Electrode Web Coating with Offset Die Coaters for Uniform Edges
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Solution Overview
Problem
Conventional die coater systems for coating web-type electrode substrates in battery production often result in irregularly shaped lateral edges of the active material layer, leading to subpar quality electrodes that can reduce battery lifespan, capacity, voltage, and energy density.
Innovation Solution
A system comprising a first die coater with a wide opening and a second die coater with a smaller, offset opening is used to precisely control the deposition of battery materials, allowing for independent adjustment of the lateral edge portions of the coating, ensuring uniform thickness and shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional die coater system with a single die block assembly is used to coat the web-type electrode substrate, then the coating process is simple and fast, but the lateral edges of the active material layer become irregular and the coating quality deteriorates
Solution Approach 1:
The single die block assembly is divided into multiple die blocks (first die block, second die block, third die block) arranged side by side in the lateral direction. Each die block has its own opening for coating the substrate, allowing independent control of coating parameters for different regions. This segmentation enables precise control of lateral edge portions while maintaining high productivity through simultaneous multi-region coating.
Solution Approach 2:
Different die blocks are configured with different opening widths to provide localized coating quality. The first die block has a wider opening for the central region requiring higher productivity, while the second and third die blocks have narrower openings specifically for lateral edge portions requiring precision control. This local differentiation resolves the contradiction between speed and precision at different locations.
2Area of stationary object
If the opening width of the die block assembly is increased to improve coating width efficiency, then more substrate area is covered, but control over lateral edge portions deteriorates
Solution Approach 1:
The total coating width is divided among multiple die blocks with different opening widths. The first die block covers the central area with a wider opening, while the second and third die blocks cover the lateral edges with narrower openings. This segmentation allows the system to achieve both wide coverage and precise edge control simultaneously.
Solution Approach 2:
Each die block is optimized for its specific region: the first die block's wider opening maximizes central area coverage, while the second and third die blocks' narrower openings provide precise control over lateral edge portions. This local optimization resolves the contradiction between overall coverage and edge precision.
3Manufacturing precision
If multiple die blocks are used to improve lateral edge control, then coating precision increases, but the device complexity increases
Solution Approach 1:
Multiple die blocks are merged into a single integrated die block assembly that functions as one coherent coating unit. The die blocks are rigidly coupled together and move simultaneously with the substrate, allowing precise control of lateral edges without proportionally increasing device complexity. The merged structure coordinates all die blocks to work in unison during the coating process.
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 enables the production of high-quality electrodes with precise control over the active material layer, enhancing battery performance and lifespan by ensuring consistent coating quality.
Implementation Method 1
The channel may be formed as a slot between two die blocks engaging one another. For supplying active material slurry, at least one of the die blocks in the assembly is provided with a manifold connected on one side to a supply line and on another side to a channel extending to the opening.
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3C
AI summary
A system (210, 310) configured for coating an web-type electrode substrate (1) travelling in a process direction (P) and having a web width extending in a lateral direction (L) perpendicular to the process direction (P) to make an electrode web material comprises a first die coater (230, 330) comprising a first opening (231, 331) for depositing a battery material onto the web-type electrode substrate, wherein the first opening (231, 331) defines a first opening width (w) extending in the lateral direction (L), a second die coater (240, 340, 440) comprising at least one second opening (241, 341, 342, 441, 442) defining a second opening width (a, b) extending in the lateral direction (L), wherein the second opening width (a, b) is smaller than the first opening width (w), and wherein the second opening (241, 341, 342, 441, 442) is offset from the first opening (231, 331) downstream in the process direction (P) and offset in the lateral direction (L), such that the second opening (241, 341, 342, 441, 442) includes a free portion arranged outward from the first opening (231, 331) in the lateral direction (L).