Ionized PVDF Copolymers for Metal-Adhesive Battery Electrodes

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Fluoropolymers, such as vinylidene fluoride polymers, exhibit poor adhesion to metals due to their low surface energies, which limits their application in electrodes for secondary batteries, despite existing surface treatments and modifications.

Innovation Solution

Subjecting vinylidene fluoride polymers to low-intensity ionizing radiation treatment, resulting in the formation of hydrophilic polymers with improved adhesion to metals, suitable for use as binders in electrodes by creating polar groups and reducing contact angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fluoropolymers are used as binders in electrodes, then chemical stability and electrochemical performance are improved, but adhesion to metal substrates deteriorates due to low surface energy

Engineering Contradiction:
Improvechemical stabilityVSAvoidadhesion to metal
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention changes the chemical composition parameters of the fluoropolymer by incorporating specific comonomers (vinyl fluoride, 1-fluoro-1,3-butadiene, and/or 3-fluoro-1,3-butadiene) in controlled amounts (0.1-10 mol% each) to modify surface energy and improve adhesion while preserving electrochemical stability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite fluoropolymer system combining VDF with specific fluorinated comonomers to achieve synergistic effects: VDF provides chemical stability while the comonomers contribute polar groups and functionalities that enhance metal adhesion

Inventive Principle:
Principle #40Composite materials

2Strength

If surface treatments are applied to fluoropolymers to improve adhesion, then binding properties to metals are enhanced, but process complexity and manufacturing steps increase

Engineering Contradiction:
Improveadhesion to metalVSAvoidprocess complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention performs preliminary action by incorporating adhesion-enhancing comonomers into the fluoropolymer chain during the polymerization stage, so that the polymer inherently possesses improved adhesion properties without requiring subsequent surface treatment steps

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention extracts the need for separate surface treatment processes by integrating adhesion functionality directly into the polymer synthesis, eliminating complex post-processing steps such as plasma treatment, corona discharge, or chemical etching

Inventive Principle:
Principle #2Taking out (Extraction)

3Strength

If higher comonomer content is used in PVDF copolymers to improve adhesion, then binding properties to metals are enhanced, but polymer crystallinity and mechanical strength may deteriorate

Engineering Contradiction:
Improveadhesion to metalVSAvoidpolymer crystallinity
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The invention optimizes comonomer content parameters within specific ranges (0.1-10 mol% for each comonomer type) to achieve the optimal balance between adhesion improvement and crystallinity preservation, preventing excessive disruption of the polymer crystal structure

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 treated polymers demonstrate enhanced hydrophilicity and adhesion to metal surfaces, leading to improved performance as binders in secondary batteries with increased binding properties between active materials and metal substrates.

Implementation Method 1

subjecting vinylidene fluoride polymers to low-intensity ionizing radiation treatment, resulting in the formation of hydrophilic polymers with improved adhesion to metals

Methodology Applied
Scientific EffectIonizing radiation: Radiation

Implementation Method 2

low intensity irradiation treatment with ionizing radiation... modified in such a way to obtain fluoropolymers that are much more hydrophilic... formation of hydrophilic polymers with improved adhesion to metals, suitable for use as binders in electrodes by creating polar groups

Methodology Applied
Scientific EffectPhoto-oxidation: Photo-oxidation

Data Source

PatentUS20240186523A1Method for manufacturing partially fluorinated polymers
Publication Date: 2024.06.06 SOLVAY SPECIALTY POLYMERS ITALY SPA

AI summary

The present invention pertains to hydrophilic vinylidene fluoride polymers, to a process for preparing these polymers and to the use of the same for producing articles characterized by improved performances.