Synthesis and Characterization of Li <sub>4</sub> (OH) <sub>3</sub> Br for Thermal Energy Storage
The peritectic compound Li<sub>4</sub>(OH)<sub>3</sub>Br has been suggested as a candidate material for latent heat thermal energy storage (TES), due to its high calculated melting enthalpy (804 J g<sup>-1</sup>) around 300 °C, however experimental reports have obtained much lower values (≤250 J g<sup>-1</sup>). In this work, we show that the crystal structure established for Li<sub>4</sub>(OH)<sub>3</sub>Br in literature corresponds to a metastable hydrated compound, and instead propose that the thermodynamically stable phase belongs to the <i>Pmnm</i> space group. The hydrated phase dehydrates at ∼175 °C, rendering the exceptional previous predictions inapplicable. An experimentally measured melting enthalpy of 263 ± 3 J g<sup>-1</sup> is found for high-purity Li<sub>4</sub>(OH)<sub>3</sub>Br. Theoretical modeling is used to suggest a crystal structure for Li<sub>4</sub>(OH)<sub>3</sub>Br, from which a melting enthalpy of 260 J g<sup>-1</sup> is calculated, in good agreement with the experimental work, and supporting that nonetheless impressive storage capacity at ∼290 °C can be offered by Li<sub>4</sub>(OH)<sub>3</sub>Br.
Authors
- Mauro Pasta (ORCID: https://orcid.org/0000-0002-2613-4555)
- Emily Milan
- James A. Dawson (ORCID: https://orcid.org/0000-0002-3946-5337)
- John Cattermull (ORCID: https://orcid.org/0009-0006-5209-3132)
- James A. Quirk (ORCID: https://orcid.org/0000-0003-3581-1615)
- Andrew L. Goodwin (ORCID: https://orcid.org/0000-0001-9231-3749)
Institutions
- University of Oxford (GB)
- Newcastle University (GB)
Publication Details
- Journal
- ACS Applied Energy Materials
- Published
- 2025-04-04
- DOI
- https://doi.org/10.1021/acsaem.5c00359
- Primary Topic
- Phase Change Materials Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- UK Research and Innovation
- Engineering and Physical Sciences Research Council
- European Research Council