Battery classifying method of retired electric cars

Abstract

The invention provides a battery classifying method of retired electric cars. The method comprises the steps that power batteries are subject to self-discharging detection, voltage drop-out value of the power batteries is obtained, and materials of the power batteries are combined for judging whether the power batteries meet the first echelon utilization requirement or not; the power batteries are subject to performance detection, the capacity retention ratio of the power batteries is obtained, and according to the capacity retention ratio, whether the power batteries meet the second echelon utilization requirement or not is judged; the power batteries are subject to temperature rise effect detection, the temperature rise amplitude of the power batteries is obtained, and according to the temperature rise amplitude, whether the power batteries meet the third echelon utilization requirement or not is judged; and according to the battery parameter threshold value range of the application condition of the power batteries, the application method of the power batteries is determined. According to the method, the batteries with the high potential safety hazard can be rapidly and effectively removed, the threshold value range of parameters of the retired power batteries applied under different conditions is determined, and the safety of the batteries in the application process is improved.

Description

technical field [0001] The invention relates to a method in the technical field of battery energy storage, in particular to a method for classifying power batteries of decommissioned electric vehicles. 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 the power battery is rea...

AI Technical Summary

Problems solved by technology

[0004] The potential safety hazards of the power battery during use come from two aspects. One is the improper use of the battery, such as excessive charging and discharging current, high operating temperature, overcharging or overdischarging, which may cause thermal runaway of the battery The second is from the internal defects of the battery, such as dust in the battery manufacturing process, lithium dendrites on the surface of the negative electrode, etc., which may cause the internal short circuit of the battery. Thermal runaway and even fire

[0005] For power batteries decommissioned from electric vehicles, in the prior art, their classification is mainly based on parameters such as battery capacity, internal resistance, self-discharge rate, etc., and the above classification methods cannot effectively exclude batteries with potential internal short circuits ; The possible application direction of cascade utilization power batteries is mainly in the field of energy storage, and there are also many application conditions in the field of energy storage, but there is no specific application method for the power of decommissioned electric vehicles in energy storage conditions.