Defect, Diffusion and Dopant Properties of NaNiO2: Atomistic Simulation Study

Ruwani Kaushalya, Poobalasuntharam Iyngaran, Navaratnarajah Kuganathan, Alexander Chroneos

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Abstract

Sodium nickelate, NaNiO2, is a candidate cathode material for sodium ion batteries due to its high volumetric and gravimetric energy density. The use of atomistic simulation techniques allows the examination of the defect energetics, Na-ion diffusion and dopant properties within the crystal. Here, we show that the lowest energy intrinsic defect process is the Na-Ni anti-site. The Na Frenkel, which introduces Na vacancies in the lattice, is found to be the second most favourable defect process and this process is higher in energy only by 0.16 eV than the anti-site defect. Favourable Na-ion diffusion barrier of 0.67 eV in the ab plane indicates that the Na-ion diffusion in this material is relatively fast. Favourable divalent dopant on the Ni site is Co2+ that increases additional Na, leading to high capacity. The formation of Na vacancies can be facilitated by doping Ti4+ on the Ni site. The promising isovalent dopant on the Ni site is Ga3+.
Original languageEnglish
Article number3094
Number of pages10
JournalEnergies
Volume12
Issue number16
DOIs
Publication statusPublished - 12 Aug 2019

Fingerprint

Atomistic Simulation
Defects
Doping (additives)
Simulation Study
Vacancy
Ions
Sodium
Vacancies
Diffusion barriers
Energy
Energy Density
Crystal lattices
Battery
Lowest
Cathodes
Crystal
Crystals

Bibliographical note

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Keywords

  • NaNiO2
  • defects
  • Na diffusion
  • dopants
  • atomistic simulation

Cite this

Defect, Diffusion and Dopant Properties of NaNiO2 : Atomistic Simulation Study. / Kaushalya, Ruwani ; Iyngaran, Poobalasuntharam; Kuganathan, Navaratnarajah; Chroneos, Alexander.

In: Energies, Vol. 12, No. 16, 3094, 12.08.2019.

Research output: Contribution to journalArticle

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