Flexible, solid-state, ion-conducting membrane with 3D garnet nanofiber networks for lithium batteries

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 113; no. 26; pp. 7094 - 7099
• Main Authors: Fu, Kun (Kelvin), Gong, Yunhui, Dai, Jiaqi, Gong, Amy, Han, Xiaogang, Yao, Yonggang, Wang, Chengwei, Wang, Yibo, Chen, Yanan, Yan, Chaoyi, Li, Yiju, Wachsman, Eric D., Hu, Liangbing
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 28-06-2016
• Subjects: 3D garnet nanofibers; Conductivity; Electrodes; ENERGY STORAGE; flexible membrane; Hydrogen; ionic conductor; Mechanical properties; Physical Sciences; Polyethylene; polyethylene oxide; solid-state electrolyte; 3D garnet nanofibers; polyethylene oxide; flexible membrane; ionic conductor; solid-state electrolyte
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1600422113

Beyond state-of-the-art lithium-ion battery (LIB) technology with metallic lithium anodes to replace conventional ion intercalation anode materials is highly desirable because of lithium’s highest specific capacity (3,860 mA/g) and lowest negative electrochemical potential (∼3.040 V vs. the standard hydrogen electrode). In this work, we report for the first time, to our knowledge, a 3D lithium-ion–conducting ceramic network based on garnet-type Li6.4La₃Zr₂Al0.2O12 (LLZO) lithium-ion conductor to provide continuous Li⁺ transfer channels in a polyethylene oxide (PEO)-based composite. This composite structure further provides structural reinforcement to enhance the mechanical properties of the polymer matrix. The flexible solid-state electrolyte composite membrane exhibited an ionic conductivity of 2.5 × 10−4 S/cm at room temperature. The membrane can effectively block dendrites in a symmetric Li | electrolyte | Li cell during repeated lithium stripping/plating at room temperature, with a current density of 0.2 mA/cm² for around 500 h and a current density of 0.5 mA/cm² for over 300 h. These results provide an all solid ion-conducting membrane that can be applied to flexible LIBs and other electrochemical energy storage systems, such as lithium–sulfur batteries.