Journal ArticleDOI
Nuclear quadrupole resonance and x-ray investigation of the structure of Na 2 / 3 CoO 2
TLDR
The atomic ordering of the Na layers is therefore at the source of this ordered distribution of cobalt charges, and the method used here to resolve the Na ordering and the subsequent Co charge order can be used valuably for similar structural determinations for various phases with $xg0.45$ for which Na ordering has been established as discussed by the authors.Abstract:
We have synthesized various samples of the $x=2/3$ phase of sodium cobaltate ${\text{Na}}_{x}{\text{CoO}}_{2}$ and performed x-ray powder diffractions spectra to compare the diffraction with the structure proposed previously from NMR and nuclear quadrupole resonance (NQR) experiments [H. Alloul, I. R. Mukhamedshin, T. A. Platova, and A. V. Dooglav, EPL 85, 47006 (2009)]. Rietveld analyses of the data are found in perfect agreement with those and confirm the concentration $x=2/3$ obtained in the synthesis procedure. They even give indications on the atomic displacements of Na inside the unit cell. The detailed NQR data allow us to identify the NQR transitions and electric field gradient parameters for four cobalt sites and three Na sites. The spin-lattice and spin-spin relaxation rates are found much smaller for the nonmagnetic ${\text{Co}}^{3+}$ sites than for the magnetic sites on which the holes are delocalized. The atomic ordering of the Na layers is therefore at the source of this ordered distribution of cobalt charges. The method used here to resolve the Na ordering and the subsequent Co charge order can be used valuably for similar structural determinations for various phases with $xg0.45$ for which Na ordering has been established.read more
Citations
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Journal ArticleDOI
Research Development on Sodium-Ion Batteries
Naoaki Yabuuchi,Kei Kubota,Kei Kubota,Mouad Dahbi,Mouad Dahbi,Shinichi Komaba,Shinichi Komaba +6 more
Journal ArticleDOI
Sodium-ion batteries: present and future
TL;DR: Current research on materials is summarized and discussed and future directions for SIBs are proposed to provide important insights into scientific and practical issues in the development of S IBs.
Journal ArticleDOI
Electrochemical investigation of the P2–NaxCoO2 phase diagram.
TL;DR: Electrochemical processes are confirmed to be an accurate route to precisely investigate in a continuous way such a complex system and provide a new way to synthesize materials with a very narrow existence range.
Journal ArticleDOI
Layered Oxide Cathodes for Sodium-Ion Batteries: Phase Transition, Air Stability, and Performance
TL;DR: A comprehensive review on the latest advances and progresses in the exploration of layered oxides for SIBs is presented, and a detailed and deep understanding of the relationship of phase transition, air stability, and electrochemical performance in layered oxide cathodes is provided in terms of refining the structure-function-property relationship to design improved battery materials as mentioned in this paper.
Journal ArticleDOI
The P2-Na(2/3)Co(2/3)Mn(1/3)O2 phase: structure, physical properties and electrochemical behavior as positive electrode in sodium battery.
Dany Carlier,Dany Carlier,J.-H. Cheng,J.-H. Cheng,Romain Berthelot,Marie Guignard,Marie Guignard,M. Yoncheva,M. Yoncheva,Radostina Stoyanova,Radostina Stoyanova,Bing-Joe Hwang,Claude Delmas,Claude Delmas +13 more
TL;DR: P Powder X-ray diffraction analysis revealed that the phase is pure in the absence of long-range ordering of Co and Mn ions in the slab or Na(+) and vacancy in the interslab space, and it appears that the P2 structure is maintained during cycling.
References
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Principles of magnetic resonance
TL;DR: In this article, the effect of changing the precession frequency of the magnetic field has been studied using NMR to study rate properties. But the effect is limited to the case of double and double resonance.