High-Energy Density Redox Flow Lithium Battery with Unprecedented Voltage Efficiency

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• 作者：Feng Pan ; Qizhao Huang ; Hui Huang ; Qing Wang
• 刊名：Chemistry of Materials
• 出版年：2016
• 出版时间：April 12, 2016
• 年：2016
• 卷：28
• 期：7
• 页码：2052-2057
• 全文大小：379K
• 年卷期：0
• ISSN：1520-5002

文摘

A redox flow lithium battery (RFLB) has decoupled energy storage and power generation units like a conventional redox flow battery, while it stores energy in solid materials by virtue of the unique redox targeting concept. Hence, it presents superior energy density and represents a promising approach for large-scale energy storage. In a RFLB, the potential difference between the redox shuttle molecules used in the same electrolyte normally brings about an intrinsic voltage hysteresis, resulting in a compromised voltage efficiency of the battery. Here we report a novel redox shuttle molecule pair to minimize the voltage hysteresis: anatase TiO₂ is reduced by bis(pentamethylcyclopentadienyl)chromium (CrCp*₂), while Li_xTiO₂ is oxidized by cobaltocene (CoCp₂). The potential difference between CoCp₂ and CrCp*₂ is only 0.15 V. A redox flow lithium battery is successfully demonstrated with an unprecedented voltage efficiency of 84%. The RFLB shows good cycling stability, and >90% Coulombic efficiency was demonstrated in the first 50 cycles.