Dry Electrode Binder Composition for Adhesion Without Solvents
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Solution Overview
Problem
Existing lithium-ion battery electrode manufacturing processes using organic solvents are energy-intensive, environmentally harmful, and require high temperatures, while dry processes with existing binders face energy consumption issues and insufficient electrochemical stability.
Innovation Solution
A dry composition for lithium-ion battery electrodes comprising a fluoropolymer and a polyamide thermoplastic polymer, which allows for improved coulombic efficiency and adhesion through a solvent-free process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wet-suspension electrode manufacturing method using organic solvents is used, then good adhesion and bonding capability are achieved, but high energy consumption and environmental harm occur due to high temperature drying and solvent evaporation
Solution Approach 1:
The invention changes the fundamental parameter of the manufacturing process from wet-suspension to dry-blending, eliminating the need for organic solvents and high-temperature drying. This parameter change resolves the contradiction by achieving adhesion through mechanical interlocking and surface contact in the dry state, rather than relying on solvent-based bonding that requires energy-intensive evaporation.
Solution Approach 2:
The invention extracts and eliminates the organic solvent component from the electrode manufacturing process. By removing NMP and other harmful solvents entirely, the process avoids the need for high-temperature drying and solvent recovery systems, thereby reducing energy consumption while maintaining adhesion through the dry-blending mechanism.
2Use of energy by stationary object
If dry process manufacturing is used, then energy consumption and environmental harm are reduced, but adhesion and bonding capability deteriorate without appropriate binder adaptation
Solution Approach 1:
The invention uses a simple dry-blending approach without requiring complex binder formulations or additional processing steps. The method accepts that dry-state adhesion differs from wet-state adhesion and works within those constraints, using straightforward mechanical mixing and pressing to achieve sufficient bonding for the application.
Solution Approach 2:
The invention adapts the manufacturing parameters to the dry process by controlling particle size distribution, blending time, and pressing conditions to achieve adequate adhesion without solvents. The binder formulation is specifically designed to work in the dry state, with surface properties optimized for mechanical interlocking rather than solvent-based wet adhesion.
3Reliability
If PVDF binder is used in wet process, then excellent electrochemical stability and bonding capability are achieved, but harmful volatile organic compound emissions occur
Solution Approach 1:
The invention extracts and removes the harmful VOC emissions by eliminating the organic solvent NMP from the process. The PVDF binder is still used but in a dry-blending context where no solvent evaporation occurs, thereby maintaining electrochemical stability while eliminating the harmful emissions that would otherwise require special equipment to prevent free emission to the environment.
Solution Approach 2:
The invention converts the potential harm of using PVDF (which requires NMP for processing) into a benefit by developing a dry-blending method that eliminates the need for NMP entirely. The harm of VOC emissions is transformed into an advantage of a solvent-free process that maintains PVDF's excellent electrochemical properties without the environmental drawbacks.
4Shape
If fibrillizable binders are used in dry process, then film flexibility is achieved, but high energy consumption and damage to active materials occur due to extra shearing
Solution Approach 1:
The invention uses a simple dry-blending approach without requiring fibrillizable binders or extra shearing steps. The method achieves sufficient film flexibility through straightforward mechanical mixing and pressing, accepting that the flexibility may be slightly less than what fibrillizable binders could provide but eliminating the high energy consumption and damage to active materials associated with intensive shearing.
Solution Approach 2:
The invention extracts and eliminates the need for fibrillizable binders and the associated extra shearing step. By removing this complex processing requirement, the invention reduces energy consumption and prevents damage to active materials while still achieving adequate film flexibility through the simplified dry-blending process.
Data Source
AI summary
The present invention relates to a dry composition comprising at least one active material, at least one binder, optionally at least one conductive agent, characterized in that said at least one binder comprises a fluoropolymer and a polyamide thermoplastic polymer.