La-based perovskites for capacity enhancement of Li-O₂ batteries

Li-O₂ batteries are a promising technology for the upcoming energy storage requirements because of their high theoretical specific energy density of 11,680 Wh kg^-1. Currently, the actual capacity of Li-O₂ batteries is much lower than this theoretical value. In many studies, perovskites have been applied as catalysts to improve the air electrode reactions in Li-O₂ batteries. The effects of structure and doping on the catalytic activity of perovskites are still unclear. La_1-xSr_xCoO_3-δ (x = 0.1, 0.3, and 0.5) and La_0.9Sr_0.1YbO_3-δ mixed with carbon black (Vulcan XC500 or Super P) were used as air electrode catalysts. Electrochemical characterizations were conducted using a Swagelok-type cell. The charge-discharge capacity and cyclic voltammetry (CV) performance were investigated in this study. The La_1-xSr_xCoO_3-δ (x = 0.1, 0.3, and 0.5) is a suitable cathode catalyst for Li-O₂ batteries. In this study, the La_0.5Sr_0.5CoO_3-δ/Super P cathode demonstrated the highest discharge capacity (6,032 mAh g^-1). This excellent performance was attributed to the large reaction area and enhanced Li₂CO₃ generation.