Abstract: An electrochemical device, including a positive electrode, a negative electrode and an electrolytic solution. The positive electrode includes a positive electrode current collector and a positive active material layer having a positive active material. The negative electrode includes a negative electrode current collector and a negative active material layer having a negative active material. The electrolytic solution includes a lithium ion and an anion represented by Formula I: n is an integer in a range of 0 to 5; and R1 is selected from substituted or unsubstituted C1-C12 alkyls, substituted or unsubstituted C2-C12 alkenyls, substituted or unsubstituted C6-C20 aryls, and substituted or unsubstituted C1-C12 hydrocarbyloxys, wherein a substituent in the substitution is independently selected from a silyl, a siloxy, an amino group, an ether group, ester group, a carboxyl, a sulfonic acid group, a mercapto group, a cyano group, a halogen, or any combination thereof.

Abstract: This application relates to an electrochemical device. The electrochemical device in this application includes a positive electrode, a negative electrode, and an electrolytic solution, where the electrolytic solution includes an anion containing a phosphoric anhydride functional group of a specific structure. By adding such anion into the electrolytic solution, this application can improve both low-temperature discharge performance and high-temperature storage performance of the electrochemical device, and improve cycle stability of the electrochemical device at a normal temperature and a high temperature.