Battery Surface Metal Debris Detection Using Far-Infrared Reflection

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Solution Overview

Problem

Existing debris detection methods struggle to accurately identify metal debris smaller than 100 µm on a battery's surface during manufacturing due to difficulties in distinguishing it from non-metallic dust and rough or curved surfaces, leading to potential electrical shorts.

Innovation Solution

A debris detection apparatus utilizing far-infrared electromagnetic waves to emit and analyze reflected waves with a thermal image recorder, enhancing detection resolution by leveraging metal's high reflectivity in the infrared region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a microscope with large magnification is used to detect metal debris with diameter of 100 μm or less, then detection precision is improved, but device complexity increases and operation becomes more difficult

Engineering Contradiction:
Improvedetection precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the wavelength parameter of the inspection light from visible light to infrared light (specifically 3 μm to 14 μm). This parameter change enables detection of metal debris without requiring high magnification microscopes, as metal debris exhibits strong reflection characteristics in the infrared region, allowing for simplified detection equipment while maintaining high detection precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/optical microscope system with an infrared reflection detection system. Instead of using magnification optics to visualize metal debris, the system uses infrared light reflection characteristics to detect and identify metal debris, thereby simplifying the device structure while improving detection capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If straight light is irradiated at a preset incident angle and reflection angle is monitored, then device structure is simplified, but measurement precision deteriorates due to false detection from rough or curved surfaces

Engineering Contradiction:
Improvedevice complexityVSAvoiddetection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the wavelength parameter from visible light to infrared light (3 μm to 14 μm). This parameter change fundamentally alters the interaction with the surface: infrared light is less sensitive to surface roughness and curvature effects that cause false detections in visible light, while maintaining the simplicity of the reflection angle monitoring method. The metal debris reflection characteristics in infrared region provide sufficient contrast for accurate detection.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If visible light is used for debris detection, then detection of metal debris is attempted, but distinction from non-metallic dust becomes difficult

Engineering Contradiction:
Improvematerial identification accuracyVSAvoidmaterial differentiation capability
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent changes the spectral parameter from visible light to infrared light (3 μm to 14 μm). This parameter change exploits the fact that metal debris and non-metallic dust have different reflection characteristics in the infrared region. Metal debris exhibits strong, characteristic reflection in this wavelength range, while non-metallic dust does not, enabling clear material differentiation and accurate identification.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The apparatus effectively identifies and specifies the size and position of metal debris on a battery's surface, distinguishing it from other contaminants, even on rough surfaces, without significantly heating the target, thereby improving detection accuracy.

Implementation Method 1

an infrared emitting unit configured to emit infrared rays toward an inspection target

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 2

an optical unit configured to amplify an infrared signal reflected from a metal debris existing on a surface of the inspection target

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

a thermal image recorder configured to detect whether the metal debris exists on the surface of the inspection target and a size and a position of the metal debris, through the amplified infrared signal

Methodology Applied
Scientific EffectThermal imaging: Thermography

Data Source

PatentEP4130721B1Foreign substance detection device and detection method
Publication Date: 2025.09.17 LG ENERGY SOLUTION LTD
  • EP4130721B1 patent drawingFigure 1
  • EP4130721B1 patent drawingFigure 2
  • EP4130721B1 patent drawingFigure 3

AI summary

Disclosed are a debris detection apparatus and a debris detection method, capable of easily detecting a metal debris existing on the surface of an inspection target by emitting electromagnetic waves having a wavelength in a far-infrared band toward the inspection target during a battery manufacturing process and then analyzing the characteristics of reflected waves from the surface of the inspection target through a thermal image recorder.