Electrochemical Exfoliation and Growth of Nickel–Cobalt Layered Double Hydroxides@Black Phosphorus Hetero‐Nanostructure Textiles for Robust Foldable Supercapacitors

Abstract

Advanced innovation of flexible electrode with adequate redox activity and stably mechanical endurance that promotes charges kinetic migration and faradaic storage is pivotal for textile‐based supercapacitors (T‐SCs). Herein, this study reports a high‐performance T‐SCs electrode based on nickel–cobalt layered double hydroxides@black phosphorus (NiCo‐LDHs@BP) on a conductive silk (c‐silk) textile (NiCo‐LDHs@BP/c‐silk). Under negative voltage‐induced electrochemical exfoliation, the Ni2+ and Co2+ are embedded into bulk BP framework to form exfoliated BP nanosheets, and the NiCo‐LDHs are in situ grown within the BP networks, generating 3D NiCo‐LDHs@BP hetero‐nanostructure. Significantly, the NiCo‐LDHs@BP exhibits a large space‐charge area, enhanced adsorption energy for OH− and accelerated charges transfer/storage as confirmed using density functional theory calculations. Additionally, the T‐SCs electrode is fabricated by loading the blended NiCo‐LDHs@BP, sericin, and carbon nanotubes on fibroin textile via a silk reconstruction strategy, producing large area production, superior mechanical flexibility, and impressive electrochemical performance. The resultant NiCo‐LDHs@BP/c‐silk electrode exhibits large specific capacitance of 1291.3 F g−1 and considerable rate capacity in 1 M KOH electrolyte. Furthermore, the flexible solid‐state asymmetric T‐SCs deliver high specific areal energy density of 279.6 µWh cm−2 and robust folding capability (85.6% capacitance retention after 5000 folding cycles), which successfully power wearable watch and heart rate meter devices.