Co-doped CeO 2 /N–C nanorods as a bifunctional oxygen electrocatalyst and its application in rechargeable Zn-air batteries

• Published in: Nanotechnology 2022-10, Vol.33 (41), p.415404
• Main Authors: Xiang, Wenjuan, Li, Yanling, Wu, Mengxue, Ma, Jinfu, Sheng, Zhilin
• Format: Article
• Language: English
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/1361-6528/ac7ed1

The development of electrocatalysts for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with high-activity and atability still remain great challenges for rechargeable Zn-air batteries. Herein, a new type of Co-doped Ce–N–C bifunctional electrocatalyst has been synthesized through a simple two-step method, which realizes the high dispersion of Co 3 O 4 on the CeO 2 carbon frame and stabilizes its specific surface area. Benefiting from the synergistic interaction between Co 3 O 4 and CeO 2 , the conductivity of the electrocatalyst is improved and the oxygen reduction reaction/oxygen storage properties are promoted. The resultant Co 3 O 4 -CeO 2 @N–C catalyst shows remarkable ORR activity with the high initial potential ( E 0  = 0.8 V), the large limiting current density ( j L  = 6 mA cm −2 ), and a low Tafel slope (81 mV dec −1 ). In full cell tests, Co 3 O 4 -CeO 2 @NC as the oxygen electrode exhibites superior charge/discharge capacity and excellent cycle stability. The assembled Zn-air battery achieves a maximum power density of 110 mW cm −2 at a current density of 180 mA cm −2 , and a high specific capacity of 780 mAh g −1 at a discharge current density of 10 mA cm −2 .