使用固态NaNMR光谱检测氧细胞中的电化学反应产物
Zoë E M Reeve1, Christopher J Franko1, Kristopher J Harris1
1Department of Chemistry and Chemical Biology, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
Journal of the American Chemical Society
|December 23, 2016
概括
在氧 (Na-O2) 阴极中的降解形成化 (NaF) 和碳酸 (Na2CO3) 以及过氧化 (Na2O2). 超氧化物 (NaO2) 与聚乙烯化物 (PVDF) 结合剂发生反应,形成NaF,表明组件不稳定.
科学领域:
- 电化学
- 材料科学
- 固态核磁共振光谱
背景情况:
- 氧 (Na-O2) 电池是一个有前途的储能系统.
- 了解阴极降解对于提高电池性能和寿命至关重要.
- 之前的研究已经确定了各种降解产物,但形成途径尚未完全阐明.
研究的目的:
- 使用23Na MAS NMR识别和量化循环Na-O2阴极中的降解物种.
- 研究超氧化物 (NaO2) 的反应性及其在降解中的作用.
- 确定Na-O2细胞中化 (NaF) 的形成机制.
主要方法:
- 使用23Na魔法角旋转 (MAS) 核磁共振 (NMR) 光谱分析循环Na-O2阴极.
- 用聚乙烯化物 (PVDF) 结合剂对固体氧化物 (NaO2) 进行反应,以研究其反应性.
- 进行Na-O2细胞的电化学循环生成降解产物.
主要成果:
- 23Na MAS NMR光谱显示出化 (NaF),碳酸 (Na2CO3) 和过氧化 (Na2O2) 的存在.
- 在循环电极中没有检测到大量的初始反应产物超氧化物 (NaO2).
- 发现电化学生成的NaO2与PVDF结合剂发生反应,形成NaF.
结论:
- 电池组件的不稳定性,特别是PVDF粘合剂,在NaO2等电化学反应产品的存在下是NaO2电池性能的一个重要问题.
- 从NaO2和PVDF中形成NaF有助于阴极降解.
- 需要进一步的研究来开发更稳定的电极材料和结合剂,用于先进的Na-O2电池化学.
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