Oxygen Evolution and Reduction Reactions on La₀.₈Sr₀.₂CoO₃(001), (110), and (111) Surfaces in an Alkaline Solution (Increasing Demands for Next Generation New Rechargeable Batteries) Oxygen Evolution and Reduction Reactions on La<sub>0.8</sub>Sr<sub>0.2</sub>CoO<sub>3</sub> (001), (110), and (111) Surfaces in an Alkaline Solution

Access this Article

Search this Article

Author(s)

    • KOMO Mamoru KOMO Mamoru
    • Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology
    • HAGIWARA Asuna HAGIWARA Asuna
    • Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology
    • HIRAYAMA Masaaki
    • Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology
    • KANNO Ryoji
    • Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology

Abstract

The oxygen evolution and reduction properties of La<sub>0.8</sub>Sr<sub>0.2</sub>CoO<sub>3</sub> are characterized using two-dimensional model electrodes with different reaction planes, synthesized on SrTiO<sub>3</sub> single crystal substrates by pulsed laser deposition. Thin-film X-ray diffraction and reflectivity measurements confirm the epitaxial growth of 29-nm-thick La<sub>0.8</sub>Sr<sub>0.2</sub>CoO<sub>3</sub> (001), (110), and (111) films on SrTiO<sub>3</sub> (001), (110), and (111) substrates, respectively. Cyclic voltammetry curves in 1-M KOH aqueous solution indicate that the (110) film has the highest activity for oxygen evolution and reduction reactions. An expansion of the La<sub>0.8</sub>Sr<sub>0.2</sub>CoO<sub>3</sub> lattice is observed after the oxygen reduction process, indicating the formation of oxygen defects, with the highest number of defects being produced in the (110) film. X-ray reflectivity analysis demonstrates the formation of a surface layer on the La<sub>0.8</sub>Sr<sub>0.2</sub>CoO<sub>3</sub> films during electrochemical cycling due to the decomposition of La<sub>0.8</sub>Sr<sub>0.2</sub>CoO<sub>3</sub>. The surface structure constructed at the electrode/electrolyte interface is a crucial factor influencing oxygen evolution and reduction activity of La<sub>0.8</sub>Sr<sub>0.2</sub>CoO<sub>3</sub>.

Journal

  • Electrochemistry

    Electrochemistry 80(10), 834-838, 2012

    The Electrochemical Society of Japan

Codes

Page Top