A niobium and tantalum co-doped perovskite electrolyte with high ionic conduction for low-temperature Ceramics Fuel cell

Abstract

In recent studies, fast ionic conduction through surface doping and coating has been a favorite subject and has indicated a promising and stable strategy to optimize ions in the developed electrolytes for low-temperature ceramic fuel cells (LT-CFCs). We have designed co-doped perovskite (Nb/Ta-SrCoO₃) to enhance further ionic properties using the Solid-state blending technique. The prepared SCNT (SrCoNb_0.3Ta_0.3O₃) was used as an electrolyte sandwiched between symmetrical electrodes and delivered attractive fuel cell performance (650 mW/cm²) with better stability at the low operating temperature of 520 °C compared to other compositions of SCNT. The low grain boundary resistance manifests SCNT's high ionic conduction + microstructural properties, assisting with higher fuel cell performance. The co-doping enables the fermi-level to move towards the -ive side, establishing a space charge region constituting BIEF (built in electric field) and helping to enhance the ions' transportation through the surface and interface. This work thus points out a new type of electrolyte with a different working mechanism from previous studies. It indicates a feasible approach to developing high-performing and stable electrolytes for LT-CFCs.