The dataset includes the electrical properties mesurements of SOFC with Ce0.9Cu0.1O2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC. 'Such prepared fuel cells were mounted in a measurement rig. They were heated up to 800 °C with argon delivered to the anode side and then, in order to reduce nickel oxide, humidified hydrogen (3% H2O) was supplied at 800 °C for 30 min and further at 750 °C for 20 h. After this time the hydrogen was replaced by wet synthetic biogas (3% H2O) consisting of methane and carbon dioxide mixed at a volume ratio of 60/40. The total flow rate of the gas mixture was 30 cm3 min−1. Two types of electrical measurements were collected during fuel cell operation in biogas: a current density versus voltage and a current density versus time at 0.65 V for the time 120 h at 750 °C.' (10.1016/j.ssi.2018.12.007Cyfrowy identyfikator dokumentu elektronicznego (otwiera się w nowej karcie))