Hierarchical structure electrodes of NiO ultrathin nanosheets anchored to NiCo2O4 on carbon cloth with excellent cycle stability for asymmetric supercapacitors

By O. Yu, Rongjiao Huang, Xifeng Xia, H. Ye, X. Jiao, Liang Wang, Wu Lei, Qingli Hao. Chemical Engineering Journal, 2019

238 citations recorded by the source corpus.

Abstract To fabricate free-standing electrodes with hierarchical structured redox-type metal oxides has become a wise strategy for the development of high-performance energy storage systems. Two types of NiCo2O4 with needle-like and slice-like morphologies act as the conducting cores and hydrothermally grow on carbon cloth (CC/NiCo2O4-N and CC/NiCo2O4-S). The mesoporous NiO ultrathin nanosheets further are anchored on the surface of the two types of CC/NiCo2O4 to form the novel high-performance electrodes (CC/NiCo2O4-N@NiO and CC/NiCo2O4-S@NiO). Particularly, the formation mechanism of NiO ultrathin nanosheets is proposed. The two integrated electrodes of CC/NiCo2O4-N@NiO and CC/NiCo2O4-S@NiO exhibit high specific capacitance of 921.9 and 852.9 mF/cm2 (or 709.1 and 775.1F/g) at 2 mA/cm2, respectively and excellent long cycling lifespan (both 100% retention after 10,000 cycles). The assembled asymmetric supercapacitors, CC/NiCo2O4-N@NiO//graphene and CC/NiCo2O4-S@NiO//graphene, can still deliver the high energy density and power density, and possess excellent cycling stability (95.2% and 92.3% retention after 10,000 cycles, respectively). Our work not only provides an attractive strategy and a two-step facile method for construction of hierarchical electrodes based on ultrathin NiO sheets and nanostructured NiCo2O4, but also offers a strategy for high-performance supercapacitors.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/3fecd4a319919b19db2a5145f6a20def37ee7968