Effect of Current Collecting Layer on the Impedance of LSM and LSM-YSZ Cathode

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J. Korean Ceram. Soc. > Volume 35(10); 1998 > Article

Journal of the Korean Ceramic Society 1998;35(10): 1070.

LSM 및 LSM-YSZ 양극의 임피던스 특성에 미치는 집전층의 효과

문지웅, 이홍림, 김구대¹, 김재동, 이해원¹

연세대학교 세라믹공학과
¹한국과학기술연구원 세라믹공정연구센터

Effect of Current Collecting Layer on the Impedance of LSM and LSM-YSZ Cathode

ABSTRACT

Effect of current collecting layer on the cathode was characterized by AC impedance spectroscopy at 800$^{circ}C$ under flowing air. LSM-YSZ composite cathode showed lower polarization resistance due to the in-crease of triple phase (LSM/YSZ/Pore) boundary length by incorporation of YSZ. Ohmic resistance {{{{ {R }_{1 } }} of LSM-YSZ was higher than that of pure LSM however because in-plane resistance of the cathode was fair-ly high due to its high specific resistivity. To reduce the in-plane resistance of LSM-YSZ cathode cathode side current collecting layer was required. Ohmic resistance {{{{ {R }_{1 } }} was reduced after forming LSM current col-lecting layer on the LSM-YSZ cathode. In case of pure LSM cathode the formation of Pt, or LSCO current collecting layer reduced polarization resistance {{{{ {R }_{p } }} but ohmic resistance {{{{ {R }_{1 } }} was relatively constant. After annealing of LSM cathode with Pt current collector at higher temperature polarization resistance {{{{ {R }_{p } }} was in-creased but ohmic resistance {{{{ {R }_{1 } }} was constant. These phenomena indicate that Pt or LSCo current col-lecting layers act as a catalytic layer for oxygen reduction of pure LSM cathode. LSCO current collector was effective in reducing the ohmic and polarization resistance of LSM-YSZ cathode.

Key words: Current collecting layer, LSM, LSM-YSZ, Impedance, In-plane resistance