Porous Organic Cage-Based Quasi-Solid-State Electrolyte with Cavity-Induced Anion-Trapping Effect for Long-Life Lithium Metal Batteries
Wei‐Min Qin, Zhongliang Li, Wenxia Su, Jiamin Hu, Hanqin Zou, Zhixuan Wu, Zhiqin Ruan, Yue‐Peng Cai, Kang Li, Qifeng Zheng
Abstract
Abstract Porous organic cages (POCs) with permanent porosity and excellent host–guest property hold great potentials in regulating ion transport behavior, yet their feasibility as solid-state electrolytes has never been testified in a practical battery. Herein, we design and fabricate a quasi-solid-state electrolyte (QSSE) based on a POC to enable the stable operation of Li-metal batteries (LMBs). Benefiting from the ordered channels and cavity-induced anion-trapping effect of POC, the resulting POC-based QSSE exhibits a high Li + transference number of 0.67 and a high ionic conductivity of 1.25 × 10 −4 S cm −1 with a low activation energy of 0.17 eV. These allow for homogeneous Li deposition and highly reversible Li plating/stripping for over 2000 h. As a proof of concept, the LMB assembled with POC-based QSSE demonstrates extremely stable cycling performance with 85% capacity retention after 1000 cycles. Therefore, our work demonstrates the practical applicability of POC as SSEs for LMBs and could be extended to other energy-storage systems, such as Na and K batteries.