Lithium ion battery self-discharge detection method and detection device

Abstract

The invention relates to a lithium ion battery self-discharge detection method and device. The method comprises the steps that: first temperature and first leakage current of a lithium ion battery are obtained, wherein the first temperature and the first leakage current are the temperature and leakage current of the lithium ion battery in a standing state; continuously heating or cooling the lithium ion battery in the standing state for a preset duration; acquiring second temperature and second leakage current of the lithium ion battery at the end of the preset duration; calculating the ratio of the difference value between the first leakage current and the second leakage current to the difference value between the first temperature and the second temperature; and when the ratio is greater than a preset threshold value, determining that the self-discharge of the lithium ion battery is abnormal. The preset duration is set by an operator, so that the operator can perform self-discharge detection on the lithium ion battery in a short time without waiting for a long time; and due to the fact that the detection is rapid, the use space does not need to be occupied for a long time, and batch detection of lithium ion batteries is facilitated.

Description

technical field [0001] The present disclosure relates to the technical field of lithium-ion batteries, and in particular, to a self-discharge detection method and a detection device of a lithium-ion battery. Background technique [0002] At present, lithium-ion batteries are widely used, especially in the vehicle industry. As for lithium-ion batteries, the primary concern of everyone is their safety. For the cell manufacturing process, strict self-discharge screening is the most powerful guarantee for battery safety performance. Abnormal self-discharge is due to the inside of the battery (such as foreign objects entering the inside, or the failure of the positive and negative pole insulating gaskets, etc.), which is a phenomenon that a micro-short circuit occurs inside the battery, forming a small circuit, and causing it to discharge spontaneously. [0003] The self-discharge of lithium-ion batteries is an inevitable problem. Normal self-discharge is like a bottle filled wi...

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Problems solved by technology

[0005] The existing detection method is to simply let the lithium-ion battery stand still for 10 days or 20 days, etc., to detect the magnitude of its voltage drop to reflect whether there is a micro-short circuit inside, but this method consumes a lot of time , and take up space, it is obviously not suitable for batch detection

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