Electrode Binder Segregation Control via Segmented Drying
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Solution Overview
Problem
The segregation phenomenon during the drying process of electrode manufacturing leads to uneven binder distribution, resulting in reduced peel strength and binding force between the active layer and the current collector in secondary batteries.
Innovation Solution
The electrode is designed with a Binder Migration Index (BMI) ranging from 0.018 to 0.300, achieved through a controlled drying process involving preheating, fixed rate evaporating, lapse rate evaporating, and residual solvent removal steps, ensuring even binder distribution and enhanced peel strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a drying process is performed to produce an electrode, then the electrode structure is formed, but binder segregation occurs and binder distribution becomes uneven
Solution Approach 1:
The drying process is divided into multiple stages with different temperature conditions. The first drying stage uses a lower temperature to prevent binder migration, while the second drying stage uses a higher temperature to complete solvent removal. This segmentation of the drying process resolves the contradiction by allowing structure formation without causing binder segregation.
Solution Approach 2:
The first drying stage is performed as a preliminary action before the second drying stage. This preliminary low-temperature drying removes a portion of the solvent while maintaining binder distribution uniformity, preparing the electrode for subsequent high-temperature drying without causing segregation.
2Strength
If binder content is increased to improve binding force, then binding force with current collector improves, but electrode flexibility deteriorates
Solution Approach 1:
The invention achieves uniform binder distribution throughout the electrode layer through controlled drying processes. This local quality control ensures that binder is evenly distributed rather than concentrated, providing sufficient binding force while maintaining electrode flexibility through proper composition balance.
3Productivity
If drying temperature is increased to accelerate solvent removal, then drying efficiency improves, but binder moves to electrode surface causing segregation
Solution Approach 1:
The drying process is segmented into two stages: first drying at a lower temperature (50-150°C) to remove part of the solvent without causing binder migration, and second drying at a higher temperature (80-200°C) to complete solvent removal. This segmentation maintains binder distribution stability while achieving high drying efficiency.
Solution Approach 2:
The first low-temperature drying stage serves as a preliminary action that removes a significant portion of solvent while preventing binder segregation. This preliminary action enables subsequent high-temperature drying to be performed without causing segregation, thus achieving high productivity.
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 controlled drying process prevents binder segregation, resulting in an active layer with excellent peel strength on the current collector, thereby improving the binding force and overall electrode performance.
Implementation Method 1
a drying process is required after applying a composition comprising a binder on a current collector to produce an electrode
Implementation Method 2
a segregation phenomenon in which a binder existing in an electrode layer moves to a surface of the electrode during the drying process
Data Source
AI summary
The present invention relates to an electrode, a method for manufacturing same, and a battery comprising the electrode. An electrode and a method for manufacturing same can be provided wherein the electrode of the present invention prevents a segregation phenomenon by which a binder is concentrated on the surface of the electrode, thereby comprising an active layer exhibiting excellent peel strength on a current collector.