1. Single Metal Site and Versatile Transfer Channel Merged into Covalent Organic Frameworks Facilitate High-Performance Li-CO2 Batteries
- Author
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Cheng Jiang, Yifa Chen, Long-Zhang Dong, Yu Zhang, Rong-Lin Zhong, Ya-Qian Lan, Guang-Kuo Gao, Jian-Hui Wang, Shun-Li Li, and Meng Lu
- Subjects
Battery (electricity) ,Materials science ,010405 organic chemistry ,General Chemical Engineering ,General Chemistry ,Overpotential ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,Porphyrin ,Cathode ,0104 chemical sciences ,Catalysis ,law.invention ,chemistry.chemical_compound ,Chemistry ,chemistry ,Covalent bond ,law ,Density functional theory ,QD1-999 ,Covalent organic framework - Abstract
The sluggish kinetics and unclear mechanism have significantly hindered the development of Li-CO2 batteries. Here, a Li-CO2 battery cathode catalyst based on a porphyrin-based covalent organic framework (TTCOF-Mn) with single metal sites is reported to reveal intrinsic catalytic sites of aprotic CO2 conversion from the molecular level. The battery with TTCOF-Mn exhibits a low overpotential of 1.07 V at 100 mA/g as well as excellent stability at 300 mA/g, which is one of the best Li-CO2 battery cathode catalysts to date. The unique features of TTCOF-Mn including uniform single-Mn(II)-sites, fast Li+ transfer pathways, and high electron transfer efficiency contribute to effective CO2 reduction and Li2CO3 decomposition in the Li-CO2 system. Density functional theory calculations reveal that different metalloporphyrin sites lead to different reaction pathways. The single-Mn(II) sites in TTCOF-Mn can activate CO2 and achieve an efficient four-electron CO2 conversion pathway. It is the first example to reveal the catalytic active sites and clear reaction pathways in aprotic Li-CO2 batteries.
- Published
- 2020