Mn-doped La0.6Sr0.4CoO3 perovskite catalysts with enhanced performances for non-aqueous electrolyte Li–O2 batteries

Abstract

Mn-doped perovskite oxides, La_0.6Sr_0.4Co_1−xMn_xO₃ (x = 0.05, 0.1), have been synthesized and Li–O₂ batteries based on La_0.6Sr_0.4Co_1−xMn_xO₃/Super P electrodes and non-aqueous electrolytes were also fabricated and measured in this work. The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity of the as-prepared electrode based Li–O₂ batteries were measured using cyclic voltammetry (CV) tests. In terms of the ORR and OER peak current, the performance is enhanced in the order of pure Super P, La_0.6Sr_0.4CoO₃, La_0.6Sr_0.4Co_0.95Mn_0.05O₃ and La_0.6Sr_0.4Co_0.9Mn_0.1O₃. The Li–O₂ batteries based on a La_0.6Sr_0.4Co_0.9Mn_0.1O₃/Super P electrode exhibited a higher first discharge capacity, lower over-potential and better cycling stability, which was in agreement with the trend shown in the CV curves. The electrochemical impedance spectroscopy measurements revealed that the impedance of the battery increased slowly during cycling due to the accumulation of undecomposed discharge products on the cathode.