High-efficiency oxygen electrocatalyst for Zn-air batteries on CoMn alloy encapsulated in N-doped carbon architectures

A low-cost efficient electrocatalyst for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is urgently required for the commercialization of Zn-air batteries. Herein, CoMn nanoalloys encapsulated in nitrogen-doped hollow carbon architectures (CoMn@NHC) as dual electrocatalysts for Zn-air batteries were developed successfully. The obtained CoMn@NHC nanohybrid expresses excellent electrocatalytic performances for ORR (E1/2 = 0.87 V) and OER (Ei=10 = 1.51 V). More encouragingly, a homemade aqueous Zn-air battery using CoMn@NHC catalyst delivers a larger peak power density of 92.3 mW cm−2 and excellent stability of nearly 300 h, outperforming the commercial Pt/C + RuO2. The remarkable electrocatalytic performances are owing to the unique microstructure and the synergistic effect between CoMn alloy and N-doped carbon substrate. This study opens a new way for designing high-efficient bifunctional electrocatalysts for application in renewable energy facilities.