Composition-tailored 2 D Mn(1-x)Ru(x)O(2) nanosheets and their reassembled nanocomposites: improvement of electrode performance upon Ru substitution.

Abstract

Composition-tailored Mn1-x Rux O2 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-x Rux O2 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-x Rux O2 lattice with mixed Ru(3+) /Ru(4+) oxidation state. The reassembled Li-Mn1-x Rux O2 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-x Rux O2 nanocomposites. The results underscore the powerful role of the composition-controllable metal oxide 2 D nanosheets as building blocks for exploring efficient electrode materials.

DOI: 10.1002/chem.201304009

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Cite this paper

@article{Kim2014Compositiontailored2D, title={Composition-tailored 2 D Mn(1-x)Ru(x)O(2) nanosheets and their reassembled nanocomposites: improvement of electrode performance upon Ru substitution.}, author={Su-Jeong Kim and In Young Kim and Sharad Bandu Patil and Seung Mi Oh and Nam-Suk Lee and Seong-Ju Hwang}, journal={Chemistry}, year={2014}, volume={20 17}, pages={5132-40} }