Phosphate additives for nonaqueous electrolyte rechargeable electrochemical cells

A lithium ion electrochemical cell having high charge/discharge capacity, long cycle life and exhibiting a reduced first cycle irreversible capacity, is described. The stated benefits are realized by the addition of at least one phosphate additive having the formula: (R¹O)P(O) (OR²) (OR³) and wherein R¹, R² and R³ are the same or different, wherein at least one, but not all three, of the R groups is hydrogen, or at least one of the R groups has at least 3 carbon atoms and contains an sp or sp² hybridized carbon atom bonded to an sp³ hybridized carbon atom bonded to the oxygen atom bonded to the phosphorous atom.