A terpolymer, poly(ethylene oxide-co-propylene oxide-co-allyl glycidyl ether) (P(EO/PO/AGE)), was reacted with linear mono-functional hydride-terminated polydimethylsiloxane (PDMS-SiH) to obtain PDMS-grafted-polyether (PDMS-g-P(EO/PO/AGE)) by hydrosilylation. Three polyelectrolytes were prepared based on PDMS-g-P(EO/PO/AGE). Best result was obtained when 8wt% of PDMS was introduced onto polyether. Cyclic voltammetry measurement of the PDMS-g-P(EO/PO/AGE polyelectrolytes showed improvement of oxidative stability.