Electrode Sheet Ink Marking for Defect Visibility After Notching

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Solution Overview

Problem

Existing methods for marking defective portions on electrode sheets during the manufacturing process are prone to tape removal during transfer and punching processes, leading to process inefficiencies and difficulty in checking the marks, which can result in degraded battery cell performance.

Innovation Solution

An electrode sheet inspection system with an inspection unit and ink marking unit that adjusts the ink marking range, allowing for real-time defect detection and marking on the electrode sheet without interrupting the manufacturing process, using a marker that moves in three-axis directions and includes a tab guide to prevent damage to electrode tabs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If tape is attached to mark defective portions, then marking is achieved, but the tape may be separated during transfer or removed during punching process

Engineering Contradiction:
Improvemarking reliabilityVSAvoidmark removal
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical tape attachment system with an ink marking system. Instead of physically attaching tape to mark defective portions (which gets removed during processing), the system uses markers to apply ink marks directly onto the electrode sheet, creating a permanent visual indication that remains through transfer and punching operations.

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

Solution Approach 2:

The patent changes the marking method from physical attachment (tape) to chemical marking (ink). This parameter change in the marking medium's properties - from mechanically bonded tape to chemically adhering ink - ensures the mark persists through subsequent mechanical processes without being removed.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If tape is used to mark defective portions, then marking is achieved, but process efficiency is reduced due to interruption of electrode sheet transfer

Engineering Contradiction:
Improvemarking reliabilityVSAvoidprocess efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent enables continuous marking of defective portions during the electrode sheet transfer process. The ink marking system operates without interrupting the flow of electrode sheets through the manufacturing line, maintaining continuous production while reliably marking defects as they pass by.

Inventive Principle:
Principle #20Continuity of useful action

3Ease of manufacture

If ink marking range is fixed, then marking is simple, but the mark may not be visible after slitting or notching processes

Engineering Contradiction:
Improvemarking simplicityVSAvoidmark visibility
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent implements a dynamic ink marking system where the marking range can be adjusted based on the specific defect location and type. The marker positioning and marking dimensions are not fixed but can be dynamically modified to ensure the mark remains visible and identifiable after subsequent slitting or notching operations, while maintaining ease of operation through automated control.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4109624B1Defect detection system for electrode sheet
Publication Date: 2025.11.05 LG ENERGY SOLUTION LTD
  • EP4109624B1 patent drawingFigure 1~2
  • EP4109624B1 patent drawingFigure 3~4

AI summary

The present invention relates to an electrode sheet inspection system including an inspection unit configured to inspect the external state of an electrode sheet and an ink marking unit configured to mark a portion to be removed on the electrode sheet, wherein the ink marking unit is configured to adjust an ink marking range, whereby it is possible to prevent removal of a mark on a defective portion of an electrode even after a process of notching the electrode sheet, and an electrode sheet inspection method using the same.