Electrode Insulating Layer Boundary Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithium ion secondary battery electrodes often experience insufficient adhesive strength between the insulating layer and the electrode layer, leading to potential short circuits.
Innovation Solution
The electrode design features an insulating layer with a boundary structure where a part of the insulating layer engages into the electrode layer, with a specific L-value ratio of 1.25 or more, enhancing the adhesion and reducing the risk of peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the insulating layer is applied separately from the active material layer with drying and pressure-molding steps, then the insulation coating can be formed, but the adhesive strength between the insulating layer and electrode layer becomes insufficient
Solution Approach 1:
The patent combines the application of the active material layer and insulating layer into a single coating step, eliminating separate drying and pressure-molding steps. This integrated approach allows the insulating layer to be applied directly over the active material layer while maintaining sufficient adhesive strength, resolving the contradiction between forming insulation coating and ensuring bond strength.
Solution Approach 2:
The patent introduces a specific boundary structure where the boundary between the insulating layer and active material layer extends in the width direction of the electrode with a boundary length LS that is 1.25 times or more the length L in the extending direction of the current collector. This dimensional change in the boundary configuration enhances adhesive strength without requiring additional processing steps.
2Productivity
If the insulating layer is applied immediately after the active material layer without drying, then processing steps are reduced, but adhesive strength between layers becomes insufficient
Solution Approach 1:
The patent merges the coating operations into a single continuous process where the insulating layer is applied immediately after the active material layer without intermediate drying. This maintains high productivity while the specific boundary structure ensures adequate adhesive strength is achieved through the extended boundary configuration in the width direction.
3Device complexity
If the boundary between insulating layer and electrode layer is short, then the structure is simpler, but peeling strength of the insulating layer becomes insufficient leading to short circuit risk
Solution Approach 1:
The patent extends the boundary between the insulating layer and active material layer in the width direction of the electrode, creating a boundary length LS that is 1.25 times or more the length L in the extending direction of the current collector. This dimensional extension of the boundary provides enhanced peeling strength and short circuit prevention while maintaining relative structural simplicity.
Solution Approach 2:
The patent enhances the boundary region specifically by extending it in the width direction, concentrating the adhesion improvement where it is most needed at the interface between layers, while the rest of the electrode structure remains relatively simple.
Data Source
AI summary
Disclosed is an electrode, comprising: a metal foil; an electrode layer formed on at least one surface of the metal foil; and an insulating layer formed on the electrode layer; wherein boundary portion between the insulating layer and the electrode layer is in a state in which a part of the insulating layer engages into a part of the electrode layer, and Ls/L is 1.25 or more, wherein a reference length of a straight line in a direction in which the metal foil extends is taken as L and a boundary length along boundary between the insulating layer and the electrode layer is taken as Ls.