Development of various solutions for complete inspection of EV batteries and related components Inspection method : OCT(Optical Coherence Tomography), X-ray, Ultrasound Testing
Korean Patent : 10-2303643,
Inspection device for detecting air void at the lead film of battery electrode
US Patent : US 11,835,468
DEVICE AND METHOD FOR INSPECTING AIR VOID AT LEAD FILM OF BATTERY
Korean Patent Pending : 10-2021-0096182
Inspection Method and Device for Aluminum Pouch Thickness of Lithium Ion Battery
Korean Patent : 10-2236815
Inspection device to detect missing or folding tab of battery electrode
Korean Patent Pending : 10-2023-0065256
Welding inspection apparatus and method of the electrode tab and electrode lead
Inspection of defects before and after forming with equivalent aluminum thickness
Korean Patent registration : 10-2303643
Inspection device for detecting air void at the lead film of battery electrode
US Patent : US 11,835,468
Automatic inspection system for detecting gaps and pores in the film fusion area in the electrode lead tab production process
Specifications :
1) Depth direction resolution : 3μm,
2) Cross sectional image (B-scan)processing speed : 50 frames/sec.
3) Detectable air void size : This is related to scan speed.
Minimum 200 μm air void can be detected under the condition of 10mm/sec. scan speed
: for 10mm width of the film.
Detectable defects
1) Inspection of delamination status between the lead tab and the film
2) Inspection of film surface and status of the film
2) Gaps and air voids in the film fusion area
Automatic Defects Detection with Deep Learning Algorithm
Compared to other X-ray images or vision images, the OCT image showing the adhesion status of the film
on the electrode tab is not easy to standardize, and it is very difficult to implement an automatic
inspection program due to irregular background noise.
TechDial has developed an inspection program that can automatically inspect defects considering various
characteristics of OCT images and continues to update them.
TechDR can provide the mechanical part for loading/unloading specimens for inspection and the control
system for interfacing with the mass production line.
If a customer wants to prepare it by himself , TechDR will provide the necessary technical information.
In this case, TechDR will supply the OCT scanner and inspection programs.
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In order to make a high-capacity battery cell in a pouch-type lithium-ion battery, the thickness of the Al pouch corresponding to the external case of the battery cell is increased. Accordingly, the forming depth of the pouch is increased, and cracks and thickness defects may occur in the curved edge portion where excessive expansion and contraction of the pouch is occurred after molding. By applying the OCT inspection technique, it is possible to inspect the weak part by detecting the change in the thickness of the upper or lower transparent layer coated on the aluminum foil.
Korean Patent Pending : 10-2021-0096182
Inspection Method and Device for Aluminum Pouch Thickness of Lithium Ion Batter
Korean Patent registration : 10-2236815, Inspection device to detect missing or folding tab of battery electrode
A simple and economical method to inspect folding and missing electrode tabs, which are known to be one of the causes of fire in pouch-type lithium-ion batteries.
Using a projection image obtained by irradiating X-rays obliquely to the stacked electrode tabs, each cross-section of the stacked electrodes can be represented in the form of steps. By comparing the step pattern and number of steps in each cross section in the scan direction, it is possible to determine whether the electrode tab is folded or missing.
In the projection image of each electrode, which is very thin, about 10 μm thick, it becomes difficult to distinguish electrode patterns as the number of stacked electrodes increasesBy combining the X-ray image taken obliquely from the top of the stacked electrode and the transmission image taken from the bottom, it is possible to easily distinguish the step pattern. Additionally, by combining step patterns created by stacked electrodes and dividing the boundaries between electrodes through deep learning, a clearer step pattern can be obtained, making it possible to inspect electrode folds and missing.
In order to form one electrode tab outside the pouch in a pouch-type lithium ion battery, after welding the stacked electrode leads, the electrode leads and an electrode tab are welded. Welding quality inspection is important because welding results affect battery performance. In general, welding inspection can be determined by the external shape of the weld by vision inspection, but there is a limit to accurate welding inspection because the internal state of the weld cannot be inspected simply as the external shape of the weld.
The quality of spot welding can be determined by applying deep learning algorithm based on the 3D welding shape which were processed from the weld image obtained with the micro X-ray tube and high-resolution X-ray detector.
Korean Patent Pending : 10-1023-0065256
(Welding inspection apparatus and method of the electrode tab and electrode lead )
When forming a pouch, there is a large change in thickness at the edges, so there is a possibility that the aluminum foil may be damaged or become thinner and lose its function. Therefore, it is necessary to measure the thickness after forming, but there is no way to measure the thickness of aluminum foil alone.
Alternatively, defects after molding can be evaluated by calculating the aluminum equivalent thickness for the entire thickness of the multi-layered aluminum pouch and comparing this equivalent thickness before and after molding.
Welding Inspection of Cylindrical Battery : Water Coupled Ultrasound Testing
Water can be used as an ultrasonic couplant to inspect the weld condition of lead tabs and battery cans to get higher resolution result. However, the water immersion method cannot be applied due to the feature of the battery. As an alternative, so-called water coupled ultasound testing is availabe to prevent moisture from remaining after inspection by simultaneously supplying and recovering water to only the battery inspection area before and after inspection.Accurate welding inspection can be applied to the mass production line without any effect on the battery.
Air-coupled Ultrasound & Water-coupled Ultrasound Testing
Liquid electrolyte impregnation test of pouch-type battery
- Inspection of the presence of air bubbles and distribution of electrolyte after vacuum injection of liquid electrolyte
Air-coupled Ultrasound Testing
Inspection of incomplete sealing, folding, and foreign materials in the pouch sealing area - Total inspection and Sampling inspection
NAUT (Non contact Air coupled Ultrasound Testing) & Water coupled Ultrasound Testing
Inspection of adhesive distribution and adhesion result between battery cell and housing when battery cell is assembled into module housing. Application to total inspection and sampling inspection of mass production line using non-contact air coupled and water-coupled ultrasonic inspection method.
