Premium
Effect of crown ether on the ionic conductivity of the poly(ethylene oxide)/lithium salt electrolyte
Author(s) -
Mehta Mary Anne,
Kaeriyama Kyoji
Publication year - 1996
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1996.021970216
Subject(s) - cyclen , chemistry , ethylene oxide , ionic conductivity , crown ether , conductivity , lithium (medication) , trifluoromethanesulfonate , electrolyte , inorganic chemistry , ether , ethylene glycol , polymer chemistry , oxide , ion , polymer , organic chemistry , copolymer , medicine , electrode , endocrinology , catalysis
The addition of small amounts of crown ethers was observed to enhance the conductivity of the system PEO 20 LiCF 3 SO 3 (PEO: poly(ethylene oxide)). Optimum conductivity enhancement was observed for the system PEO 20 LiCF 3 SO 3 (crown ether) 0.003 when 12‐crown‐4 and benzo‐12‐crown‐4 were used and for the system PEO 20 LiCF 3 SO 3 (crown ether) 0.03 containing the corresponding azacrown ether (cyclen) and thiacrown ether. Maximum conductivity enhancement was observed for PEO 20 LiCF 3 SO 3 (cyclen) 0.03 . Over the temperature range studied, the conductivity of this system was 1–1.5 orders of magnitude higher than for the system PEO 20 LiCF 3 SO 3 . The Li + diffusion coefficient for the system PEO 20 LiCF 3 SO 3 (cyclen) 0.03 was determined to be 1.5 · 10 −9 cm 2 · s −1 at 90°C. This is lower than the values obtained by other workers in the absence of cyclen using pulsed field gradient NMR techniques. The presence of cyclen thus appeared to have the effect of suppressing the Li + motion. The presence of small quantities of 18‐crown‐6 in PEO 8 Ca(CF 3 SO 3 ) 2 electrolytes was also associated with a conductivity enhancement. This showed that this effect was not limited to systems containing monovalent cations.