Co-intercalation-free ether electrolytes for graphitic anodes in lithium-ion batteries
Co-intercalation-free ether electrolytes for graphitic anodes in lithium-ion batteries
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DOI：
10.1039/d2ee01489k
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发表时间：
2022-10-11
影响因子：
32.5
通讯作者：
Amanchukwu, Chibueze, V
中科院分区：
文献类型：
--
作者：
Ma, Peiyuan;Mirmira, Priyadarshini;Amanchukwu, Chibueze, V
碳酸盐基电解质广泛用于锂离子电池，但受到工作温度窗口小和含硅石墨阳极循环不良的限制。缺乏非碳酸酯电解质替代品（例如醚基电解质）是由于石墨阳极发生了不希望的溶剂共嵌入。在这里，我们表明，氟代醚是第一类醚溶剂，本质上支持锂离子可逆嵌入石墨中，而无需在常规盐浓度下进行溶剂共嵌入。在使用石墨阳极的全电池中，它们的能量密度比传统醚高出 10 倍，并且通过产生强大的溶剂衍生固体电解质界面 (SEI)，比碳酸盐电解质（工作温度高达 60 摄氏度）具有更好的热稳定性。作为单溶剂单盐电解质，当与石墨-硅复合阳极一起循环时，它们的性能明显优于含有氟代碳酸乙烯酯（FEC）和碳酸亚乙烯酯（VC）添加剂的碳酸酯电解质。我们的分子设计策略开辟了一种新型电解质，可以使下一代锂离子电池具有更高的能量密度和更宽的工作温度范围。
Carbonate-based electrolytes are widely used in Li-ion batteries but are limited by a small operating temperature window and poor cycling with silicon-containing graphitic anodes. The lack of non-carbonate electrolyte alternatives such as ether-based electrolytes is due to undesired solvent co-intercalation that occurs with graphitic anodes. Here, we show that fluoroethers are the first class of ether solvents to intrinsically support reversible lithium-ion intercalation into graphite without solvent co-intercalation at conventional salt concentrations. In full cells using a graphite anode, they enable 10-fold higher energy densities compared to conventional ethers, and better thermal stability over carbonate electrolytes (operation up to 60 degrees C) by producing a robust solvent-derived solid electrolyte interphase (SEI). As single-solvent-single-salt electrolytes, they remarkably outperform carbonate electrolytes with fluoroethylene carbonate (FEC) and vinylene carbonate (VC) additives when cycled with graphite-silicon composite anodes. Our molecular design strategy opens a new class of electrolytes that can enable next generation Li-ion batteries with higher energy density and a wider working temperature window.