Reduced polysulfide shuttle in lithium-sulfur batteries using Nafion-based separators
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- 作者：I. Bauer ; S. Thieme ; J. Br眉ckner ; H. Althues ; S. Kaskel
- 关键词：Lithium&ndash ; sulfur battery ; Lithiated Nafion-coating ; Polysulfide inhibition ; Charge efficiency ; Coated separator
- 刊名：Journal of Power Sources
- 出版年：1 April, 2014
- 年：2014
- 卷：251
- 期：Complete
- 页码：417-422
- 全文大小：1482 K
文摘
Nafion-coated polypropylene separator (Celgard 2500) is used as cation-selective membrane for lithium sulfur batteries to suppress polysulfide diffusion enhancing the charge efficiency of the cells especially at low charge/discharge rates. The charge efficiency of the 10th cycle rises from about 70% to nearly 90% at a rate of C/20. The reduction of polysulfide penetration through the Nafion-coated Celgard 2500 is also proven by visual characterization. FTIR and SEM investigations verify a smooth and dense Nafion-coating on the porous polypropylene backbone of the separator. The influence of Nafion-loading on rate capability and discharge voltage is investigated by galvanostatic charge-discharge measurements. With the lowest Nafion-loading of 0.25聽mg聽cm鈭? we are able to achieve a rate capability comparable to uncoated Celgard 2500 up to current densities of 3聽mA聽cm鈭?, whereas the functionality as polysulfide shuttle inhibitor is largely preserved.