Health state assessment method of retired electric automobile power cell

Abstract

The invention provides a health state assessment method of a retired electric automobile power cell. The method comprises the steps of: carrying out basic performance detection, cell key performance sampling detection and cell internal characteristic detection on the retired electric automobile power cell, wherein the basic performance detection comprises cell appearance detection, cell open-circuit voltage and internal resistance detection, cell capacity and energy detection, and cell charge retention detection; the cell key performance sampling detection comprises cell life characteristic detection, cell environment adaptability detection, cell multiplying power characteristic detection and cell safety performance detection; and the cell internal characteristic detection comprises electrode slice form and material combination condition analysis, diaphragm form and aged condition analysis, material crystal structure analysis and composition analysis, material available capacity and electrochemistry cycling performance analysis, and electrode surface solid electrolyte interface analysis. By adopting the method, the basic parameters of the cell are comprehensively detected, sampling detection is carried out on the key parameters and internal characteristics of the cell, and the health state of the cell is accurately evaluated.

Description

technical field [0001] The invention relates to a method in the technical field of battery energy storage, in particular to a method for evaluating the health status of a decommissioned electric vehicle power battery. Background technique [0002] Electric vehicles have high requirements on the performance of the power battery. When the capacity of the power battery drops to a certain level, in order to ensure the power performance, driving range and safety performance of the electric vehicle, it must be replaced. The battery replaced from the electric vehicle still has a high residual capacity. Lithium-ion batteries have the advantages of high specific energy, good temperature characteristics, and long cycle life. After being decommissioned as electric vehicle power batteries, after screening and regrouping, they may be used in relatively good working conditions and relatively low requirements for battery performance. In some cases, the step-by-step utilization of power ba...

AI Technical Summary

Problems solved by technology

[0005] The external performance of the battery health status is the external characteristic parameters of the battery, mainly including the appearance, open circuit voltage, internal resistance, capacity, energy, charge retention capacity, life characteristics, environmental adaptability, rate characteristics and safety characteristics of the battery. Among the characteristics, the appearance, open circuit voltage, internal resistance, capacity, energy, and charge retention can be obtained through testing quickly, and these tests will not damage the performance of the battery; while the battery life characteristics, environmental adaptability, and rate characteristics It takes a relatively long time to obtain safety features, and these tests will damage the performance of the battery to a certain extent, and some even directly destroy the battery, making the battery unusable