title: Dynamic Cross-Linking of Polymeric Binders Based on Host-Guest Interactions for Silicon Anodes in Lithium Ion Batteries.
abstract: We report supramolecular cross-linking of polymer binders via dynamic host-guest interactions between hyperbranched β-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-guest 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-binder interaction, structural stability of electrode film, and controlled electrode-electrolyte interface, yielding enhanced cycling performance. Control experiments using both α, γ-CDp with different cavity sizes and a guest molecule incorporating a single adamantane unit verified that the enhanced cycle life originates from the host-guest interaction between β-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-guest interactions can be translated directly to the cycling performance of silicon anodes.
authors.forename: Tae-woo
authors.initials: TW
authors.lastname: Kwon
authors.forename: You Kyeong
authors.initials: YK
authors.lastname: Jeong
authors.affiliation: Department of Chemistry and Earth Sciences, College of Arts and Sciences, Qatar University , P.O. Box 2713, Doha, Qatar.
authors.forename: Erhan
authors.initials: E
authors.lastname: Deniz
authors.affiliation: Department of Chemistry and Earth Sciences, College of Arts and Sciences, Qatar University , P.O. Box 2713, Doha, Qatar.
authors.forename: Siham Y
authors.initials: SY
authors.lastname: AlQaradawi
authors.forename: Jang Wook
authors.initials: JW
authors.lastname: Choi
authors.forename: Ali
authors.initials: A
authors.lastname: Coskun
keywords: binder; dynamic cross-linking; host−guest interaction; silicon anodes; supramolecular chemistry