Fluoropolymer Binder for Flexible High-Density Battery Electrodes

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing binders in secondary batteries increase the stiffness of electrode plate film layers, deteriorating flexibility and limiting the improvement of electrochemical performance, including volumetric energy density and cycle stability.

Innovation Solution

A fluoropolymer with a weight average molecular weight of 5 million to 9 million, derived from vinylidene fluoride and unsaturated carboxylic acid monomer, is used to improve flexibility and compacted density of electrode plates, reducing battery resistance while maintaining bonding strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional polymer binders are used in electrode plates, then bonding strength is maintained, but flexibility deteriorates and stiffness increases

Engineering Contradiction:

ImproveflexibilityVSAvoidbonding strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The patent changes the chemical composition parameters of the binder by using fluoropolymer with specific weight average molecular weight (500,000 to 900,000) and controlled polydispersity coefficient (1.5 to 3.5), which fundamentally alters the mechanical properties of the electrode plate to achieve both flexibility and bonding strength

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite binder system consisting of fluoropolymer mixed with polyvinylidene fluoride at specific weight ratios (fluoropolymer content: 10-50 wt%), creating a composite material that combines the flexibility advantages of fluoropolymer with the bonding properties of PVDF

Inventive Principle:

Principle #40Composite materials

2Volume of stationary object

If conventional polymer binders are used in electrode plates, then structural integrity is maintained, but compacted density decreases

Engineering Contradiction:

Improvecompacted densityVSAvoidstructural integrity

Core Design Contradiction:

Volume of stationary objectVSStrength

Solution Approach 1:

The patent changes the physical parameters of the binder system by controlling the weight average molecular weight (500,000 to 900,000) and polydispersity coefficient (1.5 to 3.5) of fluoropolymer, which enables better particle packing and achieves higher compacted density while maintaining structural integrity

Inventive Principle:

Principle #35Parameter changes

3Strength

If binder content is increased to improve bonding, then bonding strength increases, but battery resistance increases and volumetric energy density decreases

Engineering Contradiction:

Improvebonding strengthVSAvoidvolumetric energy density

Core Design Contradiction:

StrengthVSUse of energy by moving object

Solution Approach 1:

The patent changes the chemical composition parameters by using fluoropolymer with specific molecular weight characteristics, which provides superior bonding efficiency at lower concentrations (10-50 wt%), thereby reducing the overall binder content needed and increasing volumetric energy density

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The fluoropolymer molecules with optimized molecular weight distribution create more effective bonding interfaces per unit mass, allowing reduced binder quantity while maintaining or improving bonding strength

Inventive Principle:

Principle #26Copying

4Strength

If binder content is increased to improve bonding, then bonding strength increases, but flexibility deteriorates

Engineering Contradiction:

Improvebonding strengthVSAvoidflexibility

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The patent changes the chemical composition by using fluoropolymer with specific weight average molecular weight (500,000 to 900,000) and polydispersity coefficient (1.5 to 3.5), which provides high bonding strength at lower addition amounts, thereby maintaining electrode plate flexibility

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite binder system combining fluoropolymer and PVDF in optimized ratios, where fluoropolymer provides flexibility and bonding efficiency, allowing reduced overall binder content while maintaining bonding strength

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS20260028438A1Fluoropolymer, preparation method therefor, positive electrode plate, secondary battery, and electric device

Publication Date: 2026.01.29 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD

AI summary

This application provides a fluoropolymer, a preparation method therefor, a positive electrode plate, a secondary battery, and an electric device. The fluoropolymer comprises a structural unit derived from vinylidene fluoride and a structural unit derived from an unsaturated carboxylic acid monomer, wherein a weight average molecular weight of the fluoropolymer ranges from 5 million to 9 million, and optionally, from 5 million to 8 million.