Review of Nanomaterial-Enabled Flexible Energy Storage

Flexible electronics are increasingly integrated into many aspects of daily life, including biochemical monitoring, personalized healthcare, wearable systems, and the Internet of Things (IoT). As a key constituent, energy storage systems─primarily batteries and supercapacitors─now face higher demands in flexible systems. Traditional energy storage systems are often bulky, rigid, and contain hazardous components. In this regard, next-generation flexible energy storage systems need to move toward more elasticity, biocompatibility, safety, and stability in delivering energy and power outputs under continuous deformation. Nanomaterials play a critical role in such developments by offering a large surface area, a network of conduction paths, and mechanical adaptability, providing effective solutions for the advancement of better flexible energy storage systems. This review explores the role of nanomaterials in flexible energy storage systems, focusing on electrode materials, electrolytes, and device integration. We also discuss the applications of flexible energy storage supplies, specifically in biomedical fields. Finally, we summarize the current challenges and provide future perspectives for advancing flexible, safe, and efficient solutions for the field.