Electrochemical device and electronic apparatus

The electrochemical device comprises an electrode assembly, a positive pole lug and a negative pole lug, a diaphragm in the electrode assembly is arranged between a positive pole piece and a negative pole piece, the positive pole lug is connected to the positive pole piece, the negative pole lug is connected to the negative pole piece, and the positive pole piece comprises a positive current collector and a positive active material layer arranged on the surface of the positive current collector. Wherein the number a of the positive pole lugs and the layer number b of the positive pole piece meet the relation that a/b is larger than or equal to 0.25 and smaller than or equal to 1.25, the molar percentage X of nickel in the positive active material meets the relation that X is larger than or equal to 60%, and the thickness h1 of the positive active material layer meets the relation that h1 is larger than or equal to 10 micrometers and smaller than or equal to 30 micrometers. The current density of a single posi