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Abstract All‐solid‐state rechargeable sodium (Na)‐ion batteries are promising for inexpensive and high‐energy‐density large‐scale energy storage. In this contribution, new Na solid electrolytes, Na3−yPS4−xClx, are synthesized with a strategic approach, which allows maximum substitution of Cl for S (x= 0.2) without significant compromise of structural integrity or Na deficiency. A maximum conductivity of 1.96 mS cm−1at 25 °C is achieved for Na3.0PS3.8Cl0.2, which is two orders of magnitude higher compared with that of tetragonal Na3PS4(t‐Na3PS4). The activation energy (Ea) is determined to be 0.19 eV. Ab initio molecular dynamics simulations shed light on the merit of maximizing Cl‐doping while maintaining low Na deficiency in enhanced Na‐ion conduction. Solid‐state nuclear magnetic resonance (NMR) characterizations confirm the successful substitution of Cl for S and the resulting change of P oxidation state from 5+ to 4+, which is also verified by spin moment analysis. Ion transport pathways are determined with a tracer‐exchange NMR method. The functional detects that promote Na ‐ion transport are maximized for further improvement in ionic conductivity. Full‐cell performance is demonstrated using Na/Na3.0PS3.8Cl0.2/Na3V2(PO4)3with a reversible capacity of ≈100 mAh g‐1at room temperature.
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Fast Na diffusion and anharmonic phonon dynamics in superionic Na 3 PS 4
Strongly anharmonic low-energy phonons enable the fast diffusion of Na ions in the solid-state electrolyte compound Na3PS4.
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- Award ID(s):
- 2033397
- PAR ID:
- 10476866
- Publisher / Repository:
- RSC
- Date Published:
- Journal Name:
- Energy & Environmental Science
- Volume:
- 14
- Issue:
- 12
- ISSN:
- 1754-5692
- Page Range / eLocation ID:
- 6554 to 6563
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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