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Hierarchical Mn3O4 Anchored on 3D Graphene Aerogels via C?O?Mn Linkage with Superior Electrochemical Performance for Flexible Asymmetric Supercapacitor |
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| Authors: | Lishuang Fan Yu Zhang Zhikun Guo Bing Sun Da Tian Yujie Feng Naiqing Zhang Kening Sun |
| Institution: | 1. State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology China, Harbin, 150001 P.R. China
Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology China, Harbin, 150001 P.R. China These authors contributed equally to this work.;2. State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology China, Harbin, 150001 P.R. China These authors contributed equally to this work.;3. State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology China, Harbin, 150001 P.R. China;4. Centre for Clean Energy Technology, University of Technology Sydney, Sydney, NSW, 2007 Australia;5. State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology China, Harbin, 150001 P.R. China Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology China, Harbin, 150001 P.R. China |
| Abstract: | Flexible asymmetric supercapacitors are more appealing in flexible electronics because of high power density, wide cell voltage, and higher energy density than symmetric supercapacitors in aqueous electrolyte. In virtues of excellent conductivity, rich porous structure and interconnected honeycomb structure, three dimensional graphene aerogels show great potential as electrode in asymmetric supercapacitors. However, graphene aerogels are rarely used in flexible asymmetric supercapacitors because of easily re-stacking of graphene sheets, resulting in low electrochemical activity. Herein, flower-like hierarchical Mn3O4 and carbon nanohorns are incorporated into three dimensional graphene aerogels to restrain the stack of graphene sheets, and are applied as the positive and negative electrode for asymmetric supercapacitors devices, respectively. Besides, a strong chemical coupling between Mn3O4 and graphene via the C-O-Mn linkage is constructed and can provide a good electron-transport pathway during cycles. Consequently, the asymmetric supercapacitor device shows high rate cycle stability (87.8 % after 5000 cycles) and achieves a high energy density of 17.4 μWh cm?2 with power density of 14.1 mW cm?2 (156.7 mW cm?3) at 1.4 V. |
| Keywords: | asymmetric supercapacitors carbon nanohorns flexible electronics graphene aerogels manganese |