High-Performance Oxygen Reduction Electrocatalyst Derived from Polydopamine and Cobalt Supported on Carbon Nanotubes for Metal-Air Batteries
Yiling Liu, Fengjiao Chen, Wen Ye, Min Zeng, Na Han, Feipeng Zhao, Xinxia Wang, and Yanguang Li*
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, China
The development of nonprecious metal-based electrocatalysts for the oxygen reduction reaction holds the decisive key to many energy conversion devices. Among several potential candidates, transition metal and nitrogen co-doped carbonaceous materials are the most promising, yet their activity and stability are still insufficient to meet the needs of practical applications. In this study, a core–shell hybrid electrocatalyst is developed via the self-polymerizationof dopamine and cobalt on carbon nanotubes (CNTs), followed by hightemperature pyrolysis. The polymer-derived arbonaceous shell contains abundant structural defects and facilitates the formation of Co–N/C activesites, whereas the graphitic carbon nanotube core provides high electrical conductivity and corrosion resistance. These two components separately fulfill different functionalities, and jointly afford the catalyst with excellent electrochemical performance. In 1M KOH, Co–N/CNT exhibits a positivehalf-wave potential of ≈0.91 V, low peroxide yield of <7%, as well as great stability. When used as the air catalyst of primary Zn–air and Al–air batteries, this hybrid electrocatalyst enables large discharge current density, high peak power density, and prolonged operation stability.