In Situ Fabrication of Graphdiyne Nanoisland Anchored Ti3C2Tx Film to Accelerate Intercalation Pseudocapacitance Kinetics

Abstract A key challenge in flexible supercapacitor is balancing the trade‐off between high capacity and fast charging ability caused by dense structure‐induced sluggish ionic diffusion and storage dynamics. Herein, a hydrogen‐rich graphdiyne (GDY)–Ti 3 C 2 T x electrode is reported with tunable interlayer spacing, abundant active sites, and extensive charge storage nanochannels. In particular, the GDY–Ti 3 C 2 T x (12.6 wt.%) electrode has a remarkable volumetric capacitance (2296 F cm −3 at 1 A cm −3 ) and fast charging behavior (1262 F cm −3 at 50 A cm −3 ) resulting from the shortened transport pathways, enhanced ionic diffusion rate, and facilitated electrolyte mass transport. Moreover, an all‐solid‐state supercapacitor (ASSC) delivers a high volumetric energy density of 65.6 mWh cm −3 , as well as long‐term deformable cyclic stability and high capacitance retention properties under harsh conditions. Density functional theory calculations and molecular dynamic simulation demonstrate the fast electronic responsiveness of the GDY–Ti 3 C 2 T x heterostructure owning to the stronger H + electrostatic attraction, lower migration resistance, and accelerated intercalation pseudocapacitance kinetics. In situ X‐ray diffraction reveals that a stable Ti─O─C bond bridged organic–inorganic heterostructure can tolerate the repeated high‐current charge/discharge cycling process. The state‐of‐the‐art ASSC delivers multiple functional outputs and shows great potential for efficient energy supply in practical applications.