Lithium ion battery matching method

Abstract

The invention discloses a lithium ion battery matching method which comprises the following steps of: numbering single batteries, performing a discharge capacity C test, and classifying the single batteries according to discharge capacities; testing the open-circuit voltages OCV of the single batteries; adopting DC internal resistance test, and processing data to obtain the ohmic internal resistance R0, polarization internal resistance Rpa, polarization capacitance Cpa, concentration difference internal resistance Rpc and concentration difference capacitance Cpc of each single battery; gradingthe variables C, OCV, R0, Rpa, Cpa, Rpc and Cpc respectively, and giving evaluation scores; calculating the weight of each variable by adopting a principal component analysis algorithm, and multiplying the weight of each variable by the evaluation score of the grade of the single battery under the variable to obtain a weighted evaluation score of each single battery; and grading according to theweighted evaluation scores, and grouping and applying the graded and screened single batteries. According to the method, the parameter weight influencing the consistency of the battery pack can be obtained through a principal component analysis algorithm, and similar single batteries with the same grade are selected for matching, so that the purpose of guaranteeing the cycle life of the battery pack is achieved.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a lithium ion battery assembly method. Background technique [0002] As the country continues to increase the popularity of new energy vehicles, the key technologies of new energy vehicles have developed rapidly. The power battery is the power source of new energy vehicles. In practical applications, in order to meet the requirements of long mileage and high speed, hundreds of single cells are often assembled in series or parallel to form a battery pack. In order to improve the cycle life of the battery pack, the consistency of the single cells in the battery pack is required to be as high as possible. However, due to factors such as production process, equipment, and manufacturing environment, the battery parameters produced in the same batch are different, so it is meaningful to consider the battery parameters close to the actual situation to improve the consist...

AI Technical Summary

Problems solved by technology

However, due to factors such as production process, equipment and manufacturing environment, the parameters of batteries produced in the same batch are different, so it is very meaningful to consider the battery parameters close to the actual situation to improve the consistency of the battery pack.

[0003] At this stage, in terms of single battery matching, although there are some methods that can improve the consistency of the battery pack, there are still shortcomings such as insufficient consideration of battery parameters and failure to consider the impact weight of parameters on the battery.

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