Acoustic shock wave treatment as a pathway to enhance the specific capacitance of selenium-based layered chalcogenides for supercapacitor applications

Abstract

The global energy crisis has driven the pursuit of sustainable solutions, emphasizing advanced energy storage technologies. Supercapacitors (SCs), renowned for their high power density and durability, are pivotal to efficient energy storage. This study uses acoustic shock waves to enhance the specific capacitance of layered chalcogenides, Bi₂Se₃ and CdSe. While these materials exhibit promising structural and electronic properties, achieving high capacitance with stability in SCs remains challenging, as conventional methods like doping and alloying often disrupt materials' integrity and charge–discharge efficiency. Bi₂Se₃ and CdSe were subjected to different number of shock pulses, like 100, 200, 300, and 400, and characterized via X-ray diffraction, UV-vis diffuse reflectance spectroscopy, cyclic voltammetry, galvanostatic charge–discharge, and high-resolution scanning electron microscopy. The rhombohedral structure of Bi₂Se₃ and cubic structure of CdSe retained stability under shock wave treatment, while their optical properties were fine-tuned, reducing bandgap energies. The smaller bandgap facilitated efficient charge transfer, enhanced specific capacitance, and minimized electrical resistances, significantly improving electrochemical performance. This innovative approach demonstrates that acoustic shock waves effectively optimize the balance between structural stability and electronic properties. By maintaining materials' integrity and enhancing charge transfer capabilities, this method advances the potential of layered chalcogenides in high-performance SCs, offering a sustainable pathway for addressing energy storage challenges.