Flexible supercapacitors based on carbon nanotubes

Since carbon nanotubes (CNTs) possess unique one dimensional (1D) structure, considerable attention has been paid to constructing CNTs into macroscopic materials with different dimensions, including 1D fibers, 2D films, and 3D foams. Such macroscopic CNT materials exhibit high conductivity, large surface area, as well as good mechanical properties, and thus can be directly used as the flexible supercapacitor (SC) electrodes or the scaffolds for supporting pseudo-capacitive electrode materials. Based on these macroscopic CNT electrodes, diverse SCs with different structures, including flexible, stretchable and/or compressible fiber and thin film SCs, have been designed. This review provides an overview of recent progress towards the development of flexible SCs based on macroscopic CNTs-based electrodes, with a focus on electrode preparation and configuration design as well as their integration with other multifunctional devices. Future development and prospects in the CNTs-based flexible SCs are also discussed.