Break down of losses in thin electrolyte SOFCs

The contributions of the individual components of the cell (anode, cathode, and electrolyte) to the cell resistance were determined experimentally, directly from impedance spectra obtained from a full cell. It was an anode supported thin electrolyte cell, consisting of a YSZ electrolyte, a Ni/YSZ cermet anode, and a LSM composite cathode. Additional, qualitative information was obtained using symmetric cells with LSM composite electrodes. The investigations were carried out in the temperature interval from 700 to 850 degrees C. The electrolyte and anode activation energies obtained were 0.9 and 1.1 eV, respectively, which is in relatively good agreement with literature values. The anode resistance was 0.24 Omega cm(2) and the cathode resistance was 0.58 Omega cm(2) at 700 degrees C, corresponding to 23% and 56% of the total resistance, respectively.