Intermediate-temperature protonic solid oxide fuel cell made of pulsed laser deposition-based functional layers and interlayers on an optimally tailored anode substrate

Protonic solid oxide fuel cells (P–SOFCs) is an active field in development of intermediate-temperature fuel cells to render high power density and durability. The use of pulsed laser deposition (PLD) to deposit the functional layers and interlayers of P–SOFCs supported on anode substrates offers advantages in reducing both the ohmic and polarization resistances of the cell, which however critically depends on the substrate microstructure. Here we use ashless paper fibers as pore former mixed with NiO and BaCe_0.7Zr_0.1Y_0.1Yb_0.1O_3-δ (BCZYYb) powders to prepare anode substrates with large, interconnected cylindrical pores, followed by using electrophoretic deposition to deposit NiO-BCZYYb as pore filler to fill the pores exposed on the top surface. With an anode substrate made using 20 wt% paper fiber and PLD-deposited NiO-BCZYYb anode functional layer (AFL), NiO-BCZYYb anode interlayer, and BCZYYb electrolyte layer, the peak power density reaches 550 mW/cm² at 600 °C, which is 30 % higher than that of the cell with a commercial half-cell composed of NiO-BCZYYb substrate and spin-coated BCZYYb electrolyte layer but the same cathode interlayer and cathode layer. Furthermore, the insertion of a PLD-deposited graded anode interlayer between the AFL and electrolyte layer is found to be critical for high cell durability.