A New Class of Electrochemically and Thermally Stable Lithium Salts for Lithium Battery Electrolytes: I . Synthesis and Properties of Lithium bis[1,2‐benzenediolato(2‐)‐O,O′]borate
Disclosed is a new class of nontoxic thermally, chemically, and electrochemically stable, inexpensive lithium salts based on a chelate complex anion of boron with aromatic or aliphatic diols or carboxylic acids. The synthesis, purification, and analysis of the first member of this class, lithium bis[1,2‐benzenediolato(2‐)‐O,O′]borate is described and some results are given from electrochemical experiments of its solution in various aprotic solvents. The voltage window of based solutions is limited by the oxidation of the borate at about 3.6 V vs. lithium. Lithium can be cycled in solutions of lithium bis[1,2‐benzenediolato(2‐)‐O,O′]borate based on different aprotic solvents. Cycling efficiencies depend strongly on the solvents used, but scarcely on contact times of the solution with lithium, or on the use of mixed electrolytes .