Slot Die Cavity Layout for Uniform Battery Electrode Coating
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Solution Overview
Problem
Existing slot dies for manufacturing rechargeable battery electrodes face challenges in maintaining uniformity of the active material slurry flow speed across the width direction, leading to variance in the loading level and affecting cell capacity.
Innovation Solution
The slot die design includes a first cavity and a second cavity connected through a connection passage, with inclined surfaces and planar grooves to minimize stagnation and ensure uniform flow speed of the slurry, thereby reducing loading level variance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional slot die design is used, then the manufacturing process is simple, but the loading level variance in the width direction increases
Solution Approach 1:
The slot die is divided into multiple independent cavities (first cavity, second cavity, third cavity) arranged in the width direction. Each cavity has its own inclined surface and planar groove configuration, allowing independent control of slurry flow in different regions. This segmentation enables precise control of loading level uniformity across the width direction while maintaining a relatively simple overall structure.
2Ease of manufacture
If the slot die structure is simplified, then the manufacturing cost is reduced, but the slurry flow uniformity deteriorates
Solution Approach 1:
Each cavity in the slot die is equipped with locally optimized inclined surfaces and planar grooves tailored to its specific position in the width direction. The inclined surfaces are configured with appropriate angles, and planar grooves are positioned at specific locations within each cavity to control slurry flow patterns locally. This local quality approach ensures uniform slurry flow across the entire width while keeping the overall design straightforward and manufacturable.
3Manufacturing precision
If the slot die has high manufacturing precision, then the loading level uniformity is improved, but the device complexity increases
Solution Approach 1:
The inclined surfaces and planar grooves are pre-configured in each cavity during slot die manufacturing to establish optimal slurry flow paths before the coating process begins. The inclined surfaces are formed with predetermined angles, and planar grooves are positioned at specific locations to guide slurry flow uniformly across all cavities. This preliminary action ensures that the slot die structure itself provides the necessary flow control, reducing the need for complex external control mechanisms during operation.
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 design achieves a more uniform loading level across the width of the electrode, enhancing the cell capacity of rechargeable batteries by minimizing slurry stagnation and precipitation.
Implementation Method 1
the first block forms a connection passage between the first block and the second block in the width direction and the height direction of the slot outlet, and the second block forms a second cavity that receives the active material slurry supplied through the connection passage
Implementation Method 2
the curved surface that forms a space for receiving the active material slurry and (ii) an inclined surface formed by one side of the curved surface and inclined upward toward the slot outlet
Data Source
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AI summary
A slot die for manufacturing a rechargeable battery electrode according to an embodiment includes a first block; a second block disposed on the first block; a third block disposed opposite to the second block; and a shim member that is disposed between the second block and the third block and forms a slot outlet in a width direction and a height direction. The first block forms a first cavity that receives an active material slurry supplied between the first block and the second block and forms a connection passage between the first block and the second block in a width direction and the height direction of the slot outlet. The second block forms a second cavity that receives the active material slurry supplied through the connection passage and discharges the received active material slurry through the slot outlet.