Thermally rearranged covalent organic framework with flame-retardancy as a high safety Li-ion solid electrolyte
Zhifang Wang,
Yushu Zhang,
Penghui Zhang,
Dong Yan,
Jinjin Liu,
Yao Chen,
Qi Liu,
Peng Cheng,
Michael J. Zaworotko,
Zhenjie Zhang
Affiliations
Zhifang Wang
Renewable Energy Conversion and Storage Center, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China; Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin, 300071, China
Yushu Zhang
Renewable Energy Conversion and Storage Center, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
Penghui Zhang
Renewable Energy Conversion and Storage Center, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
Dong Yan
Renewable Energy Conversion and Storage Center, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
Jinjin Liu
Renewable Energy Conversion and Storage Center, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
Yao Chen
Renewable Energy Conversion and Storage Center, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China; College of Pharmacy, Nankai University, Tianjin, 300071, China
Qi Liu
Department of Physics, City University of Hong Kong, Hong Kong, 999077, China
Peng Cheng
Renewable Energy Conversion and Storage Center, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China; Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin, 300071, China
Michael J. Zaworotko
Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick, V94 T9PX, Ireland
Zhenjie Zhang
Renewable Energy Conversion and Storage Center, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China; Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin, 300071, China; Corresponding author.
Solid polymer electrolytes have demonstrated high promise to solve the safety problems caused by conventional liquid electrolytes in lithium ion batteries. However, the inherent flammability of most polymer electrolyte materials remains unresolved, hence hindering their further industrial application. Addressing this challenge, we designed and constructed a thermal-responsive imide-linked covalent organic framework (COF) bearing ortho-positioned hydroxy groups as precursors, which can conduct a thermal rearrangement to transform into a highly crystalline and robust benzoxazole-linked COF upon heating. Benefiting from the release of carbon dioxide through thermal rearrangement reaction, this COF platform exhibited excellent flame retardant properties. By contrast, classic COFs (e.g., boronate ester, imine, olefin, imide linked) were all flammable. Moreover, incorporating polyethylene glycol and Li salt into the COF channels can produce solid polymer electrolytes with outstanding flame retardancy, high ionic conductivity (6.42 × 10−4 S cm−1) and a high lithium-ion transference number of 0.95. This thermal rearrangement strategy not only opens a new route for the fabrication of ultrastable COFs, but also provides promising perspectives to designing flame-retardant materials for energy-related applications.
