Porous Back Roll Venting for Wrinkle-Free Electrode Coating

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Solution Overview

Problem

Conventional electrode material coating devices experience delamination of the current collector fabric from the back roll due to air introduction, leading to uneven electrode material layer thickness and wrinkles, which affects the quality of secondary battery production.

Innovation Solution

The electrode material coating back roll is equipped with an inflow air discharge function, featuring an exhaust guide portion and close contact surface to prevent delamination by guiding air away from the interface between the back roll and current collector fabric, utilizing annular grooves, tangential recesses, or a porous cylinder with fine holes to facilitate air discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional smooth back roll is used to support the current collector fabric, then the fabric can be supported during coating, but air is drawn in between the back roll and fabric due to high-speed rotation, causing delamination and wrinkles

Engineering Contradiction:
Improvesupport stabilityVSAvoidair entrapment
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The back roll surface is designed with a porous structure consisting of multiple through-holes that extend from the outer peripheral surface to the inner peripheral surface. This porous structure allows air to pass through the back roll rather than being trapped between the back roll and the current collector fabric, thereby preventing delamination and wrinkles while maintaining support stability during high-speed rotation

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The harmful air that gets drawn in between the back roll and fabric is extracted by routing it through the through-holes in the back roll. The air that would otherwise cause delamination is channeled through the porous structure and discharged, removing the harmful effect while preserving the support function

Inventive Principle:
Principle #2Taking out (Extraction)

2Manufacturing precision

If the back roll rotates at high speed to maintain coating quality, then coating precision is improved, but air is drawn in more intensely causing increased delamination

Engineering Contradiction:
Improvecoating uniformityVSAvoidair intake
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The porous structure with through-holes allows the back roll to rotate at high speed while permitting air to pass through rather than be trapped. This maintains the high-speed rotation necessary for coating precision while eliminating the harmful air intake effect that would cause delamination

Inventive Principle:
Principle #31Porous materials

3Reliability

If air discharge pathways are added to the back roll, then delamination is prevented, but the back roll structure becomes more complex

Engineering Contradiction:
Improvedelamination preventionVSAvoidback roll structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Rather than adding complex external air discharge mechanisms, the solution integrates air discharge pathways directly into the back roll structure through a porous design with through-holes. This maintains structural simplicity while effectively preventing delamination by allowing air to pass through the material itself

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The back roll simultaneously performs multiple functions: supporting the current collector fabric, allowing air passage through the through-holes, and maintaining rotational stability. The porous structure integrates support and air discharge functions into a single component, reducing overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Prevents delamination and ensures a uniform electrode material layer thickness without wrinkles, enhancing the coating process efficiency and quality in secondary battery production.

Implementation Method 1

a porous cylinder formed as a cylindrical member of a certain diameter configured to receive the roll core, the porous cylinder being in close contact with the current collector fabric, the porous cylinder having a plurality of fine holes configured to allow air introduced between the current collector fabric and the back roll to pass therethrough

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP4661087A1Electrode material coating back roll having inflow air discharge function
Publication Date: 2025.12.10 PEOPLE & TECH INC
  • EP4661087A1 patent drawingFigure 1~2
  • EP4661087A1 patent drawingFigure 3~4
  • EP4661087A1 patent drawingFigure 5

AI summary

The present invention relates to an electrode material coating back roll having an inflow air discharge function. The present invention, which is arranged in correspondence to an active material coating device for manufacturing a secondary battery and supports a current collector fabric while the coating device coats the current collector fabric with an active material, comprises: a close contact surface portion in close contact with the current collector fabric; and an exhaust induction portion which is integrated with the close contact surface portion, and which discharges air flowing between the back roll and the current collector fabric to the outside so as to prevent the current collector fabric from becoming delaminated by inflow air. The electrode material coating back roll having an inflow air discharge function, of the present invention, can immediately discharge incoming air even if air flows between the back roll and the current collector fabric, and thus delamination of the current collector fabric from the back roll is prevented so that a wrinkle-free electrode material layer with uniform thickness can be applied.