| abstract |
One or more additives are selected from the group consisting of a) tertiary amines, b) amides, c) pyridine compounds, d) organophosphorus compounds, e) phosphonitrilic compounds, f) organoboron compounds, g) borate salts, h) anhydrides and i) nitrites are effective towards preventing color formation in electrolyte compositions for secondary Li ion batteries, which electrolyte compositions contain an organic solvent, one or more lithium salts and one or more cyclic sulfate additives. Advantageously, a combination of one or more compounds selected from the group consisting of a) tertiary amines, b) amides, c) pyridine compounds, d) organic phosphorus compounds and e) phosphonitrilic compounds is employed together with one or more compounds selected from the group consisting of f) organoboron compounds, g) borate salts, h) anhydrides and i) nitriles. |