Ion Transport in Polyacrylonitrile (PAN) Based Electrolytes

Polyacrylonitrile (PAN) is one of the alternative candidate polymer hosts to form solid polymer electrolytes (SPEs) besides the widely used poly(ethylene oxide). In this study, the ion transport mechanism and electrochemical properties of PAN-based SPEs are thoroughly examined. It is found that the ion transport, lithium stability and the oxidative stability of PAN-based SPEs are critically dependent on the film processing conditions, particularly the drying condition. We systematically study four different drying conditions and the resulting residual solvent is quantified by infrared (IR) spectroscopy. We demonstrate that conductivity variation across 5 orders of magnitude can be obtained depending on the drying conditions. Furthermore, the effects of residual solvent on the ion transport mechanism, electrochemical stability against lithium and the oxidative stability are elucidated. This thorough study lays the groundwork for future development of PAN based electrolytes.