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Novel Aspects of the Conduction Mechanisms of Electrolytes Containing Tetrahedral Moieties
Author(s) -
Kendrick E.,
Kendrick J.,
Orera A.,
Panchmatia P.,
Islam M. S.,
Slater P. R.
Publication year - 2011
Publication title -
fuel cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 69
eISSN - 1615-6854
pISSN - 1615-6846
DOI - 10.1002/fuce.201000044
Subject(s) - vacancy defect , thermal conduction , fast ion conductor , oxide , ion , tetrahedron , materials science , crystallography , chemical physics , electrolyte , perovskite (structure) , inorganic chemistry , chemistry , electrode , organic chemistry , composite material , metallurgy
Traditionally materials with the fluorite and perovskite structures have dominated the research in the area of oxide ion/proton conducting solid electrolytes. In such cases, the key defects are oxide ion vacancies, and conduction proceeds via a simple vacancy hopping mechanism. In recent years, there has been growing interest in alternative structure types, many of which contain tetrahedral moieties. For these new systems, an understanding of the accommodation of defects and the nature of the conduction mechanism is important for the optimisation of their conductivities, as well as to help target related structures that may display high oxide ion/proton conduction. Computer modelling studies on a range of systems containing tetrahedral moieties are presented, including apatite‐type La 9.33+ x Ge 6 O 26+3 x /2 , cuspidine‐type La 4 Ga 2– x Ti x O 9+ x /2 and La 1– x Ba 1+ x GaO 4– x /2 . The type of anion defect (vacancy or interstitial), their location and the factors affecting their incorporation are discussed. In addition, modelling data to help to understand their conduction mechanisms are presented, showing novel aspects including the important role of the tetrahedral moieties in the conduction processes.