Nonaqueous electrolyte compositions comprising lithium glycolatoborate and fluorinated solvent

A lithium-ion battery comprising:

• a housing;
• an anode and a cathode that are disposed in the housing and in ionically conductive contact with one another;
• an electrolyte composition that is disposed in the housing and providing an ionically conductive pathway between the anode and the cathode;
• and
• a porous separator between the anode and the cathode,
• wherein the cathode comprises a cathode active material which is charged to a potential greater than or equal to 4.35 V versus a Li/Li+ reference electrode, and
• wherein the electrolyte composition comprises:
• a) a non-fluorinated carbonate selected from the group consisting of ethylene carbonate, ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, vinylene carbonate, di-tert-butyl carbonate, vinylethylene carbonate, dimethylvinylene carbonate, propylene carbonate, ethyl propyl vinylene carbonate, dimethylvinylene carbonate, and mixtures thereof;
• b) a fluorinated acyclic carboxylic acid ester that is represented by formula (I):
• R1—COO—R2 (I)
• where i) R1 is H, an alkyl group, or a fluoroalkyl group;
• ii) R2 is an alkyl group or a fluoroalkyl group;
• iii) either or both of R1 and R2 comprises fluorine;
• and
• iv) R1 and R2, combined, comprise at least two carbon atoms but not more than seven carbon atoms
• c) at least one lithium glycolatoborate compound that is represented by formula (II):
• d) a fluorinated carbonate selected from the group consisting of 4-fluoroethylene carbonate, difluoroethylene carbonate isomers, trifluoroethylene carbonate isomers, tetrafluoroethylene carbonate, and mixtures thereof;
• and
• e) an electrolyte salt.