Electrochemical device and electronic device comprising the same

An electrochemical device, comprising:

• a positive electrode, wherein the positive electrode contains a positive electrode active material that contains aluminum;
• and based on a total weight of the positive electrode active material, a weight percentage of the aluminum is C %, and 0.001<C<1;
• a negative electrode;
• a separator;
• and an electrolyte,
• wherein, the electrolyte contains a nitrile compound and transition metal ions, the transition metal ions comprise cobalt ions and copper ions;
• based on a total weight of the electrolyte, a weight percentage of the cobalt ions in the electrolyte is less than 0.1%, and a weight percentage of the copper ions in the electrolyte is less than 0.1%;
• the nitrile compound comprises a compound of formula II:
• R21, R22, and R23 are each independently selected from a single bond, substituted or unsubstituted C1 to C5 alkylidene groups, and substituted or unsubstituted C1 to C10 alkyleneoxy groups, when substitution is performed, a substituent group is selected from at least one of halogen, a cyano group, or a carboxyl group;
• based on a total molar mass of the electrolyte, a molar percentage of a cyano group in the electrolyte is A %, based on the total weight of the electrolyte, a weight percentage of the transition metal ions in the electrolyte is B %, 5≤A/B≤30000, and 0.01≤A/C≤170.