| 학회 | 한국고분자학회 |
| 학술대회 | 2004년 가을 (10/08 ~ 10/09, 경북대학교) |
| 권호 | 29권 2호, p.632 |
| 발표분야 | 기능성 고분자 |
| 제목 | Solvent Effect on Decoupled Ion Conduction of Poly (vinyl alcohol)-based Solid Polymer Electrolytes |
| 초록 | Common solid polymer electrolytes (SPEs) are not entirely free from the drawback of low ionic conductivity at room temperature. To acquire the high conductivity at room temperature and the good physical properties of SPEs for practical applications, we have made an effort to produce ion-conducting polymer electrolytes based on poly (vinyl alcohol) (PVA) using solvent casting method with dimethyl sulfoxide (DMSO). DMSO has been chosen as a solvent due to its strong solvating properties towards both the salt of LiCF3SO3 and PVA. And it was known that the ‘fast cationic transport process’ made of network-like connected large ion aggregates was started to be formed at around 50wt% of salt concentration and cations could move by ion hopping decoupled from the polymer segmental motion. And prepared SPE exhibited three orders of magnitude at room-temperature on addition of 80wt% of salts. Especially, in further investigation of SPEs containing 50 and 80wt% of salts for a long time (71 days) we found that the dependence of ionic conductivity on the drying time is associated with the amount of existing solvent in SPE films. So, in this study, we attempted to further elucidate the effect of solvent on cation motion in the ‘fast cationic transport process’. At first, using FTIR measurement, we observed the changes of free ion fraction, ion aggregates fraction, and solvent fraction in SPEs containing 50 and 80wt% of salts within 71 days of drying time. And we found that the solvent fraction and free ion fraction decreased in accordance with increasing drying time, on the other hand, ion aggregates fraction showed increasing tendency during a certain period but decreased rapidly after the critical time (see Fig. 1). Then we investigated the change of crystallinity of prepared SPEs with various drying time by XRD and surveyed the change of ionic conductivity with ac impedance measurement. Our combined conductivity, FTIR and XRD investigation have revealed very important information about the effect of solvent on the ion hopping in ‘fast cationic transport process’ of PVA-based SPEs. Fig. 1. Ion aggregates fraction in SPEs with various drying time. (a) PVA:salt=50:50, (b) PVA:salt=20:80 |
| 저자 | 조윤경, 정수경, 조남주 |
| 소속 | 부산대 |
| 키워드 | solid polymer electrolyte; poly(vinyl alcohol); solvent effect |
