Core-shell CoMoO4@Ni(OH)2 on ordered macro-porous electrode plate for high-performance supercapacitor. (1st September 2018)

• Record Type: Journal Article
• Authors: Li, Mai; Yang, Hongxing; Wang, Yuanhao; Wang, Lianwei; Chu, Paul K.
• Is Part Of: Electrochimica acta. Volume 283(2018)
• Page Start: 538
• Page End: 547
• Publication Date: 2018-09-01
• Subjects: Supercapacitors -- Ordered macro-porous electrode plate -- Energy storage -- Core-shell structure -- Hybrid device; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.06.043
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Multidimensional CoMoO4 @Ni(OH)2 nanocomposite materials are fabricated on the nickel modified surface and channels of an ordered macro-porous electrode plate (OMEP) by a multistep high temperature hydrothermal method as the supercapacitor electrode in a high power density energy storage device. The effects, morphology, capacitive properties, and formation mechanism of the CoMoO4 @Ni(OH)2 composite materials are systematically investigated. Compared to nanostructured nickel grown on the OMEP or CoMoO4 @Ni(OH)2 on nickel plate with the same area, the CoMoO4 @Ni(OH)2 /OMEP shows enhanced electrochemical energy storage properties such as high energy capacitance of 8.55 F cm −2 (1812.42 F g −1 ) at 2 mA cm −2 and good cycling stability of 87.42% capacity retention after 5000 cycles. An asymmetrical supercapacitor (ASC) device is assembled with a polyethylene (PE) membrane, CoMoO4 @Ni(OH)2 /OMEP, and active carbon covered nickel foam. The ASC with the CoMoO4 @Ni(OH)2 /OMEP has an energy density of 9.66 Wh Kg −1 even at a power density of 3000 W Kg −1 as well as stable power characteristics with 86.5% retention after 10, 000 cycles at a current of 0.06 A. The device produces large instantaneous power after charging at 2.8 V for 10 s one ASC can power a 5 mm red LED with high efficiency. Graphical abstract: The mechanism, effects, and electrochemical performance of core-shell CoMoO4 /Ni(OH)2 nanocomposites coated on surface and sidewall of OMEP fabricated hydrothermally are investigated. The CoMoO4 /Ni(OH)2 /OMEP has a much higher specific capacitance than the nickel-covered OMEP or CoMoO4 /Ni(OH)2 on 2D nickel plate due to the regular macroporus nano-structure with a large specific surface area and faster redox reaction. The highest area (specific) capacitance of 8.55 F cm −2 (1812.42 F g −1 ) is achieved at a current density of 2 mA cm −2 and excellent electrochemical stability is observed up to 5000 cycles at a current density of 50 mA cm −2 . The asymmetrical supercapacitor device composed of CoMoO4 @Ni(OH)2 /OMEP//AC delivers higher specific energy densities and excellent cycling stability. The core-shell CoMoO4 @Ni(OH)2 composite materials are promising and bridge the gap between traditional NI-MH battery and power generation energy storage devices. Image 1