A method and system for optimizing the group performance of ternary batteries based on voltage secondary sorting

Abstract

The invention discloses a three-element electrical core group performance optimization method based on secondary sorting of voltage, which includes the following steps: carrying out 1C charge and discharge capacity test on target three-element electrical cores, testing the voltage and internal resistance of single electrical cores, and picking out standard three-element electrical cores; carryingout 1C charge and discharge capacity test on the standard three-element electrical cores to get a standard median voltage; and picking up standard three-element electrical cores of which the median voltages accord with the standard median voltage and putting the standard three-element electrical cores in a first electrical core group, carrying out 1C charge and discharge capacity test on the standard three-element electrical cores in the first electrical core group, and picking up standard three-element electrical cores of which the median voltages accord with the standard median voltage in the first electrical core group as optimized three-element electrical cores. The three-element electrical core optimization method presented by the invention is simple and efficient, and has a simple process. The procedure of electrical core screening is reduced. The electrical cores screened out have high capacity efficiency and small self-discharge capacity. The electrical cores screened out havea long cycle life and small system pressure difference after grouping. The battery performance can be brought into better play when battery packs are used in vehicles.

Description

technical field [0001] The invention relates to the technical field of lithium-ion electronic testing, in particular to a method and system for optimizing the group performance of ternary batteries based on voltage secondary sorting. Background technique [0002] The power battery pack is composed of single cells. The capacity of the battery pack depends on the life and consistency of the single cells, which determines the performance of the battery pack. If the consistency of the single cell is not good, even if the performance of the single cell is excellent, the voltage difference of the battery pack is too large, which will inevitably cause overcharge and overdischarge of individual cells during use, resulting in state errors and seriously reducing the battery life. The cycle life of the battery pack. At present, there are mainly several test methods before batteries are assembled into groups, such as capacity sorting method, volt-ampere characteristic curve sorting met...

AI Technical Summary

Problems solved by technology

If the consistency of the single cell is not good, even if the performance of the single cell is excellent, the voltage difference of the battery pack is too large, which will inevitably cause overcharge and overdischarge of individual cells during use, resulting in state errors and seriously reducing the battery life. Cycle life of battery pack

At present, there are mainly several test methods before batteries are assembled into groups, such as capacity sorting method, volt-ampere characteristic curve sorting method, and multi-parameter sorting method. Cells with abnormal discharge; the volt-ampere characteristic curve sorting method requires a lot of equipment for testing, and the test data is diverse, which is suitable for the laboratory when there are few cells or prototypes, and the selection efficiency is low; the multi-parameter sorting method has excellent parameters Too many, the accuracy of parameter test records is high, the pass rate of batteries is reduced, and the manufacturing cost is high; In the process, the essential voltage and internal resistance parameters of the equipment in the essential capacity separation and high-temperature aging process are used as screening criteria to select qualified batteries to improve the performance of the power battery after battery assembly and prolong the service life.

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