Dry Electrode Adhesive Layer Layout for Low-Resistance Bonding
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Solution Overview
Problem
Existing dry electrodes face issues with high interfacial resistance and reduced adhesion strength due to the use of primer layers, leading to decreased electrical performance and cycle life in batteries.
Innovation Solution
A preliminary electrode with a free-standing film structure, featuring an adhesive layer on one surface, where the adhesive binder is clustered in specific regions and absent in others, allowing for reduced interfacial resistance and improved adhesion strength by using a non-contact coating process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a primer layer is used to provide adhesion strength in dry electrodes, then adhesion strength is improved, but interfacial resistance increases
Solution Approach 1:
The adhesive layer is designed with non-uniform distribution of adhesive binder, creating adhesive layer regions with higher binder concentration and adhesive layer-absent regions with lower or no binder. This local quality variation allows different regions to serve different functions: adhesive regions provide bonding strength while absent regions maintain low interfacial resistance for electrical contact
Solution Approach 2:
The adhesive layer is segmented into multiple functional regions rather than being uniformly distributed. The adhesive layer is divided into adhesive layer regions (where binder is clustered) and adhesive layer-absent regions (where electrode film is exposed), creating a heterogeneous structure that simultaneously satisfies both adhesion and electrical conductivity requirements
2Strength
If a uniform adhesive layer is applied to ensure complete coverage, then adhesion strength is improved, but manufacturing complexity increases
Solution Approach 1:
Instead of applying adhesive binder uniformly across the entire surface, the invention uses partial action by allowing adhesive binder to be present only in specific adhesive layer regions. The non-contact coating process applies binder excessively in certain areas while leaving other areas unsubstantialized, creating the desired heterogeneous structure without requiring complex masking or patterning steps
3Manufacturing precision
If solvent is used in electrode mixture to improve coating uniformity, then coating quality is improved, but drying defects occur
Solution Approach 1:
The invention extracts and removes the solvent component from the electrode mixture, transitioning from a wet electrode process to a dry electrode process. By eliminating the solvent, the harmful drying defects such as pin holes, cracks, and non-uniform evaporation are completely avoided while maintaining coating quality through the dry forming process
Solution Approach 2:
The adhesive binder acts as an intermediary substance that enables both adhesion and maintains structural integrity without requiring solvent. The fibrillated electrode binder and adhesive binder work together to hold electrode active material particles and current collector sheets together in a dry state, replacing the solvent-mediated binding mechanism
Data Source
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AI summary
An aspect of the present disclosure is directed to providing an electrode that reduces in interfacial resistance and maintains a predetermined level of adhesion strength, a method for manufacturing the same, and an electrochemical device including the same. The electrode according to an aspect of the present disclosure is characterized in that it is manufactured by forming an adhesive layer on an electrode film and attaching the adhesive layer to a current collector, thereby improving the adhesion strength between the current collector and the electrode film and reducing the interfacial resistance between the current collector and the electrode.