Electrode Edge Insulating Layer Composition to Prevent Delamination
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Solution Overview
Problem
The separation of the end portion insulating layer from the current collector layer in electrodes is not adequately suppressed in conventional technologies.
Innovation Solution
The electrode design incorporates an end portion insulating layer with a particle and binder composition that occupies between 55% and 99.5%, and a thickness that is between 1/20 and 1/2 of the active material layer thickness, along with a manufacturing method that controls shrinkage between 1% and 40%, ensuring proper adhesion during drying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the end portion insulating layer is joined to the current collector layer and active material layer, then the insulating function is improved, but separation between layers occurs
Solution Approach 1:
The patent applies parameter changes by optimizing the occupancy percentage of particles (55-99.5%) and binder (0.5-44.5%) in the end portion insulating layer, controlling thickness ratio (1/20 to 1/2 of active material layer), and managing shrinkage rate (1-40%) during drying. These parameter adjustments ensure the insulating layer maintains adequate adhesion to both current collector and active material layers while preserving its insulating function, preventing separation between layers
Solution Approach 2:
The patent uses composite materials by formulating the end portion insulating layer as a composite structure containing particles (55-99.5% occupancy) and binder (0.5-44.5% occupancy). This composite composition provides both mechanical adhesion to prevent layer separation and electrical insulation properties, resolving the contradiction between insulating function and layer stability
2Reliability
If the occupancy percentage of particles in the end portion insulating layer is increased, then the insulating performance is improved, but the adhesion strength decreases
Solution Approach 1:
The patent resolves this contradiction through parameter changes by establishing an optimal occupancy percentage range for particles (55-99.5%) rather than using maximum particle content. This controlled parameter adjustment ensures sufficient insulating performance while maintaining adequate adhesion strength. The corresponding binder occupancy (0.5-44.5%) provides binding force to maintain layer adhesion
Solution Approach 2:
The patent applies local quality by creating a gradient composition in the end portion insulating layer where particles and binder are distributed to achieve different local functions: particles provide insulating properties while binder provides adhesion. This local differentiation allows the layer to simultaneously achieve high insulating performance and sufficient adhesion strength
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 configuration effectively suppresses the separation of the insulating layer from the current collector layer, maintaining electrode integrity and enhancing battery performance.
Implementation Method 1
The end portion insulating layer contains particles (131) and a binder (132). The occupancy percentage of the particles (131) in the end portion insulating layer (130) is at least 55% and at most 99.5%. The occupancy percentage of the binder (132) in the end portion insulating layer (130) is at least 0.5% and at most 44.5%.
Implementation Method 2
end portion insulating layer slurry that contains the particles (131), the binder (132), and a solvent having vaporability and forms the end portion insulating layer (130) after the current collector layer (110) and the active material layer (120) are coated with the end portion insulating layer slurry (1200)
Data Source
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AI summary
An electrode (positive electrode (100)) includes a current collector layer (positive electrode current collector layer (110)), an active material layer (positive electrode active material layer (120)) that is stacked on and joined to the current collector layer and contains an active material (positive electrode active material (121)), and an end portion insulating layer (130) that extends from the side of an end portion (110b) of the current collector layer to a side portion (120a) of the active material layer (positive electrode active material layer (120)) and is stacked on the current collector layer to be joined to the current collector layer and the active material layer, the end portion insulating layer (130) containing particles (131) and a binder (132). The occupancy percentage of the particles (131) in the end portion insulating layer (130) is at least 55% and at most 99.5%. The occupancy percentage of the particles (131) and the binder (132) in the end portion insulating layer (130) is at least 55.5% and at most 99%. The thickness of the end portion insulating layer (130) along a stacking direction Z is at least 1/20 and at most 1/2 of the thickness of the active material layer (positive electrode active material layer (120)) along the stacking direction Z.