IONIC-CONDUCTIVITY OF NEW DUAL-PHASE POLYMER ELECTROLYTE COMPOSED OF POLY(EPICHLOROHYDRIN-CO-OXIRANE) AND NBR

A new type of dual-phase polymer electrolyte (DPE) film was prepared b y mechanical mixing of a poly(epichlorohydrin-co-oxirane) (ECO) and po ly(acrylonitrile-co-butadiene) rubber (NBR) binary solution and then b y solution casting. Both of the polymers are commercially available. T he casting films were swollen with a LiClO4/propylene carbonate (PC) s olution to obtain DPE films. The ionic conductivity of the DPE films w as calculated on the basis of alternating current impedance measuremen ts. The results showed that the ionic conductivity is dependent on the content of the LiClO4/PC solution and the ECO/NBR blend ratio. High i onic conductivity (>10(-3) S/cm at 298 K) was achieved when the ECO co ntent in the matrix is 90% (w/w), the contentration of LiClO4/PC solut ion is at 3 mol/L, and the weight percent of LiClO4/PC is 40. The impe dance spectrum provided evidence that a dual-phase structure was creat ed, in which the ECO phase provided an ion-conductive pathway and the NBR phase acted as a supportive matrix. A new ionic conductivity mecha nism was proposed. (C) 1998 John Wiley & Sons, Inc.