Carbon nanotube fly ash composite material, preparation method and application thereof

Abstract

The application relates to the technical field of supercapacitors and geopolymer concrete preparation, and discloses a carbon nanotube fly ash composite material, a preparation method and application thereof. The carbon nanotube fly ash composite material comprises an acidized carbon nanotube fiber fabric and a fly ash compound attached to the acidized carbon nanotube fiber fabric, and the fly ash compound contains a cementing material, fine aggregate, an alkali activator and carbon fibers, wherein the cementing material is a mixture of fly ash, slag and silica ash. The carbon nanotube fly ash composite material has good strength, ductility and specific surface area, an asymmetric supercapacitor prepared by using the carbon nanotube fly ash composite material has stable performance, high charging and discharging efficiency, large energy density and power density, and can be applied to large-capacity energy storage in residential, traffic and industrial applications.

Description

Technical Field

[0001] This invention relates to the fields of supercapacitors and geopolymer concrete preparation technology, specifically to a carbon nanotube fly ash composite material, its preparation method, and its application. Background Technology

[0002] With the rapid development of electricity utilization technology and the further growth of human society's demand for energy, traditional fossil fuels have gradually transitioned to renewable energy. In order to achieve the goal of sustainable development, various countries have increased their research and development efforts in key technologies in the field of renewable energy such as wind, solar and tidal energy. This requires energy storage equipment to achieve scalability and controllability of energy supply.

[0003] Existing supercapacitors use porous materials with high specific surface area, such as activated carbon, as electrodes. The two electrodes are immersed in an electrolyte and separated by an ion-permeable membrane to prevent electrical contact. During charging, anions and cations in the electrolyte migrate towards the positive and negative electrodes, respectively, forming two electrical double layers at the electrode-electrolyte interface. This ion separation also results in a potential difference throughout the entire unit. Therefore, existing supercapacitors require ion-permeable membranes, are complex to use, have unstable performance, and low charge / discharge efficiency.

[0004] Carbon nanotubes (CNTs) have excellent electrical conductivity due to their network structure, which reduces interparticle contact resistance and thus reduces contact resistance. Therefore, they have become the main material for the fabrication of supercapacitors. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems existing in the prior art and provide a carbon nanotube fly ash composite material. The asymmetric supercapacitor prepared using this carbon nanotube fly ash composite material has good specific capacitance, rate performance, stability and cycle performance.

[0006] To achieve the above objectives, the present invention provides a carbon nanotube fly ash composite material, which includes an acidified carbon nanotube fiber fabric and a fly ash composite attached to the acidified carbon nanotube fiber fabric. The fly ash composite contains a cementing material, fine aggregate, alkali activator and carbon fiber, wherein the cementing material is a mixture of fly ash, slag and silica fume.

[0007] Preferably, the acidified carbon nanotube fiber fabric is obtained by sequentially subjecting carbon nanotube fiber fabric to heat treatment and acidification treatment.

[0008] Preferably, the raw materials for preparing the carbon nanotube fiber fabric contain liquid carbon-containing organic matter, iron-containing organic salts, and sulfur-containing organic matter.

[0009] Preferably, the weight ratio of liquid carbon-containing organic matter to iron-containing organic salt is 410-450:1, wherein the liquid carbon-containing organic matter is calculated as carbon element and the iron-containing organic salt is calculated as iron element.

[0010] Preferably, the weight ratio of liquid carbon-containing organic matter to sulfur-containing organic matter is 210-250:1, wherein the liquid carbon-containing organic matter is calculated as carbon element and the sulfur-containing organic matter is calculated as sulfur element.

[0011] Preferably, in the cementitious material, based on the total weight of the cementitious material, the content of fly ash is 70-80 wt%, the content of slag is 15-20 wt%, and the content of silica fume is 5-10 wt%.

[0012] Preferably, the fly ash is Grade I calcium ash, wherein the CaO content is not less than 90 wt%.

[0013] Preferably, the slag contains more than 50 wt% Al2O3 and SiO2, and the slag has a specific surface area of ​​600-800 m². 2 / kg, less than 1% residue on 45μm square hole sieve.

[0014] Preferably, the silica fume has a particle size of 0.1-0.3 μm and a specific surface area of ​​15000-30000 m². 2 / kg.

[0015] Preferably, the particle size of the fine aggregate is 1500-2300 μm.

[0016] Preferably, the fine aggregate is river sand.

[0017] Preferably, in the fly ash composite, the weight ratio of the fine aggregate to the cementitious material is 1:2-4.

[0018] Preferably, in the fly ash composite, the content of the alkali activator is 17.5-52.5 parts by weight relative to the total weight of 100 parts by weight of the fine aggregate and the cementitious material.

[0019] Preferably, the alkali activator is a mixture of a strong alkali and water glass.

[0020] Preferably, the weight ratio of strong alkali to water glass in the alkali activator is 0.2-0.6:1.

[0021] Preferably, in the fly ash composite, the carbon fiber content is 0.5-1 parts by weight relative to the total weight of 100 parts by weight of the fine aggregate and the cementing material.

[0022] Preferably, the amount of the acidified carbon nanotube fiber fabric is 1-18 parts by weight, more preferably 3.3-16.5 parts by weight, relative to the total weight of 100 parts by weight of the fine aggregate and the cementing material.

[0023] A second aspect of the present invention provides a method for preparing the above-mentioned carbon nanotube fly ash composite material, characterized in that the method includes the following steps:

[0024] S1: Fine aggregate, cementitious material, carbon fiber and alkali activator are mixed to obtain fly ash composite slurry;

[0025] S2: The carbon nanotube fiber fabric is subjected to heat treatment and acid treatment in sequence to obtain the acidified carbon nanotube fiber fabric.

[0026] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry obtained in step S1, and then transferred into the electrode mold for curing, demolding and polishing.

[0027] Preferably, the method further includes preparing the carbon nanotube fiber fabric according to the following steps:

[0028] A1: Carbon nanotube aerogel is obtained by calcining liquid carbon-containing organic matter, iron-containing organic salt and sulfur-containing organic matter under an inert atmosphere, and then carbon nanotube fibers are formed by water bath.

[0029] A2: Twist the carbon nanotube fibers obtained in process A1 into yarn, and then weave them into carbon nanotube fiber fabric.

[0030] Preferably, in step A1, the calcination conditions include a temperature of 350-450°C and a time of 45-75 minutes.

[0031] Preferably, in step S2, the heat treatment conditions include: a temperature of 380-420°C and a time of 45-75 minutes.

[0032] Preferably, in step S2, the acidification treatment involves mixing the heat-treated carbon nanotube fiber fabric with an acidic solution, and the mixing conditions include: a temperature of 40-50°C and a time of 5.5-6.5 h.

[0033] A third party to this invention provides an asymmetric supercapacitor comprising a first fabric electrode, a separator, and a second fabric electrode, wherein the separator is disposed between the first fabric electrode and the second fabric electrode, and the first fabric electrode is the aforementioned carbon nanotube fly ash composite material.

[0034] Preferably, the second fabric electrode comprises a nitrogen-doped carbon nanotube fiber fabric loaded with nickel cobalt nanowires and a fly ash composite attached to the nitrogen-doped carbon nanotube fiber fabric loaded with nickel cobalt nanowires.

[0035] Preferably, the second fabric electrode is prepared according to the following steps:

[0036] B1: After mixing dopamine hydrochloride, water and nanotube fiber fabric, the pH of the solution was adjusted to 8-11 to obtain polydopamine-coated nanotube fiber fabric, which was then calcined under a nitrogen atmosphere to obtain fabric A.

[0037] B2: Fabric A, nickel precursor solution, cobalt precursor solution and urea are mixed and subjected to hydrothermal reaction to obtain fabric B. Fabric B is taken out and heat-treated, then mixed with fly ash composite slurry, and then transferred into electrode mold for curing, demolding and polishing.

[0038] Compared with the prior art, the present invention has the following advantages:

[0039] (1) The carbon nanotube fly ash composite material of the present invention has good ductility and strength. This may be because the cementing material in the raw material, as an inorganic cementing material, can bond well with carbon fiber and carbon nanotube fiber fabric, thus taking into account both ductility and strength.

[0040] (2) The carbon nanotube fly ash composite material of the present invention has a large specific surface area, which can better contact with the electrolyte, thus having good electrical conductivity.

[0041] (2) The asymmetric supercapacitor described in this invention has stable performance. After 1.75 million rapid charge-discharge cycles, its capacity and internal resistance decrease by only 5-10%. It has high charge-discharge efficiency and its energy density can reach up to 284.13 μWh / cm³. 2 ;

[0042] (3) The asymmetric supercapacitor described in this invention can store large amounts of energy in residential, transportation and industrial applications, and has a wider range of applications. Attached Figure Description

[0043] Figure 1 This is an electron microscope image of the second fabric electrode prepared in Example 1 of the present invention;

[0044] Figure 2 This is an electron microscope image of the carbon nanotube fly ash composite material prepared in Example 1 of the present invention. Detailed Implementation

[0045] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0046] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0047] The present invention provides a carbon nanotube fly ash composite material, which includes an acidified carbon nanotube fiber fabric and a fly ash composite attached to the acidified carbon nanotube fiber fabric. The fly ash composite contains a cementing material, fine aggregate, alkali activator and carbon fiber, wherein the cementing material is a mixture of fly ash, slag and silica fume.

[0048] In a preferred embodiment, the acidified carbon nanotube fiber fabric is obtained by sequentially subjecting carbon nanotube fiber fabric to heat treatment and acidification treatment.

[0049] In a preferred embodiment, the raw materials for preparing the carbon nanotube fiber fabric contain liquid carbon-containing organic matter, iron-containing organic salts, and sulfur-containing organic matter.

[0050] In a preferred embodiment, the weight ratio of liquid carbon-containing organic matter to iron-containing organic salt is 410-450:1, wherein the liquid carbon-containing organic matter is calculated as carbon element and the iron-containing organic salt is calculated as iron element; specifically, it can be 410:1, 420:1, 430:1, 440:1 or 450:1.

[0051] In a preferred embodiment, the weight ratio of liquid carbon-containing organic matter to sulfur-containing organic matter is 210-250:1, wherein the liquid carbon-containing organic matter is calculated as carbon element and the sulfur-containing organic matter is calculated as sulfur element; specifically, it can be 210:1, 220:1, 225:1, 230:1, 240:1 or 250:1.

[0052] In this invention, the liquid carbon-containing organic matter refers to a carbon-containing organic matter that is liquid at room temperature. There are no special requirements regarding the specific types of the liquid carbon-containing organic matter, the iron-containing organic salt, and the sulfur-containing organic matter; any commonly used substances in the art are acceptable. In a preferred embodiment, the liquid carbon-containing organic matter is ethanol and / or acetone; the iron-containing organic salt is ferrocene; and the sulfur-containing organic matter is thiophene.

[0053] In a preferred embodiment, to improve the ductility and strength of the carbon nanotube fly ash composite material, the content of fly ash in the cementitious material is 70-80 wt%, the content of slag is 15-20 wt%, and the content of silica fume is 5-10 wt%, based on the total weight of the cementitious material; specifically, the content of fly ash can be 70 wt%, 75 wt%, or 80 wt%; the content of slag can be 15 wt% or 20 wt%; and the content of silica fume can be 5 wt% or 10 wt%.

[0054] In a preferred embodiment, the fly ash is Grade I calcium ash, wherein the CaO content is not less than 90 wt%.

[0055] In a preferred embodiment, the slag contains more than 50 wt% Al2O3 and SiO2, and the specific surface area of ​​the slag is 600-800 m². 2 / kg, less than 1% residue on 45μm square hole sieve.

[0056] In a preferred embodiment, the silica fume has a particle size of 0.1-0.3 μm and a specific surface area of ​​15,000-30,000 m². 2 / kg.

[0057] In a preferred embodiment, the particle size of the fine aggregate is 1500-2300 μm.

[0058] In a preferred embodiment, the fine aggregate is river sand.

[0059] In a preferred embodiment, the weight ratio of the fine aggregate to the cementitious material in the fly ash composite is 1:2-4; specifically, the weight ratio of the fine aggregate to the cementitious material can be 1:2, 1:2.5, 1:3, 1:3.5 or 1:4.

[0060] In a preferred embodiment, in order to better generate gel from the cementitious material, the content of the alkali activator in the fly ash composite is 17.5-52.5 parts by weight relative to 100 parts by weight of the fine aggregate and the total weight of the cementitious material; specifically, the content of the alkali activator can be 17.5 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, or 52.5 parts by weight.

[0061] In a preferred embodiment, the alkali activator is a mixture of a strong alkali and water glass.

[0062] In a more preferred embodiment, the weight ratio of strong alkali to water glass in the alkali activator is 0.2-0.6:1; specifically, the weight ratio of strong alkali to water glass in the alkali activator can be 0.2:1, 0.3:1, 0.4:1, 0.5:1 or 0.6:1.

[0063] In this invention, there are no special requirements for the strong base; any strong base conventionally used in the art can be used, such as sodium hydroxide or potassium hydroxide.

[0064] In a preferred embodiment, the carbon fiber content in the fly ash composite is 0.5-1 parts by weight relative to 100 parts by weight of the total weight of the fine aggregate and the cementing material, thereby enabling the fine aggregate and cementing material to bond well with the carbon fiber and improving the ductility and strength of the carbon nanotube fly ash composite material; specifically, the weight ratio of the total weight of the fine aggregate and cementing material to the weight of the carbon fiber can be 100:0.5, 100:0.8 or 100:1.

[0065] In a preferred embodiment, to further improve the stability of the carbon nanotube fly ash composite material, the carbon fiber has a single filament diameter of 7-14 μm, a carbon content of ≥97%, a density of 1.75-1.98 g / cm, a tensile strength of ≥3500 GPa, and a resistivity of ≤1.2 Ω / cm.

[0066] In a preferred embodiment, in order to improve the energy density and strength of the carbon nanotube fly ash composite material, the amount of the acidified carbon nanotube fiber fabric is 1-18 parts by weight, preferably 3.3-16.5 parts by weight, relative to the total weight of 100 parts by weight of the fine aggregate and the cementing material; specifically, the weight ratio of the total weight of the fine aggregate and the cementing material to the weight of the carbon nanotube fiber fabric can be 100:3.3, 100:6.6, 100:9.9, 100:15 or 100:16.5.

[0067] A second aspect of the present invention provides a method for preparing the above-mentioned carbon nanotube fly ash composite material, characterized in that the method includes the following steps:

[0068] S1: Fine aggregate, cementitious material, carbon fiber and alkali activator are mixed to obtain fly ash composite slurry;

[0069] S2: The carbon nanotube fiber fabric is subjected to heat treatment and acid treatment in sequence to obtain the acidified carbon nanotube fiber fabric.

[0070] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry obtained in step S1, and then transferred into the electrode mold for curing, demolding and polishing.

[0071] In this invention, the carbon nanotube fly ash composite material prepared by the above method has a large specific surface area and good electrical conductivity.

[0072] In a preferred embodiment, in order to improve the uniformity of the fly ash composite slurry, in step S1, the fine aggregate, cementitious material, carbon fiber and alkali activator are mixed in the presence of water by stirring at a speed of 300-500 r / min for 3-5 min. Specifically, the stirring speed can be 300 r / min, 350 r / min, 400 r / min, 450 r / min or 500 r / min; and the stirring time can be 3 min, 4 min or 5 min.

[0073] In this invention, there are no special requirements for the amount of water used, as long as the fine aggregate, cementitious material, carbon fiber and alkali activator are mixed evenly.

[0074] In a preferred embodiment, the method for preparing the above-mentioned carbon nanotube fly ash composite material further includes preparing the carbon nanotube fiber fabric according to the following steps:

[0075] A1: Carbon nanotube aerogel is obtained by calcining liquid carbon-containing organic matter, iron-containing organic salt and sulfur-containing organic matter under an inert atmosphere, and then carbon nanotube fibers are formed by water bath.

[0076] A2: Twist the carbon nanotube fibers obtained in process A1 into yarn, and then weave them into carbon nanotube fiber fabric.

[0077] In a preferred embodiment, in step A1, the inert atmosphere can be a nitrogen atmosphere, an argon atmosphere, or a helium atmosphere.

[0078] In a preferred embodiment, in step A1, the calcination conditions include: a temperature of 350-450°C and a time of 45-75 min; specifically, the temperature can be 350°C, 380°C, 400°C, 420°C, or 450°C; and the time can be 45 min, 60 min, or 75 min.

[0079] In this invention, in step A2, an automated knitting machine is used to weave the twisted carbon nanotube fibers into carbon nanotube fiber fabric (CNTFF). There are no special requirements for the twist degree; a conventional twist degree in the art is sufficient, for example, 2000 Tm. -1 .

[0080] In a preferred embodiment, in step S2, the heat treatment conditions include: a temperature of 380-420°C and a time of 45-75 minutes; specifically, the temperature can be 380°C, 400°C, or 420°C; and the time can be 45 minutes, 60 minutes, or 75 minutes.

[0081] In a preferred embodiment, in step S2, the acidification treatment involves mixing the heat-treated carbon nanotube fiber fabric with an acidic solution. The mixing conditions include a temperature of 40-50°C and a time of 5.5-6.5 hours. Specifically, the temperature can be 40°C, 45°C, or 50°C, and the time can be 5.5 hours, 6 hours, or 6.5 hours.

[0082] In this invention, there are no special requirements for the acidic solution and the amount of acidic solution used in step S2; any solution conventionally used in the art is acceptable.

[0083] In a preferred embodiment, the acid in the acidic solution is selected from one or more of sulfuric acid, nitric acid, and hydrochloric acid; the amount of acidic solution used is only enough to completely immerse the heat-treated carbon nanotube fiber fabric.

[0084] In a preferred embodiment, in step S3, the curing temperature is 10-30℃ and the curing time is 12-36h; specifically, the curing temperature can be 10℃, 20℃ or 30℃; the curing time can be 12h, 24h or 36h.

[0085] A third aspect of the present invention provides an asymmetric supercapacitor, the asymmetric supercapacitor comprising a first fabric electrode, a separator, and a second fabric electrode, wherein the separator is disposed between the first fabric electrode and the second fabric electrode, and the first fabric electrode is the aforementioned carbon nanotube fly ash composite material.

[0086] In a specific implementation, the diaphragm is made of cotton fabric.

[0087] In a preferred embodiment, the second fabric electrode comprises a nitrogen-doped carbon nanotube fiber fabric loaded with nickel cobalt nanowires and a fly ash composite attached to the nitrogen-doped carbon nanotube fiber fabric loaded with nickel cobalt nanowires.

[0088] In a preferred embodiment, the second fabric electrode is prepared according to the following steps:

[0089] B1: After mixing dopamine hydrochloride, water and nanotube fiber fabric, the pH of the solution was adjusted to 8-11 to obtain polydopamine-coated nanotube fiber fabric, which was then calcined under a nitrogen atmosphere to obtain fabric A.

[0090] B2: Fabric A, nickel precursor solution, cobalt precursor solution and urea are mixed and subjected to hydrothermal reaction to obtain fabric B. Fabric B is taken out and heat-treated, then mixed with fly ash composite slurry, and then transferred into electrode mold for curing, demolding and polishing.

[0091] In the method described in this invention, in step B1, the hydrophilicity of the polydopamine-coated nanotube fiber fabric obtained by treatment with hydrochloric acid dopamine increases, and its specific surface area is also increased. Nitrogen element is doped by calcination under a nitrogen atmosphere, and then NiCo2O4 is grown on the surface of fabric A by hydrothermal method and heat treatment to obtain fabric B. After mixing fabric B with fly ash composite slurry, a second fabric electrode with high areal specific capacitance, good rate performance and cycle performance is obtained.

[0092] In a preferred embodiment, the calcination conditions in step B1 include: a temperature of 750-850°C and a time of 1.5-2.5 hours; specifically, the temperature can be 750°C, 850°C, or 850°C; and the time can be 1.5 hours, 2 hours, or 2.5 hours.

[0093] In this invention, there are no special requirements for the amount of dopamine hydrochloride used in step B1, as long as the final polydopamine can wrap the nanotube fiber fabric.

[0094] In a preferred embodiment, in step B2, the molar equivalent ratio of the nickel precursor, cobalt precursor, and urea is 1:1.5-2.5:4-6; specifically, the molar equivalent ratio of the nickel precursor, cobalt precursor, and urea can be 1:1.5:4, 1:1.5:5, 1:1.5:6, 1:2:4, 1:2:5, 1:2:6, 1:2.5:4, 1:2.5:5, or 1:2.5:6.

[0095] In this invention, there are no special requirements for the nickel precursor and cobalt precursor in step B2. Any precursor conventionally used in the art can be used. For example, the nickel precursor can be nickel nitrate hexahydrate or nickel nitrate; the cobalt precursor can be cobalt nitrate hexahydrate or cobalt nitrate.

[0096] In a preferred embodiment, the hydrothermal reaction conditions in step B2 include: a temperature of 100-140°C and a time of 5.5-6.5h; specifically, the temperature can be 100°C, 110°C, 120°C, 130°C or 140°C; and the time can be 5.5h, 6h or 6.5h.

[0097] In a preferred embodiment, in step B2, the heat treatment conditions include: a temperature of 280-320°C and a time of 1.5-2.5h; specifically, the temperature can be 320°C, 320°C, 320°C, 320°C or 320°C; and the time can be 1.5h, 2h or 2.5h.

[0098] In this invention, step B2 further includes washing and drying between the hydrothermal reaction and the heat treatment. There are no special requirements for the drying and washing; any conventional method used in the art is acceptable.

[0099] In a preferred embodiment, in step B2, the curing temperature is 10-30℃ and the curing time is 12-36h; specifically, the curing temperature can be 10℃, 20℃ or 30℃; the curing time can be 12h, 24h or 36h.

[0100] The asymmetric supercapacitor described in this invention has stable performance, high charge and discharge efficiency, and large energy density and power density.

[0101] The following examples further illustrate the carbon nanotube fly ash composite material, its preparation method, and its application according to the present invention. The examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0102] Unless otherwise specified, the experimental methods used in the following examples are conventional methods in the art. The experimental materials used in the following examples include fine aggregate: river sand with a particle size of 1500-2300 μm, purchased commercially;

[0103] Fly ash: Grade I calcium ash, CaO content 95wt%; Slag: Specific surface area 600-800m² 2 / kg, residue less than 1% on a 45μm square-hole sieve; silica fume: particle size 0.1-0.3μm, specific surface area 15000-30000m² 2 / kg;

[0104] Carbon fiber: purchased commercially, single filament diameter 7μm, carbon content ≥97wt%, density 1.75g / cm³, tensile strength ≥3500GPa, resistivity ≤1.2Ω / cm; Ethanol: analytical grade AR99.7%, Sinopharm Chemical Reagent Co., Ltd.; Ferrocene: melting point 172-174℃, benzene-insoluble matter ≤0.1wt%, free iron ≤0.01wt%, moisture ≤0.1wt%, analytical grade 98%, Sinopharm Chemical Reagent Co., Ltd.; Thiophene: content ≥99wt%, Sigma-Aldrich. Production; the carbon nanotube fiber fabric (CNTFF) is prepared by the following steps: A1: Ethanol, ferrocene, and thiophene are mixed and calcined in a tube furnace under a nitrogen atmosphere to obtain carbon nanotube aerogel, wherein the weight ratio of ethanol to ferrocene is 430:1, and the weight ratio of ethanol to thiophene is 226:1. Ethanol, ferrocene, and thiophene are calculated as carbon, iron, and sulfur elements, respectively. The calcination temperature is 350℃ and the time is 45min. Then, carbon nanotube fibers are formed by water bath; A2: A twisting machine is used at 2000Tm -1 The ten carbon nanotube fibers obtained in process A1 are twisted into yarn, and then the six strands of the prepared carbon nanotube yarn are woven into carbon nanotube fiber fabric (CNTFF) using an automated knitting machine. Other experimental materials are commercially available unless otherwise specified.

[0105] Example 1

[0106] Preparation of carbon nanotube fly ash composite material M1:

[0107] S1: River sand and cementitious material are mixed at a speed of 300 r / min for 2 min, then carbon fiber is added, and finally water and alkali activator are added, and the mixture is stirred at a speed of 400 r / min for 3 min to obtain fly ash composite slurry K1; wherein, the weight ratio of river sand to cementitious material is 1:4, the content of fly ash in the cementitious material is 70 wt%, the content of slag is 20 wt%, the content of silica fume is 10 wt%, the weight ratio of the total weight of river sand and cementitious material to carbon fiber is 100:0.5, the weight ratio of the total weight of river sand and cementitious material to alkali activator is 100:35, and the weight ratio of NaOH to water glass in the alkali activator is 0.4:1;

[0108] S2: The carbon nanotube fiber fabric is placed in a tube furnace and heat-treated in an air atmosphere. The total weight ratio of river sand and cementing material to carbon nanotube fiber fabric is 100:3.3. The heat treatment temperature is 400℃ and the time is 1h. Then, it is acidified with 80ml of acidic solution (60mL concentrated sulfuric acid and 20mL concentrated nitric acid) at 45℃ for 6h. The acidified fabric is washed and then dried under vacuum at 60℃ for 8h to obtain acidified carbon nanotube fiber fabric.

[0109] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is impregnated in the fly ash composite slurry K1 obtained in step S1, and then transferred into an electrode mold and cured at 20°C for 24 hours. After demolding and polishing, carbon nanotube fly ash composite material M1 is obtained (its microstructure is as follows). Figure 2 (as shown)

[0110] Preparation of the second fabric electrode D1:

[0111] B1: Add 2mg / mL -1 Dopamine hydrochloride was dissolved in 50 ml of water, and then nanotube fiber fabric was added and mixed. The pH of the solution was adjusted to 8.5. The mixture was stirred at 20°C for 24 h to obtain polydopamine-coated nanotube fiber fabric. After washing and drying, the fabric was calcined under a nitrogen atmosphere to obtain fabric A. The calcination temperature was 800°C and the time was 2 h.

[0112] B2: Nickel nitrate hexahydrate (2 mmol), cobalt nitrate hexahydrate (4 mmol), and urea (10 mmol) were dissolved in 40 mL of water. After adding fabric A, the mixture was placed in a PTFE-lined stainless steel reactor at 120 °C and hydrothermally reacted for 6 h to obtain fabric B. Fabric B was then removed, washed with ethanol and deionized water, and dried in a vacuum oven at 60 °C for 12 h. Finally, it was placed in a tube furnace and heated to 300 °C (heating rate of 2 °C / min). -1 The material was heat-treated for 2 hours, then immersed in fly ash composite slurry K1, and then transferred into an electrode mold and cured at 20°C for 24 hours. After demolding and polishing, the second fabric electrode D1 was obtained (its microstructure is shown in Figure 1). Figure 1 (as shown)

[0113] Cotton fabric and a second fabric electrode D1 are sequentially stacked on the surface of carbon nanotube fly ash composite material M1 to assemble an asymmetric supercapacitor N1.

[0114] Example 2

[0115] Preparation of carbon nanotube fly ash composite material M2:

[0116] S1: River sand and cementitious material are mixed at a speed of 300 r / min for 2 min, then carbon fiber is added, and finally water and alkali activator are added, and the mixture is stirred at a speed of 400 r / min for 3 min to obtain fly ash composite slurry K1; wherein, the weight ratio of river sand to cementitious material is 1:4, the content of fly ash in the cementitious material is 70 wt%, the content of slag is 20 wt%, the content of silica fume is 10 wt%, the weight ratio of the total weight of river sand and cementitious material to carbon fiber is 100:0.5, the weight ratio of the total weight of river sand and cementitious material to alkali activator is 100:35, and the weight ratio of NaOH to water glass in the alkali activator is 0.4:1;

[0117] S2: The carbon nanotube fiber fabric is placed in a tube furnace and heat-treated in an air atmosphere. The total weight ratio of river sand and cementing material to carbon nanotube fiber fabric is 100:9.9. The heat treatment temperature is 400℃ and the time is 1h. Then, it is acidified with 80ml of acidic solution (60mL concentrated sulfuric acid and 20mL concentrated nitric acid) at 45℃ for 6h. The acidified fabric is washed and then dried under vacuum at 60℃ for 8h to obtain acidified carbon nanotube fiber fabric.

[0118] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry K1 obtained in step S1, and then transferred into an electrode mold and cured at a temperature of 20°C for 24 hours. Then, it is demolded and polished to obtain carbon nanotube fly ash composite material M2.

[0119] The second fabric electrode D1 was prepared according to the method described in Example 1;

[0120] Cotton fabric and a second fabric electrode D1 are sequentially stacked on the surface of carbon nanotube fly ash composite material M2 to assemble an asymmetric supercapacitor N2.

[0121] Example 3

[0122] Preparation of carbon nanotube fly ash composite material M3:

[0123] S1: River sand and cementitious material are mixed at a speed of 300 r / min for 2 min, then carbon fiber is added, and finally water and alkali activator are added, and the mixture is stirred at a speed of 400 r / min for 3 min to obtain fly ash composite slurry K1; wherein, the weight ratio of river sand to cementitious material is 1:4, the content of fly ash in the cementitious material is 70 wt%, the content of slag is 20 wt%, the content of silica fume is 10 wt%, the weight ratio of the total weight of river sand and cementitious material to carbon fiber is 100:0.5, the weight ratio of the total weight of river sand and cementitious material to alkali activator is 100:35, and the weight ratio of NaOH to water glass in the alkali activator is 0.4:1;

[0124] S2: The carbon nanotube fiber fabric is placed in a tube furnace and heat-treated in an air atmosphere. The total weight ratio of river sand and cementing material to carbon nanotube fiber fabric is 100:16.5. The heat treatment temperature is 400℃ and the time is 1h. Then, it is acidified with 80ml of acidic solution (60mL concentrated sulfuric acid and 20mL concentrated nitric acid) at 45℃ for 6h. The acidified fabric is washed and then dried under vacuum at 60℃ for 8h to obtain acidified carbon nanotube fiber fabric.

[0125] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry K1 obtained in step S1, and then transferred into an electrode mold and cured at a temperature of 20°C for 24 hours. Then, it is demolded and polished to obtain carbon nanotube fly ash composite material M3.

[0126] The second fabric electrode D1 was prepared according to the method described in Example 1;

[0127] Cotton fabric and a second fabric electrode D1 are sequentially stacked on the surface of carbon nanotube fly ash composite material M3 to assemble an asymmetric supercapacitor N3.

[0128] Example 4

[0129] Preparation of carbon nanotube fly ash composite material M4:

[0130] S1: River sand and cementitious material are mixed at a speed of 300 r / min for 2 min, then carbon fiber is added, and finally water and alkali activator are added, and the mixture is stirred at a speed of 400 r / min for 3 min to obtain fly ash composite slurry K2; wherein, the weight ratio of river sand to cementitious material is 1:4, the content of fly ash in the cementitious material is 70 wt%, the content of slag is 20 wt%, the content of silica fume is 10 wt%, the weight ratio of the total weight of river sand and cementitious material to carbon fiber is 100:1, the weight ratio of the total weight of river sand and cementitious material to alkali activator is 100:35, and the weight ratio of NaOH to water glass in the alkali activator is 0.4:1;

[0131] S2: The carbon nanotube fiber fabric is placed in a tube furnace and heat-treated in an air atmosphere. The total weight ratio of river sand and cementing material to carbon nanotube fiber fabric is 100:3.3. The heat treatment temperature is 400℃ and the time is 1h. Then, it is acidified with 80ml of acidic solution (60mL concentrated sulfuric acid and 20mL concentrated nitric acid) at 45℃ for 6h. The acidified fabric is washed and then dried under vacuum at 60℃ for 8h to obtain acidified carbon nanotube fiber fabric.

[0132] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry K2 obtained in step S1, and then transferred into an electrode mold and cured at a temperature of 20°C for 24 hours. Then, it is demolded and polished to obtain carbon nanotube fly ash composite material M4.

[0133] Preparation of the second fabric electrode D2:

[0134] B1: Add 2mg / mL -1 Dopamine hydrochloride was dissolved in 50 ml of water, and then nanotube fiber fabric was added and mixed. The pH of the solution was adjusted to 8.5. The mixture was stirred at 20°C for 24 h to obtain polydopamine-coated nanotube fiber fabric. After washing and drying, the fabric was calcined under a nitrogen atmosphere to obtain fabric A. The calcination temperature was 800°C and the time was 2 h.

[0135] B2: Nickel nitrate hexahydrate (2 mmol), cobalt nitrate hexahydrate (4 mmol), and urea (10 mmol) were dissolved in 40 mL of water. After adding fabric A, the mixture was placed in a PTFE-lined stainless steel reactor at 120 °C and hydrothermally reacted for 6 h to obtain fabric B. Fabric B was then removed, washed with ethanol and deionized water, and dried in a vacuum oven at 60 °C for 12 h. Finally, it was placed in a tube furnace and heated to 300 °C (heating rate of 2 °C / min). -1Heat treatment for 2 hours, then immerse it in fly ash composite slurry K2, then transfer it into an electrode mold and cure it at 20°C for 24 hours, then demold and polish it to obtain the second fabric electrode D2.

[0136] Cotton fabric and a second fabric electrode D2 are sequentially stacked on the surface of carbon nanotube fly ash composite material M4 to assemble an asymmetric supercapacitor N4.

[0137] Example 5

[0138] Preparation of carbon nanotube fly ash composite material M5:

[0139] S1: River sand and cementitious material are mixed at a speed of 300 r / min for 2 min, then carbon fiber is added, and finally water and alkali activator are added, and the mixture is stirred at a speed of 400 r / min for 3 min to obtain fly ash composite slurry K2; wherein, the weight ratio of river sand to cementitious material is 1:4, the content of fly ash in the cementitious material is 70 wt%, the content of slag is 20 wt%, the content of silica fume is 10 wt%, the weight ratio of the total weight of river sand and cementitious material to carbon fiber is 100:1, the weight ratio of the total weight of river sand and cementitious material to alkali activator is 100:35, and the weight ratio of NaOH to water glass in the alkali activator is 0.4:1;

[0140] S2: The carbon nanotube fiber fabric is placed in a tube furnace and heat-treated in an air atmosphere. The total weight ratio of river sand and cementing material to carbon nanotube fiber fabric is 100:9.9. The heat treatment temperature is 400℃ and the time is 1h. Then, it is acidified with 80ml of acidic solution (60mL concentrated sulfuric acid and 20mL concentrated nitric acid) at 45℃ for 6h. The acidified fabric is washed and then dried under vacuum at 60℃ for 8h to obtain acidified carbon nanotube fiber fabric.

[0141] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry K2 obtained in step S1, and then transferred into an electrode mold and cured at a temperature of 20°C for 24 hours. Then it is demolded and polished to obtain carbon nanotube fly ash composite material M5.

[0142] The second fabric electrode D2 was prepared according to the method described in Example 4;

[0143] Cotton fabric and a second fabric electrode D2 are sequentially stacked on the surface of carbon nanotube fly ash composite material M5 to assemble an asymmetric supercapacitor N5.

[0144] Example 6

[0145] Preparation of carbon nanotube fly ash composite material M6:

[0146] S1: River sand and cementitious material are mixed at a speed of 300 r / min for 2 min, then carbon fiber is added, and finally water and alkali activator are added, and the mixture is stirred at a speed of 400 r / min for 3 min to obtain fly ash composite slurry K2; wherein, the weight ratio of river sand to cementitious material is 1:4, the content of fly ash in the cementitious material is 70 wt%, the content of slag is 20 wt%, the content of silica fume is 10 wt%, the weight ratio of the total weight of river sand and cementitious material to carbon fiber is 100:1, the weight ratio of the total weight of river sand and cementitious material to alkali activator is 100:35, and the weight ratio of NaOH to water glass in the alkali activator is 0.4:1;

[0147] S2: The carbon nanotube fiber fabric is placed in a tube furnace and heat-treated in an air atmosphere. The total weight ratio of river sand and cementing material to carbon nanotube fiber fabric is 100:16.5. The heat treatment temperature is 400℃ and the time is 1h. Then, it is acidified with 80ml of acidic solution (60mL concentrated sulfuric acid and 20mL concentrated nitric acid) at 45℃ for 6h. The acidified fabric is washed and then dried under vacuum at 60℃ for 8h to obtain acidified carbon nanotube fiber fabric.

[0148] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry K2 obtained in step S1, and then transferred into an electrode mold and cured at a temperature of 20°C for 24 hours. Then, it is demolded and polished to obtain carbon nanotube fly ash composite material M6.

[0149] The second fabric electrode D2 was prepared according to the method described in Example 4;

[0150] A cotton fabric and a second fabric electrode D2 are sequentially stacked on the surface of carbon nanotube fly ash composite material M6 to assemble an asymmetric supercapacitor N6.

[0151] Example 7

[0152] Preparation of carbon nanotube fly ash composite material M7:

[0153] S1: River sand and cementitious material are mixed at a speed of 300 r / min for 2 min, then carbon fiber is added, and finally water and alkali activator are added, and the mixture is stirred at a speed of 400 r / min for 3 min to obtain fly ash composite slurry K3; wherein, the weight ratio of river sand to cementitious material is 1:4, the content of fly ash in the cementitious material is 80 wt%, the content of slag is 15 wt%, the content of silica fume is 5 wt%, the weight ratio of the total weight of river sand and cementitious material to carbon fiber is 100:1, the weight ratio of the total weight of river sand and cementitious material to alkali activator is 100:35, and the weight ratio of NaOH to water glass in the alkali activator is 0.4:1;

[0154] S2: The carbon nanotube fiber fabric is placed in a tube furnace and heat-treated in an air atmosphere. The total weight ratio of river sand and cementing material to carbon nanotube fiber fabric is 100:16.5. The heat treatment temperature is 400℃ and the time is 1h. Then, it is acidified with 80ml of acidic solution (60mL concentrated sulfuric acid and 20mL concentrated nitric acid) at 45℃ for 6h. The acidified fabric is washed and then dried under vacuum at 60℃ for 8h to obtain acidified carbon nanotube fiber fabric.

[0155] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry K3 obtained in step S1, and then transferred into an electrode mold and cured at a temperature of 20°C for 24 hours. Then, it is demolded and polished to obtain carbon nanotube fly ash composite material M7.

[0156] Preparation of the second fabric electrode D3:

[0157] B1: Add 2mg / mL -1 Dopamine hydrochloride was dissolved in 50 ml of water, and then nanotube fiber fabric was added and mixed. The pH of the solution was adjusted to 8.5. The mixture was stirred at 20°C for 24 h to obtain polydopamine-coated nanotube fiber fabric. After washing and drying, the fabric was calcined under a nitrogen atmosphere to obtain fabric A. The calcination temperature was 800°C and the time was 2 h.

[0158] B2: Nickel nitrate hexahydrate (2 mmol), cobalt nitrate hexahydrate (4 mmol), and urea (10 mmol) were dissolved in 40 mL of water. After adding fabric A, the mixture was placed in a PTFE-lined stainless steel reactor at 120 °C and hydrothermally reacted for 6 h to obtain fabric B. Fabric B was then removed, washed with ethanol and deionized water, and dried in a vacuum oven at 60 °C for 12 h. Finally, it was placed in a tube furnace and heated to 300 °C (heating rate of 2 °C / min). -1Heat treatment for 2 hours, then immerse it in fly ash composite slurry K3, then transfer it into an electrode mold and cure it at 20°C for 24 hours, then demold and polish to obtain the second fabric electrode D3.

[0159] Cotton fabric and a second fabric electrode D3 are sequentially stacked on the surface of carbon nanotube fly ash composite material M7 to assemble an asymmetric supercapacitor N7.

[0160] Example 8

[0161] Preparation of carbon nanotube fly ash composite material M8:

[0162] S1: River sand and cementitious material are mixed at a speed of 300 r / min for 2 min, then carbon fiber is added, and finally water and alkali activator are added, and the mixture is stirred at a speed of 400 r / min for 3 min to obtain fly ash composite slurry K2; wherein, the weight ratio of river sand to cementitious material is 1:4, the content of fly ash in the cementitious material is 70 wt%, the content of slag is 20 wt%, the content of silica fume is 10 wt%, the weight ratio of the total weight of river sand and cementitious material to carbon fiber is 100:1, the weight ratio of the total weight of river sand and cementitious material to alkali activator is 100:35, and the weight ratio of NaOH to water glass in the alkali activator is 0.4:1;

[0163] S2: The carbon nanotube fiber fabric is placed in a tube furnace and heat-treated in an air atmosphere. The total weight ratio of river sand and cementing material to carbon nanotube fiber fabric is 100:20. The heat treatment temperature is 400℃ and the time is 1h. Then, it is acidified with 80ml of acidic solution (60mL concentrated sulfuric acid and 20mL concentrated nitric acid) at 45℃ for 6h. The acidified fabric is washed and then dried under vacuum at 60℃ for 8h to obtain acidified carbon nanotube fiber fabric.

[0164] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry K2 obtained in step S1, and then transferred into an electrode mold and cured at a temperature of 20°C for 24 hours. Then, it is demolded and polished to obtain carbon nanotube fly ash composite material M8.

[0165] The second fabric electrode D2 was prepared according to the method described in Example 4;

[0166] A cotton fabric and a second fabric electrode D2 are sequentially stacked on the surface of the carbon nanotube fly ash composite material M8 to assemble an asymmetric supercapacitor N8.

[0167] Example 9

[0168] Preparation of carbon nanotube fly ash composite material M9:

[0169] S1: Mix river sand and cementitious material at a speed of 300 r / min for 2 min, then add carbon fiber, and finally add water and alkali activator, and stir at a speed of 400 r / min for 3 min to obtain fly ash composite slurry K4; wherein, the weight ratio of river sand to cementitious material is 1:4, the content of fly ash in the cementitious material is 90 wt%, the content of slag is 5 wt%, the content of silica fume is 5 wt%, the weight ratio of the total weight of river sand and cementitious material to carbon fiber is 100:1, the weight ratio of the total weight of river sand and cementitious material to alkali activator is 100:35, and the weight ratio of NaOH to water glass in the alkali activator is 0.4:1;

[0170] S2: The carbon nanotube fiber fabric is placed in a tube furnace and heat-treated in an air atmosphere. The total weight ratio of river sand and cementing material to carbon nanotube fiber fabric is 100:16.5. The heat treatment temperature is 400℃ and the time is 1h. Then, it is acidified with 80ml of acidic solution (60mL concentrated sulfuric acid and 20mL concentrated nitric acid) at 45℃ for 6h. The acidified fabric is washed and then dried under vacuum at 60℃ for 8h to obtain acidified carbon nanotube fiber fabric.

[0171] S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry K4 obtained in step S1, and then transferred into an electrode mold and cured at a temperature of 20°C for 24 hours. Then, it is demolded and polished to obtain carbon nanotube fly ash composite material M9.

[0172] Preparation of the second fabric electrode D4:

[0173] B1: Add 2mg / mL -1 Dopamine hydrochloride was dissolved in 50 ml of water, and then nanotube fiber fabric was added and mixed. The pH of the solution was adjusted to 8.5. The mixture was stirred at 20°C for 24 h to obtain polydopamine-coated nanotube fiber fabric. After washing and drying, the fabric was calcined under a nitrogen atmosphere to obtain fabric A. The calcination temperature was 800°C and the time was 2 h.

[0174] B2: Nickel nitrate hexahydrate (2 mmol), cobalt nitrate hexahydrate (4 mmol), and urea (10 mmol) were dissolved in 40 mL of water. After adding fabric A, the mixture was placed in a PTFE-lined stainless steel reactor at 120 °C and hydrothermally reacted for 6 h to obtain fabric B. Fabric B was then removed, washed with ethanol and deionized water, and dried in a vacuum oven at 60 °C for 12 h. Finally, it was placed in a tube furnace and heated to 300 °C (heating rate of 2 °C / min). -1Heat treatment for 2 hours, then immerse it in fly ash composite slurry K4, then transfer it into an electrode mold and cure it at 20℃ for 24 hours, then demold and polish to obtain the second fabric electrode D4.

[0175] Cotton fabric and a second fabric electrode D4 are sequentially stacked on the surface of carbon nanotube fly ash composite material M9 to assemble an asymmetric supercapacitor N9.

[0176] Comparative Example 1

[0177] The implementation was carried out in accordance with Example 1, except that carbon fiber was not added in step S1.

[0178] Comparative Example 2

[0179] Preparation of fly ash composite material M10:

[0180] S1: River sand and cementitious material are mixed at a speed of 300 r / min for 2 min, then carbon fiber is added, and finally water and alkali activator are added, and the mixture is stirred at a speed of 400 r / min for 3 min to obtain fly ash composite slurry K1; wherein, the weight ratio of river sand to cementitious material is 1:4, the content of fly ash in the cementitious material is 70 wt%, the content of slag is 20 wt%, the content of silica fume is 10 wt%, the weight ratio of the total weight of river sand and cementitious material to carbon fiber is 100:0.5, the weight ratio of the total weight of river sand and cementitious material to alkali activator is 100:35, and the weight ratio of NaOH to water glass in the alkali activator is 0.4:1;

[0181] S2: The fly ash composite slurry K1 obtained in step S1 is transferred into an electrode mold and cured at 20°C for 24 hours. Then, it is demolded and polished to obtain fly ash composite material M10.

[0182] The second fabric electrode D1 was prepared according to the method described in Example 1;

[0183] Cotton fabric and a second fabric electrode D1 are sequentially stacked on the surface of fly ash composite material M10 to assemble an asymmetric supercapacitor N10.

[0184] Test case

[0185] The energy density, power density, and bulb lighting time of the asymmetric supercapacitors prepared in Examples 1-9 and Comparative Examples 1-2 were tested. The method for testing the bulb lighting time is as follows: The positive and negative terminals of the asymmetric supercapacitor were connected to the positive and negative terminals of a DC power supply. The output voltage of the DC power supply was fixed at 120V. The asymmetric supercapacitor was charged until the output current of the DC power supply remained constant. Then, the asymmetric supercapacitor was disconnected from the DC power supply. The positive and negative terminals of the asymmetric supercapacitor were connected to the positive and negative terminals of a 100W bulb. The bulb lighting time was tested. The test results are shown in Table 1.

[0186] Table 1

[0187]

[0188] As can be seen from the data in Table 1, the asymmetric supercapacitor prepared using the carbon nanotube fly ash composite material described in this invention has stable performance, high charge and discharge efficiency, and high energy density and power density, and can be used in large-capacity energy storage applications such as residential, transportation and industrial applications.

[0189] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A carbon nanotube fly ash composite material, characterized in that, The carbon nanotube fly ash composite material includes an acidified carbon nanotube fiber fabric and a fly ash composite attached to the acidified carbon nanotube fiber fabric. The fly ash composite contains a cementing material, fine aggregate, alkali activator and carbon fiber. The cementing material is a mixture of fly ash, slag and silica fume. In the fly ash composite, the weight ratio of the fine aggregate to the cementitious material is 1:2-4; In the fly ash composite, relative to the total weight of 100 parts by weight of the fine aggregate and the cementing material, the content of the alkali activator is 17.5-52.5 parts by weight, the content of the carbon fiber is 0.5-1 parts by weight, and the amount of the acidified carbon nanotube fiber fabric is 1-18 parts by weight.

2. The carbon nanotube fly ash composite material according to claim 1, characterized in that, The acidified carbon nanotube fiber fabric is obtained by sequentially subjecting carbon nanotube fiber fabric to heat treatment and acidification treatment.

3. The carbon nanotube fly ash composite material according to claim 2, characterized in that, The raw materials for preparing the carbon nanotube fiber fabric contain liquid carbon-containing organic matter, iron-containing organic salts, and sulfur-containing organic matter.

4. The carbon nanotube fly ash composite material according to claim 3, characterized in that, The weight ratio of liquid carbon-containing organic matter to iron-containing organic salt is 410-450:1, where the liquid carbon-containing organic matter is calculated as carbon element and the iron-containing organic salt is calculated as iron element.

5. The carbon nanotube fly ash composite material according to claim 4, characterized in that, The weight ratio of liquid carbon-containing organic matter to sulfur-containing organic matter is 210-250:1, wherein the liquid carbon-containing organic matter is calculated as carbon element and the sulfur-containing organic matter is calculated as sulfur element.

6. The carbon nanotube fly ash composite material according to any one of claims 1-5, characterized in that, In the cementitious material, based on the total weight of the cementitious material, the content of fly ash is 70-80 wt%, the content of slag is 15-20 wt%, and the content of silica fume is 5-10 wt%.

7. The carbon nanotube fly ash composite material according to claim 6, characterized in that, The fly ash is Grade I calcium ash, wherein the CaO content is not less than 90 wt%.

8. The carbon nanotube fly ash composite material according to claim 6, characterized in that, The slag contains more than 50 wt% Al2O3 and SiO2, and has a specific surface area of ​​600-800 m². 2 / kg, less than 1% residue on 45μm square hole sieve.

9. The carbon nanotube fly ash composite material according to claim 6, characterized in that, The silica fume has a particle size of 0.1-0.3 μm and a specific surface area of ​​15,000-30,000 m². 2 / kg.

10. The carbon nanotube fly ash composite material according to any one of claims 1-5, characterized in that, The fine aggregate has a particle size of 1500-2300 μm.

11. The carbon nanotube fly ash composite material according to claim 10, characterized in that, The fine aggregate is river sand.

12. The carbon nanotube fly ash composite material according to claim 1, characterized in that, The alkali activator is a mixture of a strong alkali and water glass.

13. The carbon nanotube fly ash composite material according to claim 12, characterized in that, The weight ratio of strong alkali to water glass in the alkali activator is 0.2-0.6:

1.

14. The carbon nanotube fly ash composite material according to claim 1, characterized in that, The amount of the acidified carbon nanotube fiber fabric is 3.3-16.5 parts by weight relative to the total weight of 100 parts by weight of the fine aggregate and the cementing material.

15. A method for preparing the carbon nanotube fly ash composite material according to any one of claims 1-14, characterized in that, The method includes the following steps: S1: Fine aggregate, cementitious material, carbon fiber and alkali activator are mixed to obtain fly ash composite slurry; S2: The carbon nanotube fiber fabric is subjected to heat treatment and acid treatment in sequence to obtain the acidified carbon nanotube fiber fabric. S3: The acidified carbon nanotube fiber fabric obtained in step S2 is immersed in the fly ash composite slurry obtained in step S1, and then transferred into the electrode mold for curing, demolding and polishing.

16. The method according to claim 15, characterized in that, The method further includes preparing the carbon nanotube fiber fabric according to the following steps: A1: Carbon nanotube aerogel is obtained by calcining liquid carbon-containing organic matter, iron-containing organic salt and sulfur-containing organic matter under an inert atmosphere, and then carbon nanotube fibers are formed by water bath. A2: Twist the carbon nanotube fibers obtained in process A1 into yarn, and then weave them into carbon nanotube fiber fabric.

17. The method according to claim 16, characterized in that, In process A1, the calcination conditions include a temperature of 350-450℃ and a time of 45-75 minutes.

18. The method according to claim 17, characterized in that, In step S2, the heat treatment conditions include: a temperature of 380-420℃ and a time of 45-75 minutes.

19. The method according to any one of claims 16-18, characterized in that, In step S2, the acidification treatment involves mixing the heat-treated carbon nanotube fiber fabric with an acidic solution. The mixing conditions include a temperature of 40-50°C and a time of 5.5-6.5 hours.

20. An asymmetric supercapacitor, comprising a first fabric electrode, a separator, and a second fabric electrode, wherein the separator is disposed between the first fabric electrode and the second fabric electrode, characterized in that, The first fabric electrode is the carbon nanotube fly ash composite material according to any one of claims 1-14.

21. The asymmetric supercapacitor according to claim 20, characterized in that, The second fabric electrode comprises a nitrogen-doped carbon nanotube fiber fabric loaded with nickel cobalt nanowires and a fly ash composite attached to the nitrogen-doped carbon nanotube fiber fabric loaded with nickel cobalt nanowires.

22. The asymmetric supercapacitor according to claim 20 or 21, characterized in that, The second fabric electrode is prepared according to the following steps: B1: After mixing dopamine hydrochloride, water and nanotube fiber fabric, the pH of the solution was adjusted to 8-11 to obtain polydopamine-coated nanotube fiber fabric, which was then calcined under a nitrogen atmosphere to obtain fabric A. B2: Fabric A, nickel precursor solution, cobalt precursor solution and urea are mixed and subjected to hydrothermal reaction to obtain fabric B. Fabric B is taken out and heat-treated, then mixed with fly ash composite slurry, and then transferred into electrode mold for curing, demolding and polishing.

Images