Film-Packaged Cell Partial Sealing for Electrolyte Injection

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Solution Overview

Problem

The existing manufacturing method for film-packaged cells faces challenges in preventing electrolytic solution leakage during injection, particularly near the terminals where the solution flow is restricted, leading to potential leakage and quality issues such as defects in welding.

Innovation Solution

A manufacturing method where the upper edge of the packaging body is partially sealed near the terminals before electrolyte injection, allowing the solution to be injected in a vacuum state, thereby preventing leakage without hindering the injection process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the electrolytic solution is injected from the upper edge of the bag-shaped body, then the injection process is simple, but the electrolytic solution leaks out in the vicinity of the terminals where the gap is narrow

Engineering Contradiction:
Improveinjection process simplicityVSAvoidelectrolyte leakage prevention
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The packaging body is divided into a bag-shaped body for electrolyte injection and a seal portion that is sealed in advance. This segmentation allows the injection process to remain simple while preventing leakage at the terminal area through the pre-formed seal structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The seal portion is sealed in advance before electrolyte injection. This preliminary action creates a barrier that prevents electrolyte leakage at the terminal area during the subsequent injection process, without complicating the injection procedure itself.

Inventive Principle:
Principle #10Preliminary action

2Volume of moving object

If the gap between the bag-shaped body and power-generating element is narrow near the terminals, then the structure is compact, but the electrolytic solution flow passage cross-sectional area is reduced causing leakage

Engineering Contradiction:
Improvecell compactnessVSAvoidelectrolyte flow control
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

By separating the packaging body into distinct functional regions (bag-shaped body and seal portion), the design maintains compact overall dimensions while ensuring reliable electrolyte containment through the pre-sealed portion near terminals.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The seal portion is specifically sealed in advance at the location where leakage is most likely to occur (near terminals), while the rest of the bag-shaped body remains open for injection. This localized quality change addresses the flow control issue without affecting overall compactness.

Inventive Principle:
Principle #3Local quality

3Quantity of substance

If the electrolytic solution adheres to the terminals or packaging body, then the injection may be excessive, but quality deterioration occurs such as welding defects

Engineering Contradiction:
Improveelectrolyte injection amountVSAvoidwelding quality
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The seal portion is sealed in advance before injection, creating a controlled barrier that prevents electrolyte from adhering to terminals or packaging body during injection. This preliminary sealing action ensures precise electrolyte quantity control and prevents welding defects.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The pre-sealed seal portion acts as an intermediary barrier between the injected electrolyte and the terminals/packaging body, preventing direct contact and adhesion that would cause quality deterioration while still allowing sufficient electrolyte injection into the bag-shaped body.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 prevents electrolyte leakage while ensuring sufficient injection, reducing the risk of quality defects in the assembled battery.

Implementation Method 1

the electrolytic solution is injected in a vacuum state

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP3070779B1Method for manufacturing film-packaged cell
Publication Date: 2019.08.28 ENVISION AESC JAPAN LTD
  • EP3070779B1 patent drawingFigure 1
  • EP3070779B1 patent drawingFigure 2
  • EP3070779B1 patent drawingFigure 3~4

AI summary

A film-packaged cell has a flat rectangular shape where power-generating element (4) is housed in packaging body (5) together with an electrolytic solution, the film-packaged cell being sealed along four edges of the packaging body in a state where terminals (2, 3) are led out through one edge (11A) thereof. In an electrolyte injection step, the electrolytic solution is injected into bag-shaped body (13) where three edges (11A-11C) excluding the upper edge of the packaging body are sealed in an orientation where the terminals are protruding laterally, the electrolytic solution being injected from the side of the opening upper edge (11D). In a partial sealing step performed before the electrolyte injection step, only one section (21) of opening upper edge (11D) of the bag-shaped body near edge (11A) through which terminals (2, 3) are led out is partially sealed, thereby preventing the electrolytic solution from leaking out during electrolyte injection.