Non-Fibrillizable Fluoropolymer Binder for Thick Dry-Coated Electrodes
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Solution Overview
Problem
Existing lithium-ion battery manufacturing processes using fibrillizable binders require high energy consumption due to additional shearing steps and use of volatile organic solvents, which are hazardous and inefficient for producing electrodes with high thickness and energy density.
Innovation Solution
A non-fibrillizable fluoropolymer binder with specific melting point and viscosity properties is used in a dry-coated electrode process, eliminating the need for additional shearing and reducing energy consumption, while ensuring mechanical integrity and electrochemical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If fibrillizable binders are used in dry process electrode manufacturing, then the electrode can achieve mechanical integrity, but additional shearing steps are required which consume high energy and are destructive to active materials
Solution Approach 1:
The patent changes the key parameter of the binder from fibrillizable to non-fibrillizable, while simultaneously adjusting the processing temperature parameter to above the binder's melting point. This parameter change allows the binder to become thermoplastic and form mechanical bonds without requiring high-energy shearing steps, thus reducing energy consumption while maintaining mechanical integrity
Solution Approach 2:
The patent utilizes phase transition of the binder material by heating it above its melting point during processing. The binder transitions from a solid state to a thermoplastic state, enabling it to flow and bond components together without mechanical shearing. After cooling, it solidifies to provide mechanical strength, eliminating the need for energy-intensive shearing operations
2Ease of manufacture
If conventional wet-suspension process with organic solvents is used, then electrode components can be dispersed and formed, but harmful vapors are emitted requiring special equipment and high energy for drying
Solution Approach 1:
The patent extracts and eliminates the organic solvent component from the electrode manufacturing process. By using a dry process with non-fibrillizable binder and heating above its melting point, the process achieves component dispersion and bonding without any liquid solvent, thereby completely eliminating harmful vapor emissions while maintaining ease of manufacture
Solution Approach 2:
The patent replaces the liquid-based dispersion mechanism of wet processes with a thermal-mechanical processing system. The binder is heated above its melting point to become thermoplastic, allowing components to be distributed and bonded through thermal and mechanical action without liquid solvent, thus eliminating harmful vapors while achieving electrode formation
3Quantity of substance
If high thickness electrodes (>120 μm) are manufactured, then energy density is improved, but mechanical integrity and homogeneity become more difficult to maintain
Solution Approach 1:
The patent changes the processing temperature parameter to above the binder's melting point, making the binder thermoplastic. This allows the binder to flow and distribute uniformly throughout thick electrode structures, maintaining homogeneity even at thicknesses exceeding 120 μm while supporting high energy density
Solution Approach 2:
The patent uses a composite binder system consisting of non-fibrillizable binder (2-10 wt%) combined with conventional binder (90-98 wt%). This composite approach provides both the thermal-mechanical bonding capability for thick structures and the homogeneity distribution needed for uniform performance throughout the electrode thickness
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 fluoropolymer binder allows for the production of flexible, electrochemically stable electrodes with improved homogeneity and adhesion, reducing binder content and energy consumption, and enhancing cycle properties in lithium-ion batteries.
Implementation Method 1
a non-fibrillizable binder for a dry-coated electrode, characterized in that said binder consists of a fluoropolymer having a melting point between 145°C and 200°C
Implementation Method 2
The main objective of using a binder is to form stable networks of the solid components of the electrodes, i.e. the active materials and the conductive agents (cohesion). In addition, the binder must ensure close contact of the composite electrode to the current collector (adhesion)
Data Source
AI summary
The present invention relates to a non-fibrillizable binder for a dry-coated electrode, said binder consisting of a fluoropolymer having a melting point between 145° C. and 200° C. measured according to ASTM D3418 and a melt viscosity below 50 kP measured at 230° C. and at a shear rate of 100 s-1 measured according to ASTM D3835. More specifically. the invention relates to a dry-coated electrode for Li-ion battery. The invention also concerns the lithium-ion batteries manufactured by incorporating said electrode.