Decoupling effective Li+ ion conductivity from electrolyte viscosity for improved room-temperature cell performance
Decoupling effective Li+ ion conductivity from electrolyte viscosity for improved room-temperature cell performance
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DOI：
10.1016/j.jpowsour.2016.12.071
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发表时间：
2017-02-28
影响因子：
9.2
通讯作者：
Passerini, Stefano
中科院分区：
文献类型：
--
作者：
Giffin, Guinevere A.;Moretti, Arianna;Passerini, Stefano
离子液体是替代电解质的有吸引力的材料，以解决与常规有机碳酸酯基电解质相关的安全问题。然而，基于离子液体的电池的性能通常没有竞争力，因为高粘度和低电导率限制了速率性能。本文提出的工作表明，通过使用高锂浓度Pyr（1201）FTFSI（0.6）LiFTFSI（0.4）电解质，可以克服倍率性能方面的缺点。尽管在电导率和粘度方面存在数量级差异，但这种高浓度电解质在Li金属/LFP电池和LTO/LFP电池中的倍率性能方面优于具有相同组分的锂稀释电解质。结果表明，锂离子在浓电解液中的有效迁移率高于稀溶液。(C)© 2016 Elsevier B. V.版权所有。
Ionic liquids are attractive materials for alternative electrolytes to combat the safety issues associated with conventional organic carbonate-based electrolytes. However, the performance of ionic liquid-based cells is generally not competitive as the high viscosity and low conductivity limits the rate performance. The work presented here demonstrates that the drawbacks in terms of rate capability can be overcome through the use of the high lithium concentration Pyr(1201)FTFSI(0.6)LiFTFSI(0.4) electrolyte. Despite an order of magnitude difference in the conductivity and viscosity, this high concentration electrolyte outperforms the lithium-dilute electrolyte with the same components in terms of rate capability in Li metal/LFP cells and LTO/LFP cells. The results suggest that the effective Li ion transport in the concentrated electrolyte is higher than in the dilute solution. (C) 2016 Elsevier B.V. All rights reserved.