Electrical conductivity optimization in electrolyte-free fuel cells by single-component Ce _0.8Sm _0.2O _2-δ-Li _0.15Ni _0.45Zn _0.4 layer

Single-component electrolyte-free fuel cells possess a similar function to the traditional fuel cells with a complex three-component structure. However, how to enhance their electrical properties for practical industrial applications remains a timely and important issue. Here, we report the manipulation of concentration ratios of ionic to electronic conductors in an electrolyte-free Ce _0.8Sm _0.2O _2-δ-Li _0.15Ni _0.45Zn _0.4 by adjusting the relative weight between its two inside compositions. Our systematic investigations reveal that the fuel cell with 30% in weight of Li _0.15Ni _0.45Zn _0.4 exhibits an almost uniform distribution of the two compositions and has a total conductivity as high as 10 × 10 ^-2 S cm ^-1 at 600 °C. Such an enhancement is found to be attributed to the established balance between the numbers of its inside ionic and electronic conductors. These findings are relevant for the technological improvement of this new species of electrolyte-free fuel cell and represent an important step toward commercialization of this single-component fuel cell.