Rational Design of Self-Supported Ni3S2 Nanosheets Array for Advanced Asymmetric Supercapacitor with a Superior Energy Density

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• 作者：Jun Song ChenCao Guan ; Yang Gui ; Daniel John Blackwood
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2017
• 出版时间：January 11, 2017
• 年：2017
• 卷：9
• 期：1
• 页码：496-504
• 全文大小：689K
• ISSN：1944-8252

文摘

We report a rationally designed two-step method to fabricate self-supported Ni<sub>3sub>S<sub>2sub> nanosheet arrays. We first used 2-methylimidazole (2-MI), an organic molecule commonly served as organic linkers in metal–organic frameworks (MOFs), to synthesize an α-Ni(OH)<sub>2sub> nanosheet array as a precursor, followed by its hydrothermal sulfidization into Ni<sub>3sub>S<sub>2sub>. The resulting Ni<sub>3sub>S<sub>2sub> nanosheet array demonstrated superior supercapacitance properties, with a very high capacitance of about 1,000 F g<sup>–1sup> being delivered at a high current density of 50 A g<sup>–1sup> for 20,000 charge–discharge cycles. This performance is unparalleled by other reported nickel sulfide-based supercapacitors and is also advantageous compared to other nickel-based materials such as NiO and Ni(OH)<sub>2sub>. An asymmetric supercapacitor was then established, exhibiting a very stable capacitance of about 200 F g<sup>–1sup> at a high current density of 10 A g<sup>–1sup> for 10,000 cycles and a surprisingly high energy density of 202 W h kg<sup>–1sup>. This value is comparable to that of the lithium-ion batteries, i.e., 180 W h kg<sup>–1sup>. The potential of the material for practical applications was evaluated by building a quasi-solid-state asymmetric supercapacitor which showed good flexibility and power output, and two of these devices connected in series were able to power up 18 green light-emitting diodes.