A perovskite/noble-metal composite as a bifunctional oxygen electrocatalyst for alkaline electrochemical cells. (June 2019)

• Record Type: Journal Article
• Authors: Mattick, Victoria F.; Jin, Xinfang; White, Ralph E.; Huang, Kevin
• Is Part Of: Journal of energy storage. Volume 23(2019)
• Page Start: 537
• Page End: 543
• Publication Date: 2019-06
• Subjects: Oxygen electrocatalysis -- Perovskite -- Rotating disk electrode -- Linear sweep voltammetry -- Composite catalyst; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2019.04.023
• Languages: English
• ISSNs: 2352-152X

Abstract

Highlights: Demonstrated a balanced oxygen bifunctionality. Shown oxygen reduction reaction featuring multi-step electron transfer. Shown oxygen evolution reaction featuring single-step electron transfer. Abstract: Alkaline-based metal-air batteries require a low-resistance, bifunctional oxygen electrode to perform fast oxygen reduction and oxygen evolution reactions (ORR/OER) during discharging and charging cycles, respectively. However, achieving good ORR/OER bifunctionality with single materials has proven challenging. Here we report a composite material as a bifunctional oxygen electrode for ORR and OER. The composite oxygen electrode consists of an ORR-active 20 wt% Pt/C and an OER-active perovskite La0.6 Sr0.4 CoO3- δ (LSCO). The study focuses on identifying the optimal LSCO:Pt/C ratio through electrochemical DC voltammetry techniques. The results show that the addition of Pt/C into the LSCO catalyst greatly enhances the ORR activity, due to Pt/C's superior ORR capabilities, while LSCO retains good OER performance, which is known to be poor for Pt/C. The optimal LSCO:Pt/C ratio among the seven compositions studied is found to be 60:40 (wt%) and is tested for stability through using a square-wave potentiostatic method. Overall, this study demonstrates a synergetic effect between LSCO and Pt/C, with each one contributing towards one of the electrode reactions in a positive manner.