Preparation and Performance of LiNi_1–xAl_xO₂ Electrodes for Low-Temperature Ceramic Fuel Cells

Abstract

The electrochemical performances of LiNi 1−x Al x O 2 (LNA) doped with different amounts of Al as electrodes for lowtemperature 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 mW•cm −2 at 550 °C in H 2 /air fuel cell conditions, with the ionic conductivity of the electrolyte reaching as high as 0.679 S•cm −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, LiAlO 2 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.