Nano-composite structural Ni–Sn alloy anodes for high performance and durability of direct methane-fueled SOFCs†
Ni-based cermets have commonly been used as anode materials with good catalytic properties for hydrocarbon fuels. However, carbon deposition can occur due to the non-ideal electrochemical reaction of hydrocarbon fuel and the structural limitation resulting from the unsymmetrical Ni-based anode-supported single cells. This critical problem leads to loss of cell performance and poor long-term stability of solid oxide fuel cells (SOFCs). Our designed anode material with an extremely small amount (0.5 wt%) of Sn catalyst incorporated into the Ni and nano-composite structure was employed not only to prevent carbon deposition in oxygen deficient areas found for unsymmetrical cells, but also to increase the cell performance due to its excellent microstructure. The nano-composite Sn doped Ni-GDC cells showed a power density of 0.93 W cm−2 with stable operation in dry methane at 650 °C.