Abstract
Ionic conductivity of a redox-couple solid polymer electrolyte system, (1 - x) blend: x[0.9KI : 0.1I(2)] with x = 0 - 0.15 in weight fraction, is reported. A blend of poly(ethylene oxide) (abbreviated as PEO) and succinonitrile in equal weight fraction was used as a polymeric matrix instead of the PEO and succinonitrile because of its low-cost, electrical conductivity superior to the PEO, and thermal stability better than the succinonitrile. The electrolyte with x = 0.15 showed ionic conductivity of 7 x 10(-4) S cm(-1) and iodine ion diffusivity of nearly 4 x 10(-7) cm(2) s(-1) at 25 degrees C. The conductivity and diffusivity values were nearly two orders of magnitude higher than those of the PEO-KI-I-2 due to the improved PEO crystallinity. It also exhibited dye-sensitized solar cell efficiency of 2.2% at 100mWcm(-2), which is twice of the cell prepared using the PEO-KI-I-2 only.