Byoung-Bae Lee

Ionic liquids based on N-alkyl-N-methylmorpholinium salts as potential electrolytes

Ionic liquids based on N-alkyl-N-methylmorpholinium salts have been synthesized and the physical and electrochemical characteristics of this family of ionic liquids have been investigated for use as electrolytes.

Thermal and electrochemical properties of ionic liquids based on N-methyl-N-alkyl morpholinium cations

A series of ionic liquids based on morpholinium cations were prepared. N-alkyl-N-methylmorpholinium bromide, N-alkyl-N-methylmorpholinium tetrafluoroborate, N-alkyl-N-methylmorpholinium hexafluorophosphate and N-alkyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide were synthesized, and then thermal and electrochemical properties of prepared ionic liquids were measured. These morpholinium salts were found to be thermally stable near 673 K and electrochemically stable up to 6 V at room temperature. In conclusion, these new series of morpholinium based ILs might be potential candidates for electrolytes in batteries and other electrolytic devices.

Synthesis and Ionic Conductivities of Lithium-Doped Morpholinium Salts

A series of a new type of ionic liquids was prepared. The synthesis and purification procedure of N-alkyl-N-methylmorpholinium bromide, N-alkyl-N-methylmorpholinium tetrafluoroborate, N-alkyl-N-methylmorpholinium hexafluorophosphate, and N-alkyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide were presented. Thermal properties of morpholinium salts and ionic conductivities of lithium-doped ionic liquids were measured in the temperature range of 303.15 to 323.15 K. In the case of the pure ionic liquids, the ionic conductivities were 10-4 S·cm-1.

Quantitative Analysis of the Elastic Properties of Al-Li-Cu Alloys

Al-Li-Cu ternary alloys have recently received a great research interest because of its attractive combination of properties of the lightness and stiffness as a potential candidate for aircraft structural materials[1]. This is because the addition of Li into aluminum greatly increases its elastic modulus by decreasing its density at the same time. The primary objective of the addition of Cu is to enhance its strength and ductility by precipitating new strong particles of mostly T1 phase (Al2CuLi) in addition to the ordered δ’ particles. The T1 phase has a hexagonal structure (a=0.496nm, c=0.934nm) and nucleates with its basal plane parallel to the {111} planes of the matrix, i.e., (0001) // {1ll}; // . The θ ‘(Al2Cu) phase also precipitates to a minor population depending on the Cu/Li ratio. The θ’ phase of also plate shape has a tetragonal structure (a=0.404nm, c=0.580nm) and a cube orientation relationship.