Preparation and Performance of LiNi_1-x Al_x O₂ Electrodes for Low-Temperature Ceramic Fuel Cells

The electrochemical performances of LiNi1-xAlxO2 (LNA) doped with different amounts of Al as electrodes for low-temperature ceramic fuel cells were investigated. It was found that the maximum power density of the cell with LNA-82 as the symmetrical electrode and GDC as the electrolyte was 798 mWcm(-2) at 550 degrees C in H-2/air fuel cell conditions, with the ionic conductivity of the electrolyte reaching as high as 0.679 Scm(-1). The diffusion of the molten salts such as LiOH generated by the reduction of LNA in the cell anode by H-2 into the electrolyte to form a "GDC-Li compound" composite electrolyte with ultrahigh ionic conductivity is the key to its excellent low-temperature power generation performance. It is found that as the Al doping concentration in LNA exceeds a certain critical value, LiAlO2 begins to form in LNA. As the doping concentration of Al increased, the amount of lithium compound molten salts containing LiOH generated by the reduction of LNA electrodes in H-2 decreased, resulting in a significant decrease in the electrochemical performance of the cell.