Honeycomb-Like Perovskite Oxide Electrocatalyst for a Hybrid Li-Air Battery

Honeycomb-like Nd0.7Sr0.3CoO3−δ has been successfully prepared with a PMMA hard-template for an energy storage system and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen adsorption-desorption measurements. The prepared 3-dimensionally (3-D) ordered mesoporous Nd0.7Sr0.3CoO3−δ (3DOM-NSC) has a well-developed mesoporous structure and has high specific surface area (22.0 m2 g−1). The catalytic activity for the oxygen reduction reaction (ORR) in 0.1 M KOH solution has been studied by using a rotating-ring-disk electrode (RRDE). In the ORR test, a limiting current density of 5.83 mA cm−2 at 0.7 V (vs. Hg/HgO) with 1600 rpm was obtained, a value comparable with that of Pt/C. Moreover, the ORR mainly favors a direct four-electron pathway. Consequently, the high electrocatalytic activity and mesoporous structure result in stable, excellent performance in a hybrid Li-air cell.