High-Voltage Tolerant Covalent Organic Framework Electrolyte with Holistically Oriented Channels for Solid-State Lithium Metal Batteries with Nickel-Rich Cathodes.

作者：Chaoqun Niu, Wenjia Luo, Chenmin Dai, Chengbing Yu, Yuxi Xu · 发表于：Angewandte Chemie · 年份：2021 · DOI：10.1002/anie.202107444 · 被引用次数：127 · 研究领域：Medicine

Development of solid-state electrolytes (SSEs) with high ionic conductivity, wide electrochemical window and high mechanical strength is the key to realize high-energy-dense solid-state lithium metal batteries. Covalent organic frameworks (COFs) have recently attracted considerable interests as promising SSEs mainly due to their highly tunable molecular structures and ideally well-ordered ion migration channels. Herein, we design and synthesize flexible high-voltage tolerant COF SSE films with holistically oriented channel structure to enable solid-state lithium metal batteries with nickel-rich cathodes (NMC811) for the first time. By rationally introducing lithium-philic groups and electrochemical stable quinolyl aromatic ring linkage, the as-prepared COFs demonstrated large bandgap with ultralow HOMO value (-6.2 eV under vacuum) and the highest oxidative stability up to 5.6 V (versus Li + /Li) among all the COF SSEs. Upon convenient mechanical assembly under pre-heat treatment, the obtained flexible COF SSE thin films showed holistically oriented arrangement along the (001) facet with remarkable ionic conductivity up to 1.5 × 10 -4 S cm -1 at 60 °C, and excellent mechanical strength with a high Young's modulus of 10.5 GPa. The lithium ions transmission in this COF SSE was revealed to exhibit directional hopping paths and fast drift velocity by molecular dynamic simulations. With such multiple features, we employed this COF SSE film to assemble all-solid-state lithium-metal ...