Comparison of properties of a symmetric and an unsymmetric tetraalkylammonium salt and their nonaqueous electrolytes

摘要

prperties of Et_4NPF_6 and Et_3MeNPF_6 salts and their EC-DMC electrolytes were measured and compared to study their dependence on the symmetricity of the salt cations. We found that while the melting points and solubilities of the salts and peak-conductivity concentrations of the electrolytes were substantially different, the conductivities, densities, and electrochemical stabilities of the electrolytes were similar. The iliting molar conductivities of the two salts showed minor but significant differences. We concluded that while the differences in property stemmed from the difference in lattice energies of the two salts due to the symmetricity difference of their cations, the similarities in the properties of their electrolytes resulted from the similarity of the liquid structures of the two electrolytes.