Growing-fruits-type nanoarchitectonics of nickel‑vanadium layered double hydroxide on branches of nitrogen-rich carbon nanotube for high performance supercapacitors

An innovative structural design leverages the distinctive properties inherent in each material of three type electrode material for supercapacitors. First, polyaniline nanotubes (PN) are prepared controllably. Subsequently, the PN are carbonized into nitrogen-rich carbon nanotubes (NCN) to exploit their high electrical conductivity. Finally, a nickel‑vanadium layered double hydroxide (NiV-LDH) is grown on the surface of NCN "branches" to fabricate a nitrogen-rich carbon nanotubes/nickel‑vanadium layered double hydroxide composite material (NCN/NiV-LDH). The NCN/NiV-LDH exhibits an impressive specific capacitance of 1018.2 F g−1 at a current density of 2 A g−1, and demonstrates favorable rate capability as the capacitance value remains at 702.2 F g−1 even when the current density is tripled. Moreover, the assembled asymmetric supercapacitor comprising NCN/NiV-LDH and active carbon (AC) as the positive and negative electrodes, respectively, achieves a high energy density of 108.25 Wh kg−1, even under a power density of 7500 W kg−1.