Revealing Pseudocapacitive Mechanisms of Metal Dichalcogenide SnS2/Graphene‐CNT Aerogels for High‐Energy Na Hybrid Capacitors |
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| Authors: | Jiang Cui Shanshan Yao Ziheng Lu Jian‐Qiu Huang Woon Gie Chong Francesco Ciucci Jang‐Kyo Kim |
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| Affiliation: | 1. Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, P. R. China;2. Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology, Hong Kong, P. R. China |
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| Abstract: | SnS2 nanoplatelet electrodes can offer an exceptionally high pseudocapacitance in an organic Na+ ion electrolyte system, but their underlying mechanisms are still largely unexplored, hindering the practical applications of pseudocapacitive SnS2 anodes in Na‐ion batteries (SIBs) and Na hybrid capacitors (SHCs). Herein, SnS2 nanoplatelets are grown directly on SnO2/C composites to synthesize SnS2/graphene‐carbon nanotube aerogel (SnS2/GCA) by pressurized sulfidation where the original morphology of carbon framework is preserved. The composite electrode possessing a large surface area delivers a remarkable specific capacity of 600.3 mA h g?1 at 0.2 A g?1 and 304.8 mA h g?1 at an ultrahigh current density of 10 A g?1 in SIBs. SHCs comprising a SnS2/GCA composite anode and an activated carbon cathode present exceptional energy densities of 108.3 and 26.9 W h kg?1 at power densities of 130 and 6053 W kg?1, respectively. The in situ transmission electron microscopy and the density functional theory calculations reveal that the excellent pseudocapacitance originates from the combination of Na adsorption on the surface/Sn edge of SnS2 nanoplatelets and ultrafast Na+ ion intercalation into the SnS2 layers. |
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| Keywords: | first‐principle calculations graphene‐CNT aerogels in situ TEM Na hybrid capacitors SnS2
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