The Study of Plasticized Sodium Ion Conducting Polymer Blend Electrolyte Membranes Based on Chitosan/Dextran Biopolymers: Ion Transport, Structural, Morphological and Potential Stability.

Ahmad S.F.M Asnawi,Iver Brevik,Mohamad A Brza,Yuhanees M Yusof,Saad M Alshehri,M F Z Kadir,Tansir Ahamad,Shujahadeen B Aziz

doi:10.3390/polym13030383

Abstract

The polymer electrolyte system of chitosan/dextran-NaTf with various glycerol concentrations is prepared in this study. The electrical impedance spectroscopy (EIS) study shows that the addition of glycerol increases the ionic conductivity of the electrolyte at room temperature. The highest conducting plasticized electrolyte shows the maximum DC ionic conductivity of 6.10 × 10−5 S/cm. Field emission scanning electron microscopy (FESEM) is used to investigate the effect of plasticizer on film morphology. The interaction between the electrolyte components is confirmed from the existence of the O–H, C–H, carboxamide, and amine groups. The XRD study is used to determine the degree of crystallinity. The transport parameters of number density (n), ionic mobility (µ), and diffusion coefficient (D) of ions are determined using the percentage of free ions, due to the asymmetric vibration (υas(SO3)) and symmetric vibration (υs(SO3)) bands. The dielectric property and relaxation time are proved the non-Debye behavior of the electrolyte system. This behavior model is further verified by the existence of the incomplete semicircle arc from the Argand plot. Transference numbers of ion (tion) and electron (te) for the highest conducting plasticized electrolyte are identified to be 0.988 and 0.012, respectively, confirming that the ions are the dominant charge carriers. The tion value are used to further examine the contribution of ions in the values of the diffusion coefficient and mobility of ions. Linear sweep voltammetry (LSV) shows the potential window for the electrolyte is 2.55 V, indicating it to be a promising electrolyte for application in electrochemical energy storage devices.

Highlights

Natural solid polymer electrolytes (SPEs) have been widely applied to the development of energy storage devices [1]
The electrical impedance spectroscopy (EIS) data were fitted to an equivalent circuit consisting of two capacitors arising from the constant phase element (CPE) of the immobile polymer chains, and a resistor is the bulk resistance (Rb ) of the system, as presented in the inset of Figure 2 [39]
The addition of glycerol has increased the ionic conductivity of the electrolyte at room temperature

Summary

Introduction

Natural solid polymer electrolytes (SPEs) have been widely applied to the development of energy storage devices [1]. All electrochemical devices, such as dye-sensitized solar cells, supercapacitors (SCs), batteries, and fuel cells, consist of two electrodes (a cathode and an anode) and an electrolyte. SCs or electrical double-layer capacitors (EDLCs) are certified to be one of the important power sources in certain devices, for example, memory back-ups, electrical vehicles, and digital communications, owing to their long cycle life and large power density [2]. ELDCs are prepared using two carbon electrodes separated by an electrolyte. Electrolytes have a crucial role in determining the electrochemical devices’ performance [1,3]. Numerous studies have documented the use of gel-based electrolytes in EDLCs [4,5]. There has been plenty of research done to substitute liquid electrolytes with

Methods

Discussion

Conclusion