A cement-based supercapacitor improved by activated carbon fiber

Abstract

The present invention relates to a cement-based supercapacitor improved by using activated carbon fibers. By using a matrix material in combination with an ionic phase, a conductive phase, a toughening phase, and a binder, a cement-based supercapacitor with strong electrochemical activity, good pressure resistance, and good impact resistance is prepared. Carbon fibers with a very large aspect ratio are used to replace lamellar carbon powder and expensive graphene. The carbon fibers are both conductive and toughening phases. When combined with an appropriate amount of sucrose solution and aramid fibers, they have good pressure resistance and impact resistance. The carbon fibers are mixed with a metal salt solution and then sintered, so that the active metal on the surface of the carbon fibers is "reinforced", effectively preventing its loss. A large number of pore structures appear on the surface of the sintered carbon fibers due to oxidation etching, which is beneficial to improving the ionic conductivity and thus effectively improving the electrochemical performance of the capacitor. The raw materials used in the present invention are low in price and the preparation process is simple and easy, which broadens the prospects for the early realization of "energy storage / building integration" practical applications for cement-based supercapacitors.

Description

Technical Field

[0001] The present invention relates to the technical field of supercapacitor preparation, and in particular to an activated carbon fiber-modified cement-based supercapacitor for improving electrochemical performance and voltage resistance. Background Art

[0002] In recent decades, fossil fuel shortages and greenhouse gas emissions have impacted sustainable social development, necessitating an urgent need for new energy storage devices to store renewable energy sources such as wind and solar power. Residential and commercial buildings account for approximately 40% of total energy consumption. Therefore, researchers in materials science, civil engineering, and energy storage science are exploring the use of new energy storage materials and devices to store electricity generated by renewable energy and achieve true "energy storage / building integration." Supercapacitors, a new type of energy storage device primarily composed of electrodes, electrolytes, and interlayer materials, are gaining popularity due to their long service life and fast response time. Among these, supercapacitors using cement composites as electrolytes have emerged as a promising candidate for large-scale building energy storage due to their stable performance, low cost, and low maintenance. However, cement-based supercapacitors have yet to meet the standards for practical engineering applications, and improving their electrochemical and mechanical properties has become a key challenge in the fabrication of cement-based supercapacitors. Summary of the Invention

[0003] The purpose of the present invention is to provide a cement-based supercapacitor improved by activated carbon fiber. By combining the matrix material with an ionic phase, a conductive phase, a toughening phase, and a binder, a cement-based supercapacitor with strong electrochemical activity, good voltage resistance, and good impact resistance is prepared.

[0004] To achieve the above object, the present invention is implemented through the following technical solutions:

[0005] A cement-based supercapacitor improved by activated carbon fiber is characterized by using cement as a matrix material, a metal salt solution as an ionic phase, carbon fiber as a conductive phase, aramid fiber as a toughening phase, and a sucrose solution as a binder to prepare the activated carbon fiber improved cement-based supercapacitor. The specific operating steps are as follows:

[0006] 1) By mass percentage, 1-5% carbon fiber and 1-5% metal salt solution are mixed evenly, sintered at 400-550°C, kept at this temperature for 1-4 hours, and then cooled naturally with the furnace to obtain activated carbon fiber;

[0007] 2) The activated carbon fibers obtained in step 1) are thoroughly stirred with 50-70% cement, 1-5% aramid fibers, and 25-40% sucrose solution, and the mixture is uniformly mixed and then injected into a mold to form a cement-based electrolyte;

[0008] 3) Two electrodes were inserted parallely and vertically into both sides of the cement-based electrolyte obtained in step 2), placed on a vibration table to exhaust gas, placed in a curing box for 28 days, and demolded to obtain an activated carbon fiber modified cement-based supercapacitor.

[0009] Step 1) The carbon fiber is a non-adhesive carbon fiber with a diameter of 5-15 μm, a length of 1-9 mm, and a tensile strength of 3000-3500 MPa.

[0010] Step 1) The metal salt solution is Ba with a concentration of 0.05-1.0 mol / L 2+ 、Ni 2+ 、Mn 2+ 、Mo 6+ 、Li + , K + A salt solution.

[0011] Step 1) The temperature rise rate of the sintering process is 5-10°C / min.

[0012] Step 2) The cement is one of Portland cement, magnesium phosphate cement and magnesium oxysulfate cement.

[0013] Step 2) The aramid fibers are aramid 1313 fibers and aramid 1414 fibers with a diameter of 5-15 μm, a length of 1-9 mm, and a tensile strength of 3000-3100 MPa.

[0014] Step 2) The concentration of the sucrose solution is 0.001-0.005%.

[0015] Step 3) The electrode is one of copper mesh, aluminum mesh, nickel mesh, foam copper, foam aluminum or foam nickel.

[0016] Step 3) The curing conditions of the curing box are a temperature of 25±5°C and a relative humidity of 90±5%.

[0017] Compared with the existing technology, the beneficial effects of the present invention are: 1) The present invention uses carbon fiber with a very large aspect ratio to replace conventional lamellar carbon powder and expensive graphene. The carbon fiber is both a conductive phase and a toughening phase. Combined with an appropriate amount of sucrose solution and aramid fiber, it has good compression and impact resistance; 2) The carbon fiber and the metal salt solution are evenly mixed and then sintered. The active metal on the surface of the sintered carbon fiber is "reinforced" to effectively prevent its loss. A large number of pore structures appear on the surface of the sintered carbon fiber due to oxidation etching. The pore structure provides a place for ion conduction, improves the ion conductivity, and thus effectively improves the electrochemical performance of cement-based supercapacitors; 3) The raw materials used in the present invention are low in price and the preparation process is simple and easy, which broadens the prospects for the early realization of the practical application of "energy storage / building integration" for cement-based supercapacitors. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the process flow of the present invention DETAILED DESCRIPTION

[0019] A cement-based supercapacitor modified with activated carbon fiber is prepared using cement as the matrix material, a metal salt solution as the ionic phase, carbon fiber as the conductive phase, aramid fiber as the toughening phase, and sucrose solution as the binder. The specific operating steps are as follows:

[0020] 1) By mass percentage, 1-5% carbon fiber and 1-5% metal salt solution are mixed evenly, sintered at 400-550°C, kept at this temperature for 1-4 hours, and then cooled naturally with the furnace to obtain activated carbon fiber;

[0021] 2) The activated carbon fibers obtained in step 1) are thoroughly stirred with 50-70% cement, 1-5% aramid fibers, and 25-40% sucrose solution, and the mixture is uniformly mixed and then injected into a mold to form a cement-based electrolyte;

[0022] 3) Two electrodes were inserted parallely and vertically into both sides of the cement-based electrolyte obtained in step 2), placed on a vibration table to exhaust gas, placed in a curing box for 28 days, and demolded to obtain an activated carbon fiber modified cement-based supercapacitor.

[0023] In step 1), the carbon fiber is a non-adhesive carbon fiber with a diameter of 5-15 μm, a length of 1-9 mm, and a tensile strength of 3000-3500 MPa.

[0024] In step 1), the metal salt solution is Ba(III) with a concentration of 0.05-1.0 mol / L. 2+ 、Ni 2+ 、Mn 2+ 、Mo 6+ 、Li + , K+ A salt solution.

[0025] The temperature rise rate of the sintering process in step 1) is 5-10°C / min.

[0026] In step 2), the cement is one of silicate cement, magnesium phosphate cement and magnesium oxysulfate cement.

[0027] In step 2), the aramid fibers are aramid 1313 fibers and aramid 1414 fibers with a diameter of 5-15 μm, a length of 1-9 mm, and a tensile strength of 3000-3100 MPa.

[0028] The concentration of the sucrose solution in step 2) is 0.001-0.005%.

[0029] In step 3), the electrode is one of copper mesh, aluminum mesh, nickel mesh, foam copper, foam aluminum or foam nickel.

[0030] The curing conditions in the curing box in step 3) are a temperature of 25±5°C and a relative humidity of 90±5%.

[0031] The preparation method of the present invention will be further described below in conjunction with the embodiments:

[0032] Example 1

[0033] 2g of 10μm diameter and 3mm length of non-adhesive carbon fiber and 2g of 0.1mol / L Ba 2+ The solution was mixed evenly, sintered at 400°C, kept warm for 2 hours, and then naturally cooled with the furnace to obtain activated carbon fiber; the obtained activated carbon fiber was fully stirred with 65g of 42.5 silicate cement, 2g of aramid 1313 fiber with a diameter of 10μm and a length of 3mm, and 29g of sucrose solution with a concentration of 0.002%. After mixing evenly, the mixture was injected into a mold as a cement-based electrolyte; two copper mesh electrodes were inserted parallel and vertically into both sides of the cement-based electrolyte, placed on a vibration table to exhaust gas, placed in a curing box at 25°C and a relative humidity of 90% for 28 days, and demolded to obtain an activated carbon fiber improved cement-based supercapacitor.

[0034] The specific capacitance of the cement-based supercapacitor prepared in this example is 411.27 mF / cm 3 , the compressive strength is 39.21MPa and the impact residual strength is 9.62MPa.

[0035] Example 2

[0036] 2g of 12μm diameter and 6mm length of non-adhesive carbon fiber and 2g of 0.1mol / L Ba 2+The solution was mixed evenly, sintered at 400°C, kept warm for 2 hours, and then naturally cooled with the furnace to obtain activated carbon fiber; the obtained activated carbon fiber was fully stirred with 65g of 42.5 silicate cement, 2g of aramid 1313 fiber with a diameter of 12μm and a length of 6mm, and 29g of sucrose solution with a concentration of 0.003%. After mixing evenly, the mixture was injected into a mold as a cement-based electrolyte; two copper mesh electrodes were inserted parallel and vertically into both sides of the cement-based electrolyte, placed on a vibration table to exhaust gas, placed in a curing box at 25°C and a relative humidity of 90% for 28 days, and demolded to obtain an activated carbon fiber improved cement-based supercapacitor.

[0037] The specific capacitance of the cement-based supercapacitor prepared in this example is 396.88 mF / cm 3 , the compressive strength is 40.64MPa and the impact residual strength is 10.03MPa.

[0038] Example 3

[0039] 2g of 8μm diameter and 9mm length of non-adhesive carbon fiber and 2g of 0.1mol / L Ba 2+ The solution was mixed evenly, sintered at 400°C, kept warm for 2 hours, and then naturally cooled with the furnace to obtain activated carbon fiber; the obtained activated carbon fiber was fully stirred with 65g of 42.5 silicate cement, 2g of aramid 1313 fiber with a diameter of 8μm and a length of 9mm, and 29g of sucrose solution with a concentration of 0.001%. After mixing evenly, the mixture was injected into a mold as a cement-based electrolyte; two copper mesh electrodes were inserted parallel and vertically into both sides of the cement-based electrolyte, placed on a vibration table to exhaust gas, placed in a curing box at 25°C and a relative humidity of 90% for 28 days, and demolded to obtain an activated carbon fiber improved cement-based supercapacitor.

[0040] The specific capacitance of the cement-based supercapacitor prepared in this example is 420.71 mF / cm 3 , the compressive strength is 40.77MPa and the impact residual strength is 7.35MPa.

[0041] The above-described embodiments are only specific examples selected to illustrate the purpose, technical solutions and beneficial effects of the present invention in detail, but should not limit the scope of protection of the invention. All modifications, equivalent substitutions and improvements made without violating the spirit and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A cement-based supercapacitor improved by activated carbon fiber, characterized in that: Using cement as the matrix material, metal salt solution as the ionic phase, carbon fiber as the conductive phase, aramid fiber as the toughening phase, and sucrose solution as the binder, an activated carbon fiber-modified cement-based supercapacitor was prepared. The specific steps are as follows: 1) By mass percentage, 1-5% carbon fiber and 1-5% metal salt solution are mixed evenly, sintered at 400-550°C, kept at this temperature for 1-4 hours, and then cooled naturally with the furnace to obtain activated carbon fiber; 2) The activated carbon fibers obtained in step 1) are thoroughly stirred with 50-70% cement, 1-5% aramid fibers, and 25-40% sucrose solution, and the mixture is uniformly mixed and then injected into a mold to form a cement-based electrolyte; 3) Two electrodes were inserted parallely and vertically into both sides of the cement-based electrolyte obtained in step 2), placed on a vibration table to exhaust gas, placed in a curing box for 28 days, and demolded to obtain an activated carbon fiber modified cement-based supercapacitor.

2. The cement-based supercapacitor improved by activated carbon fiber according to claim 1, characterized in that: The carbon fiber in step 1) is a non-adhesive carbon fiber with a diameter of 5-15 μm, a length of 1-9 mm, and a tensile strength of 3000-3500 MPa.

3. The cement-based supercapacitor improved by activated carbon fiber according to claim 1, characterized in that: In the step 1), the metal salt solution is Ba(III) with a concentration of 0.05-1.0 mol / L. 2+ 、Ni 2+ 、Mn 2+ 、Mo 6+ 、Li + , K + A salt solution.

4. The cement-based supercapacitor improved by activated carbon fiber according to claim 1, characterized in that: The temperature rise regime of the sintering process in step 1) is 5-10°C / min.

5. The cement-based supercapacitor improved with activated carbon fiber according to claim 1, characterized in that: The cement in step 2) is one of silicate cement, magnesium phosphate cement and magnesium oxysulfate cement.

6. The cement-based supercapacitor improved with activated carbon fiber according to claim 1, characterized in that: In the step 2), the aramid fibers are aramid 1313 fibers and aramid 1414 fibers with a diameter of 5-15 μm, a length of 1-9 mm, and a tensile strength of 3000-3100 MPa.

7. The cement-based supercapacitor improved with activated carbon fiber according to claim 1, characterized in that: The concentration of the sucrose solution in step 2) is 0.001-0.005%.

8. The cement-based supercapacitor improved with activated carbon fiber according to claim 1, characterized in that: In the step 3), the electrode is one of copper mesh, aluminum mesh, nickel mesh, foam copper, foam aluminum or foam nickel.

9. The cement-based supercapacitor improved with activated carbon fiber according to claim 1, characterized in that: The curing conditions of the curing box in step 3) are a temperature of 25±5° C. and a relative humidity of 90±5%.

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