Electrode Coating Pressure Zoning for Flat Slurry Edges
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Solution Overview
Problem
Conventional electrode coating processes result in the formation of inclined portions due to slurry viscosity and surface tension, leading to high resistance and tab detachment issues in secondary batteries.
Innovation Solution
An electrode coating apparatus with a first chamber forming negative pressure and a second chamber for slurry discharge, combined with an image capturing unit and controller, ensures a flat coating layer by minimizing inclined portions through precise pressure adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If slurry is applied to electrode current collector using conventional coating apparatus, then coating layer is formed, but inclined portions are formed at the end of each coating layer due to slurry viscosity and surface tension
Solution Approach 1:
The patent divides the coating chamber into multiple sections (first chamber, second chamber, third chamber) with different pressure zones. This segmentation allows different parts of the slurry to experience different pressure conditions, preventing the formation of inclined portions by controlling slurry flow and distribution across the electrode current collector surface.
Solution Approach 2:
The patent changes the pressure parameter across different chambers - the first chamber maintains positive pressure, the second chamber maintains negative pressure, and the third chamber maintains positive pressure. This parameter change creates a pressure differential that controls slurry flow behavior, eliminating inclined portions and ensuring uniform coating thickness.
2Reliability
If pattern coating is performed to form coating layer at predetermined intervals, then battery performance is improved, but inclined portions are formed outside flat portion at the end of each coating layer
Solution Approach 1:
The patent segments the coating process into distinct pressure zones that work together to achieve both pattern coating and uniform flat portions. The negative pressure chamber specifically targets the regions where inclined portions would form, allowing pattern coating at predetermined intervals while maintaining flat, uniform coating layers at the ends of each patterned section.
Solution Approach 2:
The patent employs a sensor to detect the presence and characteristics of inclined portions in real-time, and a controller adjusts the pressure differential between chambers based on this feedback. This closed-loop control ensures that pattern coating is achieved with uniform flat portions, preventing defects that would compromise battery performance.
3Reliability
If inclined portion is formed at the end of coating layer, then tab detachment occurs in post-process, but conventional coating apparatus cannot prevent this
Solution Approach 1:
The patent applies preliminary anti-action by using negative pressure in the second chamber to prevent inclined portions from forming in the first place. By creating a pressure differential before the slurry completes its deposition, the system counteracts the surface tension and viscosity effects that would otherwise cause inclined portions, thereby preventing subsequent tab detachment issues.
Solution Approach 2:
The patent changes the pressure parameter dynamically across different chambers to address tab fusion quality. The negative pressure zone specifically targets the trailing edge of the coating layer where inclined portions form, ensuring proper adhesion and preventing tab detachment in subsequent processing steps.
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
Reduces electrode defect rates by maintaining a uniform coating thickness and minimizing inclined portions, thereby improving battery performance.
Implementation Method 1
a first chamber (300) located on one side of the slurry spraying unit (200), the first chamber being configured to form negative pressure
Data Source
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AI summary
Disclosed are an electrode coating apparatus including a roller configured to move an electrode current collector, a slurry spraying unit located in the vicinity of the roller, the slurry spraying unit being configured to supply an active material to one surface of the electrode current collector, a first chamber located on one side of the slurry spraying unit, the first chamber being configured to form negative pressure, a second chamber located between the slurry spraying unit and the first chamber, a predetermined area of the second chamber being located under the first chamber, and a pressure reducing member configured to form negative pressure in the first chamber, wherein at least one partition wall is in the first chamber, and an electrode coating method using the same.