Polyurethane Binder for Capacitive Deionization Electrodes
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Solution Overview
Problem
Current polymer binders used in carbon electrodes, such as PVDF, are costly, rigid, and environmentally unfriendly, and fail to provide optimal adhesion and electrochemical performance.
Innovation Solution
A polyurethane (PU) binder is formed by reacting a hydrophobic polyether polyol, a diisocyanate, and a diol with a hydrophobic side chain, offering improved flexibility, adhesion, and chemical stability, which is applied to capacitive deionization electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If PVDF binder is used to adhere electrode material particles and bind to current collector, then adhesion strength and electronic integrity are improved, but cost increases and environmental friendliness deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the binder from PVDF (polyvinylidene fluoride) to polyurethane formed by reacting hydrophobic polyether polyol, diisocyanate, and diol with hydrophobic side chain. This parameter change maintains adhesion strength while improving environmental compatibility by eliminating the environmentally harmful fluorinated compounds.
Solution Approach 2:
The patent employs a cost-effective polyurethane binder system that can be produced from relatively inexpensive raw materials (polyether polyol, diisocyanate, and diol) compared to expensive PVDF binder, thereby reducing overall electrode manufacturing cost while maintaining functional performance.
2Stability of the object's composition
If PVDF binder is used to maintain electronic integrity, then electrode performance is improved, but rigidity increases and flexibility deteriorates
Solution Approach 1:
The patent modifies the binder's physical parameters by selecting polyether polyol with specific molecular weight (affecting chain flexibility) and incorporating diol with hydrophobic side chain (affecting chain mobility). These parameter changes produce a polyurethane binder that maintains electronic integrity through adequate adhesion while providing enhanced flexibility compared to rigid PVDF.
Solution Approach 2:
The patent creates a composite polyurethane binder system combining three different components (hydrophobic polyether polyol, diisocyanate, and diol with hydrophobic side chain) in specific molar ratios. This composite approach allows optimization of both electronic integrity and flexibility by leveraging the complementary properties of each component.
3Strength
If PVDF binder is used to adhere electrode material particles, then adhesion is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive PVDF binder with a cost-effective polyurethane binder system formed from inexpensive raw materials (polyether polyol, diisocyanate, and diol), significantly reducing material cost while maintaining adequate adhesion performance for electrode fabrication.
Solution Approach 2:
The patent optimizes the molar ratios of binder components (1 part hydrophobic polyether polyol, 3-20 parts diisocyanate, and 1-6 parts diol with hydrophobic side chain) to achieve maximum adhesion performance at minimum cost, ensuring economical manufacturing without sacrificing bonding strength.
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 PU binder enhances the adhesion strength and specific capacitance of carbon electrodes, providing better electrical conduction and ionic interaction, while being more environmentally friendly and cost-effective compared to traditional PVDF binders.
Implementation Method 1
a binder for a capacitive deionization electrode, being formed by reacting a hydrophobic polyether polyol, a diisocyanate, and a diol having a hydrophobic side chain
Data Source
AI summary
A binder for capacitive deionization electrode is provided, which is formed by reacting a polyether polyol, a diisocyanate, and a diol having a hydrophobic side chain. The binder may bind an electrode material and to form a capacitive deionization electrode. The electrode material and the binder may have a weight ratio of 90:5 to 90:25.