通过现场总频率生成振动光谱探测到的精确定义的石墨烯电极上的氧气演变反应的超电位的起源
Qiling Peng1, Jiafeng Chen2, Hengxing Ji2
1Institute for Catalysis , Hokkaido University , Sapporo 001-0021 , Japan.
Journal of the American Chemical Society
|November 7, 2018
概括
研究人员使用石墨烯电极研究氧电池阴极. 他们发现氧进化反应主要发生在过氧化-石墨烯界面,导致高过电位.
科学领域:
- 电化学
- 材料科学
背景情况:
- 氧 (Li-O2) 电池提供高能量密度,但面临着阴极效率的挑战.
- 了解氧减和演化反应 (ORR和OER) 对于提高氧电池性能至关重要.
研究的目的:
- 在二甲基硫氧化物 (DMSO) 中对石墨烯电极进行ORR和OER机制的研究.
- 为了阐明在Li-O2电池中OER期间高超电位的来源.
主要方法:
- 使用总频率生成 (SFG) 光谱,一种表面选择性振动技术.
- 在ORR和OER期间研究石墨烯电极上的溶剂吸附/脱附.
- 分析了沉积的过氧化 (Li2O2) 和石墨烯电极之间的接口.
主要成果:
- SFG光谱显示,OER主要发生在Li2O2/石墨烯接口.
- OER过程减少了Li2O2和石墨烯之间的接触面积.
- 在Li2O2氧化完成之前,接触面积的减少会减少电导率.
结论:
- 优惠的OER接口机制解释了在Li-O2电池中观察到的高超电位.
- 优化Li2O2/石墨烯接口是提高阴极效率的关键.
- 这项研究提供了对2电池反应途径的基本见解.
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