Characterization of SiC-SiC Whisker Matrix Retaining Electrolyte in Phosphoric Acid Fuel Cell

,; ,; ,; ,; ,; ,; ,; ,

J. Korean Ceram. Soc. > Volume 29(8); 1992 > Article

Journal of the Korean Ceramic Society 1992;29(8): 587.

인산형 연료전지용 SiC-SiC Whisker 전해질 매트릭스의 특성

윤기현, 이현임, 이근행, 김창수¹

연세대학교 세라믹공학과
¹한국에너지기술연구소

Characterization of SiC-SiC Whisker Matrix Retaining Electrolyte in Phosphoric Acid Fuel Cell

ABSTRACT

Sheets of SiC-SiC whisker maxed matrix were prepared from the mixed slurry of SiC whisker and SiC matrix by the rolling method. With the increase of SiC whisker, the pore size, the porosity and the phosphoric acid absorbency of the matrix were increased, while the bubble pressure was decreased. The activation energy for the transfer of H+ ion was decreased with the increase of mixing ratio of SiC whisker to the SiC matrix from the measurement of hydrogen ion conductivity. The activation energy was evaluated as 0.25 eV when the mixing ratio of SiC whisker to the SiC matrix was 1 : 2 and the activation energy was 0.16 eV for the 2 : 1 matrix. It means that SiC whisker matrix contributes to attain a better microstructure for the diffusion of hydrogen ion. From the measurement of single cell performance of matrix with various mixing ratio, it is concluded that if SiC-SiC whisker maxed matrix has a sufficient bubble pressure to prevent the crossover of H2 gas, the current density of a fuel cell is increased with the increase of acid absorbency of the matrix. Current density was improved from 140 mA/$textrm{cm}^2$ for 0.25 mm thickness of matrix to 170 mA/$textrm{cm}^2$ for the 0.20 mm one at 700 mV.