Structural, Impedance and Electrochemical Characteristics of Electrical Double Layer Capacitor Devices Based on Chitosan: Dextran Biopolymer Blend Electrolytes.

Shujahadeen B Aziz,Rebar T Abdulwahid,Mohamad A Brza,Shakhawan Al-Zangana,Wrya O Karim,Mohd F Z Kadir,Iver Brevik,Muhamad H Hamsan,Muaffaq M Nofal

doi:10.3390/polym12061411

Abstract

This report presents the preparation and characterizations of solid biopolymer blend electrolyte films of chitosan as cationic polysaccharide and anionic dextran (CS: Dextran) doped with ammonium iodide (NH4I) to be utilized as electrolyte and electrode separator in electrical double-layer capacitor (EDLC) devices. FTIR and XRD techniques were used to study the structural behavior of the films. From the FTIR band analysis, shifting and broadening of the bands were observed with increasing salt concentration. The XRD analysis indicates amorphousness of the blended electrolyte samples whereby the peaks underwent broadening. The analysis of the impedance spectra emphasized that incorporation of 40 wt.% of NH4I salt into polymer electrolyte exhibited a relatively high conductivity (5.16 × 10−3 S/cm). The transference number measurement (TNM) confirmed that ion (tion = 0.928) is the main charge carriers in the conduction process. The linear sweep voltammetry (LSV) revealed the extent of durability of the relatively high conducting film which was 1.8 V. The mechanism of charge storage within the fabricated EDLC has been explained to be fully capacitive behavior with no redox peaks appearance in the cyclic voltammogram (CV). From this findings, four important parameters of the EDLC; specific capacitance, equivalent series resistance, energy density and power density were calculated as 67.5 F/g, 160 ohm, 7.59 Wh/kg and 520.8 W/kg, respectively.

Highlights

From the perspective of industrial technology, the miniaturization and flexibility of electrical appliances have been the subject of intense focus
It is evident that pure chitosan is characterized by a equations
The diffractogram of the pure chitosan sample i exhibits a characteristic peak at 2θ=21.0°, confirming

Summary

Introduction

From the perspective of industrial technology, the miniaturization and flexibility of electrical appliances have been the subject of intense focus. Based on its large surface area, activated carbon provides a large double-layer as a result of ion accumulation at the interfacial region via an energy storage mechanism. This ion accumulation at the interface region progresses via the well-defined phenomenon known as non-Faradaic reaction where ion adsorption occurs. The performance of energy storage devices can be highly affected by the electrode materials. The efforts are essentially concentrated on increasing the surface area, rising conductivity, electrochemical stability and good mechanical and thermal properties of the electrode material

Methods

Results

Conclusion