A New Class of Electrochemically and Thermally Stable Lithium Salts for Lithium Battery Electrolytes: II. Conductivity of Lithium Organoborates in Dimethoxyethane and Propylene Carbonate

A conductivity study is carried out on lithium bis[1,2 benzenediolato(2‐)‐O,O']borate and on lithium bis[3‐fluoro‐l,2‐benzenediolato(2‐)‐O,O']borate in dimethoxyethane and propylene carbonate from infinite dilution to saturation in the temperature range 228 < T (K) < 308. The electron‐drawing fluorine substituent produces a decrease of the association constant by a factor of about three for PC‐based solutions and 5.5 for solutions in dimethoyxyethane. The increase in the maximum of conductivity by about 30% (propylene carbonate) and about 80% (dimethoxyethane), independent of temperature, reveals the effect of ion‐ion interaction on the conductivity maximum, with the solvent permittivity, viscosity, and ionic radii remaining unchanged. Synthesis, analysis, and purification of lithium bis[3‐fluoro‐1,2‐benzenediolato(2‐)0,0']borate, which is a candidate for lithium batteries, is described.