Significantly Enhanced Performance of Protonic Ceramic Fuel Cells by Laser Engineering the Electrolyte/Cathode Interface

Protonic ceramic fuel cells have attracted much attention due to their good performance at intermediate temperatures (400–700 °C). However, the highly resistive electrolyte-cathode interface has been discovered to be a crucial obstacle inhibiting further cell improvements in performance. Herein, using a model cell material system of BaCe_0.7Zr_0.1Y_0.1Yb_0.1O_3-δ electrolyte, 40 wt % BaCe_0.7Zr_0.1Y_0.1Yb_0.1O_3-δ + 60 wt % NiO anode, and BaCo_0.4Fe_0.4Zr_0.1Y_0.1O_3-δ cathode, we proved that the laser ablation of electrolyte surfaces could accurately remove chemistry discrepancy, increase microroughness, and create versatile patterns for engineering electrolyte/cathode interfaces toward decreased ohmic and polarization resistances. The cells with laser cross-patterned interfaces quadrupled the peak power density of those with pristine interfaces, achieving around 1.4 W/cm² at 650 °C, among the highest performance regions. The stability testing for 180 h showed no noticeable performance degradation. This laser engineering process is more scalable and ubiquitous than the recently reported chemical-processing methodologies and is suitable for manufacturing a wide range of solid oxide cells.