In this work, a facile two-step strategy is adopted to construct hierarchical polyaniline/NiCo-layered double hydroxide (PANI/NiCo-LDH) core-shell composite nanofiber networks on carbon cloth (CC). Three-dimensional (3D) porous PANI nanofiber networks are firstly uniformly anchored on CC by in-situ oxidative polymerization, followed by growth of NiCo-LDH nanoflakes on the crosslinked PANI framework via electrochemical deposition. The morphology and electrochemical properties of PANI/NiCo-LDH composites are controlled by the deposition time of LDH. Benefiting from rapid electron transport and ion diffusion, the well-defined PANI/NiCo-LDH hierarchical composite with 200 s deposition of LDH delivers a large capacitance of 1845 F g-1 at 0.5 A g-1 and excellent cycling stability of 82% capacitance retention after 5000 cycles at a very high current density of 10.0 A g-1. Furthermore, an asymmetric supercapacitor (ASC) assembled with PANI/NiCo-LDH as a positive electrode and activated carbon (AC) as a negative electrode exhibits a high capacitance of 147.2 F g-1 in a potential range from 0 to 1.5 V and superior energy density of 46.0 Wh kg-1 at a power density of 351.6 W kg-1.
Keywords: core-shell structure; electrochemical performance; layered double hydroxides; polyaniline nanofibers; supercapacitor.