Eddy Current Sensors for Inline Battery Collector Thickness, Defect & Ni Foam Characterization

Non-contact. Inline. High precision at production speed.

Our eddy current sensor systems enable real-time thickness, defect and gap measurement for copper and aluminum battery collectors – even at line speeds exceeding 100 m/min. The technology provides stable performance under high gap conditions, making it suitable for fragile thin foils and dynamic production environments. In addition to inline production control, laboratory systems are available for Ni foam density characterization and coating evaluation during development and testing.

Designed for process engineers who need to reduce scrap, stabilize process capability and meet automotive-grade quality requirements.

Why Precise Collector Measurement Is Critical in Battery Manufacturing

Even minimal thickness deviations in the micrometer range can affect current distribution, thermal behavior and energy efficiency in lithium-ion cells. Pinholes, wrinkles, loose areas or excessive gap variations frequently cause coating instability, higher scrap or critical defects during stacking or winding.

Conventional measurement methods often fail in high-speed environments. Contact-based systems risk damaging fragile foils, while optical methods struggle with reflective or coated surfaces. Manual inspection provides no statistically reliable data.

For process engineers, this commonly results in:

  • Lack of real-time thickness visibility
  • Late defect detection → costly downstream scrap
  • Cp/Cpk deterioration without SPC feedback
  • Audit failures due to missing traceability and process proof

Conclusion: Without a stable, non-contact inline measurement approach, manufacturers risk yield losses, rising production costs and compliance challenges – especially in EV-driven markets.

Inline Production Challenges – Speed, Gaps & Defects

High-volume battery manufacturing demands precise monitoring at production speeds above 100 m/min. Under such conditions, quality deviations can propagate rapidly through downstream processes.

Typical inline challenges include:

  • Micrometer-level tolerance requirements (4–20 µm foils)
  • High gap operation with mechanical vibration
  • Detection of pinholes, surface scratches, wrinkles
  • Reflective Cu/Al and coated surfaces
  • Limited sensor installation space
  • Need for continuous SPC-compatible output

Contact-based sensors are too invasive, optical sensors are sensitive to reflection and gap variation, and manual checks are inconsistent.

A robust, gap-tolerant, non-contact solution is essential for stable and fully traceable production.

Non-Contact Eddy Current Inline Thickness Measurement for Cu/Al Collectors

Eddy current technology generates an electromagnetic field to detect changes in foil thickness and conductivity. It delivers highly accurate readings even in fast-moving production environments with variable air gaps.

Key advantages for collector monitoring:

  • Non-contact and wear-free – no risk of damaging fragile thin foils
  • High gap tolerance – stable performance even under changing mechanical conditions
  • High-speed capability – designed for continuous monitoring at >100 m/min
  • Accurate in the micrometer range – suitable for foils in the 4–20 µm range
  • Real-time response – immediate defect detection during coating, winding or calendering
  • Insensitive to optical effects – reliable on reflective or coated surfaces
  • Works with single and double-sided coated collectors

Available as single-point, line scan or array-based systems, eddy current measurement enables continuous full-width profiling or spot monitoring in critical areas.

This converts collector inspection from reactive quality control into proactive process stabilization.

Seamless Process Integration – Sensor Configuration, SPC Connectivity and Inline Control

A measurement system must integrate effortlessly into existing lines. Eddy current sensors are available in multiple configurations to match specific process environments.

Integration options:

  • Single-point, line scan or multi-sensor arrays
  • Retrofit or integrated into coater, calender or winder sections
  • Suitable for fixed or traversing sensor mounts
  • Designed for limited installation space
  • Compatible with harsh environmental conditions

Real-time process feedback:

  • Continuous SPC output (Cp/Cpk-ready)
  • Direct MES/QMS connectivity
  • Threshold-based alarms
  • Trend monitoring for predictive adjustments

This enables automatic corrective actions, minimizing scrap and optimizing process stability.

Tools for R&D and Laboratory Use – Ni Foam Density and Coating Characterization

Eddy current technology is also widely used in development and sample testing environments where precision characterization is essential.

R&D applications include:

  • Ni foam porosity and density characterization
  • Collector thickness validation
  • Coating layer performance analysis
  • Substrate vs. coating differentiation
  • Sample qualification and parameter tuning

Portable or benchtop configurations allow rapid evaluation of prototypes, supporting smooth transitions from R&D to mass production.

Consistent measurement methodology ensures data continuity from lab development to full-scale manufacturing.

ROI and Business Value – Reduced Scrap, Higher Yield and Audit Readiness

Eddy current monitoring impacts key production KPIs from day one.

  • Early defect detection → less downstream scrap
  • Stable thickness → improved Cp/Cpk → higher yield
  • Faster ramp-up phases
  • Automated SPC → easier ISO/IATF compliance
  • ROI often reached within months
  • Supports Six Sigma and Lean initiatives

What used to be a cost of non-quality becomes a driver of profitability and stability.