Electron Highways Meet Nanoconfined Reactors: Building Ultradurable Flexible Supercapacitors Through Synergistic Transport-Structure Manipulation of NiCo-LDH-Supported MXene.

Nickel-cobalt layered double hydroxides (NiCo-LDHs) are considered highly promising electrode materials for supercapacitors (SCs). Nevertheless, their limited conductivity and inherent stacking defects lead to inactive electronic states, thereby constraining their electrochemical performance. Here, a dual-conductive-engineered flexible electrode is fabricated through synergistic integration of in situ constructed 3D porous LDH with TiCT nanosheets deposition, establishing a semi-confined reaction microenvironment. The collaborative conductive architecture and confinement-enhanced effects enable continuous modulation of Faradaic reaction kinetics during charge/discharge processes, achieving breakthrough improvements in both energy density and cycling stability. The optimized TiCT/LDH/CC-50 electrode delivers a remarkable specific capacitance of 1598.7 F g⁻¹ at 1 A g⁻¹, along with excellent rate performance of 87.2% (10 A g). Furthermore, the constructed aqueous asymmetric supercapacitor (ASC) delivers an impressive energy density of 72.4 Wh kg¹ and remarkable cycling stability (90.5% retention after 10 000 cycles). A flexible solid-state asymmetric SC (FSASC) is also fabricated, showcasing a significant energy density of 83.9 Wh kg¹ at 900 W kg¹ with excellent mechanical flexibility. DFT simulations further revealed enhanced electron transport and a greater number of active sites due to the reduced energy barrier. This work contributes new insights into the structural design of LDH/MXene nanohybrid electrodes for advanced energy density supercapacitors.