ELECTROLYTE AND ELECTROCHEMICAL DEVICE

An electrolyte including a dinitrile compound, a trinitrile compound, and propyl propionate. Based on the total weight of the electrolyte, the content X of the nitrile compound and the content Y of the trinitrile compound meet the conditions represented by Formula (1) and Formula (2): {about 2 wt %≤(X+Y)≤about 11 wt % . . . (1), about 0.1≤(X/Y)≤about 8 . . . (2)}. The electrolyte further includes at least one selected from the group consisting of a cyclic carbonate ester having a carbon-carbon double bond, a fluorinated chain carbonate ester, a fluorinated cyclic carbonate ester, and a compound having a sulfur-oxygen double bond. The electrolyte is capable of effectively inhibiting the increase in DC internal resistance of an electrochemical device so that the electrochemical device has excellent cycle and storage performance.