2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 11: Physics, Advanced/Multifunctional Materials, Composite, Quasi-crystals, Coating
| Editors: | Kongoli F, Marquis F, Lu L, Xia H, Masset P, Rokicki P |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 180 pages |
| ISBN: | 978-1-987820-56-0 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Development of nickel (oxy)hydroxide/graphene hydrogels for asymmetric supercapacitors
Xu Chaohe1;1CHONGQING UNIVERSITY, Chongqing, China;
Type of Paper: Regular
Id Paper: 328
Topic: 21
Abstract:
In this presentation, our recent progress on the development of nickel (oxy)hydroxide/graphene (NiOOH or Ni(OH)2) hydrogels, with mesoporous NiOOH or flower-like Ni(OH)2 nanosheets uniformly dispersed within the highly interconnected 3D graphene network, were constructed by a mixed solvothermal and hydrothermal reaction. The effect of solvent composition on the morphology, phase, and dispersibility of nanocrystal and hydrogel strength were systematically studied. As binder-free electrodes of supercapacitors, these two hydrogels both deliver high capacitance with excellent rate capability. The charge-storage mechanisms are in-depth investigated by quantifying the kinetics of charge storage, which reveals that nickel (oxy)hydroxide exhibits both capacitive effects and diffusion-controlled battery-type behavior during charge storage. During the study, pure graphene hydrogels are also prepared and used as negative electrodes, which show an impressive specific capacitance. Benefitting from the synergistic contribution of both positive and negative electrodes, the assembled asymmetric supercapacitors achieve a remarkable energy density of 66.8 Wh/kg at a power density of 800 W/kg, and excellent cycling stability with 85.3% capacitance retention after 8000 cycles, holding great promise for energy storage applications.