Heated Roll Compression for Electrode Spreadability
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Solution Overview
Problem
Existing methods for producing electrodes, such as those used in lithium-ion secondary batteries, face challenges in improving the spreadability of granulated materials, which affects productivity.
Innovation Solution
The method involves compressing a granulated material containing an electrode active material, binder, and solvent between rolls heated to at least 40°C, reducing the viscosity of the binder and increasing the wetted surface area, thereby enhancing spreadability and liquid retainability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If granulated material is compressed at room temperature, then the compression process is simple, but the spreadability of the granulated material is poor
Solution Approach 1:
The patent applies parameter changes by heating the granulated material during compression to reduce binder viscosity. The compression temperature is increased from room temperature to 40-200°C, which changes the physical state of the binder and improves spreadability without requiring complex additional equipment
Solution Approach 2:
The patent replaces purely mechanical compression with a combined thermal-mechanical process. Instead of relying solely on mechanical pressure to achieve good spreadability, the system uses thermal energy to modify the binder properties, substituting part of the mechanical action with thermal action
2Quantity of substance
If the binder viscosity is high, then the binder provides good structural support, but the wetted surface area of electrode active material is reduced
Solution Approach 1:
The patent changes the temperature parameter during compression to dynamically adjust binder viscosity. At elevated temperatures (40-200°C), the binder viscosity decreases, allowing it to wet more surface area of the electrode active material while maintaining sufficient structural support through the compression process
3Ease of operation
If the granulated material has low solid content, then the material is easier to spread, but the liquid retainability deteriorates
Solution Approach 1:
The patent uses temperature as a controlling parameter to decouple the relationship between solid content and liquid retainability. By heating during compression, the system maintains good spreadability even at higher solid contents (75-90 mass%), and the temperature control ensures liquid retainability is preserved through optimized processing conditions
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 approach results in electrodes with improved spreadability and liquid retainability, facilitating efficient manufacturing and increasing productivity.
Implementation Method 1
the granulated material is heated when it is compressed between a pair of rolls, i.e., the first roll and the second roll, at least one of which has a temperature of 40° C. or higher, so that the viscosity of the binder dissolved in the solvent contained in the granulated material is reduced
Data Source
AI summary
A method of manufacturing an electrode includes a step of preparing a granulated material containing an electrode active material, a binder, and a solvent, a step of compressing the granulated material between a pair of rolls, to form an electrode composite layer, and a step of placing the electrode composite layer on an electrode current collector. At least one of the pair of rolls has a temperature of 40° C. or higher.