Modifying the microstructure of chitosan/methylcellulose polymer blend via magnesium nitrate doping to enhance its ionic conductivity for energy storage application

In this study, different weight percentages of Mg(NO 3 ) 2 were added to a polymer blend composed of chitosan (CS) and methylcellulose (MC). The solution casting method was adopted to prepare the polymer electrolyte films. As the host matrix, the polymer blend consists of 70 wt.% of CS and 30 wt.% of MC. The interactions between the blend and the Mg(NO 3 ) 2 salt were revealed by FTIR analysis. The deconvolution of XRD peaks followed by the calculation of crystallinity indicates that the electrolyte samples were amorphous. The bulk resistance decreased with increasing salt content, according to the results of electrical impedance spectroscopy (EIS), and this was caused by the influence of carrier concentration. The sample containing 30 wt.% of Mg(NO 3 ) 2 was determined to have a maximum value of DC conductivity of 2.12 × 10 –5 Scm −1 at room temperature by EIS analysis. The highest conducting film’s potential stability was found to be 3.65 V. It was found that the ion transference number was 0.86. The performance of the magnesium ion battery was then evaluated after it was built using the highest conducting polymer electrolyte. Considering this, the current work proposes an eco-friendly, practical, and affordable electrolyte appropriate for making electrochemical devices. Graphical abstract (made with biorender.com)