Dynamic Cross-Linking of Polymeric Binders Based on Host鈥揋uest Interactions for Silicon Anodes in Lithium Ion Batteries

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• 作者：Tae-woo Kwon ; You Kyeong Jeong ; Erhan Deniz ; Siham Y. AlQaradawi ; Jang Wook Choi ; Ali Coskun
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：November 24, 2015
• 年：2015
• 卷：9
• 期：11
• 页码：11317-11324
• 全文大小：572K
• ISSN：1936-086X

文摘

We report supramolecular cross-linking of polymer binders via dynamic host鈥揼uest interactions between hyperbranched 尾-cyclodextrin polymer and a dendritic gallic acid cross-linker incorporating six adamantane units for high-capacity silicon anodes. Calorimetric analysis in the solution phase indicates that the given host鈥揼uest complexation is a highly spontaneous and enthalpically driven process. These findings are further verified by carrying out gelation experiments in both aqueous and organic media. The dynamic cross-linking process enables intimate silicon鈥揵inder interaction, structural stability of electrode film, and controlled electrode鈥揺lectrolyte interface, yielding enhanced cycling performance. Control experiments using both 伪, 纬-CDp with different cavity sizes and a guest molecule incorporating a single adamantane unit verified that the enhanced cycle life originates from the host鈥揼uest interaction between 尾-cyclodextrin and adamantane. The impact of the dynamic cross-linking is maximized at an optimal stoichiometry between the two components. Importantly, the present investigation proves that the molecular-level tuning of the host鈥揼uest interactions can be translated directly to the cycling performance of silicon anodes.