Vinylimidazole Polymer Binders for Battery Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polymer binders used in rechargeable batteries, such as poly(vinyl difluoride) and carboxymethyl cellulose with styrene-butadiene rubber, are electrochemically inert, contribute to battery degradation, and have high production costs and environmental impacts, lacking flexibility and effective ion diffusion capabilities.
Innovation Solution
Development of polymers comprising monomeric units derived from vinylimidazole derivatives, specifically 2-vinyl-4,5-dicyanoimidazole, which can be used as binders in composite electrodes and electrolytes to enhance ionic conductivity and reduce electrode resistance, potentially replacing traditional binders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional polymer binders like PVDF dissolved in NMP are used, then effective binding and cohesion are achieved, but toxic solvents are required and production costs increase
Solution Approach 1:
The patent extracts and eliminates the toxic NMP solvent from the binder system by developing water-soluble polymer binders that achieve effective binding without requiring harmful organic solvents, thereby resolving the contradiction between binding effectiveness and toxic solvent use
Solution Approach 2:
The invention changes the chemical composition parameters of the binder from traditional PVDF to water-soluble polymers like polyacrylic acid and carboxymethyl cellulose, which fundamentally alters the solvent requirement from toxic NMP to benign water, maintaining binding effectiveness while eliminating toxicity
2Reliability
If PVDF dissolved in NMP is used as binder, then effective binding is achieved, but substantial energy is required for solvent evaporation
Solution Approach 1:
The patent removes the high-boiling-point NMP solvent from the system and replaces it with water as the solvent medium, which eliminates the need for high-energy evaporation processes while maintaining effective binding performance
Solution Approach 2:
The invention changes the solvent parameter from NMP (boiling point 202°C) to water (boiling point 100°C), and further enables aqueous-based binders that dry at ambient or low temperatures, dramatically reducing the energy parameter required for solvent removal
3Stability of the object's composition
If PVDF binder is used, then binding stability is achieved, but lithium fluoride formation accelerates binder degradation
Solution Approach 1:
The patent changes the chemical composition parameter of the binder from PVDF to water-soluble polymers with different chemical structures (polyacrylic acid, carboxymethyl cellulose) that do not react with lithium ions to form degrading products, thereby maintaining stability while extending battery life
Solution Approach 2:
The invention converts the harmful reaction between PVDF and lithium ions (which causes degradation) into a beneficial situation by using polymers that are chemically compatible with lithium ions, transforming a degradation pathway into a stable system
4Reliability
If polymers like PAN, PAA, or PVA are used as binders, then binding capability is achieved, but flexibility is lost due to high glass transition
Solution Approach 1:
The patent employs composite material strategies by combining water-soluble polymers with appropriate additives and using copolymer compositions that balance binding capability with flexibility, overcoming the rigidity issue of single-component polymers while maintaining effective binding
5Stability of the object's composition
If electrochemically inert binders are used, then chemical stability is maintained, but ion diffusion capability is limited
Solution Approach 1:
The patent changes the electrochemical parameter of the binder from inert to electrochemically active by using water-soluble polymers that can participate in electrochemical processes, thereby enabling ion diffusion while maintaining overall chemical stability of the electrode structure
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 use of vinylimidazole derivative polymers improves battery capacity retention, reduces electrode resistance, and eliminates the need for toxic solvents, offering a more efficient and environmentally friendly alternative.
Implementation Method 1
enhance ionic conductivity
Implementation Method 2
reduces electrode resistance
Data Source
AI summary
Here are described polymers comprising monomeric units from vinylimidazole derivatives and their use in electrode materials and/or electrolyte compositions, as well as their methods of preparation. Also described are electrode materials, electrodes, and electrochemical cells comprising the polymers and their use.