Transferring lithium ions in the nanochannels of flexible metal-organic frameworks featuring superchaotropic metallacarborane guests: mechanism of ionic conductivity at atomic resolution

0533405 - ÚMCH 2021 RIV US eng J - Článek v odborném periodiku
Brus, Jiří - Czernek, Jiří - Urbanová, Martina - Rohlíček, Jan - Plecháček, T.
Transferring lithium ions in the nanochannels of flexible metal-organic frameworks featuring superchaotropic metallacarborane guests: mechanism of ionic conductivity at atomic resolution.
ACS Applied Materials and Interfaces. Roč. 12, č. 42 (2020), s. 47447-47456. ISSN 1944-8244. E-ISSN 1944-8252
Grant CEP: GA ČR(CZ) GA20-01233S; GA ČR(CZ) GA18-12925S; GA MŠMT LM2018110
Výzkumná infrastruktura: e-INFRA CZ - 90140; CERIT-SC - 90085; CzechNanoLab - 90110
Institucionální podpora: RVO:61389013 ; RVO:68378271
Klíčová slova: metal-organic frameworks * lithium metallacarborane salts * all-solid-state electrolytes
Obor OECD: Polymer science; Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D)
Impakt faktor: 9.229, rok: 2020
Způsob publikování: Open access
https://pubs.acs.org/doi/10.1021/acsami.0c12293

Metal–organic frameworks (MOFs), owing to their unique architecture, attract consistent attention in the design of high-performance Li battery materials. Here, we report a new category of ion-conducting crystalline materials for all-solid-state electrolytes based on an MIL53(Al) framework featuring a superchaotropic metallacarborane (Li+CoD–) salt and present the first quantitative data on Li+ ion sites, local dynamics, chemical exchange, and the formation of charge-transfer pathways. We used multinuclear solid-state nuclear magnetic resonance (ss-NMR) spectroscopy to examine the mechanism of ionic conductivity at atomic resolution and to elucidate order–disorder processes, framework–ion interactions, and framework breathing during the loading of Li+CoD– species and transfer of Li+ ions. In this way, the MIL53(Al)@LiCoD framework was found to adopt an open-pore conformation accompanied by a minor fraction of narrow-pore channels. The inserted Li+ ions have two states (free and bound), which both exhibit extensive motions. Both types of Li+ ions form mutually communicating chains, which are large enough to enable efficient long-range charge transfer and macroscopic conductivity. The superchaotropic anions undergo high-amplitude uniaxial rotation motions supporting the transfer of Li+ cations along them, while the fluctuations of MOF aromatic linkers support the penetration of Li+ through the channel walls. Our findings provide a detailed atomic-resolution insight into the mechanism of ionic conductivity and thus have significant implications for the design of the next generation of energy-related materials.
Trvalý link: http://hdl.handle.net/11104/0312086