Electrolyte and electrochemical device

An electrolyte, consisting of:

• an organic solvent;
• a fluorinated additive;
• a compound of Formula I;
• at least one of a compound of Formula II or a compound of Formula III;
• wherein R1, R2, R3 and R4 are each independently selected from hydrogen, halo, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C6-C12 aryl, substituted or unsubstituted C1-C10 alkoxy, or substituted or unsubstituted C6-C12 aryloxy, wherein when substituted, the substituent is halo, cyano, or C1-C10 alkyl;
• and a, d and f are each independently selected from an integer from 1 to 5, and b, c, e, g, h and i are each independently selected from an integer from 0 to 5;
• a lithium salt;
• and
• at least one additive selected from vinylene carbonate, 1,3-propane sultone, ethylene sulfate, succinonitrile or adiponitrile,
• wherein the compound of Formula I is from greater than 0.01 wt % to less than or equal to 3 wt % of the weight of the electrolyte, and the compound of Formula II, the compound of Formula III, or a combination thereof is from 0.1 wt % to 5 wt % of the weight of the electrolyte;
• and
• wherein the compound of Formula I comprises at least one of:
• the compound of Formula II comprises at least one of
• the compound of Formula III comprises at least one of
• and
• wherein the fluorinated additive includes fluoroethylene carbonate and at least one of the following:
• fluorinated ethyl methyl carbonate, fluorinated dimethyl carbonate, fluorinated diethyl carbonate, fluorinated ethyl propionate, fluorinated propyl propionate, fluorinated methyl propionate, fluorinated ethyl acetate, fluorinated methyl acetate, fluorinated propyl acetate,