Abstract
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 CoN3 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 CoCl2. CoCl2 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 CoN3 surpasses CoN4 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.
NSTL