Nanoporous silver cathodes surface-treated by atomic layer deposition of Y:ZrO₂ for high-performance low-temperature solid oxide fuel cells

Abstract We report high-performance solid-oxide fuel cells (SOFCs) with silver cathodes surface-treated using yttria-stabilized zirconia (YSZ) nano-particulates fabricated by atomic layer deposition (ALD). Fuel cell tests are conducted on gadolinia-doped ceria electrolyte pellets with a platinum anode at 250-450 °C. In our tests, the fuel cell performance of the SOFCs with an optimized ALD YSZ surface treatment is close to that of SOFCs with porous Pt, which is known as the best performing catalyst in the low-temperature regime. Electrochemical impedance spectroscopy confirms that the performance enhancement is due to improved electrode kinetics by the increase in charge transfer reaction sites between the surface of supporting silver and the ALD-YSZ particulates. Fuel cell durability tests shows that the ALD YSZ surface treatment improves the long-term stability. X-ray photoelectron spectroscopy also confirms that the ALD YSZ capping prevents reduction of the surface silver oxide and destruction of the mesh morphology.