Aprotic Li–O2 Battery: Influence of Complexing Agents on Oxygen Reduction in an Aprotic Solvent

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• 作者：Chunmei Li ; Olivier Fontaine ; Stefan A. Freunberger ; Lee Johnson ; Sylvie Grugeon ; Stéphane Laruelle ; Peter G. Bruce ; Michel Armand
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：February 20, 2014
• 年：2014
• 卷：118
• 期：7
• 页码：3393-3401
• 全文大小：481K
• ISSN：1932-7455

文摘

Several problems arise at the O₂ (positive) electrode in the Li-air battery, including solvent/electrode decomposition and electrode passivation by insulating Li₂O₂. Progress partially depends on exploring the basic electrochemistry of O₂ reduction. Here we describe the effect of complexing-cations on the electrochemical reduction of O₂ in DMSO in the presence and absence of a Li salt. The solubility of alkaline peroxides in DMSO is enhanced by the complexing-cations, consistent with their strong interaction with reduced O₂. The complexing-cations also increase the rate of the 1-electron O₂ reduction to O₂^{鈥⑩€?/sup> by up to six-fold (k掳 = 2.4 脳10鈥? to 1.5 脳 10鈥? cm s鈥?) whether or not Li+ ions are present. In the absence of Li+, the complexing-cations also promote the reduction of O₂鈥⑩€?/sup> to O₂2鈥?/sup>. In the presence of Li+ and complexing-cations, and despite the interaction of the reduced O₂ with the latter, SERS confirms that the product is still Li₂O₂.}