An Electrolyte‐Free Fuel Cell Constructed from One Homogenous Layer with Mixed Conductivity

Rather than using three layers, including an electrolyte, a working fuel cell is created that employs only one homogenous layer with mixed conductivity. The layer is a composite made from a mixture of metal oxide, Li 0.15 Ni 0.45 Zn 0.4 oxide, and an ionic conductor; ion‐doped ceria. The single‐component layer has a total conductivity of 0.1–1 S cm −1 and exhibits both ionic and semiconducting properties. This homogenous one‐layer device has a power output of more than 600 mW cm −2 at 550 °C operating with H 2 and air. Overall conversion is completed in a similar way to a traditional fuel cell, even though the device does not include the electrolyte layer critical for traditional fuel‐cell technologies using the three‐component anode–electrolyte–cathode structure.