Slot Die Air Venting for Bubble-Free Electrode Slurry Coating
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Solution Overview
Problem
The existing slot die coating apparatuses suffer from contamination of uncoated areas due to bubbles in the electrode active material slurry during intermittent coating processes, leading to uneven coating and reduced efficiency.
Innovation Solution
The proposed slot die coating apparatus incorporates upper and lower air vents to remove bubbles from the electrode active material slurry before discharge, ensuring uniform coating by communicating the air vents with the slurry receptors and discharge openings, and utilizing spacers to form gaps for effective bubble removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If intermittent coating is performed by using the slot die coating apparatus, then the coating process can be paused and resumed, but bubbles in the slurry burst during discharge causing contamination of uncoated areas
Solution Approach 1:
The patent introduces an air vent positioned above the discharge opening that allows bubbles to escape from the slurry before it is discharged onto the collector. This preliminary removal of bubbles prevents them from bursting during discharge and contaminating the uncoated areas, thus resolving the contradiction between maintaining productivity through intermittent coating and preventing contamination.
2Ease of manufacture
If bubbles are present in the electrode active material slurry, then the slurry can be discharged through the discharge opening, but the bubbles cause uncoated spots and mottle contamination on the collector
Solution Approach 1:
The air vent provides a preliminary action by allowing bubbles to escape from the slurry before discharge. This ensures that only bubble-free slurry reaches the collector, eliminating uncoated spots and mottle contamination while maintaining the simplicity of the coating process.
Solution Approach 2:
The air vent acts as an intermediary element between the slurry reservoir and the discharge opening. It mediates the slurry flow by selectively allowing bubbles to escape while retaining the liquid slurry, thus improving coating uniformity without complicating the manufacturing process.
3Device complexity
If the slot die structure is simplified without air vent, then the device complexity is reduced, but bubble removal capability is lost leading to coating defects
Solution Approach 1:
The slot die structure is segmented into functional zones: the discharge opening for slurry ejection and the air vent for bubble removal. This segmentation allows each component to perform its specific function efficiently, maintaining coating quality consistency while adding minimal complexity to the overall structure.
Solution Approach 2:
The air vent serves as an intermediary component that bridges the slurry storage and discharge functions. It is a simple structural addition that provides reliable bubble removal capability, enhancing coating quality consistency without significantly increasing device complexity.
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 effectively prevents contamination of uncoated areas by removing bubbles from the slurry, resulting in improved uniformity and efficiency of the coating process, reducing the occurrence of uncoated spots and enhancing the overall performance of the slot die coating apparatus.
Implementation Method 1
an air vent, configured to remove bubbles from the electrode active material slurry introduced into the discharge opening
Data Source
AI summary
The present disclosure relates to a slot die coating apparatus for coating an electrode active material slurry onto an electrode collector, the slot die coating apparatus including a coating roller, a die comprising a lower discharge opening, through which a first electrode active material slurry is discharged, and an upper die located on the upper side of the lower die and having an upper discharge opening, through which a second electrode active material slurry is discharged, and an upper air vent may be installed in the upper die and a lower air vent may be installed in the lower die.