La_0.1Sr_xCa_0.9−xMnO_3−Δ-Sm_0.2Ce_0.8O_1.9 composite material for novel low temperature solid oxide fuel cells

Lowering the operating temperature of the solid oxide fuel cells (SOFCs) is one of the world R&D tendencies. Exploring novel electrolytes possessing high ionic conductivity at low temperature becomes extremely important with the increasing demands of the energy conversion technologies. In this work, perovskite La_0.1Sr_xCa_0.9−xMnO_3−δ (LSCM) materials were synthesized and composited with the ionic conductor Sm_0.2Ce_0.8O_1.9 (SDC). The LSCM–SDC composite was sandwiched between two nickel foams coated with semiconductor Ni_0.8Co_0.15Al_0.05LiO_2−δ (NCAL) to form the fuel cell device. The strontium content in the LSCM and the ratios of LSCM to SDC in the LSCM-SDC composite have significant effects on the electrical properties and fuel cell performances. The best performance has been achieved from LSCM-SDC composite with a weight ratio of 2:3. The fuel cells showed OCV over 1.0 V and excellent maximum output power density of 800 mW cm⁻² at 550 °C. Device processes and ionic transport processes were also discussed.