Exploring alum as a potential supercapacitor material: insights into performance and stability

This study explores the electrochemical, thermal, and structural properties of alum as a potential material for energy storage devices, particularly capacitors and pseudocapacitors. Alum, a cost-effective and abundant material, was characterized using several advanced techniques, including thermogravimetric analysis, dynamic light scattering, and zeta-potential measurements, which provided valuable insights into its thermal stability, particle size distribution, and surface charge. Surface area analysis through the BET method revealed a specific surface area of 12.6 m²/g, highlighting the material’s porous nature. Electrochemical investigations through cyclic voltammetry demonstrated capacitive behavior with potential pseudocapacitive contributions, evidenced by observable redox peaks at scan rates ranging from 20 to 120 mV/s. The highest specific capacitance recorded was 9.48 F/g at a scan rate of 20 mV/s. Galvanostatic charge–discharge measurements confirmed charge–discharge characteristics aligned with capacitor behavior, showing a decrease in specific capacitance with increasing current density. This work underscores the potential of alum as a promising low-cost alternative for supercapacitor applications, particularly for low-power energy storage devices. With further optimization of its electrochemical performance and long-term cycling stability, alum could offer a sustainable solution for the development of efficient energy storage technologies. This study contributes to the growing international interest in sustainable materials for energy storage, addressing a significant gap in research and offering new avenues for future exploration in supercapacitor and pseudocapacitor technologies. The work aligns with global efforts to innovate cost-effective and environmentally friendly energy solutions, highlighting alum’s role in advancing the field of energy storage by providing a novel, yet accessible material with high potential for widespread application.