The energy storage field is witnessing novel material innovations. Zinc oxide (ZnO) and carbon nanotube composite papers have been developed to create binder-free electrodes, presenting eco-friendly options for supercapacitors with improved performance. Advances in magnesium ion conductors based on poly(vinyl alcohol) enhance electrical double-layer capacitor efficiency. Additionally, deep eutectic electrolytes improve aluminum anode stability, indicating multifaceted approaches toward sustainable, high-performance energy storage solutions.