Electrochemical device and electronic device including same

Abstract

The invention relates to an electrochemical device and an electronic device comprising the same. The electrochemical device comprises a positive electrode, a negative electrode, an isolating membraneand an electrolyte, wherein the electrolyte contains a nitrile compound and transition metal ions, and satisfies 5 < = A / B < = 30,000, the molar percentage of cyano groups in the electrolyte is A% based on the molar weight of the electrolyte, and the weight percentage of the transition metal ions in the electrolyte is B% based on the weight of the electrolyte. The electrochemical device reduces dissolution of transition metal ions of the positive electrode active substance and stabilizes structural distortion of the positive electrode active substance in the charging and discharging process bydetermining that cyano groups and the transition metal ions in the electrolyte meet a certain relationship, so that the high-temperature cycle performance and the floating charge performance of the electrochemical device are improved.

Description

technical field [0001] The present application relates to the technical field of energy storage, in particular to an electrochemical device and an electronic device including the same. Background technique [0002] Electrochemical devices (e.g., lithium-ion batteries) are widely used in wearable devices, smartphones, drones, laptops, and other fields due to their high operating voltage, high energy density, environmental friendliness, stable cycle, and safety. With the development of modern information technology and the expansion of lithium-ion battery applications, higher requirements are put forward for lithium-ion batteries, namely high energy density, long cycle life and excellent storage characteristics. The interaction between the electrolyte and the positive and negative electrodes will affect these properties, especially when the working voltage is increased to 4.4V to improve the energy density of the lithium-ion battery, the instability of the interface between th...

AI Technical Summary

Problems solved by technology

The interaction between the electrolyte and the positive and negative electrodes will affect these properties, especially when the working voltage is increased to 4.4V to improve the energy density of the lithium-ion battery, the instability of the interface between the electrolyte and the positive active material will increase, and the lithium-ion The battery swells severely at high temperature, and the cycle performance and charge-discharge performance decrease, which seriously restricts the performance of lithium-ion batteries.

In order to improve the characteristics of lithium-ion batteries, the existing lithium-ion battery technology usually only optimizes the electrolyte or improves the positive active material, but lacks an in-depth study of the entire lithium-ion battery system, so that the overall performance of lithium-ion batteries cannot be improved.

Images