Carbon Nanotube Dispersion for Low-Viscosity Electrode Conductivity
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Solution Overview
Problem
Carbon nanotubes exhibit low dispersibility and agglomeration due to strong van der Waals attraction, leading to increased viscosity and reduced electrolyte permeability in electrode manufacturing, which affects the performance of secondary batteries.
Innovation Solution
A carbon nanotube dispersion is prepared using a first dispersant containing nitrogen atoms and a second dispersant with a compound represented by Formula 1, which enhances dispersibility and maintains low viscosity over time, with carbon nanotubes having a specific surface area of 800 to 2,000 m²/g.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon nanotubes are used as electrically conductive material in electrodes, then electrical conductivity is improved, but dispersibility deteriorates due to strong van der Waals attraction causing agglomeration
Solution Approach 1:
The patent introduces a dispersant as an intermediary substance between carbon nanotubes and the dispersion medium. The dispersant contains hydrophobic groups that interact with carbon nanotubes through van der Waals forces and hydrophilic groups that interact with the dispersion medium, thereby mediating the interaction and preventing direct agglomeration of carbon nanotubes while maintaining electrical conductivity
Solution Approach 2:
The patent changes the chemical composition parameters of the dispersion system by selecting specific dispersants with appropriate hydrophobic-hydrophilic balance and dispersion media with suitable polarity. This parameter optimization allows carbon nanotubes to maintain their conductive properties while achieving stable dispersion without agglomeration
2Stability of the object's composition
If mechanical dispersion treatment such as ultrasonic treatment is used to disperse carbon nanotubes, then dispersibility is improved, but viscosity increases and agglomeration occurs over time
Solution Approach 1:
The dispersant acts as a protective intermediary layer around carbon nanotubes, preventing direct van der Waals attraction between nanotube surfaces. This steric and electrostatic barrier provided by the dispersant maintains dispersion stability over time and prevents re-agglomeration after mechanical dispersion treatment
Solution Approach 2:
The patent extracts the problematic van der Waals interaction between carbon nanotubes by introducing the dispersant that interferes with direct nanotube-nanotube contact. The dispersant molecules position themselves between nanotubes, effectively removing the harmful attractive force that causes time-dependent agglomeration
3Stability of the object's composition
If carbon nanotubes are dispersed to improve dispersibility, then particle size is reduced, but viscosity increases
Solution Approach 1:
The patent optimizes parameters including dispersant concentration, dispersant molecular weight, hydrophobic-hydrophilic balance ratio, and dispersion medium polarity to achieve the right balance between particle size reduction and viscosity control. By carefully adjusting these parameters, the system maintains low viscosity while achieving fine particle size distribution
4Quantity of substance
If high-density electrodes are formed by molding electrode active material particles, then energy density is improved, but electrolyte solution permeability deteriorates due to reduced space between particles
Solution Approach 1:
Carbon nanotubes dispersed in the electrode act as intermediary structures between active material particles. They form a conductive network that maintains micropores and channels for electrolyte penetration while filling spaces between particles, thus improving energy density without compromising electrolyte solution permeability
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 dispersion achieves uniform carbon nanotube distribution with small particle size and stable viscosity, improving electrical conductivity and reducing resistance in electrodes.
Implementation Method 1
the carbon nanotubes have a problem that they have low dispersibility and an agglomeration phenomenon occurs due to the strong van der Waals attraction between them
Implementation Method 2
a method of dispersing carbon nanotubes in a dispersion medium through mechanical dispersion treatment such as ultrasonic treatment
Data Source
AI summary
The present invention relates to a carbon nanotube dispersion comprising carbon nanotubes, a first dispersant containing nitrogen atoms, a second dispersant containing the compound represented by Formula 1, and a solvent, and a method for preparing the same. The content of the compound represented by the Formula 1 is as defined in the specification.