Foreign Material Detection in Pouch Batteries via Light Scattering

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Solution Overview

Problem

Current methods for inspecting pouch type batteries for foreign materials are slow and inaccurate, particularly due to reliance on naked eye inspection, which cannot detect micro-sized dust and is inefficient in high-speed automated production environments.

Innovation Solution

A method using a light scattering technique with a line LED laser and CCD camera to quickly and accurately detect foreign materials by analyzing the reflection angles and diffusion of linear light on the battery case surface, employing a pre-set incident angle range of 30° to 60° and multiple sensor units positioned at various angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If naked eye inspection is used to detect foreign materials, then the inspection method is simple and low-cost, but the inspection speed is slow and cannot keep up with automated production rates

Engineering Contradiction:
Improveinspection speedVSAvoiddetection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical naked eye inspection system with an optical detection system using a line laser and CCD camera. The line laser irradiates the battery case surface and the CCD camera captures the reflected light patterns, enabling automated detection that matches production speed while maintaining high precision in detecting micro-sized foreign materials.

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

2Measurement precision

If naked eye inspection is used to detect foreign materials, then the equipment complexity is low, but the detection precision for micro-sized dust is insufficient

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

Solution Approach 1:

The patent substitutes the simple but imprecise naked eye inspection with an optical system comprising a line laser and CCD camera. This system achieves high detection precision for micro-sized dust particles by capturing light scattering patterns, while the overall device structure remains relatively simple and easy to integrate into the production line.

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

3Productivity

If sampling inspection is used instead of total inspection, then the productivity is maintained, but the reliability of battery quality control decreases

Engineering Contradiction:
Improveproduction throughputVSAvoidquality control reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent enables continuous total inspection by maintaining constant laser irradiation and continuous CCD camera imaging throughout the battery production process. The optical detection system operates without interruption, allowing every battery to be inspected while maintaining production throughput, thereby ensuring high reliability of quality control.

Inventive Principle:
Principle #20Continuity of useful action

4Productivity

If the inspection system operates at high speed to match automated production, then the productivity is improved, but the measurement precision for detecting small foreign materials deteriorates

Engineering Contradiction:
Improveinspection speedVSAvoiddetection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent employs periodic scanning where the line laser and CCD camera systematically scan across the battery case surface at controlled intervals. This periodic scanning motion allows the system to maintain high inspection speed while ensuring adequate light exposure and image capture time for detecting micro-sized foreign materials with high precision.

Inventive Principle:
Principle #19Periodic action

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

Enables rapid and precise detection of foreign materials, improving inspection efficiency and accuracy, capable of identifying micro-sized dust and protrusions on battery surfaces, enhancing battery stability and production throughput.

Implementation Method 1

a method for discriminating whether or not there is a foreign material within a battery by using a light scattering method on a surface of a battery case

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

sensing, by a sensor, light reflected from the battery case

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2479556B1Apparatus and method for detecting foreign material in pouch type battery
Publication Date: 2021.09.08 LG ENERGY SOLUTION LTD
  • EP2479556B1 patent drawingFigure 1~2

AI summary

An apparatus and method for detecting a foreign material within a pouch type battery by performing a light scattering method on a surface of a battery case are provided. The apparatus for detecting a foreign material within a pouch type battery includes: a light source irradiating linear light to a surface of a battery case at a pre-set incident angle; a sensor unit sensing light reflected from the battery case; and a foreign material detection unit detecting the presence or absence of a foreign material and the position of the foreign material within a battery through the reflected light sensed by the sensing unit. A foreign material within a battery can be quickly and accurately detected.