Slot Die Coater Flow Path Blocks for Uniform Slurry Coating

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Solution Overview

Problem

Existing slot die coating devices face issues with pressure buildup and non-uniform coating of electrode slurry due to varying flow rates and internal pressure, leading to potential leakage and non-uniformity in electrode width.

Innovation Solution

A slot die coating device with a block structure inside the coater, where the distance between internal and discharge portions is designed to be 1 to 1.2 times the discharge portion distance, using materials like MC nylon and Teflon, to stabilize pressure and prevent leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the internal pressure of the slot die coater is increased to maintain coating flow rate, then the coating speed is improved, but the uniformity of coating thickness deteriorates and leakage occurs

Engineering Contradiction:
Improvecoating speedVSAvoiduniformity of coating thickness
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the geometric parameters of the flow path, specifically the cross-sectional area and shape, to optimize flow characteristics. By adjusting the flow path dimensions rather than increasing pressure, the system achieves both adequate coating speed and uniform thickness distribution.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different flow path cross-sectional areas at different locations within the slot die coater. The flow path has a larger cross-sectional area at the inlet and a smaller cross-sectional area at the discharge end, creating localized flow control that ensures uniform coating thickness while maintaining productivity.

Inventive Principle:
Principle #3Local quality

2Productivity

If the flow path cross-sectional area is reduced to increase flow rate, then the coating productivity is improved, but the pressure loss increases and coating uniformity deteriorates

Engineering Contradiction:
Improveflow rateVSAvoidpressure loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent employs a dynamically varying flow path cross-sectional area along the flow direction. The cross-sectional area changes progressively from the inlet to the discharge end, optimizing the balance between flow rate and pressure loss at each location rather than using a constant cross-section.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent optimizes the flow path geometry by changing the cross-sectional area parameter along the flow direction. This parameter optimization reduces pressure loss while maintaining high flow rate, resolving the contradiction between productivity and energy loss.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the electrode slurry has high viscosity to reduce drying time, then the productivity is improved, but the flow uniformity deteriorates and coating quality worsens

Engineering Contradiction:
Improvedrying timeVSAvoidflow uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies hydraulic principles to design the flow path geometry, optimizing it for high-viscosity fluid flow. The flow path cross-sectional area is specifically designed to accommodate viscous electrode slurry, ensuring uniform flow distribution and preventing stagnant regions that would compromise coating quality.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent adjusts the flow path geometric parameters to suit high-viscosity electrode slurry. By optimizing the cross-sectional area and shape of the flow path, the system achieves uniform flow of viscous material, enabling both short drying time and high coating quality.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4115990B1Slot die coating device
Publication Date: 2026.02.18 LG ENERGY SOLUTION LTD
  • EP4115990B1 patent drawingFigure 1
  • EP4115990B1 patent drawingFigure 2
  • EP4115990B1 patent drawingFigure 3

AI summary

A slot die coating device according to one embodiment of the present disclosure includes a slot die coater configured to form an internal space for housing an electrode slurry and a discharge passage connected to the internal space to discharge the electrode slurry; and a block located in the internal space, wherein a distance between a first inside portion and a second inside portion forming the internal space is formed longer than a distance between a first discharge inside portion and a second discharge inside portion forming the discharge passage, and wherein the block comprises a first block facing the first inside portion and a second block facing the second inside portion.