Fast screening method for battery internal resistance and capacity

Abstract

The invention discloses a fast screening method for the battery internal resistance and capacity, wherein the method is used for rapid screening of battery monomers decommissioned from new energy vehicles and having the same specifications. The method comprises the steps: inspecting the appearance of multiple battery monomers through visual inspection, removing battery monomers with unqualified appearance, and thus obtaining battery monomers with qualified appearance; putting the battery monomers with qualified appearance into a parallel device, and carrying out parallel equalization for the time of tp, to obtain parallel-equalized battery monomers; putting the parallel-equalized battery monomers into a series device, carrying out series charging and discharging for the time of ts, recording the voltage of the battery monomers at the end moment of series charging and discharging, classifying the battery monomers according to the voltage, carrying out capacity sampling fine screening ofthe classified battery monomers, and thus obtaining fine-screened battery monomers; and calculating the capacity of the fine-screened battery monomers, to complete screening of the capacity, and determining the internal resistance of each battery monomer according to the voltage jump change of each battery monomer at the end moment 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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