Electrode Assembly Adhesive Interface for Separator Delamination

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Solution Overview

Problem

Existing secondary batteries experience electrode collapse and separation between the electrode and separator during charge and discharge, leading to short circuits, secondary battery swelling, and decreased stability and performance due to precipitates like dead Li.

Innovation Solution

An electrode assembly with an adhesive portion formed on the interface between the separator and electrodes, particularly in the region where the tab is located, to prevent separation and short circuits by enhancing adhesive strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a laminated secondary battery structure is used, then high energy density and discharge voltage are achieved, but electrode collapse and separation between electrode and separator occur during continuous charge and discharge

Engineering Contradiction:
Improveenergy densityVSAvoidelectrode-separator adhesion stability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The separator is divided into different regions: a first region without adhesive that maintains ion conductivity and electrochemical performance, and a second region with adhesive that prevents electrode-separator separation. This segmentation allows the separator to simultaneously achieve high energy density through optimized active material placement and improved reliability through localized adhesive bonding at critical interfaces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The separator is designed with non-uniform properties: the first region has pure porous structure for optimal ion transport and electrochemical activity, while the second region contains adhesive material specifically at the interface with the tab to prevent separation. This local quality differentiation resolves the contradiction by providing high energy density where needed while ensuring adhesion stability at critical locations.

Inventive Principle:
Principle #3Local quality

2Power

If continuous charge and discharge operations are performed, then high output properties are achieved, but interfacial separation between electrode and separator increases leading to dead Li precipitation

Engineering Contradiction:
Improveoutput propertiesVSAvoidinterface integrity
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The adhesive is pre-applied to the separator's second region before battery assembly. This preliminary action ensures that when high output operations cause mechanical stress and expansion/contraction, the electrode-separator interface is already bonded and resistant to separation, preventing dead Li precipitation and maintaining interface integrity throughout the battery's operational life.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If adhesive material is added to the separator, then separation between electrode and separator is prevented, but ion conductivity and electrochemical performance may be affected

Engineering Contradiction:
Improveelectrode-separator adhesionVSAvoidelectrochemical performance
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The separator is segmented into a first region without adhesive that preserves ion conductivity and electrochemical performance, and a second region with adhesive that ensures electrode-separator adhesion. This segmentation allows the battery to achieve both high reliability through prevented separation and high manufacturing precision in terms of electrochemical performance by keeping the adhesive away from the active electrochemical zones.

Inventive Principle:
Principle #1Segmentation

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 portion effectively prevents electrode-separator separation and short circuits, reducing the risk of battery swelling and maintaining stability and performance.

Implementation Method 1

at least one surface of an interface between the separator and at least one of the electrode and the counter electrode includes an adhesive portion formed in at least one end region

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP4715996A1Electrode assembly and electrochemical device including same
Publication Date: 2026.03.25 LG CHEM LTD
  • EP4715996A1 patent drawingFigure 1~2
  • EP4715996A1 patent drawingFigure 3~4
  • EP4715996A1 patent drawingFigure 5~6

AI summary

The present disclosure provides an electrode assembly and a method for manufacturing the same, the electrode assembly having an adhesive portion in a predetermined region of an interface between a separator and an electrode, thereby improving a phenomenon of separation between the separator and the electrode and a phenomenon of short circuit between the electrodes. The electrode assembly of the present disclosure comprises an electrode, a separator, and a counter electrode, wherein the electrode and the counter electrode each include a tab extending from a current collector, and at least one surface of an interface between the separator and at least one of the electrode and the counter electrode includes an adhesive portion formed in at least one end region in a direction in which the tab of the electrode is located.