Liquid crystalline lithium-ion electrolytes derived from biodegradable cyclodextrin. Issue 19 (30th April 2019)

• Record Type: Journal Article
• Authors: Champagne, Pier-Luc; Ester, David; Bhattacharya, Amit; Hofstetter, Kyle; Zellman, Carson; Bag, Sourav; Yu, Haoyang; Trudel, Simon; Michaelis, Vladimir K.; Williams, Vance E.; Thangadurai, Venkataraman; Ling, Chang-Chun
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 19(2019)
• Page Start: 12201
• Page End: 12213
• Publication Date: 2019-04-30
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9ta01852b
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A cyano-tetraethylene glycol functionalized amphiphilic cyclodextrin forms liquid crystalline self-assembly that shows promising ion conductivity (Li + ). Abstract : The first family of lithium-ion electrolytes based on thermotropic liquid crystalline (LC) cyclodextrin (CD) is reported. The new electrolytes consist of composites of self-assembling and environment-friendly amphiphilic β-CDs with lithium bistrifluoromethanesulfonimidate (LiTFSI). The unique geometry of the CD scaffold allows for efficient control of the amphiphilicity of the molecule through chemical derivatizations. The introduction of non-polar alkyl chains at the primary face of CD and multiple short and polar nitrile-terminated tetraethylene glycol chains at the other face provides a new class of LC materials capable of self-organization into homeotropically-aligned smectic mesophases, which retain long-range order over a wide temperature window. The assembly of numerous ethoxy groups at the secondary face of CD serves as an elegant pre-organization of the ion-chelating groups to form two-dimensional ion-conducting pathways, facilitating the directional motion of metal ions. Studies of several LC composites with LiTFSI have revealed promising thermal stability and ionic conductivity. Solid-state NMR studies have uncovered an activation energy of 0.14 eV for lithium diffusion, while cyclic voltammetry confirmed the composites remain electrochemically stable over a potential range of up to ∼3 V versus Li/Li + . These results demonstrate the great potential of this new class of organic electrolytes for different metal ions.