Vehicle end power battery lithium precipitation online monitoring method

Abstract

The invention provides a vehicle end power battery lithium precipitation online monitoring method. The method comprises the following steps: acquiring battery voltage data in a standing state after a battery is charged in a vehicle end or battery swap station scene, and calculating the voltage deviation degree at each moment according to the acquired voltage data; and when the calculated voltage deviation degree corresponding to a certain moment is greater than the voltage deviation degree at the previous moment, triggering the calculation of the voltage change trend of the battery, and judging whether lithium is separated from the battery or not according to the calculated voltage change trend. By means of the method, the voltage data of the battery can be accurately acquired and the voltage deviation degree can be calculated by utilizing the standing state after the battery is charged in a vehicle end or battery swap station scene, so that the calculation of the voltage change trend can be triggered according to the voltage deviation condition, and the nondestructive detection of the lithium precipitation of the battery core can be accurately and efficiently realized. The method is short in time, low in cost, high in efficiency, good in accuracy and relatively high in practical application value.

Description

technical field [0001] The invention relates to the technical field of battery lithium analysis detection, in particular to an online monitoring method for vehicle end power battery lithium analysis. Background technique [0002] There is a risk of lithium precipitation when the battery is overcharged or charged at low temperature. Lithium deposition in the battery will not only lead to the attenuation of the battery capacity and reduce the service life of the entire battery pack; the reaction of lithium dendrites with the electrolyte may also melt through the diaphragm, resulting in a local short circuit inside the battery, a rapid rise in battery temperature, and heat in the battery and even the entire battery pack. Risk of loss of control. Although the battery management system can send an alarm by monitoring the rapid change of battery temperature, this situation has seriously threatened the safety of passengers and vehicles. Therefore, if the change of battery lithium...

AI Technical Summary

Problems solved by technology

Although this method can be detected without disassembling the battery cell, the method of directly analyzing the voltage curve is prone to false positives, and the result is not accurate enough; moreover, the patent does not determine whether the voltage curve includes a plateau interval or a rebound interval. The judgment is more complicated, which affects the detection efficiency and detection accuracy

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