ELECTROLYTE AND ELECTROCHEMICAL DEVICE

An electrochemical device, including an electrode and an electrolyte. The electrolyte including a dinitrile compound, a trinitrile compound, and propyl propionate. Based on the total weight of the electrolyte, the weight percentage of the dinitrile compound is X, the weight percentage of the trinitrile compound is Y, and the weight percentage of the propyl propionate is Z. Wherein about 2 wt %≤(X+Y)≤about 11 wt %, about 0.1≤(X/Y)≤about 8. The electrode including a coating, which including a single-sided sub-coating and a double-sided coating, the electrode with the single-sided sub-coating has an electrode compaction density D1, and the electrode with the double-sided coating has an electrode compaction density D2, where about 0.8≤D1/D2≤about 1.2. The electrolyte and D1/D2 of the electrodes has a significant effect on the cycle performance of the electrochemical device.