Influence of graphene nanoplatelet on carboxymethyl cellulose for enhanced electrochemical performance

Abstract

Renewable and bio-based polymers are favored over conventional synthetic polymers because of their low-cost, abundance and sustainability, but due to their average electrochemical performance, sometimes their application is limited as battery material. This study investigates the electrochemical properties of nanocomposites composed of carboxymethyl cellulose (CMC) and graphene nanoplatelets (GNP) at varying GNP ratios. Four samples with GNP weight ratios ranging from 0 to 0.33 wt.% were subjected to analysis using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The sample containing 0.33% GNP exhibited the most favorable electrochemical behavior, demonstrating an ionic conductivity of approximately 2.54 × 10−5 S/cm at 25 °C. Cyclic Voltammogram and Nyquist plots indicated an electrochemical process governed by diffusion processes, particularly evident with 0.33% GNP. This sample displayed the highest specific capacitance at 4.290 F/g, representing an 83.07% improvement over the Pure CMC sample, along with a favorable electrochemical window at 375 mV. Bode plot analysis underscored the influence of diffusion and charge transfer on resistance and conductivity, highlighting enhanced ion mobility in this sample. SEM micrographs revealed improved GNP dispersion in the CMC matrix at higher GNP concentrations, enhancing contact. FTIR analysis confirmed effective CMC–GNP interaction, characterized by a specific peak at 1589 cm−1. These findings provide valuable insights into the electrochemical potential of CMC–GNP composites, offering prospects for their application in diverse electrochemical devices.