Lithium ion battery and electronic device

Abstract

The invention provides a lithium ion battery and an electronic device. The lithium ion battery comprises a positive plate and an electrolyte; a positive active layer of the positive plate comprises a single-walled carbon nanotube; the electrolyte comprises fluoroethylene carbonate and ethylene carbonate, and the mass percentage content of the fluoroethylene carbonate in the electrolyte is 10-25%; and the mass percentage content of the ethylene carbonate in the electrolyte is less than 9%. The lithium ion battery can effectively solve the problems of 45 DEG C interval cycle later-stage air blowing and high-temperature storage air blowing caused by the single-walled carbon nanotube contained in the positive electrode so that the lithium ion battery has excellent cycle performance and high-temperature performance.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and relates to a lithium ion battery and an electronic device. Background technique [0002] Since its commercialization, lithium-ion batteries have been widely used in the fields of digital, energy storage, power, military aerospace and communication equipment because of their advantages such as light weight, high specific energy, no memory effect, and good cycle performance. [0003] With the widespread application of lithium-ion batteries, consumers have put forward higher requirements for the energy density, cycle life, high-temperature performance, and safety performance of lithium-ion batteries. At present, there are many ways to increase the energy density of the battery, such as increasing the charging voltage of the positive electrode, using a silicon negative electrode with a higher capacity, increasing the compaction density of the positive and negative electrodes, and re...

AI Technical Summary

Problems solved by technology

Carbon nanotubes are very suitable for use as a conductive agent due to their high conductivity, unique one-dimensional tubular structure and low mass density. They can be used as a conductive agent by adding a small amount of single-walled carbon nanotubes to the positive active layer to replace traditional conductive agents. In this way, the main content of the positive electrode active material in the positive electrode sheet is increased, and the energy density of the battery is improved. However, the specific surface area of ​​the positive electrode surface will be increased after adding single-walled carbon nanotubes, which will cause side reactions to occur easily on the positive electrode surface. And it is easy to blow out during high temperature storage, which will lead to poor cycle performance and high temperature performance of lithium-ion batteries

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