Abstract
Nanocomposites of complex metal hydrides and oxides are promising solid state electrolytes. The interaction of the metal hydride with the oxide results in a highly conducting interface layer. Up until now it has been assumed that the interface chemistry is independent of the nanoconfinement method. Using 29Si solid state NMR and LiBH4/SiO2 as a model system, we show that the silica surface chemistry differs for nanocomposites prepared via melt infiltration or ball milling. After melt infiltration, a Si···H···BH3 complex is present on the interface, together with silanol and siloxane groups. However, after ball milling, the silica surface consists of Si- H sites, and silanol and siloxane groups. We propose that this change is related to a redistribution of silanol groups on the silica surface during ball milling, where free silanol groups are converted to mutually hydrogen-bonded silanol groups. The results presented here help to explain the difference in ionic conductivity between nanocomposites prepared via ball milling and melt infiltration.
Original language | English |
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Pages (from-to) | 12186−12193 |
Number of pages | 8 |
Journal | Journal of Physical Chemistry C |
Volume | 128 |
Issue number | 29 |
DOIs | |
Publication status | Published - 25 Jul 2024 |
Bibliographical note
Publisher Copyright:© 2024 The Authors. Published by American Chemical Society.
Funding
The authors thank Hans Janssen, Gerrit Janssen, and Ruud Aspers for their technical support and discussions. Jennifer S. Goomez and Angel Wong are thanked for their help with the NMR measurements at 22.3 T. The Dutch Research Council (NWO) is acknowledged for their support of the solid-state NMR facility for advanced materials science, which is part of the uNMR-NL grid (NWO Grant 184.035.002).
Funders | Funder number |
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Nederlandse Organisatie voor Wetenschappelijk Onderzoek | 184.035.002 |