Related Experiment Video
Updated: Aug 26, 2025
10:58
Focused Ion Beam Fabrication of LiPON-based Solid-state Lithium-ion Nanobatteries for In Situ Testing
Published on: March 7, 2018
10.3K
Lithium confinement and dynamics in hexagonal and monoclinic tungsten oxide nanocrystals: a 7Li solid state NMR study
René Dören1, Martin Panthöfer1, Leon Prädel2
1Department Chemie, Johannes Gutenberg-Universität, Duesbergweg 10-14, D-55128 Mainz, Germany. tremel@uni-mainz.de.
Nanoscale
|October 11, 2022
Summary
This study characterizes the new mixed hexagonal lithium ammonium tungsten bronze using solid-state NMR. Researchers analyzed lithium-ion behavior and structural changes, revealing insights into binding strength and phase transitions.
Area of Science:
- Solid-state chemistry
- Materials science
- Nuclear Magnetic Resonance (NMR) spectroscopy
Background:
- Mixed-valence tungsten bronzes (AWO3) exhibit adaptive structures, making them valuable for thermoelectrics, electrochromics, catalysis, and battery electrodes.
- Hexagonal tungsten bronzes are a key subclass, with potential for novel material properties.
Purpose of the Study:
- To characterize the novel mixed hexagonal lithium ammonium tungsten bronze (Li(NH4)WO3).
- To compare its properties with pure hexagonal tungsten bronze ((NH4)WO3).
- To investigate the behavior and environment of lithium cations (Li+) within the bronze structure.
Main Methods:
- Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy, including 7Li single pulse excitation and 1H-7Li cross-polarization (CP).
- Two-dimensional heteronuclear correlation NMR techniques to map spatial connectivity.
- 7Li exchange spectroscopy (EXSY) NMR to study chemical exchange.
- Measurement of 7Li spin-lattice (T1) and spin-spin (T2) relaxation times.
Main Results:
- Surface and nanoconfined Li+ cations were successfully characterized.
- Spatial connectivity between proton and Li+ species was elucidated.
- Structural transformation from hexagonal to monoclinic phase at 500 °C was observed, with defect characterization.
- Chemical exchange between lithium species was analyzed using EXSY.
- Li+ binding strength was correlated with measured T1 and T2 relaxation times.
Conclusions:
- Solid-state NMR is effective for characterizing lithium-ion behavior in tungsten bronzes.
- The study provides a detailed understanding of the structural and dynamic properties of Li(NH4)WO3.
- Findings contribute to the development of tungsten bronze materials for energy applications.
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