Heteroatom-doped carbon sheets as metal-free electrocatalysts for promoting the oxygen reduction reaction in Zn–air batteries

Abstract

Zn–air batteries are promising energy devices for future sustainable development. It is crucial to promote the cathodic reaction, oxygen reduction reaction (ORR), by applying active electrocatalysts. Herein, a metal-free ORR electrocatalyst has been fabricated by doping S and N atoms into carbon sheets (S–N–C), and it displays high ORR activity and outstanding performance in Zn–air batteries. The S–N–C electrocatalyst exhibits remarkable ORR activity with a half-wave potential of 0.89 V, which is far exceeding that of the commercial Pt/C benchmark and most reported carbon-based electrocatalysts. A full-cell Zn–air battery device with S–N–C as a cathode catalyst is demonstrated, which delivers high power density and good durability.