Rare-earth oxide–Li_0.3Ni_0.9Cu_0.07Sr_0.03O_2-Δ composites for advanced fuel cells

Recent development on electrolyte-free fuel cell (EFFC) holding the same function with the traditional solid oxide fuel cell (SOFC) but with a much simpler structure has drawn increasing attention. Herein, we report a composite of industrial grade rare-earth precursor for agriculture and Li_0.3Ni_0.9Cu_0.07Sr_0.03O_2-δ (RE–LNCS) for EFFCs. Both structural and electrical properties are investigated on the composite. It reveals that the RE–LNCS possesses a comparable ionic and an electronic conductivities, 0.11 S cm⁻¹ and 0.20 S cm⁻¹ at 550 °C, respectively. An excellent power output of 1180 mW cm⁻² has been achieved at 550 °C, which is much better than that of the conventional anode/electrolyte/cathode based SOFCs, only around 360 mW cm⁻² by using ionic conducting rare-earth material as the electrolyte. Engineering large size cells with active area of 25 cm² prepared by tape-casting and hot-pressing gave a power output up to 12 W. This work develops a new functional single layer composite material for EFFCs and further explores the device functions.