Enhanced performance of solid oxide fuel cells with Ni/CeO2 modified La0.75Sr0.25Cr0.5Mn0.5O3−δ anodes

The optimization of electrodes for solid oxide fuel cells (SOFCs) has been achieved via a wet impregnation method. Pure La0.75Sr0.25Cr0.5Mn0.5O3−δ (LSCrM) anodes are modified using Ni(NO3)2 and/or Ce(NO3)3/(Sm,Ce)(NO3)x solution. Several yttria-stabilized zirconia (YSZ) electrolyte-supported fuel cells are tested to clarify the contribution of Ni and/or CeO2 to the cell performance. For the cell using pure-LSCrM anodes, the maximum power density (Pmax) at 850 °C is 198 mW cm−2 when dry H2 and air are used as the fuel and oxidant, respectively. When H2 is changed to CH4, the value of Pmax is 32 mW cm−2. After 8.9 wt.% Ni and 5.8 wt.% CeO2 are introduced into the LSCrM anode, the cell exhibits increased values of Pmax 432, 681, 948 and 1135 mW cm−2 at 700, 750, 800 and 850 °C, respectively, with dry H2 as fuel and air as oxidant. When O2 at 50 mL min−1 is used as the oxidant, the value of Pmax increases to 1450 mW cm−2 at 850 °C. When dry CH4 is used as fuel and air as oxidant, the values of Pmax reach 95, 197, 421 and 645 mW cm−2 at 750, 800, 850 and 900 °C, respectively. The introduction of Ni greatly improves the performance of the LSCrM anode but does not cause any carbon deposit.