Pouch Battery Gas Vent Resealing to Prevent Continuous Discharge

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Solution Overview

Problem

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

Innovation Solution

A secondary battery design incorporating a self-restoring adhesive means with a gas discharge part that opens and reseals using a first adhesive material and a self-restoring adhesive member to prevent continuous discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a gas discharge part is provided to release gas when internal pressure increases, then gas discharge safety is improved, but the sealing part remains vulnerable to opening and continuous discharge of electrolyte and gas occurs

Engineering Contradiction:
Improvegas discharge safetyVSAvoidcontinuous discharge of electrolyte and gas
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The gas discharge part is pre-configured with a first adhesive material that has lower adhesive strength than the sealing part. This preliminary design ensures that when internal pressure increases, the gas discharge part opens first to release gas, preventing the sealing part from opening and avoiding continuous discharge of electrolyte and gas.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The adhesive strength parameter of the adhesive material is specifically controlled to be lower than that of the sealing part. This parameter differentiation ensures selective opening: the gas discharge part opens at lower pressure while the sealing part remains intact, preventing harmful continuous discharge.

Inventive Principle:
Principle #35Parameter changes

2Stress or pressure

If the gas discharge part is opened to release gas, then internal pressure is reduced, but the gas discharge part remains open causing continuous discharge of residual electrolyte and gas

Engineering Contradiction:
Improveinternal pressure reductionVSAvoidresidual electrolyte and gas discharge
Core Design Contradiction:
Stress or pressureVSLoss of substance

Solution Approach 1:

The gas discharge part implements periodic opening and closing action. It opens when internal pressure increases to release gas, then closes when pressure decreases. This periodic action prevents continuous discharge of residual electrolyte and gas while effectively managing internal pressure.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The gas discharge part is designed with dynamic opening and closing capability through the adhesive material that can break and reform. The part transitions between open and closed states based on internal pressure conditions, enabling adaptive pressure management without continuous substance loss.

Inventive Principle:
Principle #15Dynamics

3Object-affected harmful factors

If a self-restoring adhesive member is added to reseal the gas discharge part, then prevention of continuous discharge is improved, but device complexity increases

Engineering Contradiction:
Improveprevention of continuous dischargeVSAvoidadhesive material composition
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The self-restoring adhesive member contains a second adhesive material that automatically restores the sealing function of the gas discharge part after gas release. The adhesive material self-repairs the opening without external intervention, preventing continuous discharge while adding minimal complexity through a single integrated component.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The adhesive system uses composite materials with different adhesive strengths: a first adhesive material for initial sealing that breaks at lower strength, and a second adhesive material in the self-restoring member that reforms the seal. This composite approach achieves automatic resealing with controlled complexity.

Inventive Principle:
Principle #40Composite materials

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

Prevents continuous discharge of electrolyte and gas, thereby preventing secondary contamination and accidents by effectively resealing the gas discharge part.

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

Methodology Applied
Scientific EffectAdhesive force: Adhesive

Implementation Method 2

a self-restoring adhesive member configured to reseal the opened gas discharge part through the adhesive force

Methodology Applied
Scientific EffectAdhesive force: Adhesive

Implementation Method 3

when a gap between the inner circumferential surface of the discharge port and the outer circumferential surface of the opening/closing surface is widened by the gas discharged to the gas discharge part, the capsule is split or broken to allow the second adhesive material to flow out

Methodology Applied
Scientific EffectPressure-driven flow: Pressure Gradient

Data Source

PatentEP4539231B1Secondary battery
Publication Date: 2026.03.11 LG ENERGY SOLUTION LTD
  • EP4539231B1 patent drawingFigure 1
  • EP4539231B1 patent drawingFigure 2
  • EP4539231B1 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.