过电位
析氧
材料科学
阴极
催化作用
电池(电)
化学物理
纳米技术
化学
化学工程
物理化学
电化学
电极
热力学
有机化学
物理
工程类
功率(物理)
作者
Jian Zheng,Wenjing Zhang,Ruoyu Wang,Junkai Wang,Yanwu Zhai,Xiangfeng Liu
出处
期刊:Small
[Wiley]
日期:2022-12-29
卷期号:19 (10)
被引量:6
标识
DOI:10.1002/smll.202204559
摘要
The critical challenge for Li-O2 batteries lies in the large charge overpotential, leading to undesirable side reactions and inferior cycle stability. Single-atom catalysts have shown promising prospects in expediting the kinetics of oxygen evolution reaction (OER) for Li-O2 batteries. However, a present practical drawback is the limited understanding of the correlation between the unique atomic structures and the OER mechanism. Herein, a template-assisted strategy is reported to synthesize atomically dispersed Pd anchored on N-doped carbon spheres as cathode catalysts. Benefiting from the well-defined Pd-N4 moiety, the morphology and distribution of Li2 O2 products are distinctly regulated with optimized decomposition reversibility. Theoretical simulations reveal that the unique configuration of Pd-N4 will contribute to the electron transfer from Pd atoms to the adjacent N atoms, which turns the originally electroneutral Pd into positively charged and downshifts the d-band center and therefore weakens its adsorption energy with the intermediates. The Li-O2 batteries with Pd SAs/NC cathode achieve a charge overpotential of only 0.24 V and sustainable low-overpotential cycling stability (500 mA g-1 ), and can retain a low charge voltage to a very high capacity of 10 000 mAh g-1 . This work provides some insights into designing efficient single-atom catalysts for stable low-overpotential Li-O2 batteries.
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