Synthesis of the porous Co-N-doped carbon catalysts as a durable cathode for zinc-air battery.

Due to the exceptional ORR catalytic activity and stability, cobalt and nitrogen-doped carbon (Co–N–C) catalysts are regarded as highly promising candidates for cathode catalysts in zinc–air batteries. However, it remains a challenge to expose more stable and more efficient active sites. Therefore, this work focuses on the design and preparation of Co–N–C catalysts with a robust and porous structure. The results revealed that the robust and porous structure could be easily achieved by the template (SiO2)-assisted hydrothermal method. Moreover, the Co-900-50 catalyst has the highest half-wave potential, and the Co-900-100 catalyst has the highest limiting current density. Both individuals are chosen for further examination regarding their potential use in zinc–air batteries. The battery with Co-900-100 catalyst demonstrated exceptional stability across the current densities (5–20 mA cm− 2). Specifically, the voltage rose by 0.04 V following a 100 h discharge at a rate of 5 mA cm− 2, while the discharge voltage remained nearly constant at 1.24 V throughout 300 charge/discharge cycles at 5 mA cm− 2.