Computational Investigation of Copper Phosphides as Conversion Anodes for Lithium-Ion Batteries
Copyright © 2020 American Chemical Society.
| Veröffentlicht in: | Chemistry of materials : a publication of the American Chemical Society. - 1998. - 32(2020), 15 vom: 11. Aug., Seite 6629-6639 |
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| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2020
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| Zugriff auf das übergeordnete Werk: | Chemistry of materials : a publication of the American Chemical Society |
| Schlagworte: | Journal Article |
| Zusammenfassung: | Copyright © 2020 American Chemical Society. Using first-principles structure searching with density-functional theory (DFT), we identify a novel Fm3̅m phase of Cu2P and two low-lying metastable structures, an I4̅3d-Cu3P phase and a Cm-Cu3P11 phase. The computed pair distribution function of the novel Cm-Cu3P11 phase shows its structural similarity to the experimentally identified Cm-Cu2P7 phase. The relative stability of all Cu-P phases at finite temperatures is determined by calculating the Gibbs free energy using vibrational effects from phonon modes at 0 K. From this, a finite-temperature convex hull is created, on which Fm3̅m-Cu2P is dynamically stable and the Cu3-x P (x < 1) defect phase Cmc21-Cu8P3 remains metastable (within 20 meV/atom of the convex hull) across a temperature range from 0 to 600 K. Both CuP2 and Cu3P exhibit theoretical gravimetric capacities higher than contemporary graphite anodes for Li-ion batteries; the predicted Cu2P phase has a theoretical gravimetric capacity of 508 mAh/g as a Li-ion battery electrode, greater than both Cu3P (363 mAh/g) and graphite (372 mAh/g). Cu2P is also predicted to be both nonmagnetic and metallic, which should promote efficient electron transfer in the anode. Cu2P's favorable properties as a metallic, high-capacity material suggest its use as a future conversion anode for Li-ion batteries; with a volume expansion of 99% during complete cycling, Cu2P anodes could be more durable than other conversion anodes in the Cu-P system, with volume expansions greater than 150%. The structures and figures presented in this paper, and the code used to generate them, can be interactively explored online using Binder |
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| Beschreibung: | Date Revised 09.09.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 0897-4756 |
| DOI: | 10.1021/acs.chemmater.0c02054 |