New Spinel Cobalt Oxides, Potential Conductive Additives for the Positive Electrode of Ni-MH Batteries

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• 作者：Fré ; dé ; ric Tronel ; Liliane Guerlou-Demourgues ; Michel Mé ; né ; trier ; Laurence Croguennec ; Lionel Goubault ; Patrick Bernard ; Claude Delmas
• 刊名：Chemistry of Materials
• 出版年：2006
• 出版时间：December 12, 2006
• 年：2006
• 卷：18
• 期：25
• 页码：5840 - 5851
• 全文大小：260K
• 年卷期：v.18,no.25(December 12, 2006)
• ISSN：1520-5002

文摘

Temperature plays a key role in the formation of the cobalt-based conductive network at the positiveelectrode of alkaline batteries during the first charge. Electrodes pasted with CoO were oxidized in variousconcentrated alkaline media, in order to understand the phenomena involved. In these conditions, theexperiments show the formation of a Co₃O₄ type phase with defects. The presence of lithium in theelectrolyte is proven to play an important role in the conductivity of the synthesized phases. Especiallyin 2.5 M LiOH, a pure phase is isolated that has a spinel structure close to Co₃O₄ but containing H andLi. This phase is shown to be a good conductor and is also observed in (KOH, NaOH, LiOH) ternaryindustrial electrolyte. It could hence take part to the improvement of the properties of nickel electrodesobserved when the beginning of the first charge is performed at high temperature.