title: Construction of a Hierarchical NiCo2S4@PPy Core-Shell Heterostructure Nanotube Array on Ni Foam for a High-Performance Asymmetric Supercapacitor.
abstract: In this paper, a hierarchical NiCo2S4@polypyrrole core-shell heterostructure nanotube array on Ni foam (NiCo2S4@PPy/NF) was successfully developed as a bind-free electrode for supercapacitors. NiCo2S4@PPy-50/NF obtained under 50 s PPy electrodeposition shows a low charge-transfer resistance (0.31 Ω) and a high area specific capacitance of 9.781 F/cm(2) at a current density of 5 mA/cm(2), which is two times higher than that of pristine NiCo2S4/NF (4.255 F/cm(2)). Furthermore, an asymmetric supercapacitor was assembled using NiCo2S4@PPy-50/NF as positive electrode and activated carbon (AC) as negative electrode. The resulting NiCo2S4@PPy-50/NF//AC device exhibits a high energy density of 34.62 Wh/kg at a power density of 120.19 W/kg with good cycling performance (80.64% of the initial capacitance retention at 50 mA/cm(2) over 2500 cycles). The superior electrochemical performance can be attributed to the combined contribution of both component and unique core-shell heterostructure. The results demonstrate that the NiCo2S4@PPy-50 core-shell heterostructure nanotube array is promising as electrode material for supercapacitors in energy storage.
authors.affiliation: College of Materials Science and Engineering and ‡Analytical and Test Center, Sichuan University , Chengdu, Sichuan 610065, China.
authors.forename: Minglei
authors.initials: M
authors.lastname: Yan
authors.affiliation: College of Materials Science and Engineering and ‡Analytical and Test Center, Sichuan University , Chengdu, Sichuan 610065, China.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Yao
authors.affiliation: College of Materials Science and Engineering and ‡Analytical and Test Center, Sichuan University , Chengdu, Sichuan 610065, China.
authors.forename: Jiqiu
authors.initials: J
authors.lastname: Wen
authors.affiliation: College of Materials Science and Engineering and ‡Analytical and Test Center, Sichuan University , Chengdu, Sichuan 610065, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Long
authors.affiliation: College of Materials Science and Engineering and ‡Analytical and Test Center, Sichuan University , Chengdu, Sichuan 610065, China.
authors.forename: Menglai
authors.initials: M
authors.lastname: Kong
authors.affiliation: College of Materials Science and Engineering and ‡Analytical and Test Center, Sichuan University , Chengdu, Sichuan 610065, China.
authors.forename: Guanggao
authors.initials: G
authors.lastname: Zhang
authors.affiliation: College of Materials Science and Engineering and ‡Analytical and Test Center, Sichuan University , Chengdu, Sichuan 610065, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Liao
authors.affiliation: College of Materials Science and Engineering and ‡Analytical and Test Center, Sichuan University , Chengdu, Sichuan 610065, China.
authors.forename: Guangfu
authors.initials: G
authors.lastname: Yin
authors.affiliation: College of Materials Science and Engineering and ‡Analytical and Test Center, Sichuan University , Chengdu, Sichuan 610065, China.
authors.forename: Zhongbing
authors.initials: Z
authors.lastname: Huang
keywords: NiCo2S4; NiCo2S4@polypyrrole nanotube array; asymmetric supercapacitor; core−shell heterostructure; high area specific capacitance; polypyrrole