Preparation and Property of LSGM-Carbonate Composite Electrolyte for Low Temperature Solid Oxide Fuel Cell

Abstract

The LSGM-carbonate composite electrolyte is a new type of medium and low temperature SOFC electrolyte material, which has great application potential. In this paper, the molten salt infiltration method was used to prepare the LSGM-carbonate composite electrolyte. The results of SEM test proved that the molten salt infiltration method was more appropriate in preparing the LSGM-carbonate composite electrolyte comparing with direct mixing method. The influence of the type and content of pore forming agent was investigated. The result showed that the polymethyl methacrylate (PMMA) had an excellent pore forming performance and could create interconnected pore structures successfully in LSGM matrix. The XRD result indicated that the LSGM-carbonate composite electrolyte showed almost a single LSGM phase and the carbonate remained glass state. Four terminal method was used to measure the conductivity. The result showed that the conductivity of the LSGM-carbonate composite electrolytes was increased by one order of magnitude compared with pure LSGM. The conductivity of LSGM-carbonate composite electrolytes increased firstly and then decreased with the increasing of PMMA. The LSGM-carbonate composite electrolyte prepared by 25 wt.% PMMA addition has the highest conductivity during the whole range of test temperature and reached 0.3 S.cm-1 at 600°C.