Abstract: A method for enhancing battery cycle performance is applied in a battery and includes the following steps: charging, at a first stage, the battery at a first-stage current until reaching a first-stage voltage; and charging, at a second stage, the battery at a second-stage current until reaching a second-stage voltage. The second-stage voltage is greater than the first-stage voltage. The second-stage current is less than the first-stage current. The battery includes an electrolytic solution containing an additive. The additive includes a nitrile compound. A mass percent of the nitrile compound in the electrolytic solution is 0.5% to 5%. This application further provides an electronic device. The method and electronic device according to this application can enhance high-temperature cycle performance of the battery, reduce a high-temperature storage expansion rate, and enhance hot-oven safety performance.

Abstract: An electrochemical device includes a negative active material layer and an electrolyte. The negative active material layer comprises hard carbon. The negative active material layer has a porosity of 20% to 60%. The electrolyte has a conductivity of 8 mS/cm to 14 mS/cm.