Wu Mengjun, Liu Dan, Qu Deyu, Xie Zhizhong, Li Junsheng, Lei Jiaheng, Tang Haolin
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, P. R. China.
Department of Chemistry, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
ACS Appl Mater Interfaces. 2020 Nov 25;12(47):52652-52659. doi: 10.1021/acsami.0c15004. Epub 2020 Nov 10.
Composite polymer electrolytes (CPEs) are very promising for high-energy lithium-metal batteries as they combine the advantages of polymeric and ceramic electrolytes. The dimensions and morphologies of active ceramic fillers play critical roles in determining the electrochemical and mechanical performances of CPEs. Herein, a coral-like LLZO (LiLaZrAlO) is designed and used as a 3D active nanofiller in a poly(vinylidene difluoride) polymer matrix. Building 3D interconnected frameworks endows the as-made CPE membranes with an enhanced ionic conductivity (1.51 × 10 S cm) at room temperature and an enlarged tensile strength up to 5.9 MPa. As a consequence, the flexible 3D-architectured CPE enables a steady lithium plating/stripping cycling over 200 h without a short circuit. Moreover, the assembled solid-state Li|LiFePO cells using the electrolyte exhibit decent cycling performance (95.2% capacity retention after 200 cycles at 1 C) and excellent rate capability (120 mA h g at 3 C). These results demonstrate the superiority of 3D interconnected garnet frameworks in developing CPEs with excellent electrochemical and mechanical properties.
复合聚合物电解质（CPEs）对于高能锂金属电池非常有前景，因为它们结合了聚合物电解质和陶瓷电解质的优点。活性陶瓷填料的尺寸和形态在决定CPEs的电化学和机械性能方面起着关键作用。在此，设计了一种珊瑚状的LLZO（LiLaZrAlO）并将其用作聚偏二氟乙烯聚合物基体中的三维活性纳米填料。构建三维互连框架赋予所制备的CPE膜在室温下增强的离子电导率（1.51×10 S cm）以及高达5.9 MPa的拉伸强度。因此，柔性的三维结构CPE能够实现超过200小时的稳定锂电镀/剥离循环而不短路。此外，使用该电解质组装的固态Li|LiFePO电池表现出良好的循环性能（在1 C下200次循环后容量保持率为95.2%）和优异的倍率性能（在3 C下为120 mA h g）。这些结果证明了三维互连石榴石框架在开发具有优异电化学和机械性能的CPEs方面的优越性。
