Fast Li+ transport and superior interfacial chemistry within composite polymer electrolyte enables ultra-long cycling solid-state Li-metal batteries
Fast Li+ transport and superior interfacial chemistry within composite polymer electrolyte enables ultra-long cycling solid-state Li-metal batteries
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DOI：
10.1016/j.ensm.2022.07.045
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发表时间：
2022-08
影响因子：
20.4
通讯作者：
Xue-Liang Zhang;Fangming Shen;Xin Long;Siyan Zheng;Zhiqin Ruan;Yuepeng Cai;Xu-Jia Hong;Qifeng Zheng
中科院分区：
文献类型：
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作者：
Xue-Liang Zhang;Fangming Shen;Xin Long;Siyan Zheng;Zhiqin Ruan;Yuepeng Cai;Xu-Jia Hong;Qifeng Zheng
基于聚环氧乙烷（PEO）的复合聚合物电解质（CPE）被认为是下一代固态锂金属电池最有前途的电解质。然而，离子电导率不足和界面相容性差（主要是由于填料和PEO之间存在大量界面）阻碍了PEO基CPE在室温下的实际应用。在这里，我们提出了一种合理的设计策略，在基于PEO的CPE中构建新型3D离子导电金属有机框架（MOF）网络，其中致密堆积的MOF的原位生长为快速Li + 传输提供了连续的途径，并且限制在MOF孔中的离子液体显着改善了界面相容性和Li + 迁移动力学。因此，所得的PEO基CPE在室温下表现出2.57×10−4S cm−1的高离子电导率和0.59的Li+迁移数，这使得各种最先进的正极能够稳定运行，包括LiFePO4、高电压LiNi0.8Co0.1Mn0.1O2和高容量有机正极。值得注意的是，Li||LiFePO4 电池表现出前所未有的循环稳定性，在室温下循环 2500 次后容量保持率为 86%。因此，这项工作开辟了超长循环固态锂金属电池 CPE 工程的新领域。
Polyethylene oxide (PEO)-based composite polymer electrolytes (CPEs) have been considered as the most promising electrolytes for next generation solid-state Li-metal batteries. However, the insufficient ionic conductivity and the poor interfacial compatibility, primarily caused by numerous interfaces between fillers and PEO, has hindered the practical application of PEO-based CPEs at room temperature. Here, we proposed a rational design strategy to construct a novel 3D ion-conducting metal-organic framework (MOF)-based network in PEO-based CPE, where the in-situ growth of densely packed MOFs provide continuous pathways for fast Li+transport, and the ionic liquid confined in the pores of MOFs significantly improves the interfacial compatibility and Li+migration kinetics. Accordingly, the resulting PEO-based CPE exhibits a high ionic conductivity of 2.57 × 10−4S cm−1and Li+transference number of 0.59 at room temperature, which enables the stable operation of various state-of-the-art cathodes, including LiFePO4, high-voltage LiNi0.8Co0.1Mn0.1O2, and high-capacity organic cathodes. Remarkably, the Li||LiFePO4battery demonstrated an unprecedented cycling stability with 86% capacity retention after 2500 cycles at room temperature. Therefore, this work opens new frontiers in engineering CPEs towards ultra-long cycling solid-state Li-metal batteries.