Conductivity and dielectric properties of lithium-ion biopolymer blend electrolyte based film

Abstract

In the present work, the effect of lithium salt contents on the ionic conduction of blend biopolymer electrolyte (BBE) comprising chitosan (CS) and methylcellulose (MC) complexed with lithium iodide (LiI) has been explored. The maximum ionic conductivity (6.26 × 10−6 S/cm) was achieved at room temperature upon incorporating 40 wt% of LiI. The frequency-dependent ac conductivity of the BBE follows the Jonscher power law, and the analysis confirmed that the Li-ion conduction mechanism is correlated barrier hopping (CBH) type. The temperature-dependent dc conductivity follows the Arrhenius relation in the investigated temperature ranges. The highest Li-ion conducting sample has minimum activation energy. The dielectric permittivity and dielectric loss decrease regularly with an increase in the frequency of the applied field. The asymmetric and broadening of imaginary modulus peak suggesting a non-Debye type dielectric relaxation.