Multi-Layered Electrode Active Material for Battery Resistance
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Solution Overview
Problem
Lithium secondary batteries face performance deterioration due to non-uniform dispersion and exfoliation of binders in the electrode active material layer, leading to increased resistance, particularly as the loading amount of electrode active material increases.
Innovation Solution
A multi-layered electrode active material layer is formed with varying loading amounts and compositions across layers, ensuring uniform binder dispersion and improved electric conductivity, preventing binder separation and resistance increase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the loading amount of electrode active material is increased to achieve high capacity, then the battery capacity is improved, but the binder becomes non-uniformly dispersed and exfoliates from the electrode active material layer, leading to increased resistance and performance deterioration
Solution Approach 1:
The electrode active material layer is divided into multiple sub-layers (first, second, and third electrode active material layers) with different binder contents. This segmentation allows each sub-layer to have optimized binder distribution, preventing the non-uniform dispersion and exfoliation that occurs in single-layer structures with high active material loading.
Solution Approach 2:
Different regions of the electrode active material layer have different binder contents tailored to local requirements. The first layer has higher binder content for strong adhesion to the current collector, the second layer has moderate binder content, and the third layer has lower binder content to maximize active material density while maintaining sufficient binding. This local quality variation resolves the contradiction between high loading amount and uniform binder dispersion.
2Quantity of substance
If the loading amount of electrode active material is increased to achieve high capacity, then the battery capacity is improved, but the battery resistance increases due to binder exfoliation and non-uniform dispersion
Solution Approach 1:
Dividing the electrode active material layer into multiple sub-layers prevents binder exfoliation and maintains continuous electrical pathways. The segmented structure ensures that binder remains effectively distributed throughout the entire thickness of the electrode active material layer, preventing resistance increase even at high overall loading amounts.
Solution Approach 2:
By optimizing binder content locally in different layers (higher in the first layer for adhesion, lower in the third layer for density), the structure maintains low resistance throughout. The gradient distribution of binder ensures continuous conductive networks while maximizing active material content, thus improving capacity without increasing resistance.
3Device complexity
If a single-layer electrode active material layer is used to simplify the structure, then the device complexity is reduced, but the binder disperses non-uniformly and exfoliates from the electrode active material layer
Solution Approach 1:
The electrode active material layer is segmented into multiple sub-layers, each with controlled binder content. This segmentation transforms a complex stability problem in a single layer into manageable, optimized sub-structures. The increased structural complexity at the layer level actually simplifies the binder dispersion issue by providing multiple interfaces and gradient transitions.
Solution Approach 2:
Instead of attempting uniform binder distribution throughout a single thick layer (which fails), the structure uses local quality variation across multiple thin layers. Each layer has binder content optimized for its specific position and function, ensuring stable composition throughout the electrode while maintaining overall structural simplicity in the manufacturing process.
Data Source
AI summary
The present invention relates to an electrode comprising multi-layered electrode active material layer and a secondary battery comprising the same. According to the embodiments of the present invention comprises electrode having multi-layered electrode active material layer, wherein the content of the active materials which forms the electrode active material layers is equally maintained and the loading amounts at each layer are either the same or different from each other, thereby solving the problem of performance deterioration caused by an increase in battery resistance due to non-uniform dispersion of a binder or the like.