A high-performance, solution-processable polymer/ceramic/ionic liquid electrolyte for room temperature solid-state Li metal batteries
A high-performance, solution-processable polymer/ceramic/ionic liquid electrolyte for room temperature solid-state Li metal batteries
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用于室温固态锂金属电池的高性能、可溶液加工的聚合物/陶瓷/离子液体电解质
DOI：
10.1016/j.nanoen.2021.106351
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发表时间：
2021
期刊：
影响因子：
17.6
通讯作者：
Ma Yanwen
中科院分区：
文献类型：
--
作者：
Lin Xiujing;Chu Chengcheng;Li Zhuang;Zhang Tingting;Chen Jianyu;Liu Ruiqing;Li Pan;Li Yi;Zhao Jin;Huang Zhendong;Feng Xiaomiao;Xie Yannan;Ma Yanwen
全固态电解质为高能量密度锂金属电池（LMB）的安全运行提供了保障。然而，低离子电导率和锂阳极与电解质之间巨大的界面阻抗是阻碍其快速发展和实际应用的关键问题，特别是限制了其在室温下的操作。离子液体的引入有望解决上述问题。然而，IL涉及的固态电解质对锂枝晶抑制的效果还没有被清楚地揭示，仍然需要深入的评估。在这篇文章中，我们报告了一个在原位富LiF固体电解质中间相（SEI）的锂阳极引发的还原分解的IL和Li1.5Al0.5Ge1.5（PO 4）3参与的电解质。首次揭示了离子液体固体电解质中金属锂表面形成SEI膜的机理。实验和计算结果表明，Li1.5Al0.5Ge1.5（PO 4）3的存在促进了离子液体中氟离子的释放，并通过游离氟离子的还原分解原位生成了高LiF含量的SEI膜.由于Li1.5Al0.5Ge1.5（PO 4）3的高机械模量，|配备合成固态复合电解质（SSCE）的锂电池表现出超过2700小时的极稳定锂电镀/剥离行为，在0.1 mA cm−2下具有50 mV的小极化电压。此外，组装的固态Li|基于SSCE的LiFePO 4电池在室温下可稳定运行196次，容量保持率为90.7%。这些结果为SSCE的设计和高性能室温固态LMB的实现提供了有希望的见解。
All-solid-state electrolytes provide a guarantee for the safe running of Li metal batteries (LMBs) with high energy density. Nevertheless, the low ionic conductivity and huge interfacial impedance between lithium anodes and electrolytes are the critical issues baffling their rapid development and practical application, particularly limiting their operation at room temperature. The introduction of ionic liquids (IL) is expected to solve the above problems. However, the effect of the IL-involved solid-state electrolytes on lithium dendrites suppression has not been clearly revealed and still necessitates in-depth evaluation. In this article, we report an in situ LiF-rich solid-electrolyte interphase (SEI) on the lithium anode triggered by reductive decomposition of IL and Li1.5Al0.5Ge1.5(PO4)3-involved electrolyte. For the first time, the mechanism of SEI formed on Li metal based on IL-based solid-state electrolyte was unveiled. A combination of experimental and computational investigation manifests that the presence of Li1.5Al0.5Ge1.5(PO4)3promotes the release of fluorine anion from IL, and a SEI layer with high content of LiF can be generated in situ through the reductive decomposition of wandering fluorine anion. Thanks to the high mechanical modulus from Li1.5Al0.5Ge1.5(PO4)3, the symmetric Li|Li batteries equipped with synthesized solid-state composite electrolyte (SSCE) exhibit extremely stable Li plating/stripping behavior for more than 2700 h with a small polarization voltage of 50 mV at 0.1 mA cm−2. Moreover, the assembled solid-state Li|LiFePO4batteries based on SSCE could operate steadily for 196 cycles at ambient temperature, with 90.7% capacity retention. These results provide a promising insight into the design of SSCE and realization of room temperature solid-state LMBs with high performance.