A rapid screening method for battery internal resistance and capacity

Abstract

The invention discloses a quick screening method for battery internal resistance and capacity, which is used for quick screening of battery cells that have been retired from new energy vehicles and have the same specifications, including: visually inspecting the appearance of multiple battery cells, Remove the battery cells with unqualified appearance to obtain battery cells with qualified appearance; put the battery cells with qualified appearance into parallel equipment for t p The parallel equalization of the battery cell after the parallel equalization is obtained; the battery cell after the parallel equalization is put into the series device for a time of t s The battery cells are charged and discharged in series, and the voltage of the battery cells at the end of the series charge and discharge is recorded, and the battery cells are classified according to the voltage, and the classified battery cells are subjected to a fine sieve for capacity sampling, and the finely sieved battery cells are obtained. Carry out capacity calculation on the finely screened battery cells to complete the capacity screening, and determine the internal resistance of each battery cell according to the voltage jump of each battery cell at the end of series charging and discharging.

Description

technical field [0001] The invention belongs to the field of battery screening, and in particular relates to a rapid screening method for battery internal resistance and capacity. Background technique [0002] With the continuous increase in sales of new energy vehicles in China, the production and sales of new energy vehicles in my country were close to 800,000 in 2017. It is estimated that by 2020, the production capacity of pure electric vehicles and plug-in hybrid vehicles will reach 2 million, and the cumulative production and sales will exceed 5 million vehicles. If the average battery consumption per vehicle is 30kW, 5 million electric vehicles are using 150 million KW h of batteries, and based on an annual 10% scrap rate, the scrapped batteries will reach 15 million KW h. Although these scrap batteries cannot meet the requirements of electric vehicles, they can still be used in occasions that require lower battery performance, such as energy storage power stations. ...

AI Technical Summary

Problems solved by technology

[0005] However, in the actual screening process, the number and time matching problems of various equipment will be encountered, and the assembly line operation cannot be completed smoothly. In the battery screening, it is difficult to screen with the two parameters of battery capacity and self-discharge, because capacity testing and The self-discharge test takes a lot of time, so it is necessary to design a rapid screening system for the mismatch between the number of devices and the time in the process of internal resistance and capacity screening

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