Synthesis of Li1+V3O8 via a Gel Precursor: Part II, from Xerogel to the Anhydrous Materi
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- 作者：Matthieu Dubarry ; Joë ; l Gaubicher ; Dominique Guyomard ; Nathalie Steunou ; Jacques Livage ; Nicolas Dupré ; and Clare P. Grey
- 刊名：Chemistry of Materials
- 出版年：2006
- 出版时间：February 7, 2006
- 年：2006
- 卷：18
- 期：3
- 页码：629 - 636
- 全文大小：372K
- 年卷期：v.18,no.3(February 7, 2006)
- ISSN：1520-5002
文摘
The synthesis of anhydrous Li1+
V3O8 from its xerogel has been studied by using thermodiffractometryand variable temperature 51V magic-angle spinning NMR spectroscopy. Completion of dehydration leadsto a sample characterized by a bimodal grain size distribution, the larger and smaller sized particlescoming from the two components of the xerogel (liquid and solid components), respectively. The specificreactions undergone by these two components have been identified: the solid component gradually loseswater by undergoing a series of phase transitions involving layered phases with decreasing waterconcentrations, the hewettite framework being maintained throughout the reaction, whereas in the caseof the dried liquid component of the xerogel, the formation of anhydrous Li1+V3O8 occurs through thedecomposition of lithium vanadates, which is followed by the formation and then progressive dehydrationof a hydrated hewettite structure. It is shown that the biphasic nature of the pristine gel precursor has animpact on the electrochemical behavior of anhydrous Li1+V3O8.
V3O8 from its xerogel has been studied by using thermodiffractometryand variable temperature 51V magic-angle spinning NMR spectroscopy. Completion of dehydration leadsto a sample characterized by a bimodal grain size distribution, the larger and smaller sized particlescoming from the two components of the xerogel (liquid and solid components), respectively. The specificreactions undergone by these two components have been identified: the solid component gradually loseswater by undergoing a series of phase transitions involving layered phases with decreasing waterconcentrations, the hewettite framework being maintained throughout the reaction, whereas in the caseof the dried liquid component of the xerogel, the formation of anhydrous Li1+V3O8 occurs through thedecomposition of lithium vanadates, which is followed by the formation and then progressive dehydrationof a hydrated hewettite structure. It is shown that the biphasic nature of the pristine gel precursor has animpact on the electrochemical behavior of anhydrous Li1+V3O8.