Multilayer Battery Electrode Structure for Uniform Binder Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing manufacturing process of secondary batteries faces issues with non-uniform binder distribution, leading to increased electrochemical resistance and the risk of lithium precipitation, which can cause short circuits and fires due to the migration of binder materials during the drying process.
Innovation Solution
A battery electrode structure with multiple composite layers having varying binder contents and particle sizes, along with a substrate, is designed to achieve uniform binder distribution and reduced electrochemical resistance, preventing lithium precipitation and ensuring stability by sequentially stacking and laminating electrode powder films with different resistance profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hot air drying process is used to evaporate solvent, then drying efficiency is improved, but binder material migrates to electrode surface causing non-uniform distribution
Solution Approach 1:
The electrode is divided into multiple composite layers with different binder contents. The first composite layer (near separator) has lower binder content (0.1-1.5 wt%) while subsequent layers have progressively higher binder content (0.5-2.5 wt%, 1.0-3.5 wt%). This segmentation prevents binder migration to the surface by creating a gradient structure where binder is distributed according to functional requirements rather than accumulating uniformly or migrating to the drying surface.
Solution Approach 2:
Different regions of the electrode are assigned different binder qualities and concentrations. The first composite layer near the separator uses minimal binder to maintain low resistance, while outer layers use progressively more binder for structural stability. This local quality approach allows each region to have the optimal binder content for its specific function, resolving the contradiction between drying efficiency and uniform distribution.
2Productivity
If binder material migrates to electrode surface, then drying process is completed, but electrochemical resistance increases on surface
Solution Approach 1:
The binder distribution is predetermined and controlled during electrode manufacturing before the drying process. By creating a multi-layer composite structure with specific binder contents in each layer, the electrode is pre-configured to prevent binder migration during drying. The first composite layer is specifically designed with low binder content to maintain low electrochemical resistance at the separator interface, eliminating the need for binder migration to complete drying.
Solution Approach 2:
The binder content parameter is changed across different composite layers. The first composite layer has binder content of 0.1-1.5 wt%, while subsequent layers have higher contents. This parameter change creates a gradient structure that maintains low resistance at the separator interface while providing sufficient binder for structural integrity in outer layers, preventing the resistance increase that would occur with surface migration.
3Reliability
If binder content is increased to prevent migration, then binder distribution becomes non-uniform, but fire risk increases
Solution Approach 1:
Binder content is optimized locally in each composite layer rather than uniformly throughout. The first composite layer near the separator uses minimal binder (0.1-1.5 wt%) to reduce fire risk and maintain low resistance, while outer layers use progressively more binder for structural stability. This local optimization prevents both fire hazards from excess binder and mechanical failure from insufficient binder.
Solution Approach 2:
The binder content parameter is progressively changed across composite layers from low (0.1-1.5 wt%) to high (1.0-3.5 wt%). This parameter gradient allows the electrode to achieve fire prevention through low binder content at the separator interface while maintaining structural stability through higher binder content in outer layers, eliminating the need for uniform high binder content that would increase fire risk.
4Manufacturing precision
If multiple composite layers with varying binder contents are stacked, then binder distribution uniformity is improved, but device complexity increases
Solution Approach 1:
The electrode is segmented into three composite layers with progressively increasing binder content. This segmentation achieves uniform and functional binder distribution by placing appropriate binder amounts in appropriate locations. While the structure is more complex than a single-layer electrode, the segmentation is systematic and manageable, with each layer having a clear functional role that justifies the added complexity.
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 solution effectively reduces electrochemical resistance, enhances charge efficiency, and prevents lithium precipitation, thereby improving the stability and safety of the battery electrode by controlling the binder distribution and adherence between layers.
Implementation Method 1
a drying process to evaporate the solvent is required
Implementation Method 2
The hot air generates a convection phenomenon within the electrode
Data Source
AI summary
A battery electrode and its manufacturing method. In particular, the battery electrode includes: a separator; a first composite layer disposed on the separator and having a first active material, a first binder, and a first conductive material; a second composite layer disposed on the first composite layer and having a second active material, a second binder, and a second conductive material; a third composite layer disposed on the second composite layer and having a third active material, a third binder, and a third conductive material; and a substrate disposed on the third composite layer. A resistance of the first composite layer is less than that of the second composite layer, and a resistance of the second composite layer is less than that of the third composite layer.