In this paper the most suitable addition ratio of Al(OH)
3 for the growth of needle-shaped β-LiAlO
2 crystals with diameters ≤1μm and length/diameter ratio ≥10 was examined in the LiOH-Al
2O
3-Al(OH)
3-NaOH system. The needle-shaped β-LiAlO
2 crystals with a diameter of 0.9μm, length of 10.4μm and a length/diameter ratio of 11.6 was obtained at a molar ratio of 41.7:7.3:6.2:44.8 in the LiOH-Al
2O
3-Al(OH)
3-NaOH system. It was revealed that the needle-shaped β-LiAlO
2 crystals were converted to γ-LiAlO
2 crystals without morphology change by heating from 750 to 1000°C for 10 or 30h. The surface area of resulting needle-shaped γ-LiAlO
2 crystals was from 16 to 17m
2/g. The stability of the needle-shaped γ-LiAlO
2 crystals in alkali carbonates, the electrolyte of molten carbonate fuel cells, was examined. The needle-shaped γ-LiAlO
2 crystals derived from β-LiAlO
2 at 900°C for 10h underwent no deformation by the heat treatment at 650°C for 1000h.
抄録全体を表示