Overcoming Diffusion Limitation of Faradaic Processes: Property‐Performance Relationships of 2D Conductive Metal‐Organic Framework Cu3(HHTP)2 for Reversible Lithium‐Ion Storage

• Published in: Angewandte Chemie International Edition Vol. 62; no. 26; pp. e202303111 - n/a
• Main Authors: Wrogemann, Jens Matthies, Lüther, Marco Joes, Bärmann, Peer, Lounasvuori, Mailis, Javed, Ali, Tiemann, Michael, Golnak, Ronny, Xiao, Jie, Petit, Tristan, Placke, Tobias, Winter, Martin
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 26-06-2023
• Edition: International ed. in English
• Subjects: Absorption spectroscopy; Batteries; Charge transfer; Copper; Diffusion; Diffusion rate; Electrochemistry; Energy Conversion; Ion storage; Ion transport; Lithium; Lithium ions; Lithium-Ion Storage; Metal-Organic Frameworks; Morphology; Optimization; Particle Design; Storage
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202303111

Faradaic reactions including charge transfer are often accompanied with diffusion limitation inside the bulk. Conductive two‐dimensional frameworks (2D MOFs) with a fast ion transport can combine both—charge transfer and fast diffusion inside their porous structure. To study remaining diffusion limitations caused by particle morphology, different synthesis routes of Cu‐2,3,6,7,10,11‐hexahydroxytriphenylene (Cu3(HHTP)2), a copper‐based 2D MOF, are used to obtain flake‐ and rod‐like MOF particles. Both morphologies are systematically characterized and evaluated for redox‐active Li+ ion storage. The redox mechanism is investigated by means of X‐ray absorption spectroscopy, FTIR spectroscopy and in situ XRD. Both types are compared regarding kinetic properties for Li+ ion storage via cyclic voltammetry and impedance spectroscopy. A significant influence of particle morphology for 2D MOFs on kinetic aspects of electrochemical Li+ ion storage can be observed. This study opens the path for optimization of redox active porous structures to overcome diffusion limitations of Faradaic processes.
A two‐dimensional MOF, (Cu3(HHTP)2), is synthesized with two different morphologies. Flake‐ and rod‐like shaped particles were evaluated to investigate the impact of the particle morphology of MOFs on electrochemical Li+ ion storage. By optimization of the particle morphology, diffusion limitation of the Faradaic process can be strongly reduced.