A new class of electrochemically and thermally stable lithium salts for lithium battery electrolytes .3. Synthesis and properties of some lithium organoborates

Synthesis, analysis, and purification of new lithium salts for lithium batteries, lithium bis[tetrafluoro-1,2-benzenediolato(2-)-O,O']borate and Lithium bis[2,3-naphthalenediolato(2-)-O,O']borate described, and the results of electrochemical studies of these salts and of lithium bis[3-fluoro-1,2-benzenediolato(2-)-O,O']borate in propylene carbonate are reported. The effect of the electron-withdrawing substituent fluorine results in an increase of the electrochemical window by 0.1 V/fluorine per one chelate Ligand. The slope, which can be calculated from the linear correlation of the highest occupied molecular orbital energies with anodic oxidation potentials is -3.0 eV/V, a value equal to that known for aryl berates and fluoroaryl berates.