La_(1.7)Sr_(0.3)Co_(0.5)Ni_(0.5)O_(4+δ) layered perovskite as an efficient bifunctional electrocatalyst for rechargeable zinc-air batteries

摘要

In this work, a novel La1.7Sr0.3CO0.5Ni0.5O4+delta with a layered perovskite structure was synthesized by the sol-gel method and characterized by the X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). Catalytic activities of La1.7Sr0.3CO0.5Ni0.5O4+delta toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) were systematically investigated by the rotating disk electrode (RDE) technique in alkaline media. Compared to La2NiO4+delta, La1.7Sr0.3CO0.5Ni0.5O4+delta demonstrated more active for ORR in terms of the higher limiting current density ( - 4.05 mA.cm(-2)) and higher half-wave potential (0.568 V vs. RHE) at 1600 rpm. Zinc-air batteries using La1.7Sr0.3CO0.5Ni0.5O4+delta as the catalyst exhibited the higher peak power density (60 mW.cm(-2)), the lower discharge-charge voltage gap (1.26 V) after 100 cycles and good discharge-charge cycling stability than that of La2NiO4+delta.