Pouch Battery Vent Resealing to Prevent Electrolyte and Gas Leakage

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Solution Overview

Problem

Secondary batteries face issues with continuous discharge of residual electrolyte and gas from the pouch, leading to secondary contamination and accidents due to weak sealing forces in the pouch's sealing part.

Innovation Solution

The implementation of a self-restoring adhesion mechanism within the pouch's gas discharge part, utilizing a first adhesive material that breaks to open the gas discharge part when internal pressure increases and a self-restoring adhesive member that reseals the part using a second adhesive material when pressure decreases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the sealing part has weak sealing force to allow gas discharge, then gas release is improved, but the electrolyte and gas are continuously discharged causing secondary contamination and accidents

Engineering Contradiction:
Improvegas release efficiencyVSAvoidsecondary contamination and accidents
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The sealing part is segmented into two adhesive materials with different adhesion characteristics. The first adhesive material provides weak sealing force that allows efficient gas release, while the second adhesive material provides strong sealing force that prevents continuous discharge of electrolyte and gas, thereby eliminating secondary contamination and accidents.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention converts the potentially harmful continuous discharge of electrolyte and gas into a beneficial controlled gas release mechanism. By using the first adhesive material with weak adhesion, gas can be efficiently released when needed, while the second adhesive material ensures that the discharge is limited to gas only and prevents harmful continuous leakage.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If the sealing part has strong sealing force to prevent continuous discharge, then sealing integrity is improved, but gas cannot be discharged when internal pressure increases

Engineering Contradiction:
Improvesealing integrityVSAvoidgas discharge capability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The sealing part is divided into two adhesive materials with different adhesion strengths positioned at different locations. The first adhesive material with weak adhesion allows gas discharge when internal pressure increases, while the second adhesive material with strong adhesion maintains overall sealing integrity and prevents continuous discharge of electrolyte and gas.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies parameter changes by using adhesive materials with different adhesion strengths in different regions of the sealing part. This creates a pressure-responsive system where gas can escape through the weak adhesion region when pressure builds up, while the strong adhesion region maintains sealing integrity under normal conditions.

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

This solution effectively prevents the continuous discharge of residual electrolyte and gas, thereby reducing the risk of secondary contamination and accidents, while ensuring the pouch's gas discharge part is efficiently opened and resealed.

Implementation Method 1

a first adhesive material which is configured to seal the gas discharge part through adhesive force and is broken when a pressure within the pouch increases above a set pressure to open the gas discharge part

Methodology Applied
Scientific EffectAdhesive force breakdown: Adhesive

Implementation Method 2

a self-restoring adhesive member configured to reseal the opened gas discharge part through the adhesive force so as to prevent the gas from being discharged to the gas discharge part

Methodology Applied
Scientific EffectAdhesive force: Adhesive

Data Source

PatentEP4138195B1Secondary battery
Publication Date: 2025.04.30 LG ENERGY SOLUTION LTD
  • EP4138195B1 patent drawingFigure 1
  • EP4138195B1 patent drawingFigure 2
  • EP4138195B1 patent drawingFigure 3

AI summary

The present invention relates to a secondary battery comprising: an electrode assembly; a pouch in which the electrode assembly is accommodated and provided with a gas discharge part; a first adhesive material which is configured to seal the gas discharge part through adhesive force, wherein, when a pressure within the pouch increases, the adhesive force of the first adhesive material is broken to open the gas discharge part; and a self-restoring adhesive member configured to reseal the opened gas discharge part through the adhesive force so as to prevent the gas from being discharged to the gas discharge part.