TY - JOUR

T1 - Correlation between structural and transport properties of ca‐doped la nickelates and their electrochemical performance

AU - Pikalova, Elena

AU - Sadykov, Vladislav

AU - Sadovskaya, Ekaterina

AU - Yeremeev, Nikita

AU - Kolchugin, Alexander

AU - Shmakov, Alexander

AU - Vinokurov, Zakhar

AU - Mishchenko, Denis

AU - Filonova, Elena

AU - Belyaev, Vladimir

N1 - Funding Information: Acknowledgments: The materials synthesis as well as electrochemical study were performed in a framework of the budget task of the IHTE UB RAS with using the equipment of the shared access center “Composition of compounds”. The TGA and isotope exchange studies were supported by the Ministry of Science and Higher Education of the Russian Federation within the governmental order for Boreskov Institute of Catalysis (projects АААА‐А21‐121011390007‐7, АААА‐А21‐ 121011390009‐1). The SXRD experiments were performed at the shared research center SSTRC on the basis of the Novosibirsk VEPP‐3 complex at BINP SB RAS, using equipment supported by pro‐ ject RFMEFI62119X0022. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/3

Y1 - 2021/3

N2 - This work presents the results from a study of the structure and transport properties of Ca‐doped La2NiO4+δ. La2−xCaxNiO4+δ (x = 0–0.4) materials that were synthesized via combustion of organic‐nitrate precursors and characterized by X‐ray diffraction (XRD), in situ XRD using synchrotron radiation, thermogravimetric analysis (TGA) and isotope exchange of oxygen with C18O2. The structure was defined as orthorhombic (Fmmm) for x = 0 and tetragonal (I4/mmm) for x = 0.1–0.4. Changes that occurred in the unit cell parameters and volume as the temperature changed during heating were shown to be caused by the excess oxygen loss. Typical for Ruddlesden–Popper phases, oxygen mobility and surface reactivity decreased as the Ca content was increased due to a reduction in the over‐stoichiometric oxygen content with the exception of x = 0.1. This composition demonstrated its superior oxygen transport properties compared to La2NiO4+δ due to the enhanced oxygen mobility caused by structural features. Electrochemical data obtained showed relatively low polarization resistance for the electrodes with a low Ca content, which correlates well with oxygen transport properties.

AB - This work presents the results from a study of the structure and transport properties of Ca‐doped La2NiO4+δ. La2−xCaxNiO4+δ (x = 0–0.4) materials that were synthesized via combustion of organic‐nitrate precursors and characterized by X‐ray diffraction (XRD), in situ XRD using synchrotron radiation, thermogravimetric analysis (TGA) and isotope exchange of oxygen with C18O2. The structure was defined as orthorhombic (Fmmm) for x = 0 and tetragonal (I4/mmm) for x = 0.1–0.4. Changes that occurred in the unit cell parameters and volume as the temperature changed during heating were shown to be caused by the excess oxygen loss. Typical for Ruddlesden–Popper phases, oxygen mobility and surface reactivity decreased as the Ca content was increased due to a reduction in the over‐stoichiometric oxygen content with the exception of x = 0.1. This composition demonstrated its superior oxygen transport properties compared to La2NiO4+δ due to the enhanced oxygen mobility caused by structural features. Electrochemical data obtained showed relatively low polarization resistance for the electrodes with a low Ca content, which correlates well with oxygen transport properties.

KW - Ca doping

KW - Isotope exchange

KW - La2NiO4+δ

KW - Oxygen mobility

KW - Polarization resistance

KW - Synchrotron radiation studies

UR - http://www.scopus.com/inward/record.url?scp=85103574232&partnerID=8YFLogxK

U2 - 10.3390/cryst11030297

DO - 10.3390/cryst11030297

M3 - Article

AN - SCOPUS:85103574232

VL - 11

JO - Crystals

JF - Crystals

SN - 2073-4352

IS - 3

M1 - 297

ER -