复合电解质Ce_(0.8)Gd_(0.2)O_(2-α)-(Li/K)_2CO_3的中温燃料电池性能

Intermediate Temperature Fuel Cell Performance of the Composite Electrolyte Ce_(0.8)Gd_(0.2)O_(2-α)-(Li/K)_2CO_3

用溶胶凝胶法低温(900℃,通常高温烧结温度为1400℃)制备了Ce_(0.8)Gd_(0.2)O_(2-α),并与(Li/K)_2CO_3共熔体进行复合。XRD结果表明(Li/K)_2CO_3与Ce_(0.8)Gd_(0.2)O_(2-α)复合后没有发生化学反应,SEM结果表明复合电解质致密无孔洞。考察了复合电解质在400~600℃下干燥氮气气氛中的电导率,结果表明,温度为600℃时,复合电解质的电导率达到最大值6.4×10^(-2)S·cm^(-1),高于单一CeO_2材料在相同条件下的电导率。氧分压与电导率关系曲线表明复合电解质具有良好的氧离子导电性。H_2/O_2燃料电池性能测试表明,复合电解质GDC-SG-LK在600℃开路条件下的电解质阻抗、极化阻抗分别为2.7和0.8Ω,最大输出功率密度为267mW·cm^(-2)。

Ce0.8 Gd0.2 O2-α was synthesized by sol-gel method at 900℃ , which is much lower than theconventional sintering temperature （1400℃）, and was further compounded with （Li/K）2CO3. The XRD pattern showed that there is no chemical reaction between Ce0.8 Gd0.2O2-αand （Li/K）2 CO3- The SEM images demonstrated that the composite electrolyte is sufficiently dense and does not have holes. The conductivities of the composite electrolyte in dry nitrogen atmosphere were measured using electrochemical analyzer. The highest conductivity was observed to be 6.4 × 10^-2 S.cm -1 at 600℃ , which is higher than that of single CeO2 material. The H2/O2 fuel cell performance test showed that the electrolyte impedance and polarization impedance under open-circuit condition are 2. 711 and 0. 811, respectively, and the maximum output power density is 267mW·cm -2 at 600℃.