Metastable Li1+δMn2O4 (0 ≤ δ ≤ 1) Spinel Phases Revealed by in Operando Neutron Diffraction and First-Principles Calculations
| Autor: | Jinseon Park, Gabriel M. Veith, Jue Liu, Melanie J. Kirkham, Pamela S. Whitfield, Ashfia Huq, Mina Yoon, Bohang Song |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
General Chemical Engineering Neutron diffraction Spinel Analytical chemistry 02 engineering and technology General Chemistry engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Cathode 0104 chemical sciences law.invention Bond length Metal Tetragonal crystal system law visual_art Metastability Materials Chemistry engineering visual_art.visual_art_medium Density functional theory 0210 nano-technology |
| Zdroj: | Chemistry of Materials. 31:124-134 |
| ISSN: | 1520-5002 0897-4756 |
| DOI: | 10.1021/acs.chemmater.8b03199 |
| Popis: | In this work, we examine the reaction mechanisms driven by the lithiation of Li1+δMn2O4 (0 ≤ δ ≤ 1) spinels via in operando neutron powder diffraction (NPD). New reaction mechanisms are proposed involving solid-solution regions within both cubic and tetragonal spinel phases in addition to a continuous phase transition between them. In operando NPD is an ideal tool to follow the light elements such as lithium and oxygen in cathode materials which are often the key to fully understand their structural evolutions. Here, we report a novel methodology to prepare an extremely thick electrode with ∼378 mg·cm–2 loading density suitable for the in operando NPD studies. Enabled by such thick electrode, we find that the metal oxygen M–O (M = Li and Mn) bond lengths in both end members LiMn2O4 and Li2Mn2O4 experience pronounced changes larger than dictated by the change in lattice parameters because of the locally formed Jahn–Teller distorted Mn3+. First-principles density functional theory calculations confirm these... |
| Databáze: | OpenAIRE |
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