In 2021, WHEC released “CIS Application Battery Film Inspection” introducing the application of WHEC CIS and HLU series light sources in battery film coating and slitting vision inspection. CIS, as an “All-in-One solution”, has advantages such as compact size, undistorted images, and easy installation and commissioning compared to the combination of line scan camera, industrial lens and light source. It is widely used in battery production lines with limited space.

Over the past 3 years, WHEC CIS and light sources have been successfully applied in battery processes such as notching and lamination/stacking as well. In addition, in the vision inspection of lithium battery raw materials—metal films and separator films, CIS also brings unique value to System Integrators(SI) with its advantages of compact size, undistorted images, and easy installation.

Development of Battery Film Coating Inspection

In order to shorten the installation time of inspection systems for SI, WHEC introduced area light sources (SHLU series), increasing the brightness of the light source and enlarging the spot area. This not only provides SI with higher quality images but also reduces installation and commissioning time.

As for Battery Factory’s demand for higher speed, larger width, and higher resolution from inspection systems and CIS, WHEC began to develop a new generation of CoaXpress interface CIS to meet these requirements while solving the pain points of Cameralink cables during the installation of vision systems. The new CIS product has a resolution of 1200dpi, a line frequency of up to 93kHz, and a feeding speed of 118m/min. The width of the new product will continue to match the widths of battery films, including 800mm, 1500mm, and 1700mm, while being flexible to expand to other widths.

Metal Film and Separator Inspection

As the main components of lithium batteries, surface defect detection of metal films and separators is highly valued by factories. Metal film surfaces are shiny and highly reflective materials. Through the CIS camera in the detection technology, WHEC has accumulated rich experience and developed a solution for detecting reflective material surfaces. This product can clearly capture small defects on metal film surfaces, solve high-risk defects caused by scratches and holes in diaphragm materials, and has passed customer evaluation. It has been imported into production line for use.

For separator materials, scratches and holes are high-risk defects. WHEC collaborated with separator detection customers to test CIS with various light sources, ultimately determining the method of combining backlight and sidelight. By obtaining two images under backlight and sidelight, scratches and holes can be effectively detected. Additionally, the width of separator base film can exceed 6 meters, if using multiple line scan cameras, system installation would be extremely time-consuming and labor-intensive. To meet such demands for ultra wide webs, WHEC plans to increase the maximum width supported by CIS from 2 meters to 6 meters and can currently provide CIS samples with a width of 3 meters.

WHEC will showcase the three applications mentioned above at the 2024 Stuttgart Battery Show (June 18-20, hall 4-C90): ① CIS scanning battery film after coating with area light source ② CIS scanning metal film with focused light source ③ CIS scanning separator with combining backlight and sidelight. You are welcome to visit and exchange ideas at any time!