Lithium ion battery formation sectional charging method

Abstract

The invention discloses a lithium ion battery formation sectional charging method. The lithium ion battery formation sectional charging method is carried out at room temperature and comprises four stages, namely a constant current charging stage I, a constant current charging stage II, a constant current charging stage III and a constant voltage charging stage. According to the lithium ion battery formation sectional charging method, a small current charging stage is adopted for activating an electrode material, reducing impedance of positive and negative electrodes and improving battery capacity, and a large current charging stage is used for improving formation charging efficiency. The lithium ion battery formation sectional charging method has the beneficial effects that the formation efficiency of a lithium ion battery can be improved, that the good formation of an SEI (solid electrolyte interface) membrane can be guaranteed, and that the good cycle performance of the lithium ion battery can be maintained; meanwhile, formation charging time can be effectively shortened while the good performance of the lithium ion battery is maintained to be constant, and thus the production efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of charging methods for lithium ion batteries, in particular to a method for charging lithium ion batteries into segments. Background technique [0002] Lithium-ion batteries are a new type of power source developed in recent years. Compared with other rechargeable secondary batteries, lithium-ion batteries have the advantages of high voltage, high specific energy, long charge and discharge life, no memory effect, and no pollution. It is not only widely used in portable electronic devices (such as mobile phones, digital cameras and laptop computers), but also has broad application prospects in the field of large and medium-sized electric equipment such as electric vehicles, electric bicycles and electric tools. Research and development hotspots. [0003] Formation is an important process in the manufacturing process of lithium-ion batteries. The SEI film can effectively prevent the co-insertion of solvent ...

AI Technical Summary

Problems solved by technology

The traditional formation charging method is charging with a constant small current, which can fully activate the active materials on the electrode surface and help to form a stable SEI film, so that the lithium-ion battery has better performance, but the long-term Low current charging will lead to an increase in the resistance of the formed SEI film, which will affect the rate discharge performance of lithium-ion batteries. The process takes a long time and affects production efficiency.

Although the method of high-current conversion charging alone can improve production efficiency, it makes the SEI film loose and unstable, which seriously affects the cycle performance of the battery.

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