Rationalizing the catalytic surface area of oxygen vacancy-enriched layered perovskite LaSrCrO₄ nanowires on oxygen electrocatalyst for enhanced performance of Li–O₂ batteries

Abstract

Efficient electrocatalysis at the cathode is crucial to addressing the limited stability and low rate capability of Li–O₂ batteries. This study examines the kinetic behavior of Li–O₂ batteries utilizing layered perovskite LaSrCrO₄ nanowires (NWs) composed of lower oxidation states. Layered perovskite LaSrCrO₄ NWs exhibited improved rate capability over a wide range of current densities and longer cycle life in Li–O₂ batteries than V-based layered perovskite (LaSrVO₄) and simple perovskite (La_0.8Sr_0.2CrO₃) NWs. X-ray photoelectron spectroscopy and electrochemical surface area analyses showed that the observed performance variations primarily stemmed from active sites such as oxygen vacancies. In situ Raman analysis showed that these active sites significantly modulate the kinetics of oxygen reduction and evolution, which are related to LiO₂ intermediate adsorption. Electrochemical impedance spectroscopy showed that the active sites in layered perovskite LaSrCrO₄ NWs contributed to their high charge transfer capability and reduced polarization. This study presents an appealing method for the precise fabrication and analysis of Cr-based layered perovskites, aimed at achieving highly efficient and stable bifunctional oxygen electrocatalysis.

Keywords

bifunctional electrocatalysts / Cr-based layered perovskite / LaSrCrO₄ / Li–O₂ batteries / oxygen vacancies