Recent Developments in Materials Design for Advanced Supercapacitors

This review presents a comprehensive overview of recent advances in supercapacitor electrode materials, with a particular emphasis on the synergistic interactions between electrode materials and electrolytes. Beyond the conventional categorization of materials such as carbon‐based materials, conducting polymers, and metal oxides, we focus on emerging nanostructured systems including MXenes, transition metal dichalcogenides (TMDs), black phosphorus, and quantum dots. We highlight how engineering the electrode–electrolyte interface—through the use of ionic liquids, gel‐based, and solid‐state electrolytes—can enhance device performance by expanding voltage windows, improving cycling stability, and suppressing self‐discharge. In addition, we discuss recent insights from density functional theory (DFT) and density of states (DOS) analyses that elucidate charge storage mechanisms at the atomic level. By integrating materials selection, interface engineering, and application‐oriented design considerations, this review provides a forward‐looking perspective on the development of next‐generation supercapacitors for use in flexible electronics, electric vehicles, and sustainable energy systems.