Application of sodium battery electrode in low temperature ceramic fuel cells

Layered transition metal oxides are promising high energy density electrodes for lithium/sodium batteries. Herein we study the application of commercial sodium battery electrode material MS-XN-33S-Ternary sodium nickel-ferric manganate layered oxide (NFMNa) in low temperature ceramic fuel cells (LT-CFCs). We investigate its crystal structure, microstructure, surface state, and applying it as the electrolyte functional layer for fuel cells. By using electron microscopy and surface analysis characterization techniques, it is determined that in addition to layered material NaNi_0.34Fe_0.33Mn_0.33O₂, there is also polycrystalline Na₂CO₃ in the NFMNa materials. NFMNa electrolyte fuel cells devices have 0.102 S cm⁻¹ ion conductivity at 520 °C. NFMNa materials have proton conduction at 400–600 °C and no oxygen ion conduction, which is tested using hydrogen and oxygen concentration cells. BaZr_0.1Ce_0.7Y_0.2O_3-δ (BZCY) has better compatibility with electrode LiNi_0.8Co_0.15Al_0.05O₂ (NCAL) than NFMNa. Cell devices with BZCY buffer layer have better low-temperature performance, obtaining a power density of 123 mW cm⁻² at 340 °C. And the NCAL (anode)-BZCY/NFMNa-NCAL (cathode) device achieve a constant current of 100 mA cm⁻² for 110 h discharge output. This work contributes to the development of LT-CFCs electrolytes and a comprehensive understanding of the material properties of layered oxide electrodes in lithium/sodium batteries.