Detecting and sorting method for cascade utilization of lithium batteries

Abstract

The invention discloses a detecting and sorting method for cascade utilization of lithium batteries. The detecting and sorting method comprises the following steps that the to-be-detected lithium batteries are discharged to a preset voltage value; the n charging amounts are preset, wherein n is an integer which is greater than or equal to 1; according to one of the preset charging amounts, the to-be-detected lithium batteries are charged; after charging is completed, open-circuit voltage testing, frequency spectrum impedance testing and discharge amount testing are conducted on the to-be-detected lithium batteries; tested numerical values are analyzed, a charging-discharging efficiency value and a resistance valve and a capacitance value in a battery equivalent model are extracted, and deviation rates between all the numerical values and sorting gear set parameters are calculated; the steps are repeated until all the preset charging amounts are tested; and the lithium batteries suitable for cascade utilization are sorted according to the obtained deviation rates. The detecting and sorting method has the advantages of accuracy, high efficiency and energy saving, the health states ofthe sorted lithium batteries are fully represented, good consistency is displayed in the actual dynamic operation process of a possible application scenario, and the detecting and sorting method canbe applied to evaluation before cascade utilization of the large-batch lithium batteries.

Description

technical field [0001] The invention belongs to the technical field of electric energy, and in particular relates to a detection and sorting method for cascaded utilization of lithium batteries. Background technique [0002] With the gradual industrialization and commercialization of electric vehicles, the output of electric vehicles in my country has grown rapidly. In 2017, a total of 794,000 electric vehicles were produced and 772,000 were sold. By 2020, the production and sales of electric vehicles will reach 2 million. The electric vehicle industry chain has driven the explosive growth of the lithium battery industry, and the stock of lithium batteries for automotive power has also increased sharply. Usually, when the remaining capacity of the automotive power lithium battery is reduced to 70-80% of the initial capacity, it cannot meet the power performance, cruising range and safe operation requirements of the electric vehicle, and needs to be replaced. The replaced l...

AI Technical Summary

Problems solved by technology

These methods are suitable for visually analyzing the internal mechanism of the attenuation and failure of a single lithium battery, but they are expensive and time-consuming, and cannot be applied to the detection of cascaded utilization of large quantities of lithium batteries

It can be seen that there is currently no accurate and efficient detection and sorting method for the cascade utilization of lithium batteries

Images