Li Zongjian, Liu Jing, Qin Yunan, Gao Tao
Department of Chemical Engineering, University of Utah, Salt Lake City, Utah 84114, United States.
ACS Appl Mater Interfaces. 2022 Jul 27;14(29):33004-33012. doi: 10.1021/acsami.2c04319. Epub 2022 Jul 13.
To enable the mass adoption of electric vehicles, the charging performance of Li-ion batteries needs to be significantly enhanced. The development of electrolytes with enhanced transport properties and faster interfacial reaction is one critical approach to realize fast charging within 10 min. Most current electrolyte studies are focusing on ester-based electrolytes. In this work, an ether-based electrolyte is reported, which shows remarkably better charging performance than commercial carbonate electrolytes and other reported ester-based electrolytes in both half and full cells. Electrochemical and spectroscopic characterization shows that the superior charging performance of the reported electrolyte is due to significantly reduced SEI resistance and charge transfer resistance. Cycling tests show remarkable stability in Li||graphite (gr) half cells, suggesting the potential of the electrolytes to enhance battery charging performance. LiFePO (LFP)||gr full cells were further tested, and it is found that the resistance of cells builds up during cycling due to gelation of the electrolyte, which limits the cycling performance of full cells. Potential strategies to address this limitation are discussed.
为了使电动汽车能够大规模普及，锂离子电池的充电性能需要显著提高。开发具有增强传输性能和更快界面反应的电解质是实现10分钟内快速充电的一种关键方法。目前大多数电解质研究都集中在酯基电解质上。在这项工作中，报道了一种醚基电解质，它在半电池和全电池中均表现出比商业碳酸盐电解质和其他报道的酯基电解质显著更好的充电性能。电化学和光谱表征表明，所报道电解质的优异充电性能归因于显著降低的固体电解质界面（SEI）电阻和电荷转移电阻。循环测试表明，Li||石墨（gr）半电池具有显著的稳定性，这表明该电解质具有提高电池充电性能的潜力。进一步测试了LiFePO（LFP）||gr全电池，发现由于电解质的凝胶化，电池电阻在循环过程中增加，这限制了全电池的循环性能。讨论了解决这一限制的潜在策略。
