In situ initiator-free gelation of highly concentrated lithium bis(fluorosulfonyl)imide-1,3-dioxolane solid polymer electrolyte for high performance lithium-metal batteries
In situ initiator-free gelation of highly concentrated lithium bis(fluorosulfonyl)imide-1,3-dioxolane solid polymer electrolyte for high performance lithium-metal batteries
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DOI：
10.1016/j.mtener.2020.100623
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发表时间：
2021-02-19
影响因子：
9.3
通讯作者：
Wang, M.
中科院分区：
文献类型：
--
作者：
Cheng, H.;Zhu, J.;Wang, M.
高性能锂金属电池面临的主要挑战是如何解决液态电解液中锂枝晶生长失控的安全问题。传统的非原位固体电解质可以在很大程度上解决这些问题，但仍然存在离子电导率低、Li+迁移数低、界面阻抗高等问题。本文通过一种简单的无引发剂原位凝胶法，在室温下制备了一种含有高浓度(3.5M)双(氟磺酰亚胺)锂(LiFSI)的固体聚合物电解质(SPE)。这种简单而巧妙的原位固相萃取具有高的离子电导率(室温下为7.9ms cm(-1))、高的Li+迁移数(0.82)和低的界面阻抗。结果表明，3.5M LiFSI-DOL原位固相微电极表现出优异的无锂枝晶行为，使Li垂直条形Li对称电池在5 mA cm(-2)和5 mAhcm(-2)下稳定地剥离/电镀超过1000次，过电位为45 mV。此外，采用原位3.5M LiFSI-DOL固相萃取的锂竖条铜电池在5 mA cm(-2)时也表现出高的库仑效率(CE)，达到98.0%。此外，在锂垂直棒状LiFePO4电池中使用的原位3.5M LiFSI-DOL SPE具有卓越的循环寿命(500次)、CE(98.8%)、倍率性能和良好的机械灵活性。值得注意的是，现场使用3.5MLiFSI-DOL固相萃取的锂S电池也表现出良好的兼容性和稳定性。这项工作展示了将原位聚合和高浓度电解液相结合的高性能固态锂金属电池的巨大前景。(C)2020爱思唯尔有限公司。保留所有权利。
The safety concern on the uncontrollable growth of lithium dendrites in liquid electrolytes is the main challenge for high performance lithium-metal batteries. The traditional ex situ solid electrolytes can solve these issues to a great extent but are still plagued by low ionic conductivity, low Li+ transference number, and high interfacial impedance. Herein, a solid polymer electrolyte (SPE) with highly concentrated (3.5 M) lithium bis(fluorosulfonyl)imide (LiFSI) in 1,3-dioxolane (DOL) is developed via a simple in situ initiator-free gelation route at room temperature. This simple and ingeniously designed in situ SPE integrates a high ionic conductivity (7.9 mS cm(-1) at room temperature), high Li+ transference number (0.82), and low interface impedance. As a result, the in situ 3.5 M LiFSI-DOL SPE demonstrates a superior lithium dendrite-free behavior, which enables the Li vertical bar Li symmetric battery to be stably stripped/plated for more than 1000 cycles with a low overpotential of 45 mV at 5 mA cm(-2) and 5 mAh cm(-2). Moreover, the Li vertical bar Cu battery with the in situ 3.5 M LiFSI-DOL SPE also exhibits a high coulombic efficiency (CE) up to 98.0% at 5 mA cm(-2). In addition, the in situ 3.5 M LiFSI-DOL SPE used in the Li vertical bar LiFePO4 battery leads to superior cycle life (500 cycles), CE (98.8%), rate performance, and good mechanical flexibility. Remarkably, the Li-S batteries with the in situ 3.5 M LiFSI-DOL SPE also show good compatibility and stability. This work shows tremendous prospect toward high performance solid-state lithium-metal batteries by combining the in situ polymerization and high concentration electrolyte. (C) 2020 Elsevier Ltd. All rights reserved.