title: Facile assembly of Ni-Co hydroxide nanoflakes on carbon nanotube network with highly electrochemical capacitive performance.
abstract: Herein, we demonstrate the high-density assembly of Ni-Co hydroxide nanoflakes on conductive carbon nanotube (CNT) network through a simple and rapid chemical precipitation method, presenting a low-cost and high-performance scaffold for pseudosupercapacitor. It is found that the Ni-Co layered double hydroxide (LDH) nanoflakes prefer to proliferate around large-diameter CNTs (diameter>50 nm), with conductive CNT network well-maintained. Such hierarchical nanostructures show greatly improved specific surface areas compared with bare CNT network and are freestanding without other organic binder, which can be directly employed as a binder-free compact electrode assembly. By optimizing the chemical composition of as-precipitated LDH nanoflakes, the resultant Co0.4Ni0.6(OH)2 LDH/CNT composite nanostructures exhibit the largest specific electrochemical capacitance and the best rate performance, with their capacitance up to 1843 F/g under a low current density of 0.5 A/g and maintained at 1231 F/g when the current density is increased 20 times to 10 A/g. Importantly, such hierarchical nanostructures tend to prevent the electrode from severe structural damage and capacity loss during hundreds of charge/discharge under a high rate (2 A/g), ensuring the electrode with high-energy density (51 W h/kg) at power density of 3.3 kW/kg.
authors.affiliation: Suzhou Institute of Nano-Tech and Nano-Bionics and ‡Key Lab of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences , Suzhou 215123, P. R. China.
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Chen
authors.forename: Feng
authors.initials: F
authors.lastname: Cai
authors.forename: Yiran
authors.initials: Y
authors.lastname: Kang
authors.forename: Sha
authors.initials: S
authors.lastname: Zeng
authors.forename: Minghai
authors.initials: M
authors.lastname: Chen
authors.forename: Qingwen
authors.initials: Q
authors.lastname: Li
keywords: carbon nanotube paper; hierarchical nanowire; layered double hydroxide; nanoflake; supercapacitor