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Abstract Motivated by the high-performance solid-state lithium batteries enabled by lithium superionic conductors, sodium superionic conductor materials have great potential to empower sodium batteries with high energy, low cost, and sustainability. A critical challenge lies in designing and discovering sodium superionic conductors with high ionic conductivities to enable the development of solid-state sodium batteries. Here, by studying the structures and diffusion mechanisms of Li-ion versus Na-ion conducting solids, we reveal the structural feature of face-sharing high-coordination sites for fast sodium-ion conductors. By applying this feature as a design principle, we discover a number of Na-ion conductors in oxides, sulfides, and halides. Notably, we discover a chloride-based family of Na-ion conductors NaxMyCl6(M = La–Sm) with UCl3-type structure and experimentally validate with the highest reported ionic conductivity. Our findings not only pave the way for the future development of sodium-ion conductors for sodium batteries, but also consolidate design principles of fast ion-conducting materials for a variety of energy applications.
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One-Pot Aqueous Synthesis of Hierarchical Na3V2(PO4)3 Particles for High-Performance Sodium Batteries
Abstract Intermittent renewable energy sources can mitigate climate change, but they require high-performance, reliable batteries. The widely used lithium-ion batteries contain Li, Co, and Ni, and the growing demand for these elements, together with their relatively limited sources, has raised concerns about their supply chain stability. Sodium-ion batteries have become an economical alternative. Sodium vanadium phosphate, Na3V2(PO4)3 (NVP), is a compelling candidate with high stability and ionic conductivity due to its polyanionic sodium superionic conductor (NASICON) structure. However, NVP suffers from poor electronic conductivity and requires hierarchical morphology to allow facile ion and electron transfer. Spray-drying has been used to achieve hierarchical secondary particle structures, but the foremost reported NVP syntheses rely on either flammable/toxic organic solvents or expensive nanocarbon additives. In this study, we spray-dry an aqueous suspension without using expensive carbon additives. The obtained NVP sodium-ion half cells showed very high reversible capacity (114.7 mAh g-1 at 0.2C), high rate capability (80.8% capacity retention at 30C), and stable cycling performance (96.7% capacity retention after 1,500 cycles at 10C). This superior performance demonstrates the great promise for NVP batteries as an alternative energy storage option to traditional lithium-ion batteries.
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- PAR ID:
- 10603939
- Publisher / Repository:
- IOP Science
- Date Published:
- Journal Name:
- Journal of The Electrochemical Society
- ISSN:
- 0013-4651
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1149/1945-7111/ade47c
