Enhanced performance of Sr₂Fe_1.5Mo_0.5O_6-δ electrode by infiltrating dual functional barium carbonate nanoparticles in symmetrical SOFCs

In solid oxide fuel cell (SOFC) electrode catalyst, the reaction in cathode and anode involves different reactions that require diverse catalytic materials. In this work, BaCO₃ as a non-ionic/electronic conductor was infiltrated into Sr₂Fe_1.5Mo_0.5O_6-δ (SFM) electrode in symmetrical SOFC. The oxygen reduction reaction in SFM cathode could be enhanced when infiltrated with BaCO₃, as area-specific resistance (ASR) was reduced from 0.33 to 0.15 Ωcm² at 700 °C. The 0.42 Ωcm² ASR values of SFM anode are reduced to 0.35 Ωcm². The performance improvement is directly related with the loading weight of BaCO₃, which is actually the surface coverage of BaCO₃ on SFM electrode frame. And the oxygen surface exchange coefficient of SFM cathode is improved from 4.8 × 10⁻⁵ to 10.5 × 10⁻⁵ cms⁻¹ at 800 °C, but the hydrogen oxidation rate of SFM anode is slightly increased, which is consistent with the infiltrated SFM anode. For a full cell with BaCO₃ infiltrated SFM as cathode and anode, the power density is 0.81 Wcm⁻² that is 44% higher than the bare SFM electrode at 800 °C and remains stable at 0.64 Acm⁻² for the 200 h test. As a cheap and extensive synergistic catalyst for electrode reaction, barium carbonate shows great application potential in SOFC.