Perovskite Sr _0.9 Y _0.1 CoO _3-δ Nanorods Modified with CoO Nanoparticles as a Bifunctional Catalyst for Rechargeable Li-O ₂ Batteries

For practical application of lithium-oxygen batteries, one of the challenges is the development of efficient bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in cathode. In this work, perovskite Sr _0.9 Y _0.1 CoO _3-δ nanorods are synthesized by an electrospinning method. The performance of the Li-O ₂ cell with Sr _0.9 Y _0.1 CoO _3-δ catalysts is better than that of the cell only with Super-P. Furthermore, modification of CoO nanoparticles on the cathode can provide an obviously improved electrochemical performance with a reduced voltage gap (∼80-140 mV), which is ascribed to the superior catalytic activity of CoO nanoparticles toward OER. All of these results demonstrate that the perovskite Sr _0.9 Y _0.1 CoO _3-δ is an efficient bifunctional electrocatalyst for lithium-oxygen batteries, and the incorporation of CoO nanoparticles is an effective approach for improving the cathode performance as well.