Xiang Wenjuan, Li Yanling, Wu Mengxue, Ma Jinfu, Sheng Zhilin
School of Chemistry and Chemical Engineering, North Minzu University, Yinchuan 750021, People's Republic of China.
Ningxia Research Center of Silicon Target and Silicon-Carbon Negative Material Engineering Technology, Yinchuan 750021, People's Republic of China.
Nanotechnology. 2022 Jul 25;33(41). 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 CoOon the CeOcarbon frame and stabilizes its specific surface area. Benefiting from the synergistic interaction between CoOand CeO, the conductivity of the electrocatalyst is improved and the oxygen reduction reaction/oxygen storage properties are promoted. The resultant CoO-CeO@N-C catalyst shows remarkable ORR activity with the high initial potential ( = 0.8 V), the large limiting current density ( = 6 mA cm), and a low Tafel slope (81 mV dec). In full cell tests, CoO-CeO@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 cmat a current density of 180 mA cm, and a high specific capacity of 780 mAh gat a discharge current density of 10 mA cm.
开发兼具高活性和稳定性的用于氧还原反应（ORR）和析氧反应（OER）的电催化剂，对于可充电锌空气电池来说仍然是巨大的挑战。在此，通过一种简单的两步法合成了一种新型的钴掺杂铈 - 氮 - 碳双功能电催化剂，该方法实现了氧化钴在氧化铈碳骨架上的高度分散，并稳定了其比表面积。受益于氧化钴和氧化铈之间的协同相互作用，电催化剂的导电性得到改善，氧还原反应/氧存储性能得到提升。所得的氧化钴 - 氧化铈@氮 - 碳催化剂表现出显著的ORR活性，具有高起始电位（= 0.8 V）、大极限电流密度（= 6 mA cm）和低塔菲尔斜率（81 mV dec）。在全电池测试中，氧化钴 - 氧化铈@氮 - 碳作为氧电极表现出优异的充/放电容量和出色的循环稳定性。组装的锌空气电池在电流密度为180 mA cm时实现了110 mW cm的最大功率密度，在放电电流密度为10 mA cm时实现了780 mAh g的高比容量。
