Synthesis and characterization of PEO and PVDF based polymer electrolytes with Mg(NO₃)₂ ionic salt as ionic conductivity improver

Abstract

The demand for solid polymer electrolytes is increasing continuously because of their better mechanical properties, stability, and strength while compared with liquid or gel electrolytes. However, the polymers are having poor ionic conductivity that can be improved by adding ionic salt during solid electrolyte production. Further, not all the electrolytes are compatible with polymers also the concentration of ionic salt beyond some limit not only decrease the ionic conductivity of solid electrolyte but also decrease the strength as well. In the present work, the mixture of two different polymers (10% PEO and 90% PVDF) is selected as the parent polymer for the production of solid polymer electrolytes. Mg(NO3)2 is used as ionic salt to increase the ionic conductivity and other properties of electrolytes. The concentration of Mg(NO3)2 is taken in 10%, 15%, and 20% (w%w) to the parent polymer, and the effects are analyzed on ionic conductivity. It is found that the addition of Mg(NO3)2 improves the ionic conductivity of electrolytes with a higher rate initially but the rate of increase of ionic conductivity decreases after 15%. Further, better thermal conduction and other properties are observed for the electrolyte having a 15% Mg(NO3)2 concentration. The detailed results are given in the present work.