Three dimensional architectures: design, assembly and application in electrochemical capacitors

Currently, supercapacitors (SCs) are considered to be one of the most promising energy storage devices, mainly due to their unique properties such as high output power, long cycling stability, and fast charge/ discharge capability. Nevertheless, the low energy density of SCs still limits their promotion in practical applications. Given this, designing three dimensional (3D) architectures for SC electrodes is perceived as an efficient strategy because well-constructed 3D structures could enable reduced dead surface, good electron transport kinetics, hierarchical porous channels and short ionic diffusion distances. This review aims to describe the current progress of different synthetic processes with respect to the preparation of 3D SC electrodes and focuses on both template-assisted strategies and non-template strategies. We summarize recently proposed methods, novel structures, and electrochemical performances for these 3D electrodes. The advantages and disadvantages accompanying them are also analyzed. Finally, we discuss the challenges and prospects of the fabrication of 3D SC electrodes.