Covalent Organic Framework-Based Electrolytes for Fast Li+ Conduction and High-Temperature Solid-State Lithium-Ion Batteries
journal contributionposted on 2021-06-15, 13:37 authored by Zhen Shan, Miaomiao Wu, Yihan Du, Bingqing Xu, Boying He, Xiaowei Wu, Gen Zhang
It has been a long-standing challenge to design and fabricate high Li+ conductive polymer electrolytes at the atomic level with superior thermal stability for solid-state lithium-ion batteries. Covalent organic frameworks (COFs) with tailor-made 1D nanochannels provide a potential pathway for fast ion transport, but it remains elusive. In this work, three crystalline thiophene-based imine-linked COFs were constructed and explored as Li+-conducting composite electrolytes by doping ionic liquids into their 1D nanochannels. The COF–IL composite electrolytes exhibited excellent thermal stability (up to 400 °C) and high Li+ conductivity (up to 2.60 × 10–3 S/cm at 120 °C, one of the highest values of doped porous organic materials). Furthermore, the COF–IL composite electrolytes exhibited stable cycling in a LiFePO4–Li full cell with a high initial discharge specific capacity of 140.8 mA·h/g at 100 °C, more stable than common poly(ethylene oxide)-based electrolytes, indicating great potential application under a high-temperature operation. This work opens a new avenue for the development of fast Li+-conducting COF-based electrolytes for high-temperature solid-state lithium-ion batteries.
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three crystalline thiophenesuperior thermal stabilitysup >+</ supdoping ionic liquidscovalent organic frameworkscovalent organic framework60 × 10400 ° c120 ° c100 ° cconductive polymer electrolytesfast ion transportfabricate high liion batteriesfast libased electrolytes· htemperature operationstate lithiumstanding challengeremains elusivepotential pathwaynew avenuehighest valueshigh libased imineatomic level1d nanochannels