An electrochemical apparatus, including a positive electrode, a negative electrode, an separator, and an electrolyte, wherein the positive electrode comprises a current collector and a positive active material layer, and the positive active material layer comprises a positive active material; and the electrolyte comprises a compound of Formula I: wherein R11, R12, R13, R14, R15 and R16 are each independently selected from: H, halogen, and the following substituted or unsubstituted groups: a C1-8 alkyl group, a C2-8 alkenyl group, a C2-8 alkynyl group, or a C6-12 aryl group; and an amount of the compound of Formula I required per 1 g of the positive active material is about 0.001 g to about 0.064 g. The present application can effectively improve high-temperature storage and high-temperature cycle performance of an electrochemical apparatus.