Synthesis and Characterization of Magnesium Vanadates as Potential Magnesium‐Ion Cathode Materials through an Ab Initio Guided Carbothermal Reduction Approach

• Published in: Angewandte Chemie International Edition Vol. 61; no. 8; pp. e202112688 - n/a
• Main Authors: Lee, Jeongjae, Dey, Sunita, Dutton, Siân E., Grey, Clare P.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 14.02.2022; Wiley Blackwell (John Wiley & Sons)
• Edition: International ed. in English
• Subjects: Ab initio calculations; Catalysis; Cathodes; Electrode materials; Energy storage; Magnesium; Magnetic resonance spectroscopy; NMR; NMR spectroscopy; Nuclear magnetic resonance; Oxidation; Solid-phase synthesis; Vanadates; Ab initio calculations; Magnesium; NMR spectroscopy; Solid-phase synthesis; Vanadates
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202112688

Many technologically relevant materials for advanced energy storage and catalysis feature reduced transition‐metal (TM) oxides that are often nontrivial to prepare because of the need to control the reducing nature of the atmosphere in which they are synthesized. Herein, we show that an ab initio predictive synthesis strategy can be used to produce multi‐gram‐scale products of various MgVxOy‐type phases (δ‐MgV2O5, spinel MgV2O4, and MgVO3) containing V3+ or V4+ relevant for Mg‐ion battery cathodes. Characterization of these phases using 25Mg solid‐state NMR spectroscopy illustrates the potential of 25Mg NMR for studying reversible magnesiation and local charge distributions. Rotor‐assisted population transfer (RAPT) is used as a much‐needed signal‐to‐noise enhancement technique. The ab initio guided synthesis method is seen as a step forward towards a predictive synthesis strategy for targeting specific complex TM oxides with variable oxidation states of technological importance. Ab initio prediction of thermodynamic parameters leads to a predictive synthesis strategy utilizing solid carbon for facile preparation of a series of magnesium vanadate compounds. 25Mg solid‐state NMR spectroscopy of these compounds is shown to be a practical way for characterizing their local Mg structures.