Multiple Anionic Transition-Metal Oxycarbide for Better Lithium Storage and Facilitated Multielectron Reactions
| Autor: | Wei Kong Pang, Zaiping Guo, You Zhou, Jing Cuan, Xuebin Yu, Jian Zhang, Sean Li, Gemeng Liang, Tengfei Zhou |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Valence (chemistry) Nanocomposite General Engineering Oxide General Physics and Astronomy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 7. Clean energy 01 natural sciences 0104 chemical sciences Metal chemistry.chemical_compound Transition metal Chemical engineering chemistry visual_art Electrode visual_art.visual_art_medium General Materials Science 0210 nano-technology Powder diffraction |
| Zdroj: | ACS Nano. 13:11665-11675 |
| ISSN: | 1936-086X 1936-0851 |
| DOI: | 10.1021/acsnano.9b05580 |
| Popis: | As an important class of multielectron reaction materials, the applications of transition-metal oxides (TMOs) are impeded by volume expansion and poor electrochemical activity. To address these intrinsic limitations, the renewal of TMOs inspires research on incorporating an advanced interface layer with multiple anionic characteristics, which may add functionality to support properties inaccessible to a single-anion TMO electrode. Herein, a transition-metal oxycarbide (TMOC, M = Mo) with more than one anionic species was prepared as an interface layer on a corresponding oxide. A multiple anionic TMOC possesses advantages of structural stability, abundant active sites, and elevated metal cation valence states. Such merits mitigate volume changes and enhance multielectron reactions significantly. The TMOC nanocomposite has a well-maintained capacity after 1000 cycles at 2 A·g-1 and fully resumed rate performance. In situ synchrotron X-ray powder diffraction (SXRPD) analysis unveils negligible volume expansions occurring upon oxycarbide layer coupling, with lattice spacing variation less than 1% during cycling. The lithium storage mechanism is further inspected by combined analysis of kinetics, SXRPD, and first-principles calculations. Superior to TMO, multielectron reactions of the TMOC electrode have been boosted due to easier rupture of the metal-oxygen bond. Such improvements underscore the importance of incorporating an oxycarbide configuration as a strategy to expand applications of TMOs. |
| Databáze: | OpenAIRE |
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