Michael T. Benson

Protonic ceramic electrochemical cells (PCECs) are promising platforms for efficient energy conversion, hydrogen production, and high-value chemical synthesis at intermediate temperatures. However, large-scale deployment of PCECs remains constrained by the poor sinterability, high fabrication cost, and long processing time associated with state-of-the-art proton-conducting ceramic (PCC) electrolytes. Here, we report a time-efficient, ball-milling-free solid-state reaction approach using nano-sized precursor particles (n-SSR) to synthesize Ba (Zr,Ce,Y,Yb)O _{3− δ} proton-conducting electrolytes with enhanced manufacturability and performance. Compared with the conventional solid-state reaction route using micro-sized precursors ( μ -SSR), the n-SSR process largely shortens powder fabrication time by eliminating ball-milling process while producing fine electrolyte particles (200–600 nm) with superior sintering activity. As a result, PCECs fabricated with n-SSR electrolytes exhibit lower densification temperature and markedly improved electrochemical performance, delivering a 32% higher peak power density in fuel cell mode and a 40% higher electrolysis current density at 600 °C, primarily due to reduced ohmic resistance. Long-term stability exceeding 500 h without measurable degradation is demonstrated. Importantly, a techno-economic analysis reveals that the n-SSR process reduces total electrolyte fabrication costs by 25%–29% by minimizing comminution, calcination time, and processing complexity. Large-area (5 cm × 5 cm) single-cell fabrication further validates the scalability of this approach. These results establish n-SSR as a practical and generalizable manufacturing strategy for high-performance PCCs, addressing a key bottleneck for the large-scale deployment of protonic ceramic energy technologies.

Metallic fuels hold numerous advantages over conventional uranium dioxide fuels and are a key component of several liquid metal-cooled advanced reactor concepts including sodium fast reactors. These fuels undergo rapid swelling during early burnup; consequently, they spend most of their reactor lifetime in a porous state. The presence of this porosity alters many of the mechanical properties of the fuel including creep impacting fuel deformation during axial swelling. This work investigates the creep behavior of the porous fuel using a spark plasma sintering technique. Creep tests were performed for the first time on porous α-phase uranium and uranium with 10 wt. % zirconium (U-10Zr) samples. The samples of α-phase uranium and U-10Zr were fabricated from depleted uranium by spark plasma sintering and subjected to uniaxial compressive creep testing. Calculated stress exponents were found to be 2.6±1.6 and 5.7±1.4 for α-U and U-10Zr, respectively, and calculated activation energies were found to be 61.6±1.1kJ/mol for α-U. The creep data were also used to evaluate existing porosity inclusive in creep models.