Hybrid Electrolytes Based on Optimized Ionic Liquid Quantity Tethered on ZrO2 Nanoparticles for Solid-State Lithium-Ion Conduction

• Published in: ACS applied materials & interfaces Vol. 13; no. 13; pp. 15159 - 15167
• Main Authors: Bidal, Jennifer, Becuwe, Matthieu, Hadad, Caroline, Fleutot, Benoît, Davoisne, Carine, Deschamps, Michaël, Porcheron, Benjamin, Nhien, Albert Nguyen Van
• Format: Journal Article
• Language: English
• Published: American Chemical Society 07-04-2021
• Subjects: Energy, Environmental, and Catalysis Applications; ionic liquid; electrochemical impedance spectroscopy; ionic conductivity; ZrO2 nanoparticles; coordination grafting; solid-state electrolyte; hybrid electrolyte
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.0c22422

This paper describes the simple, highly reproducible, and robust synthesis of a new solid organic/inorganic electrolyte based on the ionic liquid (IL) 1-butyl-3-(carboxyundecyl)­imidazolium bis­(trifluoromethylsulfonyl)­imide tethered to zirconia nanoparticles (15–25 nm) by coordination and named ZrO2@IL. The IL monolayer formation, ensured by two-dimensional solid-state NMR, at the nanoparticles’ surface considerably reduces both the IL’s consumption and the IL amount at the ZrO2 surface compared to the IL-based hybrid electrolytes reported in the literature. After LiTFSI, used as a lithium source, content optimization (26 wt %), the hybrid exhibits unprecedented stable conductivity passing from 0.6 × 10–4 S.cm–1 to 0.15 × 10–4 S.cm–1, respectively, from 85 °C to room temperature (25 °C). Unlike silica which is commonly adopted for this type of hybrid material, zirconia makes it possible to produce more impact-resistant pellets that are easier to compact, thus being favorable for accurate conductivity studies and battery development by electrode/composite/solid electrolyte layer stacking. The ZrO2@IL/LiTFSI solid hybrid electrolyte’s thermal stability (up to 300 °C) and performance make this electrolyte suitable for lithium conduction in all-solid-state batteries.