A kind of fast charging method of lithium ion battery

Abstract

The invention relates to a fast charging method for a lithium ion battery, which includes the following steps: (1) Calibrating the support rate of fast charging in stages: discharge the fully charged battery cell to a set voltage value at a set constant current, and calculate the battery cell Capacity: set the SOC interval of the battery capacity and divide it into several intervals to be tested, and charge it to the set value in the SOC interval with a constant current at different rates in the empty state, and obtain the charging rate in different SOC intervals; (2) Stage-by-stage fast charge verification: set the SOC interval, and divide the SOC interval into several continuous verification intervals for charge verification; if the negative solid-liquid phase potential is above 0V, select the above stage-by-stage fast charge rate for charging ; If the solid-liquid phase potential of the negative electrode is below 0V in a certain section of SOC, then reduce the SOC charging rate of the section for continuous fast charge verification until the solid-liquid phase potential of the negative electrode is above 0V. The invention can quickly obtain the fast charging mode of the battery cell, greatly improving and exerting the performance of the battery cell.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery charging, and in particular relates to a lithium ion battery fast charging method. Background technique [0002] Lithium batteries have the advantages of high power density, high energy density, long cycle life, high output voltage, and environmental protection. They are widely used in various fields. Improving the charging rate, service life and usable capacity of lithium batteries is a hot research topic. [0003] At present, in the fast charging strategy of most OEMs and battery factories, the constant current and constant voltage method is used for direct charging in the 0-80% SOC range. Reduce the charging current to 0.05C cut-off. This traditional charging mode is single, with fixed parameters and may not achieve the purpose of fast charging. [0004] The supported charging rate of the lithium-ion battery charging process is affected by SOC state, temperature, polarization, etc....

AI Technical Summary

Problems solved by technology

In the actual use of batteries, the biggest disadvantage of the charging process is the phenomenon of lithium precipitation, and the results obtained by charging at a constant rate and then dismantling are not so regular and the error is too large

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