Water-Based Fluoropolymer Electrode Binder for Low-Temp Processing

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Solution Overview

Problem

Current fluoropolymer compositions used in electrode production, such as those for lithium batteries, face challenges with high environmental impact due to the use of organic solvents and reduced chemical inertness, and they often damage heat-sensitive electrode materials during processing.

Innovation Solution

A water-based fluoropolymer composition is developed, comprising melt-processable fluoropolymer particles with a high perfluorinated monomer content, electro-active materials, and an organic liquid with a boiling point between 70°C and 200°C, which allows for high electro-active material loading and low-temperature processing, reducing environmental concerns and material damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If PTFE is used as binder and high temperatures are applied for film formation, then film-forming properties are improved, but heat-sensitive electrode materials are damaged or reactivity is reduced

Engineering Contradiction:
Improvefilm-forming propertiesVSAvoiddamage to heat-sensitive electrode materials
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

The patent changes the temperature parameter from high temperature (required by PTFE) to low temperature (below decomposition temperature of electrode materials) by using a water-soluble fluoropolymer binder that can form films at lower temperatures, thus resolving the contradiction between film-forming properties and protection of heat-sensitive materials

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the high-temperature-resistant but heat-damaging PTFE binder with a water-soluble fluoropolymer binder that is designed to be processed at low temperatures and then removed or decomposed, allowing film formation without damaging electrode materials

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Shape

If PVDF is used as binder to dissolve in organic solvents, then film-forming properties are improved, but environmental impact increases due to organic solvent use

Engineering Contradiction:
Improvefilm-forming propertiesVSAvoidenvironmental impact from organic solvents
Core Design Contradiction:
ShapeVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes the organic solvent component from the binder system by developing a water-soluble fluoropolymer binder, thereby eliminating the environmental harm associated with organic solvent production, use, and disposal while maintaining film-forming capabilities

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the solvent parameter from organic solvents to water by designing a fluoropolymer binder with water solubility, thus improving environmental compatibility while maintaining adequate film-forming properties for electrode production

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If PVDF with high partial fluorination is used, then chemical inertness is reduced, but service temperature is also reduced

Engineering Contradiction:
Improvechemical inertnessVSAvoidservice temperature
Core Design Contradiction:
Stability of the object's compositionVSTemperature

Solution Approach 1:

The patent changes the fluorination degree parameter by using perfluorinated monomers (100% fluorinated) instead of partially fluorinated monomers, thereby achieving both high chemical inertness and high service temperature stability, resolving the contradiction between these two properties

Inventive Principle:
Principle #35Parameter changes

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 composition enables the production of electrodes with high electro-active material loading, suitable for lithium batteries, while minimizing environmental impact and preserving the reactivity of heat-sensitive materials, with improved film-forming properties and easy removal of organic liquids, facilitating safe handling and efficient processing.

Implementation Method 1

an organic liquid having a boiling point between 70° C. and 200° C. which allows for high electro-active material loading and low-temperature processing, reducing environmental concerns and material damage

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentUS10947378B2Fluoropolymer compositions with high content of inorganic material
Publication Date: 2021.03.16 3M INNOVATIVE PROPERTIES CO

AI summary

A fluoropolymer composition particles comprising electro-active material, wherein the electro-active material comprises graphite and metal compounds and combinations thereof. The compositions also comprise water and an organic liquid having a boiling point between 70 C and 200 C. Also provided are methods of making a paste and methods of making electrodes and electrodes made with the paste.