Battery Electrode Adhesive Coating to Prevent Separator Bending

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Solution Overview

Problem

Existing lithium secondary batteries face issues with separator bending and potential internal short circuits due to inadequate adhesion between the electrode and separator, which can lead to safety hazards, especially at high temperatures.

Innovation Solution

An adhesive coating portion is added to the electrode, specifically on the electrode tab and mixture layer surfaces, using a non-electric conductive adhesive with a glass transition temperature of 100°C or lower, to enhance adhesion and prevent separator bending and short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the separator is laminated to the electrode without adhesive coating, then the manufacturing process is simple, but the separator bends and rolls during transfer and stacking

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidseparator position stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

An adhesive coating is applied to the electrode surface before separator lamination, creating a bonding layer that prevents separator bending during subsequent handling and stacking operations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The adhesive coating acts as an intermediary substance between the electrode and separator, providing the necessary adhesion to maintain separator stability without complicating the overall manufacturing process

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If adhesive tape is used to fix the separator at high temperatures, then the separator position is stable, but the adhesive tape melts above its melting point causing short circuit

Engineering Contradiction:
Improveseparator position stabilityVSAvoidshort circuit prevention
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The adhesive coating is designed with specific material properties including a glass transition temperature of 100°C or lower and no melting point, allowing it to maintain flexibility and adhesion at high temperatures without melting like conventional adhesive tapes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The adhesive coating undergoes glass transition rather than melting at elevated temperatures, maintaining its functional properties and continuing to hold the separator in place even when exposed to high temperatures that would cause short circuits

Inventive Principle:
Principle #36Phase transitions

3Temperature

If the separator shrinks due to heat generation, then the battery operates normally, but the positive and negative electrodes come into contact causing internal short circuit

Engineering Contradiction:
Improvebattery operating temperatureVSAvoidinternal short circuit prevention
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The adhesive coating creates a permanent bonding structure between the separator and electrode that counteracts the separator's natural tendency to shrink when heated, preventing the electrodes from coming into contact and causing short circuits

Inventive Principle:
Principle #9Preliminary anti-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

The adhesive coating secures stable adhesion between the electrode and separator, preventing separator bending and ensuring insulation between positive and negative electrodes, thereby enhancing battery safety and preventing short circuits even at high temperatures.

Implementation Method 1

an adhesive coating portion which is disposed on at least a portion of an upper surface of the electrode tab and an upper surface of the electrode mixture layer

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

using a non-electric conductive adhesive with a glass transition temperature of 100°C or lower, to enhance adhesion and prevent separator bending and short circuits

Methodology Applied
Scientific EffectGlass transition:

Data Source

PatentEP4250431B1Electrode for lithium secondary battery having adhesive coating portion added thereto and method of manufacturing the same
Publication Date: 2026.04.01 LG ENERGY SOLUTION LTD
  • EP4250431B1 patent drawingFigure 1
  • EP4250431B1 patent drawingFigure 2
  • EP4250431B1 patent drawingFigure 3

AI summary

The present invention relates to an electrode for a lithium secondary battery, the electrode including an electrode mixture layer disposed on at least one of a first surface and a second surface of an electrode current collector, wherein the electrode current collector includes an electrode tab extending from an outer periphery of the electrode mixture layer as a portion other than a portion at which the electrode mixture layer is disposed, and an adhesive coating portion is disposed at at least a portion of an upper surface of the electrode tab and an upper surface of the electrode mixture layer, and the electrode may be coupled to a separator via the adhesive coating portion.