Zur Kenntnis der Lithiumaluminate. I. Über eine neue Modifikation des LiAlO₂

Abstract

Beim Tempern eines äquimolaren Gemisches von Li2CO3 und α‐Al2O3 bei 600° entsteht eine Tieftemperaturform des LiAlO2 mit der Dichte 3,38 g · cm−3, die sich oberhalb 600°C langsam und anscheinend irreversibel in die bekannte Hochtemperaturform umlagert. T‐ und H‐LiAlO2 stehen wahrscheinlich im gleichen Verhältnis zueinander wie α‐ und β‐NaFeO2.

Effect of Al Addition on Formation of Layer-Structured LiNiO2

“…It is well known that Li 2 O and Al 2 O 3 can form stable a-LiAlO 2 with the a-NaFeO 2 structure at temperatures below 6001C (8)(9)(10). The intercalation of a-LiAlO 2 gives a voltage of B5 V vs Li/ Li + , which is higher than other lithium transition-metal oxides.…”

A first principles investigation of new cathode materials for advanced lithium batteries

“…It has been shown theoretically [11,12] and experimentally [13,14] that Al as a substitutive substitution transition metal cation increases the cell voltage. Moreover, LiAlO 2 is stable in the α-NaFeO 2 structure at temperatures below ∼600 • C [15] and it has a stabilizing effect on the structure as reported for monoclinic LiAl y Mn 1−y O 2 [16]. Its low cost and low density makes LiAlO 2 attractive as a constituent intercalation compound.…”

Theoretical investigations on the α-LiAlO2 properties via first-principles calculation

“…Therefore, the corresponding numbers of phonon vibrational modes are 12, three of them are acoustic modes and 9 of remainder are optical modes. Since ␣-LiAlO 2 is in a rhombohedral symmetry structure with space group R-3 m [5], the corresponding point group is −3m. According to Group-theoretical analysis [34], the irreducible representations of normal modes at the center of the BZ can be expressed as…”

“…It has been reported that LiAlO 2 has at least four different phases, the hexagonal ␣-phase [5,6], the orthorhombic ␤-phase [7], the tetragonal ␥-phase [8], and the tetragonal ␦-phase [9]. It is thought that the ␥-LiAlO 2 powder has been considered to be the most stable form and is commonly used as the electrolyte material because of its stability at high temperature [10].…”

“…The lattice parameters of ␥-LiAlO 2 were determined by Marezio with a general Electric XRD-3 spectrometer [8]. The hexagonal ␣-LiAlO 2 with NaHF2 structure was obtained for the first time by Lehmann [5] by heating Li 2 CO 3 and ␣-Al 2 O 3 at 873 K N. Tomimatsu et al [14] studied the phase stability of LiAlO 2 in Molten Carbonate, and found that ␣-LiAlO 2 powder with 0.3 m diam is preferred over conventional ␥-LiAlO 2 powder as an electrolyte-retaining material in MCFCs. The problems of stability associated with conventional ␥-LiAlO 2 matrix has been studied by Vidya S.Batra et al [12], and it was found that ␣-LiAlO 2 has become the preferred choice for the matrix support.…”