Lithium- and Proton-Driven Redox Reactions in BIMEVOX-Type Phases

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• 作者：Sé ; bastien Patoux ; Rose-Noë ; lle Vannier ; Gaë ; tan Mairesse ; Guy Nowogrocki ; and Jean-Marie Tarascon
• 刊名：Chemistry of Materials
• 出版年：2001
• 出版时间：February 2001
• 年：2001
• 卷：13
• 期：2
• 页码：500 - 507
• 全文大小：307K
• 年卷期：v.13,no.2(February 2001)
• ISSN：1520-5002

文摘

Bi₄V₂O₁₁ reduction was followed using two methods: high-temperature X-ray diffractionunder H₂ flow and oxygen removal with Zr acting as an oxygen acceptor. In both cases, thereversible domain of reduction of Bi₄V₂O₁₁ appeared to be limited to one-third of V^V andtherefore to the formation of a Bi₆V₃O₁₆ (Bi₄V₂O_10.66) phase. Various BIMEVOX/electrolyte/Li cells were characterized evidencing the progressive reduction of the BIMEVOX materials.Pursuing the cell discharge down to 0.02 V resulted in a full amorphization of the materialtogether with an uptake of 32 lithium ions per formula unit. From both electrochemical andin situ X-ray diffraction data extended to the BIMEVOX (ME = Bi, Ta), a two-step mechanismis proposed involving first an oxygen removal concomitant with the formation of Li₂O andthe Bi₆V₃O₁₆ (Bi₄V₂O_10.66) phase, followed by a Li-driven decomposition of the latter in aninert Li₂O matrix, a Li-alloying Bi phase and a vanadate.