Miao Gao, Zhi-Yan Guo, Xingming Wang
Dec 19, 2019
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0
Influential Citations
16
Citations
Journal
ChemSusChem
Abstract
Nickel hydroxide (Ni(OH) 2 ) is promising for supercapacitor application due to its low cost and tunable electrochemical properties, but its performance is usually restricted by insufficient conductivity and surface reactivity. In this work, sulfate functionalized Ni(OH) 2 (SNO) nanoplates were in-situ grown on nickel foam (NF) via a green and facile one-step hydrothermal treatment of NF without need for external Ni source or surfactant addition. The resulting material showed 9.3 times higher areal capacity and 1.8 times higher rate capability than the sulfate-free control, and retained 81.3% capacity after 5000 cycles. When being used as the positive electrode in a hybrid supercapacitor, the SNO/NF//activated carbon system achieved >95% columbic efficiency, maximum energy density of 3.59 W h m -2 and maximum power density of 44.63 W m -2 , outperforming most of the existing Ni-based supercapacitor. Detailed material characterization and density functional theory calculation revealed that the sulfate introduction expanded the layer spacing of Ni(OH) 2 and improved electrical conductivity and wettability to favor more efficient electrolyte diffusion, charge transfer and reactant adsorption. The high loading of reactive component and inherited porous structure also contributed to the superior capacitive performances of the SNO/NF electrodes. Therefore, the SNO/NF holds great potential for commercialized supercapacitor application.