Ag Decorated Co3O4-Nitrogen Doped Porous Carbon as the Bifunctional Cathodic Catalysts for Rechargeable Zinc-Air Batteries

The use of transition metals as bifunctional catalysts for rechargeable zinc-air batteries has recently attracted much attention. Due to their multiple chemical valence states, the cobalt oxides are considered be promising oxygen reduction reaction (ORR) and evolution (OER). In this work, Ag-decorated Co3O4-nitrogen doped porous carbon composite (Co3O4-NC&Ag) were synthesized by annealing ZIF-67 in N2 O2, respectively, followed Ag deposition using bath deposition. decoration nanoparticles high specific surface area (46.9 m2 g?1), electrochemical activity Co3O4 increased significantly. optimized Co3O4-NC&Ag possessed superior ORR performance with a half-wave potential 0.84 V (vs. RHE) OER an overpotential 349 mV at 10 mA cm?2. open circuit voltage Co3O4-NC&Ag-based battery was 1.423 V. Meanwhile, power density reached 198 mW cm?2 discharge capacity 770 mAh g?1 cm?2, which higher than that Pt/C-based (160 705 g?1). At current charge-discharge stable 120 h (360 cycles), exhibiting better long-term stability Pt/C&RuO2 counterpart.