Publicação

Benchmarking the ambipolar conductivity of composite electrolytes for gas separation membranes

Ver documento

Detalhes bibliográficos
Resumo:Composite electrolytes including an oxide (Gd-doped ceria, 70, 80, and 90vol%) and a eutectic mixture of alkaline carbonates (Na2CO3 and Li2CO3) were produced by joint milling and firing of all constituents. The microstructure of these composites was studied by scanning electron microscopy/energy-dispersive X-ray spectroscopy, and they were further studied by impedance spectroscopy in air. Analysis of impedance data at low and high temperature was used to separate the electrical performance of each constituent phase, providing valuable information on the membrane electrical microstructure. Furthermore, a new tool is introduced for the assessment of the electrical microstructure efficiency of composite membranes, as a diagram relating the partial ionic transport numbers of main charge carriers and the membrane ambipolar conductivity. Using this type of diagram, the electrical features of actual composite membranes were mapped against an ideal membrane performance where microstructural effects are absent. The potential of this procedure to benchmark and discriminate the electrical characteristics of distinct membranes is demonstrated in this manner. Copyright (c) 2016 John Wiley \& Sons, Ltd.
Autores principais:Patricio, Sonia G.
Outros Autores:Marques, Fernando M. B.
Assunto:CARBON-DIOXIDE SEPARATION DUAL-PHASE MEMBRANES HIGH-TEMPERATURE ION-TRANSPORT FUEL-CELLS PERFORMANCE PERMEATION OXIDE STABILITY DIFFUSION
Ano:2016
País:Portugal
Tipo de documento:artigo
Tipo de acesso:acesso restrito
Instituição associada:Universidade de Aveiro
Idioma:inglês
Origem:RIA - Repositório Institucional da Universidade de Aveiro
Descrição
Resumo:Composite electrolytes including an oxide (Gd-doped ceria, 70, 80, and 90vol%) and a eutectic mixture of alkaline carbonates (Na2CO3 and Li2CO3) were produced by joint milling and firing of all constituents. The microstructure of these composites was studied by scanning electron microscopy/energy-dispersive X-ray spectroscopy, and they were further studied by impedance spectroscopy in air. Analysis of impedance data at low and high temperature was used to separate the electrical performance of each constituent phase, providing valuable information on the membrane electrical microstructure. Furthermore, a new tool is introduced for the assessment of the electrical microstructure efficiency of composite membranes, as a diagram relating the partial ionic transport numbers of main charge carriers and the membrane ambipolar conductivity. Using this type of diagram, the electrical features of actual composite membranes were mapped against an ideal membrane performance where microstructural effects are absent. The potential of this procedure to benchmark and discriminate the electrical characteristics of distinct membranes is demonstrated in this manner. Copyright (c) 2016 John Wiley \& Sons, Ltd.

Atividades financiadas

Não foram encontrados projetos financiados.