Cho Hyunwoo, Kil Eunwoo, Jang Jihun, Kang Jinbum, Song Ilseob, Yoo Yangmo
Department of Electronic Engineering, Sogang University, Seoul 04107, Korea.
Medical Solutions Institute, Sogang University, Seoul 04107, Korea.
Sensors (Basel). 2022 Sep 5;22(17):6718. doi: 10.3390/s22176718.
Inspecting the sealing integrity of lead tabs is an important means of ensuring the reliability and safety of pouch-type lithium-ion (Li-ion) batteries with a thin multi-layered aluminum (Al) laminated film. This paper presents a new air-coupled ultrasonic non-destructive testing (NDT) inspection method based on leaky Lamb wave transmission; and reception for evaluating the sealing integrity between the lead tab and the Al pouch film. The proposed method uses the critical incidence angle between the air and the layer with the fastest Lamb wave velocity to maximize the signal-to-noise ratio in the through-transmission mode. To determine the critical incidence angle, phantom experiments with two test pieces (i.e., an Al tab and an Al tab sealed with an Al pouch film) are conducted. In addition, 2D scans are performed at various incidence angles for an inhouse pouch-type Li-ion battery with a 1-mm-wide foreign material inserted as a defect. At the critical incidence angle (i.e., 22°), the proposed air-coupled ultrasonic NDT method in through-transmission mode successfully identifies the shape and location of the defect through c-scan image reconstruction. These preliminary results indicate that the proposed air-coupled ultrasonic NDT method with leaky Lamb waves can be used to inspect the sealing integrity of Li-ion pouch batteries in dry test conditions.
检查引线片的密封完整性是确保采用多层铝（Al）复合薄膜的软包型锂离子（Li-ion）电池可靠性和安全性的重要手段。本文提出了一种基于泄漏兰姆波传输和接收的新型空气耦合超声无损检测（NDT）方法，用于评估引线片与铝软包薄膜之间的密封完整性。该方法利用空气与具有最快兰姆波速度的层之间的临界入射角，在穿透传输模式下最大化信噪比。为了确定临界入射角，对两个试件（即一个铝片和一个用铝软包薄膜密封的铝片）进行了模拟实验。此外，对内部插入1毫米宽异物作为缺陷的软包型锂离子电池，在不同入射角下进行了二维扫描。在临界入射角（即22°）下，所提出的穿透传输模式空气耦合超声无损检测方法通过C扫描图像重建成功识别了缺陷的形状和位置。这些初步结果表明，所提出的具有泄漏兰姆波的空气耦合超声无损检测方法可用于在干燥测试条件下检测锂离子软包电池的密封完整性。
