Investigation on the Electrical Properties of Lithium Ion Conducting Polymer Electrolyte Films Based on Biodegradable Polymer Blends

Abstract

In the present work, the polyvinyl alcohol/poly (N-vinyl pyrrolidone)/Lithium carbonate (PVA/PVP/Li2CO3) blend polymer electrolyte films were prepared via the solution casting technique, with varying concentration of Li2CO3 salt (0 to 25 wt%). The surface morphology of these blend electrolyte films was examined using polarized optical microscopy (POM). The electrical properties such as impedance (Z), quality factor (Q-factor) and phase angle () of PVA/PVP/Li2CO3 blend electrolyte films were elucidated using impedance analyzer in the frequencies from 50 Hz to 20 MHz and temperatures from 30 °C to 150 °C. It was observed that the inclusion of Li2CO3 salt into the PVA/PVP blend matrix led to an increase in the Z,  and Q-factor values. The maximum Z of 1.19 x 107 Ω (50 Hz, 30 °C) was observed for blend electrolyte film containing 25 wt% Li2CO3 salt. The  also increased from 139° (20 MHz, 90 °C) for PVA/PVP blend to 179° (20 MHz, 40 °C) for blend electrolyte film containing 25 wt% Li2CO3 salt. The Q-factor values was increased from 27.4 (10 MHz, 140 °C) for PVA/PVP blend to 56.2 (5 MHz,salt, 80 °C) for blend electrolyte film containing 25 wt% Li2CO3 salt.