Battery systems based on two-additive electrolyte systems including 2-furanone, and method of formation process of same

An energy storage device, comprising:

• a positive electrode comprising a cathode active material of a lithium nickel manganese cobalt oxide (NMC);
• a negative electrode comprising an anode active material selected from the group consisting of artificial graphite, natural graphite, graphite/SiO blends, and combinations thereof;
• and
• a nonaqueous electrolyte comprising:
• a lithium salt;
• a first nonaqueous solvent selected from at least one of ethylene carbonate, ethyl methyl carbonate, propylene carbonate, dimethyl carbonate, and diethyl carbonate;
• a second nonaqueous solvent of methyl acetate;
• and
• an additive mixture comprising a first operative additive and a second operative additive;
• wherein the first operative additive comprises fluoroethylene carbonate;
• wherein the second operative additive comprises 2-furanone having the following formula (I):
• wherein the concentrations of each of the first nonaqueous solvent and the second nonaqueous solvent are greater than 6% by weight;
• wherein the concentration of the first operative additive is 2% by weight;
• wherein the concentration of the second operative additive is in a range from 0.5% to 1% by weight;
• and
• wherein the nonaqueous electrolyte is configured to generate at least 50% less gas during the formation process compared to gas generated during a formation process of an energy storage device comprising only the first operative additive at 4.2 V.