材料科学
钴
双功能
催化作用
电催化剂
电池(电)
X射线光电子能谱
析氧
阴极
化学工程
X射线吸收光谱法
吸收光谱法
电化学
碳纤维
电极
化学
有机化学
复合材料
冶金
物理化学
功率(物理)
工程类
物理
复合数
量子力学
作者
Peng Yu,Lei Wang,Fanfei Sun,Ying Xie,Xu Liu,Jingyuan Ma,Xiuwen Wang,Chungui Tian,Jinghong Li,Honggang Fu
标识
DOI:10.1002/adma.201901666
摘要
Abstract Developing non‐precious‐metal bifunctional oxygen reduction and evolution reaction (ORR/OER) catalysts is a major task for promoting the reaction efficiency of Zn–air batteries. Co‐based catalysts have been regarded as promising ORR and OER catalysts owing to the multivalence characteristic of cobalt element. Herein, the synthesis of Co nanoislands rooted on Co–N–C nanosheets supported by carbon felts (Co/Co–N–C) is reported. Co nanosheets rooted on the carbon felt derived from electrodeposition are applied as the self‐template and cobalt source. The synergistic effect of metal Co islands with OER activity and Co–N–C nanosheets with superior ORR performance leads to good bifuctional catalytic performances. Wavelet transform extended X‐ray absorption fine spectroscopy and X‐ray photoelectron spectroscopy certify the formation of Co (mainly Co 0 ) and the Co–N–C (mainly Co 2+ and Co 3+ ) structure. As the air‐cathode, the assembled aqueous Zn–air battery exhibits a small charge–discharge voltage gap (0.82 V@10 mA cm −2 ) and high power density of 132 mW cm −2 , outperforming the commercial Pt/C catalyst. Additionally, the cable flexible rechargeable Zn–air battery exhibits excellent bendable and durability. Density functional theory calculation is combined with operando X‐ray absorption spectroscopy to further elucidate the active sites of oxygen reactions at the Co/Co–N–C cathode in Zn–air battery.
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