A High‐Energy‐Density Hybrid Supercapacitor with P‐Ni(OH)2@Co(OH)2 Core–Shell Heterostructure and Fe2O3 Nanoneedle Arrays as Advanced Integrated Electrodes. Issue 32 (1st July 2020)

• Record Type: Journal Article
• Authors: Li, Kunzhen; Zhao, Bangchuan; Bai, Jin; Ma, Hongyang; Fang, Zhitang; Zhu, Xuebin; Sun, Yuping
• Is Part Of: Small. Volume 16:Issue 32(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-07-01
• Subjects: core–shell heterostructures -- Fe 2O 3/CC -- hybrid supercapacitors -- integrated electrodes -- P‐Ni(OH) 2@Co(OH) 2/NF; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202001974
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Transition metal hydro/oxides (TMH/Os) are treated as the most promising alternative supercapacitor electrodes thanks to their high theoretical capacitance due to the various oxidation states and abundant cheap resources of TMH/Os. However, the poor conductivity and logy reaction kinetics of TMH/Os severely restrict their practical application. Herein, hierarchical core–shell P‐Ni(OH)2 @Co(OH)2 micro/nanostructures are in situ grown on conductive Ni foam (P‐Ni(OH)2 @Co(OH)2 /NF) through a facile stepwise hydrothermal process. The unique heterostructure composed of P‐Ni(OH)2 rods and Co(OH)2 nanoflakes boost the charge transportation and provide abundant active sites when used as the intergrated cathode for supercapacitors. It delivers an ultrahigh areal specific capacitance of 4.4 C cm −2 at 1 mA cm −2 and the capacitance can maintain 91% after 10 000 cycles, showing an ultralong cycle life. Additionally, a hybrid supercapacitor composed with P‐Ni(OH)2 @Co(OH)2 /NF cathode and Fe2 O3 /CC anode shows a wider voltage window of 1.6 V, a remarkable energy density of 0.21 mWh cm −2 at the power density of 0.8 mW cm −2, and outstanding cycling stability with about 81% capacitance retention after 5000 cycles. This innovative study not only supplies a newfashioned electronic apparatus with high‐energy density and cycling stability but offers a fresh reference and enlightenment for synthesizing advanced integrated electrodes for high‐performance hybrid supercapacitors. Abstract : A P‐Ni(OH)2 @Co(OH)2 /NF integrated electrode is fabricated through a stepwise hydrothermal approach. Such an amazing hierarchical core–shell heterostructure can not only efficiently ensure the synergetic effect of the two component materials, but also promote the diffusion and migration of electrolyte ions during the rapid charge/discharge process. Moreover, a hybrid supercapacitor assembled by P‐Ni(OH)2 @Co(OH)2 /NF and Fe2 O3 /CC electrodes achieves high energy density.