Investigation on electrical and electrochemical behaviour of cellulose acetate: Ammonium iodide: Silica composite biopolymer electrolyte for proton exchange membrane (PEM) fuel cell performance

Abstract

Cellulose acetate (CA): ammonium iodide (NH4I) solid biopolymer electrolyte and cellulose acetate (CA): ammonium iodide (NH4I): silica (SiO2) particle composite-based biopolymer electrolytes were developed via solution casting route for single proton-exchange membrane fuel cells (PEMFC) applications. X-ray diffraction (XRD) analysis was used to identify the diffraction peaks and their corresponding angles, which led to the confirmation of the aforementioned biopolymer. The admixture of SiO2 into the 50CA:50NH4I improves the amorphous nature than 50CA:50NH4I in the XRD pattern. Using electrochemical impedance spectroscopy (EIS) analysis, the CA:NH4I:SiO2 has found higher ionic conductivity, lower electrical resistance, and a lesser CPE value than the CA and CA:NH4I. The highest-conducting CA:NH4I:SiO2 and CA:NH4I developed were used in the construction of a single PEMFC, where the obtained power density values were 122.4 and 106.4 mWcm−2. The introduction of SiO2 admixtures with CA:NH4I has found relatively higher power density value than CA:NH4I.