Eco-Friendly flexible energy storage: Cerium-Doped natural fiber composite electrodes

The growing demand for flexible and eco-friendly electrodes in modern energy storage systems has driven research toward sustainable materials and innovative fabrication techniques. This study presents the development of freestanding, paper-based electrodes using cerium oxide (CeO?) and manganese-doped cerium oxide (Ce?.??Mn?.??O?) nanoparticles synthesized via a co-precipitation method. To enhance flexibility and environmental sustainability, lignocellulosic (LC) fibers extracted from Monochoria vaginalis, a self-growing plant, were utilized as a natural binder. Structural and optical characterizations were conducted using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), confirming the successful incorporation of Mn ions into the CeO? lattice. Surface morphology and elemental composition were analyzed through scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and selected area electron diffraction (SAED), verifying the uniform dispersion of nanoparticles within the lignocellulosic matrix. Electrochemical performance was evaluated using a three-electrode system in a 2 M KOH electrolyte. Cyclic voltammetry (CV) measurements revealed specific capacitances of 401.5 F/g and 544 F/g for CeO?/LC and Ce?.??Mn?.??O?/LC composite sheets, respectively. Further assessment via a two-electrode symmetric cell using galvanostatic charge-discharge (GCD) tests demonstrated improved capacitance values of 436 F/g (CeO?/LC) and 560 F/g (Ce?.??Mn?.??O?/LC). Notably, the Mn-doped composite exhibited excellent cycling stability, retaining 80% of its initial capacitance after 1000 charge-discharge cycles at 3.3 A/g. The findings highlight the potential of these freestanding, binder-free electrodes as sustainable alternatives for flexible energy storage devices. By eliminating synthetic substrates, the developed composites offer dual advantages, high electrochemical performance and environmental safety, making them suitable for next-generation wearable and bendable energy storage applications.

Dr. Aneeqa Masood is currently a Postdoctoral Researcher at South China University of Technology (SCUT), where she pioneers the development of xylan-based biosensors for non-invasive detection of biomarkers in sweat. She earned her PhD from COMSATS University Islamabad, Lahore Campus, where she was the youngest PhD graduate in her department and the first in Pakistan to develop paper-based electrodes. During her PhD, she published nine peer-reviewed research articles, including three as first author. Previously, she worked as a Research Assistant at COMSATS, focusing on sustainable energy storage materials. Her current work advances flexible, eco-friendly biosensing technologies for healthcare applications, bridging sustainable materials science with cutting-edge biomedical innovations.