Zigzag Slot Die Coating for Irregular Battery Electrodes
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Solution Overview
Problem
The manufacturing of irregular-shaped rechargeable battery electrodes results in significant waste of electrode slurry and increased costs due to unnecessary coating and notching of metal sheets, which is inefficient and wasteful of expensive materials.
Innovation Solution
A method involving the use of a slot die to coat electrode slurry in a zigzag pattern on a metal sheet, with specific coating lines and uncoated regions, followed by notching that excludes these uncoated areas, minimizing slurry usage and optimizing material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the metal sheet is notched with an irregular shape to match the desired electrode shape, then the electrode can be applied to diversified devices with curved lines or surfaces, but part of the electrode line is abandoned and expensive raw materials are wasted
Solution Approach 1:
The patent applies preliminary action by pre-defining a coating pattern that matches the exact irregular shape of the desired electrode before the coating process begins. The coating head is configured to coat only the required areas, preventing waste before it occurs. This is achieved by designing the coating mask or template with the precise irregular geometry needed, so that only the necessary portions of the metal sheet receive electrode slurry.
Solution Approach 2:
The patent applies local quality by varying the coating properties across different regions of the metal sheet. The coating head deposits electrode slurry with different patterns, thicknesses, or presence/absence in specific local areas corresponding to the irregular electrode shape. This ensures that material is applied only where needed, with the exact local characteristics required for each portion of the final electrode.
2Productivity
If the slot die coats electrode slurry continuously on the metal sheet, then the coating process is simple and fast, but electrode slurry is coated on uncoated regions and material waste increases
Solution Approach 1:
The patent applies segmentation by dividing the continuous coating process into discrete coated and uncoated regions. The coating head is designed with multiple nozzles or a patterned mask that segments the slurry flow, delivering coating material only to specific zones that correspond to the desired electrode shape. This segmentation allows the coating process to maintain high speed while eliminating waste in uncoated regions.
Solution Approach 2:
The patent applies periodic action by implementing an intermittent or oscillating coating motion. The coating head moves back and forth or follows a periodic pattern that precisely traces the irregular electrode boundary, coating slurry only during the forward stroke or at specific intervals. This periodic motion ensures complete coverage of the required areas while leaving uncoated regions untouched, maintaining productivity without material waste.
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 approach reduces material waste and lowers manufacturing costs by precisely coating and cutting the electrode slurry, allowing for the production of irregular-shaped electrodes with reduced material expenditure.
Implementation Method 1
European patent application EP 2 799 154 discloses a slot-die coating method comprising controlling an intermittent transfer of the coating fluid from a slot-die coating head onto the substrate surface to provide coated areas on the substrate surface separated by uncoated areas.
Data Source
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AI summary
The present invention provides a method for manufacturing an electrode for a rechargeable battery, including: with reference to a virtual center axis that divides a metal sheet left and right, setting a first coating line that is parallel with the center axis at a location deflected to one side, and a second coating line that is parallel with the center axis at a location deflected to the other side so as to correspond to the first coating line with reference to the virtual center axis; and coating an electrode slurry on the metal sheet while alternately moving a slot die to the first coating line and the second coating line.