A SnO sub(2)-samarium doped ceria additional anode layer in a direct carbon fuel cell

The role of a SnO sub(2)-samarium doped ceria (SDC) additional anode layer in a direct carbon fuel cell (DCFC) with SDC-(Li sub(0.67)Na sub(0.33)) sub(2)CO sub(3) composite electrolyte and lithiated NiO-SDC-(Li sub(0.67)Na sub(0.33)) sub(2)CO sub(3) composite cathode is investigated and compared with a NiO-SDC extra anode layer. Catalytic grown carbon fiber mixed with (Li sub(0.67)Na sub(0.33)) sub(2)CO sub(3) is used as a fuel. At 750 degree C, the maximum power outputs of 192 and 143 mW cm super(-2) are obtained by the cells with SnO sub(2)-SDC and NiO-SDC layers, respectively. In the SnO sub(2)-SDC layer, the reduction of SnO sub(2) and the oxidation of Sn happen simultaneously during the cell operation, and the Sn/SnO sub(2) redox cycle provides an additional route for fuel conversion. The formation of an insulating dense interlayer between the anode and electrolyte layers, which usually happens in DCFCs with metal anodes, is avoided in the cell with the SnO sub(2)-SDC layer, and the stability of the cell is improved consequently.