetics. Recently, the graphene-based oxygen reduction reaction catalysts (GORRC) with high catalytic activity have been intensively reported. In this review, we focus on the recent progress and current situation of GORRC, and divide them into three categories, graphene as catalyst support, nitrogen doped graphene as the catalyst, and hybrids of nitrogen doped graphene and other catalysts as the catalyst. As an outstanding catalyst support, graphene can not only decrease the application amount of active components but also improve their catalytic activity and long-term stability. After doped by nitrogen, the graphene catalysts exhibit enhanced catalytic activity for the oxygen reduction reaction. In addition, the excellent catalysts can be obtained as the nitrogen doped graphene and other type of catalysts are hybridized. The catalytic activity and long-term stability of the hybrids are even better than that of the commercial Pt/C catalyst. Furthermore, the remarks on the challenges and perspectives of research directions are proposed for further development of GORRC which can be used in the metal air batteries.