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DOE OSTI · 2532491

Sodium Superionic Conductors Based on Clusters

Fang, Hong·Jena, Puru
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Abstract

Owing to the high abundance and low cost of sodium (Na), Na-based rechargeable batteries hold great potential for large-scale applications in the future energy industry. However, as key component of the battery electrolyte, only a few Na-based superionic conductors can reach the ionic conductivity comparable to that of liquid or gel electrolytes. Here, we provide a guideline for the development of cluster-based Na-rich antiperovskite superionic conductors using computational studies. With a selected cluster ion BCl 4 – , we are able to achieve high-room-temperature Na-ionic conductivity over 10 –3 S/cm and low activation energies below 0.2 eV in the antiperovskite crystals Na 3 S(BCl 4 ) and Na 3 S(BCl 4 ) 0.5 I 0.5 . In addition, these materials have large bandgaps and favorable mechanical properties. Here, a comprehensive study of the stability and formation energy of these materials further illustrates possible routes for their synthesis. New insights into the conduction mechanism of these cluster-based superionic conductors are provided, including the cooperative motion of Na ions and the significant reduction of the migration barrier due to the changing orientation of the cluster ion.

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25 ENERGY STORAGEantiperovskitecluster ionselectrical conductivityenergyionic conductivitylow activation energymaterialsmechanical propertyquasi rigid unit modessodium-ion batterysolid electrolytesuperionic conductivity

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Fang, Hong, Jena, Puru. 2018-12-14. Sodium Superionic Conductors Based on Clusters. https://doi.org/10.1021/acsami.8b19003

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