Comparison of nanostructured composite cathodes synthesized by liquid self-assembly and nanosolid mechanical-mixing for solid oxide fuel cell

Abstract

The composite perovskites are promising low/intermediate-temperature solid oxide fuel cell (LT/IT-SOFC) cathode materials, which can combine the complementary advantages of multi-components. Here, novel liquid self-assembly (SA) is compared with nanosolid mechanical-mixing (MM) for the high-performance nanostructured composite. The same composition of the active BaCo0.96Zr0.04O2.6+δ (12hBC, 38 mol%) with the stable BaZr0.82Co0.18O3-δ (BZC, 62 mol%) is designed to compare the effects of different syntheses on composite properties. The BZC-12hBC (SA) can achieve molecular-level contact of multiple phases, which exhibits superior electrical conductivity, surface and heterointerface activity to those of BZC-12hBC (MM). When further applied on LT/IT-SOFC, the cell with BZC-12hBC (SA) cathode achieves the remarkable peak power densities of 2.06–0.24 W cm−2 at 700–500 °C, while the cell with BZC-12hBC (MM) cathode only exhibits 0.63–0.11 W cm−2. The electrochemical analysis reveals that BZC-12hBC (SA) cathode possesses better oxygen dissociative adsorption and species transportation than those of the BZC-12hBC (MM) cathode.