Aqueous PVDF Electrode Composition for Battery Safety
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Solution Overview
Problem
Existing electrode manufacturing processes for non-aqueous electrochemical devices face challenges with high viscosity at high PVDF concentrations, requiring large amounts of organic solvents, which are hazardous, environmentally unfriendly, and inefficient, while also lacking interconnectivity and stability in aqueous systems.
Innovation Solution
Aqueous polyvinylidene fluoride (PVDF) composition with fugitive adhesion promoters, free of fluorinated surfactants, providing interconnectivity and stability, allowing for safer, more environmentally friendly production of electrodes with reduced solvent use and improved conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If organic solvents are used to dissolve PVDF for electrode manufacturing, then good adhesion and interconnectivity are achieved, but safety hazards, environmental pollution, and health risks increase
Solution Approach 1:
The patent changes the fundamental parameter of the solvent system from organic to aqueous. By using water as the dispersion medium instead of organic solvents like NMP, the invention eliminates the harmful effects of organic solvents while maintaining PVDF's binding functionality. The aqueous PVDF dispersion achieves the same adhesion and interconnectivity properties without the safety and environmental hazards associated with organic solvents.
2Quantity of substance
If high concentration of PVDF is used to reduce solvent amount, then material efficiency improves, but viscosity increases making processing difficult
Solution Approach 1:
The patent introduces a dispersant as an intermediary substance in the aqueous PVDF dispersion system. The dispersant mediates between the PVDF particles and water, preventing aggregation and maintaining low viscosity even at high PVDF concentrations. This allows the system to achieve high material efficiency while remaining easy to process and apply in electrode manufacturing.
3Object-affected harmful factors
If aqueous systems are used to eliminate organic solvents, then safety and environmental issues are resolved, but interconnectivity and stability are compromised
Solution Approach 1:
The patent creates a composite aqueous dispersion system combining PVDF particles, dispersants, and water. This composite formulation maintains the electrochemical stability and interconnectivity properties of PVDF while utilizing the safety and environmental benefits of an aqueous base. The dispersant component ensures stable distribution and maintains the functional properties needed for electrode performance.
4Reliability
If large amounts of organic solvent are used for PVDF dispersion, then good adhesion is achieved, but manufacturing cost and environmental footprint increase
Solution Approach 1:
The patent fundamentally changes the solvent parameter from organic to aqueous, enabling the use of water as the dispersion medium. This parameter change eliminates the need for large amounts of organic solvent while maintaining adhesion properties through the combined action of PVDF and dispersant. The aqueous system reduces both material consumption and environmental impact.
Solution Approach 2:
The patent extracts and removes the harmful organic solvent component from the PVDF dispersion system, replacing it with water. By taking out the problematic organic solvent and substituting it with an environmentally benign aqueous medium, the invention achieves the same adhesion performance without the associated environmental footprint and manufacturing costs.
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 aqueous PVDF composition enables the production of high-quality electrodes with non-reversible interconnectivity, reduced electrical resistance, and enhanced lithium ion mobility, while being safer and more environmentally friendly than traditional solvent-based methods.
Implementation Method 1
one or more fugitive adhesion promoters are added
Implementation Method 2
provides non-reversible adhesion in electrodes
Implementation Method 3
PVDF binder solution in organic solvents with a powdery electrode material for use in forming an electrode
Implementation Method 4
PVDF binder solution in organic solvents
Implementation Method 5
upon evaporation of the organic solvent
Data Source
AI summary
The invention relates to an aqueous fluoropolymer, and preferably polyvinylidene fluoride (PVDF), composition for manufacturing electrodes for use in non-aqueous-type electrochemical devices, such as batteries and electric double layer capacitors. The composition contains aqueous PVDF binder, and one or more powdery electrode-forming materials. In one embodiment, the composition is free of fluorinated surfactant In another embodiment, one or more fugitive adhesion promoters are added. The electrode formed from the composition of the invention exhibits interconnectivity and irreversibility that is achieved from the use of aqueous PVDF binder.