Multiscale structured low-temperature solid oxide fuel cells with 13 W power at 500 °C

Low-temperature solid oxide fuel cells (LT-SOFC) operating below 650 °C have attracted attention as a next-generation fuel cell. Although much effort has been paid to develop such fuel cells, it still remains challenging to satisfy all the requirements ensuring practical operation, such as power output and durability. Here we demonstrate 4 cm × 4 cm multiscale structured LT-SOFCs having a record high power output of 13 W per single cell at 500 °C via a large-area ceramic micropatterning and thin-film depositions. Our cell exhibits excellent long-term stability with performance degradation of less than 0.05% per 500 h. Quantitative microstructure and electrochemical analyses reveal that the proposed cell significantly lowered both ohmic and polarization losses than the reference planar cells. This work features a facile and powerful tool to implement robust and large-area 3D architectures in LT-SOFCs, which opens up opportunities to produce practical LT-SOFC systems satisfying both power and durability.