Lithium ion battery and electronic device

A lithium ion battery (1) and an electronic device (10). The lithium ion battery (1) includes a negative electrode, a positive electrode, a separator, and an electrolyte. The positive electrode includes a positive active material. The isolating membrane is arranged between the cathode and the anode. The electrolyte comprises cyclic sulfonate, the cyclic sulfonate comprises 1, 3-propane sultone and a compound shown in the formula (I) except the 1, 3-propane sultone, the content of the compound shown in the formula (I) is A2% based on the mass n of the electrolyte, and the value range of A2 is 0.5-5. The provided electrolyte comprises 1, 3-propane sultone and a compound shown in the formula (I), the mass A2 of the compound shown in the formula (I) meets the condition that A2/n is larger than or equal to 0.5% and smaller than or equal to 5%, the 1, 3-propane sultone and the compound shown in the formula (I) can play a synergistic role, a compact CEI film layer can be formed on the surface of a positive electrode