Pouch Battery Case Sealing Sequence to Reduce Wrinkles

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Solution Overview

Problem

Pouch-type batteries face issues with wrinkles during the sealing process due to interference between the laminate sheet and the electrode assembly, leading to increased defect rates, manufacturing costs, and reduced aesthetic appeal.

Innovation Solution

A method involving a bending operation, followed by a first and second sealing operation, where the pouch-type battery case is divided into a first and second case unit, allowing for precise bonding of extensions to accommodate the electrode assembly, thereby reducing wrinkles without requiring changes to conventional manufacturing processes or equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If the laminate sheet is bent to form the pouch-type battery case, then the battery case can accommodate the electrode assembly, but wrinkles are generated on the battery case due to interference with the electrode assembly

Engineering Contradiction:

Improvebattery case shapeVSAvoidwrinkle generation

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The battery case is divided into a body portion and a sealing portion. The sealing portion is further segmented into multiple sealing regions (first, second, third, fourth sealing regions) that are sealed at different stages. This segmentation allows the body portion to be formed first, accommodating the electrode assembly, and then the sealing portion to be folded and sealed separately, preventing wrinkles during the bending process.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The body portion of the battery case is formed and the electrode assembly is accommodated before the sealing portion is folded and sealed. The first and second sealing regions are sealed before the third and fourth sealing regions, creating a staged sealing process that prevents interference between the laminate sheet and electrode assembly during bending.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If the sealing part is thermally fused in a state where the laminate sheet is not completely bent, then the manufacturing process can proceed, but the amount of wrinkles generated on the battery case increases

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidwrinkle generation

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The body portion is formed and the electrode assembly is accommodated before the sealing portion is folded and sealed. The first and second sealing regions are sealed before the third and fourth sealing regions, creating a staged sealing process that prevents interference between the laminate sheet and electrode assembly during bending.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sealing portion is divided into multiple sealing regions that are sealed at different stages. This allows the sealing process to proceed systematically without requiring the entire laminate sheet to be completely bent at once, reducing wrinkle generation while maintaining manufacturing efficiency.

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If wrinkles are generated on the battery case, then the defect rate and defect misrecognition rate increase, but the manufacturing process remains the same

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoiddefect rate

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The sealing portion is divided into multiple sealing regions (first, second, third, fourth sealing regions) that are sealed at different stages. This segmentation allows the body portion to be formed first, accommodating the electrode assembly, and then the sealing portion to be folded and sealed separately, preventing wrinkles during the bending process.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Inventive Principle:

Principle #10Preliminary action

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 method effectively reduces wrinkles on the pouch-type battery case, minimizing defects and manufacturing costs while enhancing the aesthetic appeal and sales of the pouch-type secondary battery.

Implementation Method 1

The extensions of the first case unit and the second case unit may be bonded

Methodology Applied

Scientific EffectThermal fusion:

Data Source

PatentUS20230402691A1Method of Sealing Pouch-Type Battery Case and Pouch-Type Secondary Battery

Publication Date: 2023.12.14 LG ENERGY SOLUTION LTD

AI summary

The present disclosure provides a method of sealing a pouch-type battery case including first and second case units. An electrode assembly accommodated in the first and second case units. The method including a bending operation, a first sealing operation, and a second sealing operation. Each of the first and second case units including an accommodation portion and an extension at least partially surrounding the accommodation portion. The electrode assembly being disposed between the accommodation portions of the first and second case units. First regions or second regions of the extensions of the first and second case units adjacent to an end portion of one side or the other are bonded. In the second sealing operation, seventh or eighth regions of the extensions of the first and second case units positioned at the one side or the other side of the electrode assembly facing each other are bonded.