Polyacrylic Acid Binder Crosslinking Control for Negative Electrode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing binders for negative electrodes in power storage devices, such as polyacrylic acid derivatives, often suffer from deteriorated cycle characteristics due to excessive crosslinking, leading to reduced flexibility and impaired lithium occlusion/release performance.
Innovation Solution
A polymer compound formed by condensing polyacrylic acid with a polyfunctional amine and an aromatic monoamine, which creates a chain structure with free carboxyl groups and crosslinked structures, preventing excessive acid anhydride formation and maintaining flexibility, even at low molecular weights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyacrylic acid derivatives are used as binders for negative electrodes, then binding capability is improved, but cycle characteristics deteriorate due to excessive crosslinking
Solution Approach 1:
The patent introduces a specific molecular weight parameter (number average molecular weight of 5,000 to 50,000) for the polyacrylic acid component to control the degree of crosslinking. By precisely controlling the molecular weight parameter, the binder achieves optimal binding capability while preventing excessive crosslinking that would harm cycle characteristics
Solution Approach 2:
The patent creates a composite binder system by combining polyacrylic acid with specific additives (polyethyleneimine and/or carboxymethyl cellulose) in controlled ratios. This composite approach allows the polyacrylic acid to provide binding capability while the other components modulate the crosslinking behavior to maintain good cycle characteristics
2Strength
If crosslinked structures are formed in the binder, then binding strength is improved, but flexibility is reduced
Solution Approach 1:
The patent controls the molecular weight parameter (number average molecular weight of 5,000 to 50,000) to regulate the density and distribution of crosslinked structures. This parameter control ensures sufficient binding strength while maintaining adequate flexibility by preventing overly dense crosslinking
3Strength
If excessive crosslinking occurs, then binding strength increases, but lithium occlusion/release performance is impaired
Solution Approach 1:
The patent precisely controls the number average molecular weight parameter (5,000 to 50,000) to optimize the balance between binding strength and lithium ion transport. This parameter optimization ensures that crosslinking provides sufficient binding while leaving adequate pathways for lithium occlusion and release
Solution Approach 2:
The patent applies partial crosslinking rather than complete crosslinking by controlling the molecular weight and additive ratios. This partial action approach provides sufficient binding strength while maintaining open structures that allow lithium ion diffusion, preventing the excessive crosslinking that would block lithium pathways
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 polymer compound enhances the cycle characteristics and productivity of negative electrodes by maintaining flexibility and facilitating lithium occlusion/release, while suppressing excessive crosslinking and densification.
Implementation Method 1
A polymer compound formed by condensing polyacrylic acid with a polyfunctional amine and an aromatic monoamine
Implementation Method 2
formed by condensing a polyacrylic acid, a polyfunctional amine represented by the following general formula (1), and an aromatic monoamine
Data Source
AI summary
A polymer compound is formed by condensing a polyacrylic acid, a polyfunctional amine represented by the following general formula (1), and an aromatic monoamine. A chain structure constituted by the polyacrylic acid has free carboxyl groups and carboxyl groups to which the aromatic monoamines are bonded.Y is a straight-chain alkyl group having 1 to 4 carbon atoms, a phenylene group, or an oxygen atom. R1 and R2 are each independently one or more hydrogen atoms, a methyl group, an ethyl group, a trifluoromethyl group, or a methoxy group.