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

Abstract 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.