Slot Die Vent Structure for Uniform Multilayer Slurry Coating

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Solution Overview

Problem

The existing slot die coating apparatuses suffer from contamination of uncoated areas due to the bursting of bubbles in the electrode active material slurry during the coating process, leading to uneven coating and reduced efficiency.

Innovation Solution

The proposed slot die coating apparatus incorporates upper and lower air vents to remove bubbles from the slurry before discharge, ensuring uniform coating by preventing bubble formation and burst-related contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If bubble removal is not performed, then the coating process is simple and fast, but bubbles burst during discharge causing contamination of uncoated areas

Engineering Contradiction:
Improvecoating uniformityVSAvoidslot die structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The slot die is divided into multiple chambers (first chamber, second chamber, third chamber) with separate air vents for each. This segmentation allows independent bubble removal from each discharge opening, preventing contamination while maintaining a manageable structure that can be implemented in existing coating systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Air vents are introduced as intermediary components that provide a dedicated pathway for bubble removal. The air vents act as mediators between the slurry chambers and the external environment, allowing bubbles to escape through controlled openings without disrupting the coating process or requiring major structural changes to the slot die.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If air vents are added to remove bubbles, then coating uniformity is improved, but the slot die structure becomes more complex

Engineering Contradiction:
Improvecoating qualityVSAvoidslot die structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The slot die structure is segmented into multiple functional chambers, each with its own air vent. This modular approach improves reliability by allowing targeted bubble removal from each discharge opening while keeping the overall structure organized and maintainable, rather than requiring a single complex bubble removal system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Air vents serve as intermediary components that enhance coating quality without requiring fundamental redesign of the slot die. These relatively simple additive components provide the bubble removal function while integrating into the existing slot die architecture, minimizing the increase in overall structural complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If multiple discharge openings are used for multilayer coating, then productivity increases, but bubble-related contamination increases

Engineering Contradiction:
Improvecoating efficiencyVSAvoidcontamination
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

Each discharge opening in the multilayer slot die is equipped with its own dedicated air vent. This segmentation allows simultaneous bubble removal from multiple discharge openings, enabling multilayer coating operations to maintain high productivity while preventing contamination at each layer interface through independent bubble management.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple air vents are introduced as intermediary components, one for each discharge opening. These intermediaries enable the system to handle multiple slurry discharges simultaneously without the bubble contamination problems that would otherwise increase with the number of discharge openings, thus maintaining both productivity and coating quality.

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

The implementation of air vents in the slot die coating apparatus effectively removes bubbles from the electrode active material slurry, preventing contamination and ensuring consistent, uniform coating of electrode active material layers.

Implementation Method 1

an upper air vent, which extends through the first upper die to communicate with the upper slurry receiving part, and a lower air vent, which extends through the first lower die to communicate with the lower slurry receiving part

Methodology Applied
Scientific EffectBubble removal: Bubble

Data Source

PatentEP3915687B1Slot die coating device having air vent
Publication Date: 2024.02.21 LG ENERGY SOLUTION LTD
  • EP3915687B1 patent drawingFigure 1
  • EP3915687B1 patent drawingFigure 2
  • EP3915687B1 patent drawingFigure 3

AI summary

The present disclosure relates to a slot die coating apparatus for coating an electrode active material slurry onto an electrode collector, the slot die coating apparatus including a coating roller, a die comprising a lower discharge opening, through which a first electrode active material slurry is discharged, and an upper die located on the upper side of the lower die and having an upper discharge opening, through which a second electrode active material slurry is discharged, and an upper air vent may be installed in the upper die and a lower air vent may be installed in the lower die.