Preparation of a nano-size (La0.2Nd0.2Sm0.2Sr0.2Ba0.2)Co0.2Fe0.8O3-δ/SDC high-entropy oxide composite cathode

The nano-size (La0.2Nd0.2Sm0.2Sr0.2Ba0.2)Co0.2Fe0.8O3/Ce0.8Sm0.2O1.9（SDC)composite cathodes were prepared by impregnating high entropy (La0.2Nd0.2Sm0.2Sr0.2Ba0.2)Co0.2Fe0.8O3 (HE-LNSSB) catalytic phase into the SDC electrode skeleton. The catalytic activity and the stability of the nano-size LNSSB phase are investigated. The XRD results show that the orthorhombic perovskite phase was obtained when the HE-LNSSB precursor was calcined at 800 °C. At 700 °C, the pristine nano-size HE-LNSSB/SDC composite cathode shows a specific polar resistance (Rasp) of 0.30 Ω·cm2. The Rasp of the pristine nano-size HE-LNSSB composite cathode was reduced by 50.8 % compared with that of the sintered HE-LNSSB cathode. The Rasp of the aged nano-size HE-LNSSB composite cathode was 0.31 Ω·cm2 at 700 °C and the catalytic activity did not decay. The SEM and the XPS results show that the particle micrograph of the nano-size HE-LNSSB catalytic phase hardly changes and Sr elements do not segregate on the HE-LNSSB phase surface after being aged. The research results show that the nano-size HE-LNSSB/SDC composite cathode will be a potential cathode material for the intermediate temperature solid oxide fuel cells.