Core-shell structural PANI-Derived Carbon@Co-Ni LDH electrode for high-performance asymmetric supercapacitors
Abstract
Carbon/metal nanocomposites have been considered as a promising electrode material for application in supercapacitors owing to the combination of good electrical conductivity, excellent cycle stabilities of electronic double layer capacitor (EDLC) and high specific capacitance of pseudocapacitor. Here, a core-shell structured polyaniline derived carbon nanowire @ Co-Ni layered double hydroxide (PANC@Co-Ni LDH) nanomaterials were successfully synthesized via a novel facile electrodeposition-carbonization-electrodeposition route. The core-like PANC full of N atom remains innate long-chain structure and provides a lot of active sites for the uniform growth of the shell-like Co-Ni LDH, resulting in a cross-linked active network structure with numerous electroactive sites, abundant pore, adequate large space and reaction interface, which contribute to the rapid diffusion and transportation of the electrolyte ions and electrons. Therefore, as-obtained PANC@Co-Ni LDH showed a high specific capacitance of 1529.52 F g-1 at 0.5 A g-1 in three electrode system and offered an outstanding rate properties with no obvious capacitance attenuation (1425.17 F g-1) when the current density increased up to 10 A g-1. Moreover, the asymmetric supercapacitor using PANC@Co-Ni LDH as the positive electrode and PANC as the negative electrode were fabricated, which revealed a high specific capacitance of 241.06 F g-1 and superior energy density of 42.14 W h kg-1 with a power density of 0.39 kW kg-1, suggesting great potential in practical energy storage devices.
