Ionic conductivity by correlated barrier hopping in NH4I doped chitosan solid electrolyte

Chitosan-NH4I and chitosan-NH4I-EC films have been prepared by solution cast technique. The sample containing 45 wt% ammonium iodide (NH4I) exhibited the highest room temperature conductivity of 3.7x10-7 S cm-1. The conductivity of the sample increased to 7.6x10-6 S cm-1 when 40 wt% ethylene carbonate (EC) was added to the 55 wt% chitosan-45 wt% NH4I sample. The conductivity-temperature relationship is Arrhenian. From dielectric loss variation with frequency, the power law exponent was obtained. The temperature dependence of the power law exponent for chitosan-NH4I system follows the correlated barrier hopping (CBH) model while conduction mechanism of the plasticized system can be represented by the small polaron hopping (SPH) model.