Electrode Lead Attachment via Intermittent Slurry Coating
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Solution Overview
Problem
The formation of current collecting foil exposed portions in electrochemical devices using hot pressing and a bush leads to detachment of the active layer and increased surface roughness, resulting in higher resistance and degraded performance.
Innovation Solution
A method involving intermittent application of a slurry containing activated carbon and a binder with an elastomer content between 0.25 and 3 mass% to form a non-applied region on the current collecting foil, followed by attaching the lead member to this region, enhancing adhesion and reducing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the formation of the current collecting foil exposed portion is performed by hot pressing and scraping using a bush, then the active layer can be removed to expose the current collecting foil, but the active layer is likely to be detached from the current collecting foil and the surface roughness is increased, resulting in higher resistance
Solution Approach 1:
The patent applies a release agent to the current collecting foil before applying the active layer slurry. This preliminary action creates a non-stick region where the exposed portion will form, preventing the active layer from adhering in that area. This allows the exposed portion to be formed simply by removing excess slurry without hot pressing, thus preventing active layer detachment while maintaining manufacturing simplicity.
Solution Approach 2:
The release agent acts as an intermediary substance between the current collecting foil and the active layer. It creates a controlled non-adhesive region that enables the exposed portion formation without direct contact between the active layer and the foil in that area, thereby preventing detachment while allowing easy removal of excess material.
2Ease of manufacture
If hot pressing is used to form the current collecting foil exposed portion, then the active layer can be removed, but the surface roughness of the exposed portion increases, leading to increased resistance between electrode and lead member
Solution Approach 1:
The release agent is applied beforehand to the current collecting foil at the location where the exposed portion will form. This preliminary action ensures that when excess slurry is removed, the exposed portion has a smooth surface without the roughness caused by hot pressing or mechanical scraping, thereby reducing resistance while maintaining ease of manufacture.
Solution Approach 2:
The release agent serves as an intermediary that prevents active layer adhesion in the exposed portion area. This allows the exposed portion to be formed by simple slurry removal rather than aggressive hot pressing or scraping, resulting in a smoother surface with lower roughness and reduced electrical resistance.
3Ease of operation
If the active layer is removed by hot pressing and scraping, then the current collecting foil is exposed for lead member attachment, but the resistance between electrode and lead member increases due to increased surface roughness
Solution Approach 1:
The release agent is applied to the current collecting foil before slurry application, creating a predetermined non-stick region. This preliminary action ensures that the exposed portion will have a smooth surface after slurry removal, providing good electrical contact for lead member attachment while minimizing resistance.
Solution Approach 2:
The release agent acts as an intermediary that controls where the active layer will not form, creating a clean exposed portion with smooth surface. This allows easy lead member attachment while maintaining low electrical resistance at the connection interface, thus improving both ease of operation and reliability.
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 method suppresses detachment of the active layer and reduces surface roughness, leading to lower internal resistance and improved performance of the electrochemical device.
Implementation Method 1
the binder includes an elastomer, and a content of the elastomer in the active layer is greater than 0.25 mass % and less than 3 mass %
Data Source
AI summary
A method for producing a lead member-equipped electrochemical device electrode includes: preparing a slurry including activated carbon and a binder, and a surface-roughened current collecting foil; applying the slurry to a surface of the current collecting foil, and drying the slurry to form an active layer, thus obtaining an electrode; and connecting the electrode and a lead member to each other. During the application of the slurry to the current collecting foil, the application is performed intermittently to form, on a portion of the electrode, a non-applied region where the surface of the current collecting foil is exposed, during the connecting of the electrode and the lead member, the lead member is attached to the non-applied region, the binder includes an elastomer, and a content of the elastomer in the active layer is greater than 0.25 mass % and less than 3 mass %.