Boosting the Ionic Conductivity of Pyrrolidinium-Based Ionic Plastic Crystals by LLZO Fillers

Abstract

Organic ionic plastic crystals (OIPCs) have attracted attention as novel organic solid electrolyte materials, but their insufficient mechanical strength and ionic conductivity have prevented their application. In this study, a lithium salt, lithium bis(fluorosulfonyl)amide (LiFSA), and an inorganic solid electrolyte, Li 7 La 3 Zr 2 O 12 (LLZO), were added to an OIPC, N,Ndiethylpyrrolidinium bis(fluorosulfonyl)amide ([C 2 epyr][FSA]). The fabricated organic−inorganic hybrid solid electrolytes were evaluated thermally, mechanically, and electrochemically to reveal which factors affect the properties of the electrolytes. All samples showed excellent thermal stability regardless of LiFSA or LLZO concentration, and they were found to be highly plastic and ionconductive solids at a wide range of temperatures. It was also revealed that the addition of LLZO raised the nanoindentation stiffness (H IT ) of the [C 2 epyr][FSA]/LiFSA composites. The ionic conductivity of the hybrid electrolytes was higher than that of the pristine OIPC, reaching a value of 2.1 × 10 −4 S cm −1 at 25 °C upon addition of appropriate amounts of LiFSA and LLZO. Overall, samples with higher LiFSA concentration and moderate LLZO concentration exhibited higher ionic conductivity. Cyclic voltammetry results showed that the [C 2 epyr][FSA]/LiFSA/LLZO composites were lithium-ion conductors. These findings indicate that by optimizing the concentrations of lithium salt and LLZO, it would be possible to realize their applications as solid electrolytes.

Bio-gel nanoarchitectonics in tissue engineering

“…As human social life has become larger and more diverse, social demands have increased dramatically. For example, functional materials have been developed to confront many problems such as energy production, 1 energy storage, 2 various sensing, 3 environmental protection, 4 carbon neutrality, 5 device development, 6 drug delivery, 7 regenerative medicine, 8 pathogen control, 9 and cancer treatment. 10 Most of them do not rely on the inherent performance of the material itself.…”