Electrocatalysis Paradigm for Protection of Cathode Materials in High-Voltage Lithium-Ion Batteries

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• 作者：Ilya A. Shkrob ; Daniel P. Abraham
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：July 21, 2016
• 年：2016
• 卷：120
• 期：28
• 页码：15119-15128
• 全文大小：512K
• 年卷期：0
• ISSN：1932-7455

文摘

A new mechanistic framework is suggested to account for the protective action of certain electrolyte additives on high-voltage positive electrode (cathode) materials. The mechanism involves inactivation of catalytically active centers on the electrode active materials through fragmentation reactions involving molecules at its surface. The cathode protection additives oxidize before the solvent and serve as sacrificial inhibitors of the catalytic centers. Without the additive, the surface oxidation of the solvent (like solvent oxidation in the bulk) yields H loss radicals and releases the proton that can combine with anions forming corrosive acids. This proton-release reaction is demonstrated experimentally for boronate additives. Specific radical reactions for the latter additives on the electrode surface are suggested. The same approach can be used to rationalize the protective action of other additives and account for various observations regarding their performance.