Flexible supercapacitors based on carbon nanomaterials

Flexible energy storage devices are essential for the development of flexible and wearable electronics. Flexible supercapacitors (also known as electrochemical capacitors or ultracapacitors) have attracted increasing attention for advanced energy storage because of their high capability, long cycle life, low cost, and easy fabrication. Carbon nanomaterials, including 1D carbon nanotubes, 2D graphene, and 3D mesoporous carbon, are promising as electrode materials for flexible supercapacitors due to their extremely large surface area, excellent mechanical and electrical properties, and high electrochemical stability. Much effort has been devoted to developing flexible, carbon-based, all-solid-state supercapacitors with different structure/performance characteristics, including conventional planar, ultrathin in-plane, wearable fiber-shaped, stretchable, transparent, and integrated devices with aesthetic appeal. The aim of this article is to provide an overview of recent progress towards the development of advanced flexible supercapacitors based on carbon nanomaterials. The challenges and perspectives in this emerging field are also discussed.