Project leadership
Prof. Dr. Eike Brunner
Technische Universität Dresden
Fakultät Chemie und Lebensmittelchemie
Professur für Bioanalytische Chemie
Prof. Dr. Xinliang Feng
Technische Universität Dresden
Fachrichtung Chemie und Lebensmittelchemie
Professur für Molekulare Funktionsmaterialien
Prof. Dr. Stefan Kaskel
Technische Universität Dresden
Fakultät Chemie und Lebensmittelchemie
Professur für Anorganische Chemie I
Project description
Owing to the natural abundance and reversible multielectron redox chemistries, multivalent metal-ion batteries (divalent: Mg2+, Zn2+, Ca2+, etc. trivalent: Al3+, etc.) have gained significant attention as the promising alternatives for post-Li-ion battery technologies. However, the big challenge lies in the limited availability of high-performance cathode materials with high capacity, good reversibility and long-term cyclability. In this regard, redox-active covalent organic frameworks (COFs) are of immense interest as host materials for multivalent metal ions, as COFs show large specific surface areas, tailorable pore structure and active sites, and unique coordination chemistry with multivalent metal ions.
This project plans to design and synthesize new redox-active COFs, explore their applications as cathode materials for multivalent metal-ion storage (Zn2+, Mg2+, and Al3+ in the first stage of SPP project), and try to uncover the multivalent metal-ion storage mechanism with the assistance of in-situ/ex-situ solid-state nuclear magnetic resonance characterization technology.
Ex-situ solid-state NMR experiments on electrolyte-loaded samples will deliver information about ion intercalation in the electrode materials. Interaction sites and the coordination state of NMR-active ions like 27Al will be determined. In-situ NMR experiments will provide information on electrode material - cation interactions under applied voltage. The materials will also be studied by solid-state NMR after cycling in order to evaluate possible aging and degradation processes at the molecular level.
The success of this project will provide insightful knowledge about the design and synthesis of favorable COFs with rich redox active centers (like imide, carbonyl, hexaazatrinaphthalene, sulfidic, polysulfide), chemically stable linkages (such as sp2-carbon (C=C), imide (C(=O)-N) and triazine (cyclic –C=N)), and precisely defined porous structures. Through the electrochemical research and mechanistic studies, the project will offer significant understanding underlying the multivalent metal-ion storage chemistries and establish the structure-performance relationship, which will guide the future development of novel high-performance COF electrodes for multivalent metal-ion batteries.