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 LixNiO2 (x = 0.2, 0.4, 0.5, 0.8) (LxNO) for symmetrical electrode and electrolyte application. The composite of semiconductor LxNO and proton conductor BaZr0.5Y0.5O3（BZY）are applied as electrolyte with L0.5NO as symmetrical electrode to assemble solid oxide fuel cells. There is no negative impact on cell performance after introducing the electronic conductor LxNO into BZY as electrolyte membrane. On the contrary, the cell based on L0.5NO -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 L0.5NO. When the mass ratio of BZY to L0.5NO was 8:2, the open circuit voltage (OCV) of the cell was 1.11 V, and the maximum power (Pmax) 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.