Method for manufacturing carbon nanotube dispersion

A method for preparing a carbon nanotube dispersion, comprising:

• preparing a carbon nanotube bundle;
• post-processing the carbon nanotube bundle to reduce an average length of the carbon nanotube bundle to 50 μm or less;
• and
• dispersing the carbon nanotube bundle in a solution, wherein a volume-based particle size Dv (90) of the carbon nanotube bundle is 50 μm or less,
• wherein the solution includes a solvent and a dispersant,
• wherein the solvent is at least one of deionized water, N-methyl-2-pyrrolidone, or a combination thereof,
• wherein the dispersant is at least one of polyvinylpyrrolidone, hydrogenated nitrile rubber, or a combination thereof,
• wherein the dispersing is performed using a bead mill,
• wherein the post-processing is performed by dry milling using an air dry mill,
• wherein a saturation point according to a dispersion energy of a viscosity (μ) of the carbon nanotube dispersion is proportional to an average length value of the carbon nanotube bundle, and
• wherein the viscosity of the carbon nanotube dispersion increases and then becomes saturated as the dispersion energy increases.