Lithium salts doped biodegradable gel polymer electrolytes for supercapacitor application

Abstract

A biodegradable gel polymer (GPE) consisting of Xanthan gum (XG), glycerol, lithium salts like lithium perchlorate and lithium tetraborate were prepared. Using Fourier transform infrared spectroscopy (FTIR), thermal and scanning electron microscopy characterizations the interactions between the components in the gel matrix were studied. Furthermore, a unique electrochemical property was exhibited by GPEs as measured by AC impedance and dielectric studies. The role of anion in the enhancement of conductivity was important in the present study and highest conductivity of 6.4×10-2 S cm-1 at 333K was achieved among lithium salts. Supercapacitor was fabricated using GPE and tested for its electrochemical properties. Supercapacitor showed specific capacitance of was 82 Fg-1 at a scan rate of 5 mV s-1 for Li<inf>2</inf>B<inf>4</inf>O<inf>7</inf> and 74 Fg-1 at a scan rate of 5 mV s-1. specific energy and specific power. Galvanostatic charge-discharge studies showed excellent cyclic stability.