Optimizing the Surface Characteristics of La<sub>0.6</sub>Sr<sub>0.4</sub>CoO<sub>3−δ</sub> Perovskite Oxide by Rapid Flash Sintering Technology for Easy Fabrication and Fast Reaction Kinetics in Alkaline Medium
Maria Christy, Hashikaa Rajan, Hwichul Yang, Young‐Beom Kim
Abstract
Perovskites are a challenging new class of highly efficient bifunctional catalysts that hold huge significance in advanced batteries and water electrolysis. The surface chemistry and surface electronic structures of the La0.6Sr0.4CoO3−δ (LSC) perovskite is greatly modified upon postsynthesis sintering. Herein, a new strategy has been demonstrated by intense pulsed light technology to accomplish the sintering process in milliseconds, and is comparatively explored with conventionally sintered LSC. The optimized sintering conditions rejuvenated a new class of a highly active bifunctional LSC electrocatalyst. The electrochemical activity and surface characteristics are orders of magnitude superior to those of the thermally sintered LSC. The best performing LSC catalyst known as LSC 30 exhibits outstanding bifunctionality with a low overpotential (∼0.89 V). Furthermore, LSC 30 shows a positively shifted onset potential of 0.92 V and a high limiting current of −6.1 mA cm–2 at 20 mV s–1, during the oxygen reduction reaction in alkaline medium. When tested as the air cathode of a zinc–air battery, LSC 30 delivered a steady performance for 200 cycles. This study highlights the role of the new concept in the agile synthesis of perovskite oxides for oxygen catalysis and possible application as the air cathode in metal air batteries.