A facile method to conduct 3D self-supporting Co-FeCo/N-doped graphene-like carbon bifunctional electrocatalysts for flexible solid-state zinc air battery

The rapid development of wearable and portable electronics is triggering a lot of researches on flexible energy device. Flexible zinc-air batteries (ZABs) with high bifunctional oxygen electrocatalytic activity and superb flexible can be employed as promising power supplies to fulfill these novel electronic devices. Considering the major challenges to the flexible ZABs such as low power density, poor energy efficiency and unsatisfactory mechanical stability, we propose a novel plasma-assistance strategy to prepare highly foldable self-supporting air-electrodes based on nitrogen-doped carbon layer encapsulated Co and FeCo nanoparticles hybrid nanowire arrays (Co-FeCo/N-G). The obtained Co-FeCo/N-G air-electrode show superior oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) activity. Thus, the flexible ZABs using Co-FeCo/N-G air-electrode achieve a high open circuit voltage of 1.419 V. Furthermore, it exhibits an outstanding peak power density of 82 mW cm(-2), a small discharge-charge voltage gap of 0.61 V at 1 mA cm(-2) and long-term durability. Specially, the flexible Co-FeCo/N-G ZAB displays excellent mechanical stability under large deformation conditions, which can be folded into 180 degrees without obvious decay of its performance. Thereby, our work offers a unique insight into design of highly flexible air electrodes with favorable electrocatalytic activity for emerging wearable and portable electronics.