COPPER SINTERING IN Cu-CERIA-Sm_(0.2)Ce_(0.8)O_(1.9) (SDC) ANODES

摘要

A Cu_(25%)-ceria_(16%)-SDC composite-anode SOFC is characterized in hydrogen (H_2) at 973K using electrochemical-cell and impedance-spectroscopy measurements. The cell maximum power density decreases from 129mW/cm~2 to 25mW/cm~2 over 9-hour operation. Impedance characterization indicates continuously decreasing cell conductance, which accounts for the cell-performance degradation. The conductance variation is attributed to Cu sintering taking place in the anode, which is supported by conductivity-measurement results and microscopic investigation. An approach is proposed to impede Cu sintering in the Cu-ceria composite anodes, and a SOFC with a proposed anode displays improved stability.