Bifunctional electrocatalyst with CoN3 active sties dispersed on N-doped graphitic carbon nanosheets for ultrastable Zn-air batteries

Realizing large-scale production of low-cost bifunctional catalysts is pivotal to promoting the practical application of Zn-air batteries. Herein, we successfully constructed unique bifunctional CoN 3 catalytic sites atomically dispersed on N-doped graphitic carbon nanosheets (CoSA/NCs), which enable Zn-air batteries with ultrahigh durability for over 6000 cycles (~ 2000 h). The 2D carbon construction and single-atom Co formation were achieved simultaneously in salt-assisted process employing CoCl 2 . CoCl 2 serves as a recyclable template, a pore-making agent, and a catalyst for graphitization, which effectively enables the catalyst with abundant active sites catalyze ORR and OER. Our experimental and theoretical modeling results confirm that of CoN 3 surpasses CoN 4 in term of the ORR and OER catalytic activity. The Zn-air battery based on CoSA/NCs catalyst exhibits a high peak power density of 255 mW cm −2 . With unparalleled catalytic performance and low production cost, this catalyst paves the way for the potential large-scale application of Zn-air batteries. • A facile method by employing CoCl2 as a multi-function agent is introduced. • 2D construction and single-atom Co formation can be achieved simultaneously. • The concept of bifunctional CoN3 catalytic sites is experimentally validated. • The assembled Zn-air battery exhibits ultrastable cyclability up to 6000 cycles.