Magnetic, electrochemical and thermoelectric properties of P2-Nax(Co7/8Sb1/8)O2

M. H.N. Assadi; S. Li; R. K. Zheng; S. P. Ringer; A. B. Yu

doi:10.1016/j.cplett.2017.09.026

Magnetic, electrochemical and thermoelectric properties of P2-Na_x(Co_7/8Sb_1/8)O₂

M. H.N. Assadi
, S. Li
, R. K. Zheng
, S. P. Ringer
, A. B. Yu

Chemical & Biological Engineering

Research output: Contribution to journal › Article › Research › peer-review

9 Citations (Scopus)

Abstract

We theoretically investigated the electronic, electrochemical and magnetic properties of Sb doped Na_xCoO₂(x = 1, 0.75 and 0.50). Sb _Co dopants adopt 5+ oxidation state in Na_xCoO₂ host lattice for all Na concentrations (x). Due to high oxidation states, Sb⁵⁺ strongly repels Na ions and therefore it decreases the Na ⁺/Na electrochemical potential. The electrons introduced by Sb ⁵⁺ localize on nearby Co ions creating Co ²⁺ species which are absent in undoped Na_xCoO₂. Co²⁺ ions reduce the spin entropy flow decreasing the Seebeck coefficient in the Sb doped compounds. The results can be generalized to other dopants with high oxidation state.

Original language	English
Pages (from-to)	233-237
Number of pages	5
Journal	Chemical Physics Letters
Volume	687
DOIs	https://doi.org/10.1016/j.cplett.2017.09.026
Publication status	Published - 1 Jan 2017

Keywords

Density functional theory
Magnetism
Sodium cobaltate
Sodium ion battery
Thermoelectric

Access to Document

10.1016/j.cplett.2017.09.026

Cite this

@article{5e978aa9360046098e24417d6fe80f8a,

title = "Magnetic, electrochemical and thermoelectric properties of P2-Nax(Co7/8Sb1/8)O2",

abstract = " We theoretically investigated the electronic, electrochemical and magnetic properties of Sb doped NaxCoO2(x = 1, 0.75 and 0.50). Sb Co dopants adopt 5+ oxidation state in NaxCoO2 host lattice for all Na concentrations (x). Due to high oxidation states, Sb5+ strongly repels Na ions and therefore it decreases the Na +/Na electrochemical potential. The electrons introduced by Sb 5+ localize on nearby Co ions creating Co 2+ species which are absent in undoped NaxCoO2. Co2+ ions reduce the spin entropy flow decreasing the Seebeck coefficient in the Sb doped compounds. The results can be generalized to other dopants with high oxidation state. ",

keywords = "Density functional theory, Magnetism, Sodium cobaltate, Sodium ion battery, Thermoelectric",

author = "Assadi, \{M. H.N.\} and S. Li and Zheng, \{R. K.\} and Ringer, \{S. P.\} and Yu, \{A. B.\}",

year = "2017",

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doi = "10.1016/j.cplett.2017.09.026",

language = "English",

volume = "687",

pages = "233--237",

journal = "Chemical Physics Letters",

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TY - JOUR

T1 - Magnetic, electrochemical and thermoelectric properties of P2-Nax(Co7/8Sb1/8)O2

AU - Assadi, M. H.N.

AU - Li, S.

AU - Zheng, R. K.

AU - Ringer, S. P.

AU - Yu, A. B.

PY - 2017/1/1

Y1 - 2017/1/1

N2 - We theoretically investigated the electronic, electrochemical and magnetic properties of Sb doped NaxCoO2(x = 1, 0.75 and 0.50). Sb Co dopants adopt 5+ oxidation state in NaxCoO2 host lattice for all Na concentrations (x). Due to high oxidation states, Sb5+ strongly repels Na ions and therefore it decreases the Na +/Na electrochemical potential. The electrons introduced by Sb 5+ localize on nearby Co ions creating Co 2+ species which are absent in undoped NaxCoO2. Co2+ ions reduce the spin entropy flow decreasing the Seebeck coefficient in the Sb doped compounds. The results can be generalized to other dopants with high oxidation state.

AB - We theoretically investigated the electronic, electrochemical and magnetic properties of Sb doped NaxCoO2(x = 1, 0.75 and 0.50). Sb Co dopants adopt 5+ oxidation state in NaxCoO2 host lattice for all Na concentrations (x). Due to high oxidation states, Sb5+ strongly repels Na ions and therefore it decreases the Na +/Na electrochemical potential. The electrons introduced by Sb 5+ localize on nearby Co ions creating Co 2+ species which are absent in undoped NaxCoO2. Co2+ ions reduce the spin entropy flow decreasing the Seebeck coefficient in the Sb doped compounds. The results can be generalized to other dopants with high oxidation state.

KW - Density functional theory

KW - Magnetism

KW - Sodium cobaltate

KW - Sodium ion battery

KW - Thermoelectric

UR - https://www.scopus.com/pages/publications/85029531535

U2 - 10.1016/j.cplett.2017.09.026

DO - 10.1016/j.cplett.2017.09.026

M3 - Article

AN - SCOPUS:85029531535

SN - 0009-2614

VL - 687

SP - 233

EP - 237

JO - Chemical Physics Letters

JF - Chemical Physics Letters