Wu Xinsheng, Liu Tong, Lee Young-Geun, Whitacre Jay F
Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States.
Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States.
ACS Appl Mater Interfaces. 2024 May 15;16(19):24590-24600. doi: 10.1021/acsami.4c02323. Epub 2024 May 6.
Rechargeable batteries that can operate at elevated temperatures (>70 °C) with high energy density are long-awaited for industrial applications including mining, grid stabilization, naval, aerospace, and medical devices. However, the safety, cycle life, energy density, and cost of the available high-temperature battery technologies remain an obstacle primarily owing to the limited electrolyte options available. We introduce a flame-retardant electrolyte that can enable stable battery cycling at 100 °C by incorporating triacetin into the electrolyte system. Triacetin has excellent chemical stability with lithium metal, and conventional cathode materials can effectively reduce parasitic reactions and promises a good battery performance at elevated temperatures. Our findings reveal that Li-metal half-cells can be made that have high energy density, high Coulombic efficiency, and good cycle life with triacetin-based electrolytes and three different cathode chemistries. Moreover, the nail penetration test in a commercial-scale pouch battery using this new electrolyte demonstrated suppressed heat generation when the cell was damaged and excellent safety when using the triacetin-based electrolyte.
能够在高温（>70°C）下以高能量密度运行的可充电电池，是采矿、电网稳定、海军、航空航天和医疗设备等工业应用长期以来所期待的。然而，现有高温电池技术的安全性、循环寿命、能量密度和成本仍然是一个障碍，主要原因是可用的电解质选择有限。我们引入了一种阻燃电解质，通过将三醋精加入电解质体系，可使电池在100°C下稳定循环。三醋精与锂金属具有优异的化学稳定性，传统的阴极材料可有效减少寄生反应，并有望在高温下实现良好的电池性能。我们的研究结果表明，使用基于三醋精的电解质和三种不同的阴极化学组成，可以制造出具有高能量密度、高库仑效率和良好循环寿命的锂金属半电池。此外，在使用这种新型电解质的商业规模软包电池中进行的针刺试验表明，当电池受损时发热受到抑制，并且使用基于三醋精的电解质时安全性极佳。
