燃料电池用LSGM-碳酸盐复合电解质材料的稳定性

Thermal Stability of LSGM-carbonates Composite Electrolytes for Low-temperature Solid Oxide Fuel Cells

摘要:

目前研究较多的固体氧化物电池用碳酸盐复合电解质体系中，碳酸盐在工作温度下的熔融状态使其稳定性受到质疑。本文通过聚丙烯酰胺溶胶凝胶法制得La0.9Sr0.1Ga0.8Mg0.2O2.85（LSGM）粉体与二元碳酸盐复合，制备了新型LSGM-碳酸盐复合电解质，从老化、循环和电池输出三方面考察了LSGM- (Li/Na)2CO3复合电解质的稳定性。在600℃、650 h的测试中，复合电解质的电导率长期稳定在0.07~0.09 S?cm-1；在室温~700℃循环中碳酸盐基本没有损失，电导率也较稳定；单电池在0.6 A?cm-2恒流放电，1 h内平均功率密度为256 mW?cm-2。

Abstract:

The carbonates composite electrolytes for solid oxide cells have aroused more attention. However, the thermal stability of carbonates composite electrolytes remains in doubt due to the molten state of the carbonates at operating temperature. The novel composite electrolytes were obtained by mixing LSGM powders which were synthesized by acrylamide polymerization with binary carbonates. Ageing, cycling and longtime fuel cell performance tests were used to evaluate the stability of LSGM-(Li/Na)2CO3 composite materials. The sample shows a relatively stable conductivity of 0.07-0.09 Scm-1 during a 650 h measurement in air at 600℃.The composites keep weight stable during thermal cycling below 700℃, and demonstrate a good stability after 5 thermal cycles. The cell based on LSGM-(Li/Na)2CO3 composite electrolyte delivers an average output of 256 mWcm-2 in 1h operation corresponding to the constant current density 0.6Acm-2.