A Thiazole-linked Covalent Organic Framework for Lithium-Sulphur Batteries |
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Authors: | Rui Yan Bikash Mishra Dr. Michael Traxler Dr. Jérôme Roeser Nicolas Chaoui Bidhan Kumbhakar Dr. Johannes Schmidt Prof. Shuang Li Prof. Arne Thomas Dr. Pradip Pachfule |
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Affiliation: | 1. College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065 China;2. Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata—, 700106 India;3. Department of Chemistry / Functional Materials, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany |
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Abstract: | Lithium-sulphur (Li−S) batteries are a promising alternative power source, as they can provide a higher energy density than current lithium-ion batteries. Porous materials are often used as cathode materials as they can act as a host for sulphur in such batteries. Recently, covalent organic frameworks (COFs) have also been used, however they typically suffer from stability issues, resulting in limited and thus insufficient durability under practical conditions and applications. Herein, we report the synthesis of a crystalline and porous imine-linked triazine-based dimethoxybenzo-dithiophene functionalized COF (TTT-DMTD) incorporating high-density redox sites. The imine linkages were further post-synthetically transformed to yield a robust thiazole-linked COF (THZ-DMTD) by utilizing a sulphur-assisted chemical conversion method, while maintaining the crystallinity. As a synergistic effect of its high crystallinity, porosity and the presence of redox-active moieties, the thiazole-linked THZ-DMTD exhibited a high capacity and long-term stability (642 mAh g−1 at 1.0 C; 78.9 % capacity retention after 200 cycles) when applied as a cathode material in a Li−S battery. |
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Keywords: | Chemical Stability Covalent Organic Frameworks Crystallinity Lithium-Sulphur Batteries Post-Synthetic Modification |
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