POLYETHERALKANOL AMINE DISPERSANTS FOR NANOTUBE MATERIALS
The present disclosure provides a nanotube dispersion that includes a dispersion medium, a polyetheralkanol amine dispersant and carbon nanotube material. The nanotube dispersion may be used in various applications, such as in the production of electrodes for secondary batteries.
1 . A nanotube dispersion comprising a dispersion medium, a polyetheralkanol amine dispersant comprising a compound having a structure of formula (1) and a compound having a structure of formula (2)
wherein each R 1 is a C 1 -C 100 hydrocarbyl group; each R 2 is an alkoxylated hydrocarbyl group having a structure
wherein R 3 is a C 1 -C 24 hydrocarbyl group, X 1 , X 2 , X 3 , X 4 , X 5 , and X 6 in each occurrence are independently selected from the group consisting of hydrogen, methyl and ethyl, subject to the proviso that at least one of the two X groups that are attached to the same alkoxy unit are hydrogen, p, q, and r may each independently be any integer from zero to about 100, subject to the proviso that at least one of p, q, and r is not zero; and each n is any integer from 1 to about 5, and a carbon nanotube material.
2 . The nanotube dispersion of claim 1 , wherein the carbon nanotube material comprises carbon nanotubes characterized as having one or more of the following characteristics: (i) a diameter of between about 1-100 nm, (ii) a length of between about 0.01-10 mm, (iii) a density of between about 0.3-1.9 g/cm 3 , (iv) an aspect ratio of at least about 10,000, (v) a strain to failure of between about 1.8-7%, and (vi) a surface area from about 100-300 m 2 /g.
3 . The nanotube dispersion of claim 1 , wherein the dispersion medium is an aqueous dispersion medium.
4 . The nanotube dispersion of claim 3 , wherein the aqueous dispersion medium comprises a substantial fraction of water.
5 . The nanotube dispersion of claim 1 , wherein the dispersion medium comprises at least one of 3-methyl-2-oxazolidinone, 2-methyloxolane, dihydrolevoglucosenone, and N,N′-dimethylethyleneurea.
6 . The nanotube dispersion of claim 1 , further comprising poly(vinylpyrrolidone), polyvinyl pyridine, polystyrene, poly(4-vinylpyridine-co-styrene), poly(styrenesulfonate), lignosulfonic acid, lignosulfonate, poly(phenylacetylene), poly(meta-phenylenevinylene), polypyrrole, poly(p-phenylenebenzobisoxazole), an anionic aliphatic surfactant, poly(vinyl) alcohol, a polyoxyethylene surfactant, poly(vinylidene fluoride), carboxymethyl cellulose or a mixture thereof.
7 . The nanotube dispersion of claim 1 , further comprising a conductive material selected from graphite, carbon black, carbon nanohorns, vapor-grown carbon fiber, milled carbon fiber obtained by pyrolyzing and then pulverizing polymer fiber, single layer graphene, multilayer graphene, a carbon non-woven fabric sheet obtained through pyrolysis of non-woven fabric made from polymer fiber and a mixture thereof.
8 . The nanotube dispersion of claim 1 , wherein the carbon nanotube material is dispersed in the dispersion medium.
9 . An article comprising a substrate and a nanotube film formed on a surface of the substrate using the nanotube dispersion of claim 1 .
10 . The article of claim 9 , wherein the nanotube film has a thickness ranging from about 0.02 m to about 500 m.
11 . The article of claim 9 , wherein the substrate comprises paper, a metal, foil, fiberglass, a polymer, wood, silicon, glass, or quartz.
12 . The article of claim 11 , wherein the substrate is paper or foil and the article is a current collector.
13 . A slurry for a secondary battery electrode comprising an electrode active material and a nanotube dispersion comprising an aqueous dispersion medium, a polyetheralkanol amine dispersant and a carbon nanotube material.
14 . The slurry of claim 13 , wherein the electrode active material is a positive electrode active material.
15 . The slurry of claim 14 , wherein the positive electrode active material comprises a lithium-containing cobalt oxide, a lithium manganate, a lithium-containing nickel oxide, a lithium-containing composite oxides of Co—Ni—Mn, a lithium-containing composite oxide of Ni—Mn—Al, a lithium-containing composite oxide of Ni—Co—Al, an olivine-type iron lithium phosphate, an olivine-type manganese lithium phosphate, a Li 2 MnO 3 —LiNiO 2 -based solid solution, a lithium-rich spinel compound represented by Li 1+x Mn 2−x O 4 (0<X<2), Li[Ni 0.17 Li 0.2 Co 0.07 Mn 0.56 ]O 2 , or LiNi 0.5 Mn 1.5 O 4 .
16 . The slurry of claim 13 , wherein the electrode is a negative electrode active material.
17 . The slurry of claim 16 , wherein negative electrode active material comprises a carbon-based negative electrode active material, a metal-based negative electrode active material or a mixture of the carbon-based negative electrode active material and the metal-based negative electrode active material.
18 . The slurry of claim 17 , wherein the metal-based negative electrode active material is a silicon-based negative electrode active material.
19 . The slurry of claim 13 , wherein the carbon nanotube material is dispersed in the dispersion medium
20 . An electrode comprising a current collector and a layer formed on the current collector using the slurry of claim 12 .
21 . A secondary battery comprising the electrode of claim 20 .
22 . The secondary battery of claim 21 , wherein the secondary battery is a lithium-ion battery, a lithium-sulfur battery, a sodium-ion battery, or a lithium air battery.