LiNi-oxide simultaneously as electrolyte and symmetrical electrode for low-temperature solid oxide fuel cell

LiNi-oxide showed triple (oxygen ionic, protonic and electronic) conduction properties and were considered as the promising cathode for proton conducting solid oxide fuel cells (H–SOFC). In this work, we pioneeringly explore the potential of Li x NiO 2 (x = 0.2, 0.4, 0.5, 0.8) (L x NO) for symmetrical electrode and electrolyte application. The composite of semiconductor L x NO and proton conductor BaZr 0.5 Y 0.5 O 3 （BZY）are applied as electrolyte with L 0.5 NO as symmetrical electrode to assemble solid oxide fuel cells. There is no negative impact on cell performance after introducing the electronic conductor L x NO into BZY as electrolyte membrane. On the contrary, the cell based on L 0.5 NO -BZY composite electrolyte is significantly higher than that of pure BZY electrolyte. The cell performance can be improved by optimizing the weight ratio of BZY and L 0.5 NO. When the mass ratio of BZY to L 0.5 NO was 8:2, the open circuit voltage (OCV) of the cell was 1.11 V, and the maximum power (P max ) was 814 mW ⋅ cm −2 at 550 °C. This work demonstrated that the LiNi-oxide can be simultaneously used as electrolyte and symmetrical electrode for low-temperature solid oxide fuel cell. 1 LiNi-oxide act as symmetrical electrode of LT-SOFC. 2 LiNi-oxide/BaZr 0.5 Y 0.5 O 3 composites used as electrolyte of LT-SOFC. 3 Schottky junction between anode and semiconductor electrolyte is proved. 4 The device avoids high temperature sintering and obtain good performance. 5 LiNi-oxide has good catalytic activity.