A high-performance battery-like supercapacitor electrode with a continuous NiTe network skeleton running throughout Co(OH)2/Co9S8 nanohybrid

There has been an ongoing effort in pursuing high-energy-density supercapacitor to facilitate its practical applications in energy storage devices. Currently, constructing a composite electrode using multiple battery-type materials or battery-like capacitive materials has been perceived as a promising solution. On one hand, the rational composition/microstructure design is highly desirable to improve the volumetric stress distribution and enhance the overall electrical conductivity. Accordingly, we develop a battery-like (Co(OH)(2)/Co9S8)@NiTe/Ni composite electrode, in which the continuous NiTe network skeleton running throughout Co(OH)(2)/Co9S8 nanohybrid acts as the fast electron transfer channel and the buffer against volumetric strain. The electrode delivers a high areal capacitance of 5.28 F cm(-2) at a current density of 10 mA cm(-2) and demonstrates a super-long cycle life of 50,0 0 0 cycles due to the good electrical conductivity, buffer effect of NiTe skeleton and the capacitance contributions from multiple constituents. Thereafter, the assembled aqueous or quasi-solid-state (Co(OH)(2)/Co9S8)@NiTe/Ni//AC asymmetric supercapacitor demonstrates high areal energy density exceeding 0.88 mWh cm(-2) as well as long cycle life exceeding 35,000 cycles. The fabricated battery-like supercapacitor electrode can be engineered to satisfy the long-term, high-power and high-energy-density application requirements. (c) 2020 Elsevier Ltd. All rights reserved.

Automated summary

Efforts have been made to pursue a high-energy-density supercapacitor for practical applications in energy storage devices. By developing a battery-like composite electrode, with a rational composition design and continuous NiTe network skeleton, high areal capacitance and super-long cycle life were achieved. The electrode demonstrated good electrical conductivity, buffer effect, and contributions from multiple constituents, leading to high energy density and long cycle life in the assembled supercapacitor.