Composition‐Tailored 2 D Mn1−xRuxO2 Nanosheets and Their Reassembled Nanocomposites: Improvement of Electrode Performance upon Ru Substitution |
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| Authors: | Su‐Jeong Kim In Young Kim Dr Sharad B Patil Seung Mi Oh Dr Nam‐Suk Lee Prof?Dr Seong‐Ju Hwang |
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| Affiliation: | 1. Center for Intelligent Nano‐Bio Materials (CINBM), Department of Chemistry and Nano Sciences, College of Natural Sciences, Ewha Womans University, Seoul 120‐750 (Korea), Fax: (+82)?2‐3277‐3419;2. National Institute for Nanomaterials Technology (NINT), Pohang University of Science and Technology (POSTECH), Pohang 790‐784 (Korea) |
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| Abstract: | Composition‐tailored Mn1?xRuxO2 2 D nanosheets and their reassembled nanocomposites with mesoporous stacking structure are synthesized by a soft‐chemical exfoliation reaction and the subsequent reassembling of the exfoliated nanosheets with Li+ cations, respectively. The tailoring of the chemical compositions of the exfoliated Mn1?xRuxO2 2 D nanosheets and their lithiated nanocomposites can be achieved by adopting the Ru‐substituted layered manganese oxides as host materials for exfoliation reaction. Upon the exfoliation–reassembling process, the substituted ruthenium ions remain stabilized in the layered Mn1?xRuxO2 lattice with mixed Ru3+/Ru4+ oxidation state. The reassembled Li–Mn1?xRuxO2 nanocomposites show promising pseudocapacitance performance with large specific capacitances of approximately 330 F g?1 for the second cycle and approximately 360 F g?1 for the 500th cycle and excellent cyclability, which are superior to those of the unsubstituted Li–MnO2 homologue and many other MnO2‐based materials. Electrochemical impedance spectroscopy analysis provides strong evidence for the enhancement of the electrical conductivity of 2 D nanostructured manganese oxide upon Ru substitution, which is mainly responsible for the excellent electrode performance of Li–Mn1?xRuxO2 nanocomposites. The results underscore the powerful role of the composition‐controllable metal oxide 2 D nanosheets as building blocks for exploring efficient electrode materials. |
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| Keywords: | doping layered compounds nanostructures self‐assembly supercapacitors |
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