Distribution of Oxygen Vacancies in an External Electric Field and Oxygen-Ion Conductivity in Acceptor-Doped Fluorite-Structured Ionic Conductors

(La0.6Sr0.4)(Co0.2Fe0.8)O3–δ (LSCF) has been promised as a cathode material of solid oxide fuel cells at intermediate temperatures. Despite the many previous studies of LSCF that have been reported, the role of Co and Fe atoms in the oxygen ion conduction is still unclear. In this work, we aimed at presenting each valence, oxygen chemical diffusion coefficient (Dchem) and activation energy (Ea) related to Co and Fe in LSCF by in situ X-ray absorption spectroscopy (XAS) at high temperatures and during reduction. For quantitative analysis of X-ray absorption near edge structure (XANES) spectroscopy, these results indicated that the Co valence decreased more easily than the Fe valence. On the other hand, from relaxation plots of the Co and Fe valence during reduction, the values of Dchem and Ea related to Co and Fe were nearly equal. Considering equations showing the oxygen ion conductivity, these results would indicate that oxygen ion conductivity was contributed by Co with more oxygen vacancies rather than Fe. According to these results, a structural model with and without oxygen vacancies and the oxygen ion conduction mechanism of LSCF was speculated, that is, we found that oxygen ion conductivity was more closely related to Co than Fe in LSCF by direct observations of in situ XAS.

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Oxygen ion conductivity and mechanical properties of Lu2O3-doped ZrO2 as a solid electrolyte

Ceramics International ◽

10.1016/j.ceramint.2021.03.158 ◽

2021 ◽

Author(s):

Min-sung Park ◽

Kanghee Jo ◽

Hwanseok Lee ◽

Bola Yoon ◽

Heesoo Lee

Keyword(s):

Mechanical Properties ◽

Solid Electrolyte ◽

Ion Conductivity ◽

Oxygen Ion Conductivity ◽

Oxygen Ion

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Oxygen-ion Conductivity of Re Tungstates Ln14W4O33 (Ln = Nd, Sm, Gd)

2021 IEEE International Symposium on Applications of Ferroelectrics (ISAF) ◽

10.1109/isaf51943.2021.9477315 ◽

2021 ◽

Author(s):

Anna Shlyakhtina ◽

Nikolay Lyskov ◽

Sergei Cheryak ◽

Igor Kolbanev ◽

Anna Kasyanova ◽

...

Keyword(s):

Ion Conductivity ◽

Oxygen Ion Conductivity ◽

Oxygen Ion

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Doped Ceria Based Solid Oxide Fuel Cell Electrolytes and their Sintering Aspects: An Overview

Materials Science Forum ◽

10.4028/www.scientific.net/msf.835.199 ◽

2016 ◽

Vol 835 ◽

pp. 199-236 ◽

Cited By ~ 1

Author(s):

Pradyot Datta

Keyword(s):

Power Generation ◽

Fuel Cell ◽

Solid Oxide Fuel Cell ◽

Operating Temperature ◽

Solid Oxide ◽

Ion Conductivity ◽

Doped Ceria ◽

Oxide Fuel ◽

Oxygen Ion Conductivity ◽

Oxygen Ion

Depletion of fossil fuel at an alarming rate is a major concern of humankind. Consequently, researchers all over the world are putting a concerted effort for finding alternative and renewable energy. Solid oxide fuel cell (SOFC) is one such system. SOFCs are electrochemical devices that have several advantages over conventional power generation systems like high efficiency of power generation, low emission of green house gases and the fuel flexibility. The major research focus of recent times is to reduce the operating temperature of SOFC in the range of 500 to 700 °C so as to render it commercially viable. This reduction in temperature is largely dependent on finding an electrolyte material with adequate oxygen ion conductivity at the intended operating temperature. One much material is Gadolinia doped Ceria (CGO) that shows very good oxygen ion conductivity at the intended operation temperature. The aim of this overview is to highlight the contribution that materials chemistry has made to the development of CGO as an electrolyte.

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