Planarized Primer-Coated Current Collector for Stronger Electrode Adhesion
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Solution Overview
Problem
The existing current collectors in secondary batteries face issues with non-uniform primer coating layers leading to decreased adhesive force between the electrode active material layer and the primer coating layer, resulting in performance deterioration.
Innovation Solution
A current collector with a primer coating layer that is uniformly planarized by rolling, incorporating a carbon-based material and a binder, optionally with a binder layer, to enhance adhesive force and minimize pores.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a primer coating layer is formed by applying slurry using a roller, then the adhesive force between current collector and electrode active material layer is improved, but the surface of the primer coating layer becomes non-uniform, causing spaces between layers and decreasing adhesive force
Solution Approach 1:
The patent changes the physical state and application parameters of the primer coating layer by replacing liquid slurry application with a film-forming process. The primer coating layer is formed as a film with controlled thickness and uniformity, then subjected to heat treatment to enhance adhesion. This parameter change from liquid coating to film formation resolves the contradiction between adhesion improvement and surface uniformity.
Solution Approach 2:
The patent replaces the mechanical roller application system with a film-forming system. Instead of using a roller to apply slurry, the primer coating layer is formed as a uniform film through a controlled process, eliminating the surface non-uniformity caused by mechanical roller application while maintaining adhesive benefits.
2Reliability
If a primer coating layer is formed to prevent decrease of adhesive force, then binding force is improved, but surface non-uniformity causes spaces between layers and deteriorates electrode performance
Solution Approach 1:
The patent changes the formation method from slurry application to film formation with controlled parameters. The film is formed with specific thickness control and then heat-treated at controlled temperatures to optimize both binding force and surface uniformity, preventing performance deterioration while maintaining reliability.
Solution Approach 2:
The patent performs preliminary heat treatment of the primer coating layer film before forming the electrode active material layer. This preliminary action ensures the primer layer has optimal adhesive properties and uniform surface characteristics in advance, preventing subsequent performance deterioration and ensuring high productivity.
3Ease of manufacture
If slurry is applied using a roller to form the primer coating layer, then coating is achieved, but the surface becomes non-uniform requiring additional processing
Solution Approach 1:
The patent replaces the roller-based mechanical coating system with a film-forming system. This substitution maintains ease of manufacture through a straightforward film formation process while achieving superior surface flatness and uniformity, eliminating the need for additional surface correction processing.
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 planarized primer coating layer improves the adhesive force between the electrode active material layer, preventing performance deterioration and enhancing productivity and processability.
Implementation Method 1
a surface of the primer coating layer has a flat surface uniformly planarized by rolling
Data Source
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AI summary
The present invention relates to a current collector having improved adhesive strength, and is a structure comprising a metal foil and a primer coating layer formed on at least one surface of the metal foil, wherein the surface of the primer coating layer is a flat surface that is rolled so as to be evenly flat.