Measure the thicknesses of separators, electrodes, and coating layers without contact using a multicolor confocal coaxial displacement sensor. It supports both double-sided (sandwiching) and single-sided measurement, enabling inline thickness control immediately after coating or pressing.
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Inquiries about battery material thickness measurement
Three Reasons Why Measuring the Thickness of Battery Materials Is Difficult
Thickness variation in separators and electrodes directly affects battery capacity, safety, and yield rate. Choosing the wrong measurement method leads to defects and waste.
Thickness Variation Directly Leads to Uneven Capacity and Internal Short Circuits
If the coating thickness of the electrode varies, the amount of active material becomes uneven, causing capacity differences between cells and uneven charging/discharging. In areas where the separator is thin, the positive and negative electrodes come close together, increasing the risk of internal short circuits, heat generation, and ignition. Electrode thickness tolerance is generally controlled to within ±2 to 5 µm after pressing, requiring measurement with a repeatability of the 0.1 µm class. Failure to stably control thickness increases the outflow of defective products and disposal waste.
Limitations of Contact and Beta-Ray Methods on-Site
Contact methods such as micrometers make continuous measurement during travel difficult, and pressing against a soft coating layer causes deformation and scratches. Although the beta-ray method is non-contact, it requires radiation source management, qualified personnel, and controlled areas, making the hurdles for introduction and operation high in reality. There is a need for a means of measurement that can keep up with production speeds without being affected by regulations or contact.
Transparent, Multi-Layer, and Copper Foil Processes Are Difficult to Measure
Separators and coating layers are semi-transparent, and general displacement sensors cannot separate reflections from the front and back surfaces, resulting in errors. Current collectors also have multi-layer configurations of copper foil and aluminum foil, requiring the thickness of each layer to be measured separately. Furthermore, in battery processes, requirements to avoid copper and copper alloy jigs, as well as installation environment constraints such as dry rooms and explosion-proof environments immediately after coating, make measurement difficult.
Battery Material Manufacturing Processes and Thickness Measurement Points
By understanding the thickness in each process from coating to stacking, variations and defects can be detected at an early stage.
- 1 Coating – Thickness measurement ①. Active material slurry is applied to the current collector foil. The total thickness immediately after coating and before drying is measured, providing immediate feedback on the coating amount. With an explosion-proof head, measurement is possible even before the drying process in a solvent atmosphere.
- 2 Drying – The solvent is volatilized to fix the coating layer. The electrode thickness after drying is measured to control the reference values for basis weight and density.
- 3 Roll pressing – Thickness measurement ②. The electrode is pressurized to increase density. The thickness after pressing is measured by sandwiching to detect uneven wear of rolls on one side or thickness variation.
- 4 Slitting, winding/stacking – Thickness measurement ③. The electrode and separator are cut to a specified width and laminated. The separator thickness and width after stacking are confirmed without contact to guarantee final quality before assembly.
Comparison of Battery Material Thickness Measurement Methods
Depending on the measurement method, there are significant differences in non-contact capability, legal regulations, compatibility with transparent objects, and inline suitability.
Non-contact/Impact on target
CL-3000 Series (Multicolor Confocal/Coaxial)
○ Non-contact, does not scratch the target
Beta-ray method
○ Non-contact
Contact method (micrometer, etc.)
× Deformation/scratches due to pressing
Radiation and legal regulation management
CL-3000 Series (Multicolor Confocal/Coaxial)
○ Not required
Beta-ray method
× Radiation source management, qualified personnel, and controlled areas are required
Contact method (micrometer, etc.)
○ Not required
Measurement of transparent/semitransparent objects
CL-3000 Series (Multicolor Confocal/Coaxial)
○ Separate measurement of front and back surfaces (from 15 µm)
Beta-ray method
△ Dependent on density and material
Contact method (micrometer, etc.)
× Difficult
Single-sided and double-sided (sandwiching) measurement
CL-3000 Series (Multicolor Confocal/Coaxial)
○ Supports both single-sided and double-sided (sandwiching) measurements
Beta-ray method
△ Transmission arrangement is required
Contact method (micrometer, etc.)
△ Single-sided contact only
Multilayer (layer-by-layer) thickness measurement
CL-3000 Series (Multicolor Confocal/Coaxial)
○ Separates reflections from front and back surfaces
Beta-ray method
× Total thickness only
Contact method (micrometer, etc.)
× Not possible
Inline continuous measurement
CL-3000 Series (Multicolor Confocal/Coaxial)
○ Measurement while moving with high-speed sampling
Beta-ray method
○ Possible
Contact method (micrometer, etc.)
× Stopping required
Avoids copper/copper alloys / Compatible immediately after coating
CL-3000 Series (Multicolor Confocal/Coaxial)
○ Compatible with full SUS jigs and explosion-proof heads
Beta-ray method
△ Depends on configuration
Contact method (micrometer, etc.)
△ Depends on configuration
Why Choose the CL-3000 Series
The CL-3000 Series uses a multicolor confocal method that does not require radiation control, allowing high-accuracy, non-contact measurement of transparent and multi-layer battery materials such as separators and coating layers. It supports both single-sided and double-sided (sandwiching) measurement, and is compatible with explosion-proof environments immediately after coating as well as processes where copper must be avoided. It achieves inline thickness control while eliminating the limitations of beta-ray and contact methods.
CL-3000 Series for Battery Material Thickness Measurement
This coaxial displacement sensor uses a multicolor confocal method and is suitable for measuring the thickness of battery materials in transparent, multi-layer, and copper foil processes.
Compatible With Battery Material Thickness Measurement - CL-3000 Series
Confocal Displacement Sensor
With the multicolor confocal method and Quad processing system, a single unit can measure various targets such as transparent, rough, and multi-layer surfaces with high accuracy. The thickness measurement type CL-S015 features a resolution of 0.003 µm and linearity of ±0.1 µm (high-accuracy range). The dedicated adjustment jig OP-88864 is made of full stainless steel (SUS) and is compatible with battery processes where copper and copper alloys must be avoided, as well as dry clean rooms. The optical axis alignment function suppresses errors caused by optical axis misalignment even during double-sided measurement. The explosion-proof type CL-S015EX (compatible with Zone 0/Division 1) allows total thickness measurement immediately after coating and before drying. The CL-3050 controller can synchronously measure up to 6 heads, enabling collective multi-point and double-sided thickness control.
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Get Detailed Materials for the CL-3000 Series
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Inquiries about battery material thickness measurement
Application Examples of Battery Material Thickness Measurement
The CL-3000 Series is used for thickness measurement of various battery materials, such as separators, electrodes, and coating layers.
Double-Sided Thickness Measurement of Separators and Electrodes
By sandwiching the target between two heads, the optical axis alignment function suppresses errors caused by optical axis misalignment. This allows high-accuracy, non-contact measurement of the thickness of electrodes and separators after pressing.
Electrode Thickness Measurement After Pressing
Measurement is possible without being affected by heat generation from rolls or electrodes. Controlling the press rolls helps improve the yield rate.
Width and Case Height Measurement After Battery Stacking
The width after stacking, which is difficult to measure with large calipers, and the case height before electrolyte injection are measured using coaxial, non-contact measurement to check the quality before assembly.
Frequently Asked Questions About Battery Material Thickness Measurement (CL-3000 Series)
Yes, they can. Because the multicolor confocal method can separate the reflected light from the front and back surfaces, the thickness of transparent and translucent objects from approximately 15 µm can be measured without contact.
Yes, it can. Both single-sided measurement and double-sided measurement by sandwiching with two heads are supported. During sandwiching, the optical axis alignment function suppresses errors caused by optical axis misalignment.
Yes, it can. Because the multicolor confocal method does not use a radiation source, controlled areas and qualified personnel are not required. High-accuracy inline measurement can be continued without contact.
Yes, it can. With the explosion-proof type CL-S015EX (compatible with Zone 0/Division 1), the total thickness of the coating layer can be measured even before the drying process in a solvent atmosphere.
Yes, it can. The dedicated adjustment jig OP-88864 is made entirely of stainless steel (SUS), allowing it to be used with confidence in battery processes where copper and copper alloys must be avoided, as well as in dry clean rooms.
Yes, they can. The CL-3050 controller can synchronously measure up to 6 heads, allowing multi-point and double-sided thicknesses to be managed together.
- Confocal Displacement Sensor CL-3000 series
Confocal Displacement Sensor
CL-3000 series
