Abstract
Nowadays, Ni0.8Co0.15Al0.05LiO2-δ (NCAL) has been increasingly applied into the solid oxide fuel cell (SOFC) field as a promising electrode material. Here, the performances of NCAL cathode were investigated for low-temperature SOFCs (LT-SOFCs) on Ce0.8Sm0.2O2-δ (SDC) electrolyte. After on-line reduction of NCAL for 30 min, the partially reduced NCAL, i.e., NCAL(r), was employed as the new cathode and its performances were also investigated. The area specific resistances of NCAL and NCAL(r) cathodes on SDC electrolyte are 7.076 and 1.214 Ω cm2 at 550 °C, respectively. Moreover, NCAL(r) exhibits the activation energy of 0.46 eV for oxygen reduction reaction (ORR), which is much lower than that of NCAL (0.88 eV). The fuel cell consisted of NCAL electrodes and SDC electrolyte shows an open circuit voltage (OCV) of 0.95 V and power output of 436 mW cm−2 at 550 °C. After cathode on-line optimization, the cell's OCV and power output are significantly increased to 1.01 V and 648 mW cm−2, which mainly attributed to the accelerated ORR and decreased electrode polarization resistance. These results demonstrate that NCAL(r) is a promising cathode material for LT-SOFCs.
[Display omitted]
•Partially reduced NCAL was applied as the novel cathode material.•ORR mechanism for NCAL and NCAL(r) cathodes were investigated.•The fuel cell's OCV and Pmax were enhanced to 1.01 V and 648 mW cm−2 at 550 °C.•NCAL(r) showed better ORR activity than NCAL with a lower Ea of 0.46 eV.