Multi-parameter sorting method for lithium ion power batteries

Abstract

The invention relates to a multi-parameter sorting method for lithium ion power batteries. The method comprises the following steps that firstly, battery code scanning is carried out, then single discharge pulses and single charge pulses are tested respectively, battery end voltage-time curves are drawn, and difference values delta U1 and delta U2 between initial voltage values and minimum voltagevalues on the curves are extracted to serve as discharge polarization voltages and charge polarization voltages correspondingly, then an internal resistance tester is used for carrying out internal resistance test and voltage test on the tested batteries to obtain an internal resistance R and a voltage U of each battery, and finally delta U1, delta U2, R and U are taken as sorting parameters to carry out clustering to obtain a clustering result of each battery so as to finish battery sorting. According to the multi-parameter sorting method for the lithium ion power batteries, the polarizationvoltages are taken as one of the bases of battery sorting, static parameters such as the battery internal resistances and the battery voltages are combined, lithium battery multi-parameter sorting combining the dynamic characteristics and the static parameters is achieved, high comprehensive consistency is achieved, and meanwhile, the time can be saved, and the sorting efficiency of the batteriesis improved.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a multi-parameter sorting method for lithium-ion power batteries. Background technique [0002] Electric vehicles rely on batteries for power supply, and the performance of batteries and battery systems determines the power performance of electric vehicles. Lithium-ion batteries are widely used in electric vehicle battery systems due to their advantages such as high specific energy, high cycle times, and long charge and discharge life. However, due to the limited capacity, voltage, and energy of the single battery, it must be connected in series and parallel to form a group to meet the energy supply requirements. The battery system of an electric vehicle is generally composed of single cells grouped together to form a battery module, and then the modules form a battery pack. An electric vehicle may have a very large number of batteries, so inconsistencies between cells may li...

AI Technical Summary

Problems solved by technology

At present, the battery sorting on the production line is through static screening of the external characteristics such as the capacity, voltage, and internal resistance of the single battery. The screening time is short and the efficiency is high, but it can only ensure that these indicators of the selected single battery are consistent. , unable to reflect the dynamic characteristics of the battery at work

If the dynamic sorting method is used to conduct a complete charge and discharge test on the battery, it will consume a lot of time and seriously reduce the production efficiency of the production line

Images