CoO Enhanced Oxygen Evolution Kinetics of LaMnO<sub>3</sub> Perovskite As a Potential Cathode for Rechargeable Zn-Air Batteries
Qilong Zheng, Yidan Zhang, Chunchang Wang, Chuanhui Zhang, Youmin Guo
Abstract
For an ideal electrocatalyst for Zn-air batteries (ZABs) air electrode, it should possess efficient dual-functional catalytic activity for both oxygen reduction and oxygen evolution reactions in an alkaline electrolyte. Although LaMnO3 perovskite oxide presents excellent ORR catalytic activity, its OER activity is inadequate to serve as a dual-functional catalyst for ZABs. To enhance the OER activity of LaMnO3 perovskite, this work used a simple and easy-to-operate ultrasonic mixing technique to prepare the LaMnO3–CoO composite. The enhancement of OER and ORR catalytic activity of LaMnO3 perovskite by CoO was investigated. Meanwhile, the cycling stability and polarization behavior of the assembled ZABs using LaMnO3–CoO composite as an air electrode were further evaluated. The battery delivered a maximum power density of 101.48 mW cm–2 and a high energy efficiency of up to 58.6% after 150 cycles. The LaMnO3–CoO composite exhibited better cycling stability than commercial Pt/C catalyst, which indicates that the LaMnO3–CoO composite is a promising dual-functional catalyst and can be applied in commercial Zn-air battery with an effective electrocatalytic activity.