CN115893395A - High-specific-surface-area reduced graphene oxide/carbon tube composite powder, and preparation method and application thereof - Google Patents
High-specific-surface-area reduced graphene oxide/carbon tube composite powder, and preparation method and application thereof Download PDFInfo
- Publication number
- CN115893395A CN115893395A CN202211524221.XA CN202211524221A CN115893395A CN 115893395 A CN115893395 A CN 115893395A CN 202211524221 A CN202211524221 A CN 202211524221A CN 115893395 A CN115893395 A CN 115893395A
- Authority
- CN
- China
- Prior art keywords
- graphene oxide
- composite powder
- carbon
- sodium bicarbonate
- carbon tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 213
- 229910021389 graphene Inorganic materials 0.000 title claims abstract description 115
- 239000000843 powder Substances 0.000 title claims abstract description 102
- 239000002131 composite material Substances 0.000 title claims abstract description 71
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 55
- 238000002360 preparation method Methods 0.000 title claims abstract description 16
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims abstract description 90
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims abstract description 45
- 235000017557 sodium bicarbonate Nutrition 0.000 claims abstract description 45
- 239000002041 carbon nanotube Substances 0.000 claims abstract description 42
- 229910021393 carbon nanotube Inorganic materials 0.000 claims abstract description 42
- 239000006185 dispersion Substances 0.000 claims abstract description 21
- 238000010438 heat treatment Methods 0.000 claims abstract description 16
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 8
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 8
- 239000007788 liquid Substances 0.000 claims abstract description 6
- 238000003780 insertion Methods 0.000 claims abstract description 4
- 230000037431 insertion Effects 0.000 claims abstract description 4
- 239000011229 interlayer Substances 0.000 claims abstract description 4
- 239000002002 slurry Substances 0.000 claims description 49
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 19
- 238000000034 method Methods 0.000 claims description 15
- 239000011259 mixed solution Substances 0.000 claims description 15
- 238000001035 drying Methods 0.000 claims description 14
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 14
- 239000007787 solid Substances 0.000 claims description 14
- 239000002270 dispersing agent Substances 0.000 claims description 13
- 238000002156 mixing Methods 0.000 claims description 13
- 238000001694 spray drying Methods 0.000 claims description 13
- 239000004576 sand Substances 0.000 claims description 12
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 claims description 9
- 229920000036 polyvinylpyrrolidone Polymers 0.000 claims description 9
- 239000001267 polyvinylpyrrolidone Substances 0.000 claims description 9
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims description 8
- 238000005406 washing Methods 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 5
- 230000001681 protective effect Effects 0.000 claims description 4
- 238000003801 milling Methods 0.000 claims description 2
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 2
- 239000010410 layer Substances 0.000 abstract description 9
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 abstract description 9
- 239000000463 material Substances 0.000 abstract description 7
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 abstract description 6
- 125000002887 hydroxy group Chemical group [H]O* 0.000 abstract description 5
- 238000003756 stirring Methods 0.000 description 22
- 239000000243 solution Substances 0.000 description 21
- 239000011268 mixed slurry Substances 0.000 description 14
- 230000001007 puffing effect Effects 0.000 description 14
- 206010042674 Swelling Diseases 0.000 description 8
- 230000008961 swelling Effects 0.000 description 8
- 239000007921 spray Substances 0.000 description 6
- 241000446313 Lamella Species 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000001338 self-assembly Methods 0.000 description 5
- 238000010008 shearing Methods 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- -1 graphite alkene Chemical class 0.000 description 3
- 239000002048 multi walled nanotube Substances 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 2
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 description 2
- 238000004299 exfoliation Methods 0.000 description 2
- 125000000524 functional group Chemical group 0.000 description 2
- 238000000265 homogenisation Methods 0.000 description 2
- 229910001416 lithium ion Inorganic materials 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- CSJDCSCTVDEHRN-UHFFFAOYSA-N methane;molecular oxygen Chemical compound C.O=O CSJDCSCTVDEHRN-UHFFFAOYSA-N 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 239000002109 single walled nanotube Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Carbon And Carbon Compounds (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention provides reduced graphene oxide/carbon tube composite powder with high specific surface area, a preparation method and application thereof, wherein the preparation method comprises the following steps: s1, performing interlayer insertion on a carbon nano tube attached by sodium bicarbonate in a graphene oxide dispersion liquid to obtain composite powder; and S2, reducing and stripping the composite powder through heat treatment to obtain reduced graphene oxide/carbon tube composite powder with a high specific area. In the heat treatment reduction stage, sodium bicarbonate can be decomposed to release gas between graphene oxide layers at a low-temperature section, hydroxyl is mainly released and outgassed at a medium-temperature section, and carboxyl is deoxidized and outgassed at a high-temperature section; and (3) combining instantaneous high-temperature heat treatment, the intercalated graphene oxide powder can be instantaneously and violently expanded and instantaneously reduced and stripped, so that the highly-stripped graphene composite powder is obtained. The powder obtained by the invention is graphene carbon tube composite powder with high specific surface area, has excellent conductivity, and can be applied to the fields of lithium battery materials and the like.
Description
Technical Field
The invention relates to the technical field of graphene raw material preparation, in particular to reduced graphene oxide/carbon tube composite powder with a high specific surface area, a preparation method and application thereof, and the reduced graphene oxide/carbon tube composite powder can be particularly used in lithium ion batteries.
Background
Reduced Graphene Oxide (GO) is used as a raw material, and graphene powder is obtained by reduction treatment of Graphene Oxide (GO), has the characteristics of high conductivity and the like, and can be used in materials such as lithium ion batteries. Due to the special properties of graphene, the conductivity of graphene after the reduction stage is mainly related to two factors, namely carbon content and exfoliation degree. Wherein the higher the degree of exfoliation, the larger the specific surface area and the better the conductivity.
At the present stage, reduced graphene oxide powder is prepared on a large scale by using graphene oxide, a thermal reduction process is mainly adopted for treatment, oxygen-containing functional groups such as carboxyl and the like are removed by a high-temperature deoxidation method, and a puffing effect is generated at the moment of violent release of gas, so that the graphene is subjected to lamellar stripping. However, graphene oxide has a self-assembly effect, and properties are affected by the arrangement of oxygen-containing functional groups, such as carboxyl groups concentrated at the edges of sheets, hydroxyl groups in the middle of sheets, carboxyl carbon-oxygen double bonds broken at 600 degrees, and high release energy, because the arrangement can only expand the edge seams between layers: and hydroxyl is a carbon-oxygen single bond, is removed at 200 ℃, releases less energy, and has a limit on the stripping degree of the deoxidation released gas to the lamella. At present, the specific surface area of the prepared reduced graphene oxide powder is mainly concentrated at 200-400 m 2 About/g, 2600m from the theoretical specific surface area of graphene 2 There is also a large gap in/g, which results in some degree of impact on its use.
Disclosure of Invention
In view of this, the invention provides reduced graphene oxide/carbon tube composite powder with a high specific surface area, a preparation method and an application thereof.
The invention provides a preparation method of reduced graphene oxide/carbon tube composite powder with high specific surface area, which comprises the following steps:
s1, performing interlayer insertion on a carbon nano tube attached by sodium bicarbonate in a graphene oxide dispersion liquid to obtain composite powder;
and S2, reducing and stripping the composite powder through heat treatment to obtain the reduced graphene oxide/carbon tube composite powder with a high specific area.
Preferably, the sodium bicarbonate-attached carbon nanotubes in the S1 step are obtained by:
mixing and dispersing sodium bicarbonate and carbon nano tubes in a water phase in the presence of a dispersing agent to obtain a mixed solution of the sodium bicarbonate and the carbon nano tubes; the dispersant is preferably polyvinylpyrrolidone.
Preferably, in the step S1, sodium bicarbonate is dissolved in water to make the mass concentration 2% to 5%, and a dispersant and carbon nanotube slurry with a solid content of 2.5% to 20% are added, and stirred and sanded to obtain a mixed solution of sodium bicarbonate and carbon nanotubes.
Preferably, in the step S1, the mass ratio of the mixed solution of sodium bicarbonate and carbon nanotubes to the graphene oxide dispersion is 1: 8-10.
Preferably, in the step S1, the mixed solution of sodium bicarbonate and carbon nanotubes and the graphene oxide dispersion solution are mixed and stirred, and then are subjected to sand milling and dispersion to obtain a mixed slurry, and a carbon tube intercalation graphene oxide dry film is obtained by drying and film making, and finally is crushed to obtain the composite powder.
Preferably, in the step S2, the composite powder is subjected to heat treatment by using a puffing device under a protective atmosphere, so as to obtain reduced graphene oxide/carbon tube composite powder with a high specific area.
Preferably, in the step S2, the protective atmosphere is nitrogen; the temperature of the heat treatment is 800-900 ℃.
Preferably, the heat treatment further comprises: and washing the obtained powder with dilute hydrochloric acid, and then carrying out spray drying to obtain the reduced graphene oxide/carbon tube composite powder with a high specific area.
The invention provides reduced graphene oxide/carbon tube composite powder obtained by the preparation method, and the specific surface area of the reduced graphene oxide/carbon tube composite powder is more than 750m 2 /g。
In addition, the invention provides the application of the reduced graphene oxide/carbon tube composite powder in the lithium battery.
In this application scheme, at first adopt the adnexed carbon nanotube of sodium bicarbonate, to inserting between the graphite alkene layer in the oxidation graphite alkene dispersion, after the dry self-assembly of oxidation graphite alkene, can play the separation effect with carbon nanotube between the layer, avoid the layer fully to combine, reduce the self-assembly effect. In the heat treatment reduction stage, sodium bicarbonate can be decomposed to release gas between graphene oxide layers at a low-temperature section, hydroxyl is mainly released and outgassed at a medium-temperature section, and carboxyl is deoxidized and outgassed at a high-temperature section; and (3) combining instantaneous high-temperature heat treatment, the intercalated graphene oxide powder can be instantaneously and violently expanded and instantaneously reduced and stripped, so that highly stripped graphene composite powder is obtained, and the specific surface area of the highly stripped graphene composite powder can reach more than 1000m & lt 2 & gt/g. The powder obtained by the invention is graphene carbon tube composite powder with high specific surface area, has excellent conductivity, and can be applied to the fields of lithium battery materials and the like.
Detailed Description
The technical solutions in the embodiments of the present application are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The invention provides a preparation method of reduced graphene oxide/carbon tube composite powder with high specific surface area, which comprises the following steps:
s1, performing interlayer insertion on a carbon nano tube attached by sodium bicarbonate in a graphene oxide dispersion liquid to obtain composite powder;
and S2, reducing and stripping the composite powder through heat treatment to obtain reduced graphene oxide/carbon tube composite powder with a high specific area.
The method can prepare the graphene composite powder with high stripping and high specific surface area, further improves the conductivity, and is beneficial to application in lithium batteries and the like.
The embodiment of the invention firstly provides a carbon nanotube material attached with sodium bicarbonate, and preferably prepares a sodium bicarbonate and carbon nanotube mixed solution according to the following operations:
dissolving sodium bicarbonate in water to prepare a sodium bicarbonate aqueous solution with the concentration of 2-5%, and preferably adding 0.5-1.5% of polyvinylpyrrolidone (PVP) in mass ratio to the aqueous solution to serve as a dispersing agent; in the stirring process, the carbon nano tube water slurry with the solid content of 0.5-2% is preferably added in 5-10 times in equal amount, the slurry after stirring and mixing can be uniformly stirred at the rotating speed of 500-1500 r/min by a stirrer, a sand mill is used for dispersing to enable the sodium bicarbonate to be attached to the carbon nano tube, and the rotating speed is preferably set to be 1500-2000 r/min, so that the carbon nano tube water slurry is obtained.
The carbon nano tube is a coaxial circular tube with a plurality of layers to tens of layers, mainly composed of carbon atoms arranged in a hexagon shape, is a one-dimensional nano material, has the characteristics of light weight, good conductivity, heat transfer performance and the like, and comprises a single-wall carbon nano tube and a multi-wall carbon nano tube; the surface of the multi-wall carbon nano tube is relatively active and is combined with a large number of surface groups, such as carboxyl and the like. In the embodiment of the invention, the multi-walled carbon tube powder can be wound by adopting the commercially available nano-gang 3003, and the solid content can be 2.5 to 20 percent, or 0.5 to 2 percent and added for a plurality of times.
According to the embodiment of the invention, a small amount of sodium bicarbonate and carbon nanotube slurry are stirred and mixed in a water phase at normal temperature and are subjected to sanding and dispersing treatment under the condition of adding PVP dispersing agent, so that a mixed solution containing the carbon nanotubes attached by the sodium bicarbonate is obtained. The mass concentration of the sodium bicarbonate solution is preferably 2-5%, and more preferably 2-3%; the mass ratio of the dispersant in the aqueous solution can be 0.5%,0.8%,1%,1.2%,1.5% and the like.
In the embodiment of the present invention, a commercially available graphene oxide cake with an oxygen content of 45% to 50% may be stirred in water, preferably, the solid content of graphene oxide is controlled to be 3% to 5%, and then, a homogenizer is used to perform homogenization treatment under a certain pressure, preferably, the pressure of the homogenization treatment is 700 bar to 900bar, so as to prepare a uniform graphene oxide slurry or graphene oxide dispersion liquid.
After the sodium bicarbonate and carbon nanotube mixed solution and the graphene oxide dispersion solution are respectively obtained, the sodium bicarbonate and carbon nanotube mixed solution and the graphene oxide dispersion solution are mixed and stirred in the embodiment of the invention, the rotation speed of a stirrer is preferably 700-900 r/min, the mixture is stirred for a certain time, and then a sand mill is used for carrying out slurry dispersion treatment under the condition of 1500-2000 r/min, and the mixed slurry can be obtained after 1 hour of treatment.
The mass ratio of the sodium bicarbonate and carbon nanotube mixed solution to the graphene oxide dispersion liquid is preferably 1:8 to 10, more preferably 1:9. the mixed slurry is poured into a tray and placed into an oven for low-temperature drying and baking, preferably baking at 40-60 ℃ for 5-10h, so as to obtain a carbon tube intercalated graphene oxide dry film; taking out the dry film, manually cutting, and pulverizing into powder with wall breaking machine. Preferably, the particle size of the composite powder obtained is in the range of 100 to 500. Mu.m.
In the embodiment of the invention, the obtained composite powder is subjected to reduction puffing treatment at 800-900 ℃ by using a puffing furnace under the protection conditions of nitrogen and the like; in the heat treatment reduction stage, sodium bicarbonate decomposes and releases gas between graphene oxide layers at a low-temperature section, hydroxyl is mainly released and outgassed at a medium-temperature section, carboxyl is deoxidized and outgassed at a high-temperature section, and the intercalated graphene oxide powder can be instantaneously and violently expanded and instantaneously reduced and stripped by combining instantaneous high-temperature heat treatment to obtain the reduced graphene oxide/carbon tube composite powder with a high specific area.
Finally, in the embodiment of the invention, the obtained composite powder can be washed by dilute hydrochloric acid (such as 0.5% mass concentration dilute hydrochloric acid solution) to remove sodium bicarbonate reaction residues, and then spray-dried at the cavity temperature of 180 ℃ and the flow rate of 20L/h by a spray dryer to obtain the reduced graphene oxide/carbon tube composite powder with high purity and high specific area.
The invention provides reduced graphene oxide/carbon tube composite powder obtained by the preparation method, which is graphene carbon tube composite powder; its specific surface area is greater than 750m 2 A further higher than 800m 2 G, up to 1000m 2 More than g, e.g. 900-1200 m 2 In terms of/g (BET test).
The reduced graphene oxide/carbon tube composite powder has excellent conductivity and can be used in the field of lithium battery materials; the invention also provides the application of the reduced graphene oxide/carbon tube composite powder in the lithium battery.
In order to better understand the technical content of the invention, specific examples are provided below to further illustrate the invention. Wherein, the raw materials used in the embodiment of the invention are commercially available; the related graphene oxide is a graphene oxide cake with the oxygen content of 45-50% provided by Yunnan Merui company; the carbon nanotube is powder of multi-walled carbon nanotube wound by nanometer gang 3003.
Example 1
A preparation method of reduced graphene oxide composite powder with high specific surface area comprises the following steps:
(1) Preparing a mixed solution of sodium bicarbonate and carbon nanotubes: sodium bicarbonate was dissolved in water to prepare a 2% strength solution. 0.5 percent of PVP dispersant is added into the solution, and 0.5 percent of solid content carbon nano tube slurry is added in 5 times in equal amount in the stirring process. The mixed slurry is evenly stirred by a stirrer at the rotation speed of 500r/minn, and then is dispersed by a sand mill at the rotation speed of 1500r/min.
(2) Preparing graphene oxide slurry: and stirring the graphene oxide material cake in water at a stirring speed of 500r/min for 2 hours to prepare graphene oxide slurry with the solid content of 3%, and homogenizing the graphene oxide slurry by using a homogenizer at a pressure of 800 bar.
(3) Mixing and dispersing treatment: respectively taking two slurries, mixing and stirring the two slurries with the mass ratio of the carbon tube mixed slurry to the graphene oxide slurry being 1:9, stirring the two slurries for 2 hours at the rotating speed of a stirrer of 800r/min, and then dispersing the two slurries for 1 hour under the condition of 2000r/min of a sand mill.
(4) And (3) drying and film making: pouring the mixed slurry into a tray, placing the tray into an oven for low-temperature drying and baking, and baking for 8 hours at 50 ℃ to obtain a carbon tube intercalated graphene oxide dry film; taking out the dry film, manually shearing the dry film, and crushing the dry film into powder by using a wall breaking machine.
(5) Puffing: and (3) carrying out swelling treatment on the composite powder at 900 ℃ by using a swelling furnace under the protection of nitrogen to obtain the reduced graphene oxide/carbon tube composite powder with high specific surface area.
(6) Spray drying to prepare powder: washing the powder obtained in the step (5) with 0.5% dilute hydrochloric acid solution to remove sodium bicarbonate reaction residue, and spray-drying at 180 deg.C and 20L/h flow rate (the same as the following examples) in a spray dryerDrying to obtain the reduced graphene oxide/carbon tube composite powder with high purity and high specific surface area. The BET test shows that the specific surface area of the composite powder is 1020m 2 /g。
Example 2
The invention discloses a preparation method of reduced graphene oxide composite powder with high surface area, which comprises the following steps:
(1) Preparing a mixed solution of sodium bicarbonate and carbon nanotubes: sodium bicarbonate was dissolved in water to prepare a 2% strength solution. PVP dispersant with the proportion of 1 percent is added into the solution, and carbon nano tube slurry with the solid content of 1 percent is added in 5 times in an equal amount in the stirring process. After the mixed slurry is uniformly stirred at the rotating speed of 1000r/minn of a stirrer, a sand mill is used for dispersion treatment, and the rotating speed is set to be 1500r/min.
(2) Preparing graphene oxide slurry: and stirring the graphene oxide cake in water at a rotation speed of 500r/min for 2h by using a stirrer to prepare graphene oxide slurry with the solid content of 3%, and homogenizing the graphene oxide slurry by using a homogenizer at a pressure of 800 bar.
(3) Mixing and dispersing treatment: respectively taking two kinds of slurry, mixing and stirring the carbon tube mixed slurry and the graphene oxide slurry according to the mass ratio of 1:9, stirring for 2 hours at the rotating speed of 800r/min of a stirrer, and then performing slurry dispersion treatment for 1 hour under the condition of 2000r/min of a sand mill.
(4) Drying and film making: pouring the mixed slurry into a tray, placing the tray into an oven for low-temperature drying and baking, and baking for 8 hours at 50 ℃ to obtain a carbon tube intercalated graphene oxide dry film; taking out the dry film, manually shearing the dry film, and crushing the dry film into powder by using a wall breaking machine.
(5) Puffing: and (3) carrying out swelling treatment on the composite powder at 900 ℃ by using a swelling furnace under the protection of nitrogen to obtain the reduced graphene oxide/carbon tube composite powder with high specific surface area.
(6) Spray drying to prepare powder: and (3) washing the powder obtained in the step (5) by using a 0.5% dilute hydrochloric acid solution, removing sodium bicarbonate reaction residues, and performing spray drying by using a spray dryer to obtain the reduced graphene oxide/carbon tube composite powder with high purity and high specific surface area. The BET test shows that the specific surface area of the composite powder is 1103m 2 /g。
Example 3
The invention discloses a preparation method of reduced graphene oxide powder with high surface area, which comprises the following steps:
(1) Preparing a mixed solution of sodium bicarbonate and carbon nanotubes: sodium bicarbonate was dissolved in water to prepare a 2% strength solution. 0.8 percent of PVP dispersant is added into the solution, and the carbon nano tube slurry with the solid content of 2 percent is added in 8 times in equal amount in the stirring process. After the mixed slurry is uniformly stirred at the rotating speed of 800r/minn of the stirrer, a sand mill is used for dispersion treatment, and the rotating speed is set to 2000r/min.
(2) Preparing graphene oxide slurry: and stirring the graphene oxide cake in water at the rotating speed of 1500r/min for 2h by using a stirrer to prepare graphene oxide slurry with the solid content of 3%, and homogenizing the graphene oxide slurry by using a homogenizer at the pressure of 800 bar.
(3) Mixing and dispersing treatment: respectively taking two kinds of slurry, mixing and stirring the carbon tube mixed slurry and the graphene oxide slurry according to the mass ratio of 1:9, stirring for 2 hours at the rotating speed of 800r/min of a stirrer, and then performing slurry dispersion treatment for 1 hour under the condition of 2000r/min of a sand mill.
(4) And (3) drying and film making: pouring the mixed slurry into a tray, placing the tray into an oven for low-temperature drying and baking, and baking for 8 hours at 50 ℃ to obtain a carbon tube intercalated graphene oxide dry film; taking out the dry film, manually shearing the dry film, and crushing the dry film into powder by using a wall breaking machine.
(5) Puffing: and (3) carrying out swelling treatment on the composite powder at 900 ℃ by using a swelling furnace under the protection of nitrogen to obtain the reduced graphene oxide/carbon tube composite powder with high specific surface area.
(6) Spray drying to prepare powder: and (3) washing the powder obtained in the step (5) by using a 0.5% dilute hydrochloric acid solution, removing sodium bicarbonate reaction residues, and performing spray drying by using a spray dryer to obtain the reduced graphene oxide/carbon tube composite powder with high purity and high specific surface area. The BET test of the composite powder shows that the specific surface area is 1009m 2 /g。
Comparative example 1
(1) Preparing a sodium bicarbonate solution: sodium bicarbonate was dissolved in water to prepare a 2% strength solution.
(2) Preparing graphene oxide slurry: and stirring the graphene oxide cake in water at the rotating speed of 1500r/min for 2h by using a stirrer to prepare graphene oxide slurry with the solid content of 3%, and homogenizing the graphene oxide slurry by using a homogenizer at the pressure of 800 bar.
(3) Mixing and dispersing treatment: respectively taking the two kinds of slurry, mixing and stirring the two kinds of slurry according to the mass ratio of sodium bicarbonate solution to graphene oxide slurry of 1:9, stirring the mixture for 2 hours at the rotating speed of a stirrer of 800r/min, and then performing slurry dispersion treatment for 1 hour under the condition of 2000r/min of a sand mill.
(4) And (3) drying and film making: pouring the mixed slurry into a tray, placing the tray into an oven for low-temperature drying and baking, and baking for 8 hours at 50 ℃ to obtain a sodium bicarbonate intercalated graphene oxide dry film; taking out the dry film, manually shearing the dry film, and crushing the dry film into powder by using a wall breaking machine.
(5) Puffing: and (3) carrying out 900 ℃ puffing treatment on the composite powder in a puffing furnace under the protection of nitrogen.
(6) Spray drying to prepare powder: and (5) washing the powder obtained in the step (5) with a 0.5% dilute hydrochloric acid solution to remove sodium bicarbonate reaction residues, and performing spray drying by using a spray dryer to obtain reduced graphene oxide powder. The powder is subjected to BET test, and the specific surface area is 727m 2 (ii) in terms of/g. The introduction of the carbon tube is helpful for preventing graphene oxide lamella from self-assembly, facilitating lamella swelling separation and improving the specific surface area of the powder.
Comparative example 2
(1) Preparing a carbon nanotube solution: PVP dispersant with the proportion of 1% is added into water, and carbon nano tube slurry with the solid content of 1% is added in 5 times in an equal amount in the stirring process.
(2) Preparing graphene oxide slurry: and stirring the graphene oxide cake in water at the rotating speed of 1500r/min for 2h by using a stirrer to prepare graphene oxide slurry with the solid content of 3%, and homogenizing the graphene oxide slurry by using a homogenizer at the pressure of 800 bar.
(3) Mixing and dispersing treatment: respectively taking the two slurries, mixing and stirring the two slurries according to the mass ratio of the carbon nano tube solution to the graphene oxide slurry of 1:9, stirring the two slurries for 2 hours at the rotating speed of 800r/min of a stirrer, and then performing slurry dispersion treatment for 1 hour under the condition of 2000r/min of a sand mill.
(4) And (3) drying and film making: pouring the mixed slurry into a tray, placing the tray into an oven for low-temperature drying and baking, and baking for 8 hours at 50 ℃ to obtain a carbon tube intercalated graphene oxide dry film; taking out the dry film, manually shearing the dry film, and crushing the dry film into powder by using a wall breaking machine.
(5) Puffing: and (3) carrying out puffing treatment on the composite powder at 900 ℃ by using a puffing furnace under the condition of nitrogen protection to obtain the reduced graphene oxide/carbon tube composite powder.
(6) Spray drying to prepare powder: and (5) carrying out spray drying on the powder obtained in the step (5) by using a spray dryer to obtain reduced graphene oxide powder. The powder has a specific surface area of 687m by BET test 2 /g。
The contrast shows that the introduction of the carbon tube is beneficial to blocking the self-assembly of graphene oxide lamella, is beneficial to the swelling separation of the lamella and improves the specific surface area of the powder.
Comparative example 3
The reduced graphene oxide powder is obtained by preparing the graphene oxide slurry into powder through drying, membrane making, puffing treatment and spray drying. The powder is measured by BET and has a specific surface area of 423m 2 /g。
The reduced graphene oxide powders obtained in the above examples 1 to 3 and comparative examples 1 to 3 were added to a battery as a conductive agent, and an electrical property test was performed, with the results as follows.
Table 1 performance results of reduced graphene oxide/carbon tube composite powder prepared in the examples of the present invention
As is clear from the above examples, the powder obtained by the method of the present invention was a highly exfoliated graphene carbon tube composite powder (specific surface area: 1000 m) 2 More than/g) and excellent conductivity (the larger the specific surface area is, the better the cycle capacity retention is, the smaller the amount of the additive required to achieve a given resistivity is, namely, the conductive effectThe better), can be applied to the fields of lithium battery materials and the like.
The description of the specific embodiments of the invention, as set forth for purposes of illustration and example, is not intended to limit the invention to the precise forms disclosed, but is intended to explain certain principles of the invention and the practical application, and that various parameters may be varied in accordance with the teachings set forth herein. The scope of the invention is defined by the claims and their equivalents.
Claims (10)
1. A preparation method of reduced graphene oxide/carbon tube composite powder with high specific surface area is characterized by comprising the following steps:
s1, performing interlayer insertion on a carbon nano tube attached by sodium bicarbonate in a graphene oxide dispersion liquid to obtain composite powder;
and S2, reducing and stripping the composite powder through heat treatment to obtain the reduced graphene oxide/carbon tube composite powder with a high specific area.
2. The method for preparing reduced graphene oxide/carbon tube composite powder according to claim 1, wherein the carbon nanotubes attached to the sodium bicarbonate in the step S1 are obtained by:
mixing and dispersing sodium bicarbonate and carbon nano tubes in a water phase in the presence of a dispersing agent to obtain a mixed solution of the sodium bicarbonate and the carbon nano tubes; the dispersant is preferably polyvinylpyrrolidone.
3. The method for preparing reduced graphene oxide/carbon tube composite powder according to claim 2, wherein in the step S1, sodium bicarbonate is dissolved in water to a mass concentration of 2% to 5%, a dispersant and a carbon nanotube slurry with a solid content of 2.5% to 20% are added, and the mixture is stirred and sanded to obtain a mixed solution of sodium bicarbonate and carbon nanotubes.
4. The method of claim 3, wherein in the step S1, the mass ratio of the mixed solution of sodium bicarbonate and carbon nanotubes to the graphene oxide dispersion is 1: 8-10.
5. The method according to claim 4, wherein in the step S1, the mixture of sodium bicarbonate and carbon nanotubes is mixed with the graphene oxide dispersion, and then the mixture is subjected to sand milling to obtain a slurry, drying to obtain a dry film of carbon nanotube intercalated graphene oxide, and finally the dry film is crushed to obtain the composite powder.
6. The method according to claim 5, wherein in the step S2, the composite powder is subjected to heat treatment in a protective atmosphere by using a bulking device to obtain the reduced graphene oxide/carbon tube composite powder with a high specific area.
7. The method according to claim 6, wherein in the step S2, the protective atmosphere is nitrogen; the temperature of the heat treatment is 800-900 ℃.
8. The method for preparing reduced graphene oxide/carbon tube composite powder according to any one of claims 1 to 7, further comprising, after the heat treatment: and washing the obtained powder with dilute hydrochloric acid, and then carrying out spray drying to obtain the reduced graphene oxide/carbon tube composite powder with a high specific area.
9. The reduced graphene oxide/carbon tube composite powder obtained by the preparation method according to any one of claims 1 to 8, wherein the specific surface area is higher than 750m2/g.
10. The use of the reduced graphene oxide/carbon tube composite powder according to claim 9 in a lithium battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211524221.XA CN115893395A (en) | 2022-11-29 | 2022-11-29 | High-specific-surface-area reduced graphene oxide/carbon tube composite powder, and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211524221.XA CN115893395A (en) | 2022-11-29 | 2022-11-29 | High-specific-surface-area reduced graphene oxide/carbon tube composite powder, and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115893395A true CN115893395A (en) | 2023-04-04 |
Family
ID=86482252
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211524221.XA Pending CN115893395A (en) | 2022-11-29 | 2022-11-29 | High-specific-surface-area reduced graphene oxide/carbon tube composite powder, and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115893395A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180339906A1 (en) * | 2015-11-16 | 2018-11-29 | Fudan University | Preparation method for large-size graphene oxide or graphene |
| CN110228805A (en) * | 2019-07-24 | 2019-09-13 | 西南交通大学 | Redox graphene/carbon nano tube compound material and preparation method thereof |
| JP2020011872A (en) * | 2018-07-20 | 2020-01-23 | 東洋インキＳｃホールディングス株式会社 | Carbon nanotube dispersion liquid and its use |
| CN110970620A (en) * | 2018-09-30 | 2020-04-07 | 山东欧铂新材料有限公司 | Preparation method of high-stability graphene/carbon nanotube composite conductive slurry |
| CN111117164A (en) * | 2020-01-08 | 2020-05-08 | 广东墨睿科技有限公司 | Preparation method of graphene oxide modified epoxy resin |
| CN114933300A (en) * | 2022-06-27 | 2022-08-23 | 广东墨睿科技有限公司 | Graphene foam support with high specific surface area |
-
2022
- 2022-11-29 CN CN202211524221.XA patent/CN115893395A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180339906A1 (en) * | 2015-11-16 | 2018-11-29 | Fudan University | Preparation method for large-size graphene oxide or graphene |
| JP2020011872A (en) * | 2018-07-20 | 2020-01-23 | 東洋インキＳｃホールディングス株式会社 | Carbon nanotube dispersion liquid and its use |
| CN110970620A (en) * | 2018-09-30 | 2020-04-07 | 山东欧铂新材料有限公司 | Preparation method of high-stability graphene/carbon nanotube composite conductive slurry |
| CN110228805A (en) * | 2019-07-24 | 2019-09-13 | 西南交通大学 | Redox graphene/carbon nano tube compound material and preparation method thereof |
| CN111117164A (en) * | 2020-01-08 | 2020-05-08 | 广东墨睿科技有限公司 | Preparation method of graphene oxide modified epoxy resin |
| CN114933300A (en) * | 2022-06-27 | 2022-08-23 | 广东墨睿科技有限公司 | Graphene foam support with high specific surface area |
Non-Patent Citations (3)
| Title |
|---|
| HAILIN WANG: "Synthesis of 3D graphite oxide-exfoliated carbon nanotube carbon composite and its application as catalyst support for fuel cells", JOURNAL OF POWER SOURCES, no. 260, 15 March 2014 (2014-03-15) * |
| MASOUMEH SALEHI等: "Application of RGO/CNT nanocomposite as cathode material in lithium-air battery", JOURNAL OF ELECTROANALYTICAL CHEMISTRY, vol. 832, 1 January 2019 (2019-01-01), pages 165 - 173, XP085571292, DOI: 10.1016/j.jelechem.2018.10.053 * |
| WENYAO YANG: "Reduced Graphene Oxide/Carbon Nanotube Composites as Electrochemical Energy Storage Electrode Applcations", NANOSCALE RESEARCH LETTERS, vol. 13, 16 June 2018 (2018-06-16), XP021257423, DOI: 10.1186/s11671-018-2582-6 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8691441B2 (en) | Graphene-enhanced cathode materials for lithium batteries | |
| Muraliganth et al. | Nanoscale networking of LiFePO 4 nanorods synthesized by a microwave-solvothermal route with carbon nanotubes for lithium ion batteries | |
| EP3358650B1 (en) | Graphene dispersion, process for producing particles of graphene/active material composite, and process for producing electrode paste | |
| Zou et al. | NiO nanosheets grown on graphene nanosheets as superior anode materials for Li-ion batteries | |
| US11605810B2 (en) | Method to prepare composite graphite particles for nonaqueous secondary battery negative electrode, active material for nonaqueous secondary battery negative electrode, and nonaqueous secondary battery | |
| CN108028366B (en) | Graphene/organic solvent dispersion liquid, method for producing same, and method for producing electrode for lithium ion battery | |
| JP2020507547A (en) | Core-shell composite particles for anode material of lithium ion battery | |
| EP3226257A1 (en) | Method for manufacturing electroconductive paste, and electroconductive paste | |
| US11223035B2 (en) | Graphene-enabled niobium-based composite metal oxide as an anode active material for a lithium-ion battery | |
| JP2023009119A (en) | Method for purifying raw carbon nanotubes | |
| KR20150109377A (en) | Ultra-fine fibrous carbon for non-aqueous electrolyte secondary battery, ultra-fine fibrous carbon aggregate, composite body, and electrode active material layer | |
| Hassanzadeh et al. | Ball mill assisted synthesis of Na3MnCO3PO4 nanoparticles anchored on reduced graphene oxide for sodium ion battery cathodes | |
| CN110350161B (en) | Preparation method of silicon-carbon negative electrode precursor | |
| WO2018110386A1 (en) | Granular composite, negative electrode for lithium ion secondary battery, and method for manufacturing same | |
| CN106410199B (en) | A kind of lithium ion battery graphene/ferro-tin alloy composite negative pole material preparation method | |
| WO2017057769A1 (en) | Granular composite for manufacturing negative electrode of lithium-ion secondary cell | |
| CN113443620B (en) | Preparation method and application of few-layer graphene powder | |
| Song et al. | Construction of high-performance LiMn0. 8Fe0. 2PO4/C cathode by using quinoline soluble substance from coal pitch as carbon source for lithium ion batteries | |
| CN113582182A (en) | Silicon-carbon composite material and preparation method and application thereof | |
| CN115893395A (en) | High-specific-surface-area reduced graphene oxide/carbon tube composite powder, and preparation method and application thereof | |
| TWI782192B (en) | Positive electrode active material for lithium ion secondary battery, positive electrode material for lithium ion secondary battery, and lithium ion secondary battery | |
| JP2015219989A (en) | Negative electrode active material for lithium ion secondary battery and method for producing the same | |
| Yao et al. | Surfactant assisted synthesis of rod-like LiFePO4/C composite with cluster texture as cathode material for lithium ion batteries | |
| CN114864863B (en) | Preparation method of self-supporting electrode slice based on nano carbon material | |
| CN115172743A (en) | Graphite modified material, graphite-based negative electrode active material, and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |