Highly Conductive Trimethylsilyl
Oligo(Ethylene Oxide) Electrolytes for Energy Storage Applications
Lingzhi Zhang, Zhengcheng Zhang, Scott Harring, Megan Straughan, Rachel
Butorac, Zonghai Chen, Leslie Lyons, Khalil Amine and Robert West
Abstract
 Monomethyl ethers of oligoethylene glycols with different chain lengths were
converted to trimethylsilyl derivatives by reacting with trimethylchlorosilane
in the presence of triethylamine, or by directly refluxing with excess
trimethylchlorosilane or hexamethyldisilazane. Similarly, two oligoethylene
glycols were converted to bis(trimethylsilyl) derivatives. When doped with
lithium bis(trifluoromethanesulfonyl)imide, these electrolytes have very high
conductivity, generally >10-3 S cm-1. A full cell
performance test using one of these new electrolytes (1NM3) showed excellent
cyclability at room temperature. Introducing a second trimethylsilyl group
decreases the conductivity of trimethylsilylated compounds. The thermal
properties, viscosities and dielectric constants of the compounds were measured,
and the effect of those on the conductivity is reported. Cyclic voltammetry
experiments show that the trimethylsilylated compound (1NM2) of diethylene
glycol monomethyl ether has greater electrochemical stability than its germanium
and carbon analogues.
Journal of Materials Chemistry 18, 3713-3717 (2008)
©RSC Publishing 2008 |
