Lithium Battery Electrode Coating Thickness Measurement

New Energy01.Lithium Battery Electrode Coating Thickness Measurement with Laser Triangulation Sensors

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New Energy01.Lithium Battery Electrode Coating Thickness Measurement with Laser Triangulation Sensors

Aug 19, 2025

1. Importance of Coating Thickness Measurement

In lithium battery manufacturing, electrode coating thickness directly influences:

Energy density – coating uniformity ensures stable capacity.
Battery life – excessive thickness variations may cause uneven current distribution.
Safety – incorrect thickness can lead to overheating or short circuits.
Yield and efficiency – real-time monitoring reduces scrap and improves production consistency.

Accurate and reliable thickness measurement is therefore essential for high-performance lithium batteries.

2. Common Measurement Methods

Measurement Method	Principle	Advantages	Limitations
Contact micrometer	Physical probe measures thickness	Simple, low cost	Slow, risk of surface damage, not inline
Beta-ray / X-ray gauge	Absorption of radiation by coating material	High accuracy, used in coating thickness control	Safety concerns, requires radiation shielding
Optical interferometry	Interference fringes determine thickness	Very high resolution	Sensitive to vibration, limited to lab use
Laser triangulation sensor	Laser reflection angle used to calculate distance	Non-contact, high-speed, inline applicable	May be influenced by highly reflective surfaces

3. Principle and Process of Laser Triangulation

Laser triangulation displacement sensors work as follows:

Laser projection – a laser beam is projected onto the electrode surface.
Reflection capture – reflected light is received by a position-sensitive detector (PSD/CMOS).
Angle calculation – the reflection position indicates distance.
Thickness result – by measuring the distance to both coated and uncoated areas (or reference), the system derives coating thickness.

Why it fits electrode coating:

Non-contact, preventing damage to sensitive coatings.
High sampling rate supports real-time inline monitoring.
Detects micro-scale thickness variations with high repeatability.

4. TronSight’s Solution

The TronSight TS-P Series Laser Triangulation Displacement Sensor provides:

Up to 160kHz sampling rate, ideal for fast-moving coating lines.
±0.02% of F.S. linear accuracy, ensuring consistent electrode coating evaluation.
0.02μm repeatability, enabling detection of micro-thickness variations.
Wide measuring range (2~2000mm), adaptable to different electrode formats.
Customizable optics (laser line width, wavelength, structure dimensions).
Built-in controller for simplified integration into coating inspection systems.

Application example (conservative wording):
In a lithium battery coating process, TS-P sensors measure electrode thickness differences across coated surfaces. The collected data can support inline inspection systems to verify uniformity and production quality.