Method and device for determining safe charging condition of lithium ion battery

Abstract

The invention provides a method and device for determining a safe charging condition of a lithium ion battery, wherein the method and device includes a step or unit adopting a preset charging rate for charging a three-electrode lithium ion battery at a preset temperature; if voltage difference between a negative electrode and a reference electrode is greater than zero, the three-electrode lithium ion battery is determined not to generate lithium precipitation, that is to say, in the step or unit, a condition of adopting the preset charging rate for charging the lithium ion battery at the preset temperature is a safe charging condition. The safe charging condition of the lithium ion battery is determined, so that lithium evolution of the lithium ion battery caused by unreasonable charging conditions is avoided, the safety performance of the lithium ion battery is avoided from being affected, the purposes of improving the service life and the safety performance of the lithium ion battery are achieved, and the method and device have the advantages of simple and easy operation.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a method and device for determining safe charging conditions of lithium ion batteries. Background technique [0002] Lithium-ion batteries have significant advantages such as high energy density, long cycle life, high working voltage, fast charging speed, and small self-discharge, making them the most advantageous secondary batteries. At present, lithium-ion batteries have been widely used in digital products, energy storage power stations, electric automotive and other fields. With the continuous expansion of the application field of lithium-ion batteries, its application conditions are becoming more and more stringent. Especially in the field of electric vehicles, due to the requirements of the use conditions, there is a demand for fast charging, especially when charging at a high rate at low temperature, it will cause a large polarization of the battery and lead...

AI Technical Summary

Problems solved by technology

On the one hand, for lithium-ion batteries, especially automotive lithium-ion batteries, the battery volume and capacity are large, and some batteries are still steel shell batteries. Dismantling the battery requires manpower and material resources, and it is impossible to visually inspect a small amount of lithium. Based on observation and judgment, it is proposed to use energy spectrum and XRD analysis methods to observe whether there is lithium precipitation on the surface of the negative electrode. It is very active and often reacts to produce lithium carbonate and other products before testing, which will lead to wrong judgments

The patent application with the publication number CN106093777A mentioned that by comparing the Coulombic efficiency during the battery cycle to judge whether the battery has lithium deposition, on the one hand, the lithium deposition of the battery will lead to a change in the Coulombic efficiency, but the change in the Coulombic efficiency does not necessarily appear. Lithium analysis; on the other hand, the process of this method is cumbersome, in order to obtain the law of the battery Coulombic efficiency, it is necessary to carry out multiple cycles

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