Introduction to the Airtightness Testing Method for Lithium-ion Batteries

Product leakage issues across various industries pose significant risks. In the lithium-ion battery sector, poor sealing can lead to severe performance degradation, electrolyte leakage, battery swelling, and even explosions, severely damaging product credibility. With an increasing focus on product safety in today's society, the quality of lithium-ion battery sealing is of paramount importance.

Lithium-ion batteries on the market are primarily categorized into three types based on their casing: plastic casing, metal casing, and aluminum-plastic film soft packaging. Early in the lithium-ion battery industry, the positive pressure bubble leak detection method was commonly used. This detection method is prone to causing irreversible deformation in the battery casing, particularly unsuitable for metal casings and aluminum-plastic film soft packaging lithium-ion batteries. Additionally, the low efficiency and accuracy of the detection process necessitate the urgent exploration of a suitable leak detection method.

The current methods of leak detection in the lithium-ion battery industry mainly include: water sight leak detection, helium mass spectrometry leak detection, direct pressure leak detection, flow leak detection, and differential pressure leak detection, among others. Due to the dominant repulsive forces between gases, from the perspective of the leak mechanism, airtightness leak detection technology is entirely feasible.[1]Leak detection equipment on the market is generally categorized into three types: positive pressure leak detectors, negative pressure leak detectors, and helium mass spectrometry leak detectors. Helium mass spectrometry leak detectors offer high precision, widely used in products with stringent sealing requirements. However, they also demand strict sealing of the detection pipelines and fixtures, necessitating frequent maintenance. Their high detection costs also deter many industries. Therefore, it is crucial to find an economically feasible detection method through repeated practice, ensuring the detection results fully meet production needs.