A Plastic Electrolyte Material in a Highly Desirable Temperature Range: N-Ethyl-N-methylpyrrolidinium Bis(fluorosulfonyl)amide

A novel organic ionic plastic crystal, N-ethyl-N-methylpyrrolidinium bis(fluorosulfonyl)amide ([C2mpyr][FSA]), was synthesized, and its thermal properties and conductivity were investigated. [C2mpyr][FSA] showed a high melting point at 205 °C and exhibited plastic crystalline behavior over a wide temperature range from −22 °C to melting, which was also in a desirable temperature range for electrochemical devices. The ionic conductivity of [C2mpyr][FSA] was 1.23 × 10−6 S cm−1 at 25 °C.