The effect of isothermal annealing on the AC conductivity of Polyvinyl Alcohol-based polymer as an energy storage system

Polyvinyl Alcohol-based polymer was prepared using a casting technique. Impedance spectroscopy has been used to study the effect of isothermal heat treatment on the AC conductivity of doped polyvinyl alcohol (PVA) with silicon dioxide (SiO2), magnesium triflate (MgTIF), and 2-Ethylhexylamine (EHA). The frequency dependence of the AC conductivity for the investigated samples has been studied according to Jonscher's power law at different annealing temperatures and annealing times. The frequency exponent (s) of Jonscher's law has been estimated by fitting the experimental data with this law. It has been found that (s) increases at low annealing time and temperature and then decreases at high annealing time and temperature, which could be interpreted in terms of NSPT and CHB models. The temperature dependence of the AC and DC conductivity at different annealing temperatures and different annealing times for the investigated samples according to the Arrhenius equation were studied, where the activation energies are Eg and Ea for the DC and the AC conductivity respectively were derived. It has been found that Ea and Eg increase with increasing annealing times.