A lithium battery with improved safety that utilizes one or more additives in
the
battery electrolyte solution wherein a lithium salt is dissolved in an organic
solvent, which may contain propylene, carbonate. For example, a blend of 2 wt %
triphenyl phosphate (TPP), 1 wt % diphenyl monobutyl phosphate (DMP) and 2 wt %
vinyl ethylene carbonate additives has been found to significantly enhance the
safety and performance of Li-ion batteries using a LiPF6 salt in EC/DEC
electrolyte solvent. The invention relates to both the use of individual additives
and to blends of additives such as that shown in the above example at concentrations
of 1 to 4-wt % in the lithium battery electrolyte. This invention relates to additives
that suppress gas evolution in the cell, passivate graphite electrode and protect
it from exfoliating in the presence of propylene carbonate solvents in the electrolyte,
and retard flames in the lithium batteries.