Preparation method of lithium ion battery and lithium ion battery

Abstract

The invention discloses a lithium ion battery and a preparation method thereof. Lithium cobaltate or a ternary material doped with lithium cobaltate is used as a positive electrode active material, and natural modified graphite coated with carbon is used as a negative electrode active material. Substance, the electrolyte uses a mixed solvent of DEC, EC, and PC, and adds vinylene carbonate and propylene sulfite additives to preferentially form an SEI film, inhibit the co-embedding of organic solvents, and have excellent high-temperature performance. The battery system significantly improves the high-temperature storage performance of the battery on the premise of meeting the safety performance, high-low temperature discharge performance and cycle performance of conventional lithium-ion batteries. The preparation method is simple, the manufacturing process is easy to control, and it is easy for industrial popularization and application.

Description

technical field

[0001] The invention relates to the field of lithium ion battery manufacturing, in particular to a lithium ion battery and a preparation method thereof. Background technique

[0002] Lithium-ion batteries have the characteristics of good safety performance, high energy density, high specific power, good cycle performance, no memory effect, and no pollution. They are widely used in mobile phones, digital cameras, notebook computers, GPS and other fields. In recent years, as the functions of electronic digital products have become more and more abundant, the applications have become more and more popular, and the use environment has become more and more extensive. The requirements of digital products on the energy carrier-battery have become higher and higher, and the requirements for high-temperature performance higher. However, the internal resistance of lithium-ion batteries increases under high temperature conditions, and the capacity decays quickly, espec...

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