A Novel NASICON-Type Na4 MnCr(PO4 )3 Demonstrating the Energy Density Record of Phosphate Cathodes for Sodium-Ion Batteries
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Veröffentlicht in: | Advanced materials (Deerfield Beach, Fla.). - 1998. - 32(2020), 11 vom: 01. März, Seite e1906348 |
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1. Verfasser: | |
Weitere Verfasser: | , , , , , , , , |
Format: | Online-Aufsatz |
Sprache: | English |
Veröffentlicht: |
2020
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Zugriff auf das übergeordnete Werk: | Advanced materials (Deerfield Beach, Fla.) |
Schlagworte: | Journal Article density functional theory (DFT) computations energy density phosphate cathodes reaction mechanisms sodium-ion batteries |
Zusammenfassung: | © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Sodium-ion batteries (SIBs) have attracted incremental attention as a promising candidate for grid-scale energy-storage applications. To meet practical requirements, searching for new cathode materials with high energy density is of great importance. Herein, a novel Na superionic conductor (NASICON)-type Na4 MnCr(PO4 )3 is developed as a high-energy cathode for SIBs. The Na4 MnCr(PO4 )3 nanoparticles homogeneously embedded in a carbon matrix can present an extraordinary reversible capacity of 160.5 mA h g-1 with three-electron reaction at ≈3.53 V during the Na+ extraction/insertion process, realizing an unprecedentedly high energy density of 566.5 Wh kg-1 in the phosphate cathodes for SIBs. It is intriguing to reveal the underlying mechanism of the unique Mn2+ /Mn3+ , Mn3+ /Mn4+ , and Cr3+ /Cr4+ redox couples via X-ray absorption near-edge structure spectroscopy. The whole electrochemical reaction undergoes highly reversible single-phase and biphasic transitions with a moderate volume change of 7.7% through in situ X-ray diffraction and ex situ high-energy synchrotron X-ray diffraction. Combining density functional theory (DFT) calculations with the galvanostatic intermittent titration technique, the superior performance is ascribed to the low ionic-migration energy barrier and desirable Na-ion diffusion kinetics. The present work can offer a new insight into the design of multielectron-reaction cathode materials for SIBs |
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Beschreibung: | Date Revised 30.09.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
ISSN: | 1521-4095 |
DOI: | 10.1002/adma.201906348 |