Pouch Battery Sealing Surface Heating via Solvent Phase Change

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Solution Overview

Problem

Existing sealing devices for pouch type secondary batteries fail to maintain a constant temperature of the sealing surface, leading to inconsistent pouch sealing quality and potential defects such as leakage or damage.

Innovation Solution

A sealing device that utilizes a solvent phase change mechanism, where a heat source heats the solvent to vaporize it, which is then condensed back into a liquid by a condenser, maintaining a constant temperature at the sealing surface through a continuous cycle of vaporization and condensation, with a heat insulating part to prevent heat exchange between the heat source and condenser.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a heat source is used to heat the sealing surface, then the sealing temperature can be raised, but the temperature cannot be maintained constantly and fluctuates in a wave pattern

Engineering Contradiction:
Improvesealing surface temperatureVSAvoidtemperature stability
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The patent utilizes the phase transition (evaporation) of a solvent as the heat transfer medium. When the solvent evaporates, it absorbs latent heat from the heat source, maintaining a constant temperature during the phase change process. This resolves the temperature fluctuation issue by replacing direct heat source contact with phase-change-mediated heat transfer, where the solvent's boiling point acts as a natural temperature regulator.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent introduces a solvent as an intermediary heat transfer medium between the heat source and the sealing surface. The solvent absorbs heat from the heat source through evaporation and transfers it to the sealing surface, preventing direct thermal contact and temperature overshoot. This intermediary approach smooths temperature fluctuations and achieves stable sealing temperature control.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the sealing temperature is increased to ensure proper sealing, then sealing effectiveness improves, but quality uniformity deteriorates due to temperature fluctuations

Engineering Contradiction:
Improvesealing effectivenessVSAvoidsealing quality uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The solvent's phase transition from liquid to gas occurs at a constant temperature (boiling point), which serves as a natural thermostat. This ensures that the sealing surface receives heat at a consistent temperature, improving both sealing effectiveness and quality uniformity by eliminating temperature-induced variations in sealing quality.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent implements a continuous evaporation-condensation cycle of the solvent. The solvent continuously evaporates from the sealing surface, absorbs heat, and then condenses elsewhere, creating a sustained and stable heat transfer process. This continuous action ensures consistent sealing temperature and quality throughout the sealing operation.

Inventive Principle:
Principle #20Continuity of useful action

3Use of energy by moving object

If direct heating is applied to the sealing surface, then heating efficiency is high, but temperature control precision is poor

Engineering Contradiction:
Improveheating efficiencyVSAvoidtemperature control precision
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The solvent's phase transition provides inherent temperature control precision. During evaporation, the solvent maintains a constant temperature equal to its boiling point, acting as a self-regulating thermal buffer. This naturally precise temperature control improves upon direct heating methods while maintaining high heating efficiency through the latent heat of vaporization.

Inventive Principle:
Principle #36Phase transitions

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

Ensures uniform and excellent quality in the pouch sealing process by maintaining a consistent sealing temperature, preventing defects and ensuring reliable pouch type secondary battery production.

Implementation Method 1

a heat source (130) configured to heat the solvent (120) so that at least a portion of the solvent (120) is phase-changed into a gas

Methodology Applied
Scientific EffectVaporization: Evaporation

Implementation Method 2

a condenser (150) configured to condense the solvent (120), which is phase-changed into the gas, into a liquid

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

a heat insulating part (260) is disposed between the heat source (130) and the condenser (150)

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4371738B1Sealing device
Publication Date: 2025.08.27 LG ENERGY SOLUTION LTD
  • EP4371738B1 patent drawingFigure 1
  • EP4371738B1 patent drawingFigure 2
  • EP4371738B1 patent drawingFigure 3

AI summary

The present invention relates to a sealing device, and more particularly, to a sealing device in which a temperature of a sealing surface of the sealing device is constantly maintained even though an appropriate solvent is continuously heated using a phase change of a material, thereby manufacturing a pouch sealing part having excellent quality in a product of a pouch type secondary battery. The sealing device according to the present invention includes a sealing body provided with a sealing surface, which is configured to seal a sealing target object, on one surface thereof, a solvent that is in contact with the other surface of the sealing body to supply heat to the sealing body, and a heat source configured to heat the solvent so that at least a portion of the solvent is phase-changed into a gas.