Masahiro YOSHIZAWA-FUJITA1, Takuto OOTAHARA1, Kan HATAKEYAMA-SATO2, Shinkoh NANBU1, Morgan Leslie THOMAS1, Yuko TAKEOKA1, Masahiro RIKUKAWA1
1Department of Materials and Life Sciences, Sophia University, Tokyo, Japan
2School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
Plastic crystals have recently been studied as a new class of ion conductive materials due to their partly liquid-like degrees of freedom that lead to high small-ion mobility such as Li-ion as shown in Fig. 1. In particular, ionic plastic crystals (IPCs) are attractive materials as flexible solid electrolytes because they are non-volatile, which is a desirable safety feature of electrochemical devices. In 1999, MacFarlane et al. reported that N-ethyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide exhibited plastic crystalline behavior and reasonable Li-ion conductivity. Since then, various IPCs have been reported by many researchers. Recently, we synthesized novel IPCs based on pyrrolidinium salts, and their thermal properties and conductivity were investigated. The relationship between the chemical structure and properties of pyrrolidinium-based IPCs must be investigated to allow for suitable molecular design and thus, control of the physicochemical properties. In addition, we developed rechargeable devices with pyrrolidinium-based IPCs as solid electrolyte materials. In this presentation, the effect of the chemical structure on the physicochemical properties of pyrrolidinium-based IPCs will be discussed, and the development of rechargeable devices such as Li-ion batteries and supercapacitors will be introduced.