Separator Coating Bar for Thicker Edge Adhesion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for coating layers in secondary battery manufacturing, such as wire bar coating, fail to achieve uniform thickness variations, leading to low adhesive strength at the ends of the electrode-separator interface, which can result in adhesion failures.
Innovation Solution
A coating bar design with a cylindrical bar having a smaller diameter at the ends than at the center, and wires wound with larger diameters at the ends than at the center, allowing for increased slurry thickness at the ends to ensure uniform adhesive strength across the interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wire bar coating is used to form a uniform coating layer, then coating uniformity is improved, but the ability to form varying thicknesses is worsened
Solution Approach 1:
The coating bar is designed with locally different wire diameters: larger wire diameters at the end portions and smaller wire diameters at the center portion. This local variation in wire diameter creates local thickness variations in the coating layer, allowing the coating to have different thicknesses at different locations while maintaining overall coating quality
Solution Approach 2:
The coating bar structure intentionally introduces asymmetry by using different wire diameters at different locations along the bar. The end portions have larger wire diameters while the center has smaller wire diameters, creating an asymmetric coating thickness distribution that addresses the adhesion problem at the ends of the electrode-separator interface
2Strength
If lamination is applied to increase adhesive strength, then adhesion between separator and electrode is improved, but adhesion at the end portions is worsened due to insufficient thickness
Solution Approach 1:
The coating bar applies local quality by using larger wire diameters at the end portions, which directly compensates for the insufficient coating thickness at these locations. This ensures that the end portions have adequate coating thickness and adhesive strength, matching the quality needed at these critical locations
Solution Approach 2:
The invention applies preliminary anti-action by pre-compensating for the expected thickness reduction at the end portions through the larger wire diameters. This prevents the adhesion problem before lamination occurs, eliminating the need for additional corrective measures and ensuring uniform adhesive strength across the entire interface
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
The solution effectively forms a coating layer with varying thicknesses, enhancing adhesive strength at the ends and maintaining uniformity across the electrode-separator interface, preventing adhesion failures and ensuring consistent battery performance.
Implementation Method 1
the coating bar includes a cylindrical bar and a wire wound on a surface of the cylindrical bar, the cylindrical bar has a smaller diameter at two ends than a diameter at a center
Data Source
AI summary
The present disclosure relates to a coating bar and a method for manufacturing a separator using the same.The coating bar according to the present disclosure may form a coating layer having an area with different thicknesses by one coating.Additionally, the method for manufacturing a separator according to the present disclosure includes forming a porous coating layer using a predetermined coating bar, to manufacture a separator including the porous coating layer having an area with different thicknesses. In particular, the present disclosure manufactures the separator having a larger thickness at the two ends than at the center, thereby avoiding a lack of adhesive strength at the two ends in a transverse direction in the adhesion between the separator and the electrode, and exhibiting uniform adhesive strength over the whole interface between the separator and the electrode.