Oxygen Stoichiometry in Cation Deficient (La,Sr)_{1-z}MnO_3 SOFC Cathode Materials

Birgit Zachau-Christiansen, Torben Jacobsen, Steen Skaarup

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Abstract

The variation of oxygen stoichiometry with oxygen partial pressure is determined for perovskites, ABO3, with the general composition: (La1-xSrx)_{1-z}MnO_{3+y}. The measurements are performed as linear sweep voltammetry on an oxygen pumping cell, where the oxygen partial pressure is controlled by the imposed potential.It is found that the oxygen stoichiometry and hence the defect chemistry is different whether A-site charge deficiency is established by Sr-doping or by A-site vacancies. Furthermore,A-site deficient lanthanum strontium manganates expel a secondary phase of manganese oxide when exposed to low oxygen partial pressures. The presence of small amounts of secondary phase isobserved and identified by its reoxidation peak. The amount of this foreign phase is determined by the charge used for its oxidation.
Original languageEnglish
Title of host publicationSolid Oxide Fuel Cells V
Place of PublicationPennington
PublisherThe Electrochemical Society
Publication date1997
Pages795-804
Publication statusPublished - 1997
EventSold Oxide Fuel Cells V - Aachen
Duration: 1 Jan 1997 → …

Conference

ConferenceSold Oxide Fuel Cells V
CityAachen
Period01/01/1997 → …

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