Xu Yanan, Wang Kai, An Yabin, Liu Wenjie, Li Chen, Zheng Shuanghao, Zhang Xiong, Wang Lei, Sun Xianzhong, Ma Yanwei
Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
School of Engineering Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
J Phys Chem Lett. 2021 Nov 4;12(43):10603-10609. doi: 10.1021/acs.jpclett.1c02701. Epub 2021 Oct 26.
High-quality solid electrolyte is the key to developing high-performance all-solid-state lithium-metal batteries (ASSLMBs). Herein, we report a thin composite polymer electrolyte (CPE) based on nanosized LiLaZrTaO (N-LLZTO) and the PVDF-HFP matrix through a simple film-casting method. N-LLZTO induces partial dehydrofluorination of the poly(vinylidene fluoride--hexafluoropropylene) (PVDF-HFP) matrix that activates the coordination of Li with PVDF-HFP and LLZTO due to Lewis acid-base interactions, which facilitates dissociation of lithium salt to increase the Li carrier density. As a result, the as-fabricated composite polymer electrolyte with a 20 wt % N-LLZTO (CPE-20) membrane possesses high ionic conductivity (1.7 × 10 S cm), a high lithium-ion transference number (0.57), a wide electrochemical window (∼4.8 V), and good thermal stability. Moreover, the CPE-20 membrane displays excellent electrochemical stability to suppress the lithium dendrite and serves more than 2000 h. The solid-state Li|CPE-20|LiFePO pouch cells exhibit excellent cycling and rate performance, as well as high energy density. This study presents an effective strategy to design promising solid-state electrolyte for next-generation ASSLMBs.
高质量的固体电解质是开发高性能全固态锂金属电池（ASSLMBs）的关键。在此，我们通过一种简单的流延成膜法报道了一种基于纳米尺寸的LiLaZrTaO（N-LLZTO）和聚偏氟乙烯-六氟丙烯（PVDF-HFP）基体的复合聚合物电解质（CPE）薄膜。N-LLZTO引发聚（偏氟乙烯-六氟丙烯）（PVDF-HFP）基体的部分脱氟化氢反应，由于路易斯酸碱相互作用，这激活了Li与PVDF-HFP和LLZTO的配位，从而促进锂盐的解离以增加Li载流子密度。结果，制备的含20 wt% N-LLZTO的复合聚合物电解质（CPE-20）膜具有高离子电导率（1.7×10 S cm）、高锂离子迁移数（0.57）、宽电化学窗口（约4.8 V）和良好的热稳定性。此外，CPE-20膜表现出优异的电化学稳定性以抑制锂枝晶生长，并且能持续工作超过2000小时。固态Li|CPE-20|LiFePO软包电池表现出优异的循环性能、倍率性能以及高能量密度。本研究提出了一种有效的策略来设计用于下一代ASSLMBs的有前景的固态电解质。
