Battery Cell Sealing Structure for Directional Venting

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Solution Overview

Problem

Conventional battery cells lack directional control for venting high-temperature particles and gases when internal pressure increases, leading to potential ignition and explosion risks.

Innovation Solution

A battery cell design with a first area receiving additional heat to enhance crystallinity and a second area with reduced crystallinity, allowing controlled venting of gases and particles in a specific direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the battery cell pouch is sealed completely without any weak points, then the sealing strength is improved, but the ability to control venting direction when internal pressure increases deteriorates

Engineering Contradiction:
Improvesealing strengthVSAvoidventing direction control
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The sealing portion is designed with different crystallinity in different areas: a first area with higher crystallinity for strong sealing, and a second area with lower crystallinity that serves as a controlled weak point for directional venting. This local differentiation allows the sealing portion to simultaneously provide both strong sealing and controlled venting direction when internal pressure increases.

Inventive Principle:
Principle #3Local quality

2Strength

If heat is applied uniformly to the entire sealing portion, then the sealing strength is improved, but the ability to direct gas venting to a specific area deteriorates

Engineering Contradiction:
Improvesealing strengthVSAvoidventing direction precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

Heat is applied selectively only to the first area of the sealing portion, not uniformly across the entire sealing portion. This localized heat treatment increases the crystallinity specifically in the first area, creating a strong sealing region while leaving the second area with lower crystallinity as a controlled venting path, thus achieving both strong sealing and precise venting direction control.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sealing portion is divided into two distinct areas: a first area that receives heat treatment for enhanced crystallinity and sealing strength, and a second area that does not receive heat treatment and serves as a controlled weak point for directional venting. This segmentation allows differential properties to be achieved within the same sealing portion.

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 design improves the mechanical properties and stability of the battery cell by enhancing the sealing strength and directing the discharge of high-temperature particles and gases, reducing the risk of indiscriminate ejection.

Implementation Method 1

a first area of the sealing portion receiving additional heat from an external heat source

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 2

change the crystallinity of the battery case by transferring additional heat to a first area of the sealing portion

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Data Source

PatentEP4345991B1Battery cell and manufacturing method thereof
Publication Date: 2026.04.01 LG ENERGY SOLUTION LTD
  • EP4345991B1 patent drawingFigure 1~2
  • EP4345991B1 patent drawingFigure 3
  • EP4345991B1 patent drawingFigure 4~5

AI summary

The present disclosure relates to a battery cell and a manufacturing method thereof. The battery cell according to one embodiment of the present disclosure includes an electrode assembly including a cathode, an anode and a separator; and a battery case including a sealing portion that houses the electrode assembly and seals an outer periphery of the electrode assembly, wherein the sealing portion includes a first area, and a second area excluding the first area, and wherein the first area is an area where the crystallinity of the battery case is higher than that of the second area.