Ionic conductivity enhancement of PVA: carboxymethyl cellulose poly-blend electrolyte films through the doping of NaI salt

Vipin Cyriac,Saraswati P Masti,I M Noor,Rajashekhar F Bhajantri,Kuldeep Mishra,Ismayil Ismayil,Chetan Chavan

doi:10.1007/s10570-022-04483-z

Vipin Cyriac, Saraswati P Masti + Show 5 more

Open Access

https://doi.org/10.1007/s10570-022-04483-z

Copy DOI

Abstract

In this paper, we report the effect of doping sodium iodide (NaI) salt into a polymer blend matrix of sodium carboxymethyl cellulose (NaCMC) and poly(vinyl alcohol) (PVA). Solution casting approach was used to prepare solid polymer electrolyte (SPE) films. The films were characterized by Fourier-transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), electrical impedance spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). XRD showed that NaI incorporation decreased the crystallinity of NaCMC/PVA-based SPE. FTIR technique confirmed the complexation of salt with polymer matrix due to the formation of the coordination bond between Na+ and –OH group and hydrogen bond between I− and –CH group. The sample with 30 wt% NaI showed the highest conductivity of 2.52 × 10–3 S cm−1, strongly influenced by the highest charge concentration (n), not its mobility (μ). DSC analysis revealed an increase in glass transition temperature ({T}_{g}) with increasing salt content. TGA studies showed a decrease in thermal stability with salt inclusion. The transference number was found to be 0.99 for the highest conducting sample showing the primary charge carriers are ions. The highest conducting sample exhibited a mechanical strength of 15.42 MPa at room temperature, and it has been used to fabricate a battery to evaluate its suitability in energy storage devices.Graphical abstractGraphical abstract created with https://biorender.com.

Highlights

In recent years, researchers have studied polymer electrolytes extensively due to their wide application in batteries, supercapacitors, sensors, solar cells, and fuel cells (Singh et al 2016)
Since the moiety attached to the polar group is lighter in our case, the wavenumber shift is expected to occur at the higher wavenumber region (Yadav et al 2017; Zulkifli et al 2020)
Based on the Fourier-transform infrared spectroscopy (FTIR) spectra of the pure NaCMC/ poly(vinyl alcohol) (PVA) blend, seven prominent absorption bands appears at 1050 cm−1, 1263 cm−1, 1322 cm−1, 1414 cm−1, 1583 cm−1, 2921 cm−1 and 3285 cm−1, which correspond to C–O–C stretching, C–H wagging, O–H bending, CH2 scissoring, C OOstretching, C–H stretching, and O–H stretching, respectively (Ramlli and Isa 2016; Saadiah et al 2019; Zulkifli et al 2020)

Summary

Mishra Department of Physics, Jaypee University, Anoopshahr, Uttar Pradesh 203390, India

C. Chavan · R. F. Bhajantri Department of Studies in Physics, Karnataka University, Pavate Nagar, Dharwad, Karnataka 580003, India S. P. Masti Department of Chemistry, Karnataka University’s Karnataka Science College, Dharwad, Karnataka 580001, India Graphical abstract created with https://biorender.com. Keywords Polymer blend · NaCMC-PVA hybrid · Solid polymer electrolyte · Degree of crystallinity · Ionic conductivity · Transport properties

Introduction

Results and discussion

Conclusions