Characterization of biopolymer electrolytes based on cellulose acetate with magnesium perchlorate (Mg(ClO4)2) for energy storage devices

Abstract

Magnesium ion conducting biopolymer electrolytes have been prepared using cellulose acetate and different wt. % of magnesium perchlorate with DMF as a solvent by the solution casting technique. As-prepared membranes were subjected to different characterization techniques such as XRD, FTIR, DSC, ac impedance analysis and transference number measurement. The amorphous/crystalline nature of the prepared biopolymers was studied by using XRD. FTIR study has revealed the formation of complexes between the cellulose acetate and the magnesium perchlorate. Glass transition temperatures for the biopolymer electrolytes were found using a differential scanning calorimeter. From the ac impedance analysis, the ionic conductivity was calculated. The biopolymer membrane (40%CA: 60% Mg (ClO4)2) has shown the highest conductivity of 4.05 × 10−4 S/cm at room temperature. The ionic transference number of Mg2+ was found as 0.31 by the Evan's method. The electrochemical stability of 3.58 V has been observed for the 40%CA:60%Mg(ClO4)2 biopolymer membrane by the linear sweep voltammetry study. The Mg+ ion primary battery has been constructed using the highest ionic conducting biopolymer membrane. The performance of the battery was studied and the open circuit voltage of the battery was found as 1.9 V. Keywords: Biopolymer electrolyte, Cellulose acetate, Magnesium perchlorate, ac impedance technique, Mg+ ion primary battery