Structural behavior and ion dynamics of methylcellulose/tri-potassium phosphate-based solid biopolymeric electrolytes

In this article, the complexation of methylcellulose (MC) with tri-potassium phosphate (K3PO4) is investigated using an ultrasonication-assisted solution cast process. X-ray diffraction (XRD) analysis indicates that varying concentrations of K3PO4 salt (7-35 wt.%) disrupt the crystalline segment of the MC host matrix. The considerable shift in the intensity and orientation of the Fourier transforms infrared spectroscopy (FTIR) transmittance bands indicate the establishment of a charge-transfer entanglement between the polymer host and the dispersed salt. The optimum sample (28 wt.%) exhibits a high ionic conductivity of 1.74 x 10(-5) S cm(-1), potential stability of 3.48 V, and a cation transference number (t(i)) of 0.945. These findings show the relevance of the developed SPEs for possible application in electrochemical devices.