Self‐Reinforcing Carbon Nanotube Framework with Aligned Network Structure for Flexible and Compact Energy Storage

Developing robust yet porous film electrodes toward flexible and compact capacitive energy storage remains challenging. Herein, a compact buckypaper framework with outstanding mechanical properties and efficient pore utilization is designed by aligning single-walled carbon nanotubes. With further loading the nickel-cobalt compounds on the optimized buckypaper framework, the resulting flexible electrode achieves exceptional volumetric, gravimetric, and areal properties (1057.1 F cm^-3, 792.8 F g^-1 and 1.0 F cm^-2 at a current density of 1 mA cm^-2). Additionally, the asymmetric flexible supercapacitors based on the buckypaper framework deliver an eminent volumetric energy density of 43.3 Wh L^-1 at a power density of 788.5 W L^-1, representing a breakthrough for designing robust yet porous film electrodes toward the practically feasible capacitive energy storage.