Doped ceria electrolytes have attracted intensive attentions owing to their high ionic conductivity, low activation energy, good catalytic activity and feasibility for intermediate or even low temperature operations. This work reports an interesting industrial grade rare earth LaCe1.85Pr0.03Nd0.06-oxide composited with sodium carbonate (LCPN-oxide/Na2CO3) as the electrolyte in solid oxide fuel cells (SOFCs). The ‘symmetrical’ anode/electrolyte/cathode SOFC devices are fabricated using LCPN-oxide/Na2CO3 electrolyte and the lithiated transition metal oxide Ni0.8Co0.15Al0.05LiO2 (NCAL) pasted onto nickel foam as both anode and cathode. A power density of 362 mW/cm 2 is achieved at 550 o C for this device. A novel fuel cell device, semiconductor-ionic membrane fuel cell (SIMFC) is introduced here using the LCPN-oxide/Na2CO3 and NCAL as the mixed semiconductor-ionic conductor layer. The peak power density for this new energy conversion device reaches 916 mW/cm 2 at 550 o C with an open circuit voltage of 1.05 V. The results demonstrate that industrial grade LCPN-oxide/Na2CO3 can provide a new approach to utilize the enriched natural resources for next-generation cost-effective fuel cells.