Use of additives in electrolyte for electrochemical cells

An electrolyte comprising a lithium containing conductive salt selected from the group consisting of methanides, triflates, and imides dissolved in an aprotic solvent, wherein the electrolyte further comprises at least one organic alkali metal salt as an additive, wherein the organic alkali metal salt is a lithium borate of the formula (I)

• Li+B−(OR1)m(OR2)p (I)
• in which
• m and p are 0, 1, 2, 3, or 4, where m+p=4
• and
• R1 and R2 are identical or different,
• are optionally bonded directly to one another by a single or double bond,
• and are each, individually or together, an aromatic or aliphatic carboxylic,
• dicarboxylic or sulfonic acid, or
• are each, individually or together, an aromatic ring selected
• from the group consisting of phenyl, naphthyl, anthracenyl and phenanthrenyl, which is optionally unsubstituted or mono- to tetrasubstituted by A or Hal, or
• are each, individually or together, a heterocyclic aromatic ring selected from the group consisting of pyridyl, pyrazyl and bipyridyl, which is optionally unsubstituted or mono- to trisubstituted by A or Hal, or
• are each, individually or together, an aromatic hydroxy acid selected from the group consisting of aromatic hydroxycarboxylic acids and aromatic hydroxysulfonic acids, which is optionally unsubstituted or mono- to tetrasubstituted by A or Hal,
• and
• Hal is F, Cl or Br
• and
• A is alkyl having 1 to 6 carbon atoms, which may be mono- to trihalogenated,
• wherein the organic alkali metal salt additive is present in concentrations of from 0.1 to 10% by weight based on the weight of conductive salt.