Lithium Battery Safety Performance Testing Method

I, Surface defect detection

The surface defects of lithium batteries are mainly caused by damage to the raw materials themselves or accidental contact on the production line. They are mainly manifested as scratches, wrinkles, bulges, dents, pits, pinholes, exposed aluminum, dirt, etc. Among them, serious defects such as pinholes and exposed aluminum will affect the safety performance of the battery.

At present, the surface detection method of lithium batteries in industry is mainly manual detection. The quality inspector carefully observes the surface of each product under strong light environment and detects dents and pits on the surface of lithium batteries by touch.

II, Electrode detection

The production process of electrode plates is complex and the processes are numerous. 70% of the battery quality is related to the plates. The defects of the plates will directly affect the performance of the battery. At the least, it will cause the battery capacity to decrease and the life to decrease. At the worst, it will cause a short circuit inside the battery. The defect detection of the plates is an important part of the battery quality inspection.

The production process of the plates includes winding, scraping powder, rolling, cutting, welding of pole ears, pasting adhesive tape, winding and other links. The plates may be damaged in the coating and rolling links. Lithium battery pole defects include pole breakage, pole metal leakage, pole scratches and wrinkles.

III, Battery internal structure defect detection

Battery internal structure defects are mainly divided into two types, one is the presence of foreign matter inside the battery, and the other is the presence of too much gas inside the battery. Foreign matter inside the battery is mainly caused by process defects in the battery production process, which can be detected by X-rays. Since X-rays are sensitive to high-density materials, they can mainly detect metal foreign matter. Excessive air in the electrolyte is mainly caused by factors such as poor packaging, chemical reactions inside the battery core, and poor electrolyte infiltration.