Rapid charging method for lithium-ion battery

Abstract

The invention provides a rapid charging method for a lithium-ion battery and belongs to the technical field of battery management. The method comprises the steps that an observed over-potential value of a negative electrode of the battery is calculated according to a calibrated battery model; on-line dynamic control is performed on charging current according to the observed over-potential value of the negative electrode and a preset lithium precipitation potential warning threshold; the observed over-potential value of the negative electrode is enabled to be stabilized within a range of the lithium precipitation potential warning threshold plus or minus 5 mV until terminal voltage reaches the upper limit of cut-off voltage. With adoption of the method, the over-potential of the negative electrode is located on critical lithium precipitation potential all along in a battery charging process, lithium precipitation is avoided for the battery, the service life of the battery is prolonged, the battery safety is improved, and the charging speed of the battery is increased.

Description

technical field [0001] The invention belongs to the technical field of battery management, in particular to a fast charging method for a lithium ion battery. Background technique [0002] The environmental crisis, energy shortage and other issues make the environmentally friendly and recyclable secondary lithium-ion battery as a clean energy source, which has received more and more attention. Due to the advantages of high specific energy, long cycle life, and no memory effect, lithium-ion batteries are widely used as energy sources in products and systems such as mobile phones, notebook computers, new energy vehicles, and energy storage power stations. However, the rapid charging of lithium-ion batteries has always been a problem. not effectively resolved. [0003] The charging process of lithium-ion batteries is limited by the rate of many electrochemical reactions inside it, and the rapid charging effect cannot be achieved simply by increasing the charging current rate. ...

AI Technical Summary

Problems solved by technology

Due to the advantages of high specific energy, long cycle life, and no memory effect, lithium-ion batteries are widely used as energy sources in products and systems such as mobile phones, notebook computers, new energy vehicles, and energy storage power stations. However, the rapid charging of lithium-ion batteries has always been a problem. not effectively resolved

[0006] 1. Represented by ZL200810029444.2, etc., the constant current charging cut-off voltage is increased to replace the constant voltage charging process and reduce the charging time. This method does not consider the damage to battery life after the cut-off voltage is increased;

[0007] 2. The multi-step and multi-stage fast charging method represented by ZL200910042369.8, ZL201110141456.6, etc. generally adopts 3-10 constant current charging gears, the charging current decreases gradually, and the electricity is gradually charged; the essence of this method is to use Phased constant current charging replaces constant voltage charging to increase the charging capacity, but a large number of experiments are required to determine how many stages are divided into, and the value of the current rate of each stage, and the room for increasing the charging speed is limited;

[0008] 3. The fast charging method that introduces pulse current depolarization, represented by ZL200710079984.7, ZL200910163012.5, etc., introduces a short-time pulse discharge current during the high-rate charging process, which can effectively reduce voltage polarization, but it will waste electric energy in vain , reducing charging efficiency

However, due to the complex manufacturing process and poor stability of the three-electrode battery, it cannot be applied in the actual vehicle battery system.

Therefore, it is impossible to monitor the negative electrode overpotential in real time through the three-electrode battery like measuring the terminal voltage and battery temperature signals on the real vehicle.

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