Investigation of Time Stability of Sr-Doped Lanthanum Vanadium Oxide Anode and Sr-Doped Lanthanum Cobalt Oxide Cathode Based on SDC Electrolyte Using SIMS

Ceramic materials with the perovskite structure are considered as promising alternatives to Ni-based SOFC anodes. In this study La_0.7Sr_0.3VO_3–δ-Ce_0.85Sm_0.15O_2–δ (SDC) anode and La_0.8Sr_0.2CoO_3–δ-SDC cathode were fabricated by infiltration the porous SDC scaffold with an aqueous solution of corresponding nitrates. The time stability of the SOFC single cell has been studied at temperatures 600 and 700°C. As a fuel the mixture of humidified hydrogen (partial pressure 0.2) and argon (partial pressure 0.8) has been used. During 220 h of operating (at 0.6 V) the decrease in maximum power density values at both temperatures was approximately 1%. The microstructure of the single cells, mostly the mobility of Sr within the cell, before and after the time stability measurements have been analyzed using secondary ion mass spectrometry. No degradation was observed during the cell preparation process and only minor elemental mobility was seen after 24 h of operation time. However, noticeable Sr mobility was seen after 220 h operating at 700°C.