Fe₃C@Fe/N Doped Graphene-Like Carbon Sheets as a Highly Efficient Catalyst in Al-Air Batteries

It is still challenging to develop non-precious catalysts instead of Pt/C to address the sluggish oxygen reduction reaction (ORR) in metal-air batteries. Herein, we proposed a facile one-step method to synthesize Fe 3 C@Fe/N doped graphene-like carbon nanosheets (Fe 3 C@Fe/N-G) by the pyrolysis of iron source, methylbenzene and melamine with the assistant of Pluronic F127 surfactant. It is found that F127 played an important role in enhancing the electrocatalytic activity of the as-prepared samples. The optimized Fe 3 C@Fe/N-G exhibited a remarkable ORR activity in alkaline medium (e.g., half-wave potential of 0.84 V and limiting current density of 5.35 mA/cm 2 ), which even outperformed the benchmark Pt/C (20%). Much better durability was also observed by the much less negative shift of the half-wave potential (7 mV for Fe 3 C@Fe/N-G vs 35 mV for Pt/C after 2000 cycles). We tested the practical electrocatalytic properties in full Al-air cell, in which the as-prepared sample displayed a relatively higher discharge voltage plateau and larger power density than the commercial Pt/C.