An activated carbon electrode material for supercapacitors and its preparation process

Abstract

The application relates to an activated carbon electrode material for a super capacitor and a preparation process thereof, and belongs to the technical field of activated carbon electrode materials. The preparation process specifically comprises the following steps: mixing sucrose, ammonium dihydrogen phosphate, deionized water and zinc gluconate, performing 80 DEG C spray drying to obtain a precursor powder with a loose structure, performing carbonization, then performing pulse activation, water vapor hole expansion, cooling, post-treatment, mixing a composite material obtained in the step of post-treatment with carbon nanofibers, a PTFE binder and anhydrous ethanol, performing ball milling, standing and defoaming, coating an aluminum foil with slurry obtained in the step of standing and defoaming, drying, roll pressing, hot pressing and forming, and the like. In the application, sucrose is used as a carbon source, and zinc gluconate is introduced to assist in forming a honeycomb-shaped pore framework. With the further increase of the carbonization temperature and the multiple cycle pulse activation and water vapor hole expansion processes, a honeycomb-shaped porous structure is formed, so that the ion transmission efficiency is improved, the loss of the specific capacitance value under a high current density is reduced, and the capacitance performance of the material is improved.

Description

Technical Field

[0001] This invention belongs to the field of activated carbon electrode material technology, and relates to an activated carbon electrode material for supercapacitors and its preparation process. Background Technology

[0002] Supercapacitors are energy storage devices that fall between traditional capacitors and batteries. Their core function is to efficiently store and release energy in a short period of time, making them suitable for scenarios requiring rapid charging and discharging and high power output. They are widely used in hybrid vehicles, smart electronic products, and many other fields. The electrode material of a supercapacitor is a key factor determining its performance. Activated carbon, due to its low cost, large specific surface area, well-developed pores, and ease of preparation, has become the most widely used double-layer electrode material in supercapacitors. However, activated carbon electrode materials also have significant limitations in use. For example, the large specific surface area of ​​activated carbon results in mostly micropores, making it difficult for electrolyte ions to enter. Furthermore, activated carbon has relatively high resistance, leading to a significant decrease in specific capacitance at high current densities, which in turn affects the high-current discharge capability and the lifespan of the supercapacitor. These issues require further solutions. Summary of the Invention

[0003] The purpose of this invention is to provide an activated carbon electrode material for supercapacitors and its preparation process. This invention uses sucrose as a carbon source and introduces zinc gluconate to assist in forming a honeycomb-like porous framework. With further increases in carbonization temperature and multiple cycles of pulse activation and water vapor pore expansion processes, a honeycomb-like porous structure is formed, thereby improving ion transport efficiency, reducing the loss of specific capacitance under high current density, and improving the capacitance performance of the material.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A process for preparing activated carbon electrode material for supercapacitors, the process comprising the following steps:

[0006] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0007] Step 2: After carbonizing the precursor powder with a loose structure, pulse activation, water vapor pore expansion, cooling, and post-treatment are performed to obtain the composite material.

[0008] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0009] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0010] Furthermore, the mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water, and zinc gluconate in step one is 1-1.2:0.2-0.3:10-12:0.15-0.25.

[0011] Furthermore, the mixing described in step one refers to stirring at 80-160 rpm for 30-40 minutes in a 60°C water bath.

[0012] Furthermore, the carbonization described in step two refers to heating to 240-280℃ at a heating rate of 4-6℃ / min under a nitrogen atmosphere, holding at that temperature for 25-35min, and then heating to 640-660℃ at a heating rate of 8-12℃ / min, holding at that temperature for 0.8-1.2h.

[0013] Furthermore, the pulse activation described in step two refers to first heating to 760-800℃ at a heating rate of 18-22℃ / min, holding at that temperature for 8-12 minutes, then cooling to 680-720℃ and holding at that temperature for 25-35 minutes, and repeating this heating-holding-cooling-holding operation twice.

[0014] Furthermore, the steam pore expansion in step two refers to heating the temperature to 760-780℃ at 1-2℃, then introducing steam at a flow rate of 55-65mL / min for 13-15min.

[0015] Furthermore, the post-treatment described in step two refers to washing with 0.1 mol / L HCl at room temperature for 20 min, rinsing with deionized water until neutral, and then vacuum drying at 80°C.

[0016] Furthermore, the mass ratio of the composite material, carbon nanofiber, PTFE binder, and anhydrous ethanol in step three is 2.5-2.9:0.4-0.8:2.2-2.6:3.6-4.2.

[0017] Furthermore, the ball milling mentioned in step three refers to ball milling at a speed of 120-160 rpm for 2.1-2.3 hours.

[0018] Further, in step four, the amount of slurry coated is 1.4-1.8 mg; the aluminum foil has a size of 1 cm × 1 cm; the drying refers to drying in an oven at 60°C for 10 min; the rolling temperature is 80°C; and the hot pressing refers to hot pressing at 120°C and 10 MPa for 5 min.

[0019] The beneficial effects of this invention are:

[0020] (1) This invention uses sucrose as a carbon source and introduces zinc gluconate. By spray drying at 80°C, a precursor powder with a loose structure is formed to prevent premature decomposition of zinc gluconate, which is beneficial to subsequent activation. When zinc gluconate reaches the first carbonization temperature, zinc oxide particles and gas are initially generated, which helps to form a honeycomb pore framework. With the further increase of carbonization temperature and multiple cycles of pulse activation and water vapor pore expansion process, a honeycomb porous structure is formed, thereby improving ion transport efficiency, reducing the loss of specific capacitance value under high current density, and improving the capacitance performance of the material. On this basis, this invention further introduces carbon nanofibers to construct a conductive network, which makes up for the insufficient conductivity of activated carbon and reduces the limitation of internal resistance on power output.

[0021] (2) In this invention, zinc gluconate generates zinc oxide particles and gas at high temperature, wherein zinc oxide exists as a pore-expanding template and is removed in the subsequent acid washing step to further expand the pores; in addition, zinc gluconate may have zinc residue under high temperature treatment, resulting in a zinc-doped carbon skeleton, which enhances the electronic conductivity and synergistically improves the capacitance performance of the material. Detailed Implementation

[0022] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0023] Zinc gluconate in all embodiments and comparative examples of this invention was purchased from Hubei Shiteng Chemical Technology Co., Ltd., CAS No. 4468-02-4; carbon nanofibers were purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd., CAS No. 308068-56-6.

[0024] Example 1

[0025] A process for preparing activated carbon electrode material for supercapacitors, the process comprising the following steps:

[0026] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0027] Step 2: After carbonizing the precursor powder with a loose structure, pulse activation, water vapor pore expansion, cooling, and post-treatment are performed to obtain the composite material.

[0028] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0029] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0030] The mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water, and zinc gluconate in step one is 1:0.2:10:0.15.

[0031] The mixing described in step one refers to stirring at 80 rpm for 30 minutes in a 60°C water bath.

[0032] The carbonization described in step two refers to heating to 240°C at a heating rate of 4°C / min under a nitrogen atmosphere, holding at that temperature for 25 min, and then heating to 640°C at a heating rate of 8°C / min and holding at that temperature for 0.8 h.

[0033] The pulse activation described in step two refers to first heating the temperature to 760°C at a rate of 18°C / min, holding it at that temperature for 8 minutes, then cooling it down to 680°C and holding it for 25 minutes. This heating-holding-cooling-holding operation is repeated twice.

[0034] The water vapor pore expansion mentioned in step two refers to heating the temperature to 760°C by 1°C, then introducing water vapor at a flow rate of 55 mL / min for 13 min.

[0035] The post-treatment described in step two refers to washing with 0.1 mol / L HCl at room temperature for 20 min, rinsing with deionized water until neutral, and then vacuum drying at 80°C.

[0036] The mass ratio of the composite material, carbon nanofibers, PTFE binder, and anhydrous ethanol in step three is 2.5:0.4:2.2:3.6.

[0037] The ball milling mentioned in step three refers to ball milling at a speed of 120 rpm for 2.1 hours.

[0038] The amount of slurry coated in step four is 1.4 mg; the size of the aluminum foil is 1 cm × 1 cm; the drying refers to drying in an oven at 60°C for 10 min; the rolling temperature is 80°C; the hot pressing refers to hot pressing at 120°C and 10 MPa for 5 min.

[0039] Example 2

[0040] A process for preparing activated carbon electrode material for supercapacitors, the process comprising the following steps:

[0041] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0042] Step 2: After carbonizing the precursor powder with a loose structure, pulse activation, water vapor pore expansion, cooling, and post-treatment are performed to obtain the composite material.

[0043] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0044] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0045] The mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water, and zinc gluconate in step one is 1.06:0.23:10.5:0.18.

[0046] The mixing described in step one refers to stirring at 100 rpm for 31 minutes in a 60°C water bath.

[0047] The carbonization described in step two refers to heating to 250°C at a heating rate of 4.5°C / min under a nitrogen atmosphere, holding at that temperature for 28 min, and then heating to 645°C at a heating rate of 9°C / min and holding at that temperature for 0.9 h.

[0048] The pulse activation described in step two refers to first heating the temperature to 770℃ at a heating rate of 19℃ / min, holding it at that temperature for 9 minutes, then cooling it down to 690℃ and holding it at that temperature for 27 minutes, and repeating this heating-holding-cooling-holding operation twice.

[0049] The water vapor pore expansion step two refers to heating the temperature to 765°C by 1°C, then introducing water vapor at a flow rate of 58 mL / min for 13 min.

[0050] The post-treatment described in step two refers to washing with 0.1 mol / L HCl at room temperature for 20 min, rinsing with deionized water until neutral, and then vacuum drying at 80°C.

[0051] The mass ratio of the composite material, carbon nanofibers, PTFE binder, and anhydrous ethanol in step three is 2.6:0.5:2.3:3.8.

[0052] The ball milling mentioned in step three refers to ball milling at 130 rpm for 2.1 hours.

[0053] The amount of slurry coated in step four is 1.5 mg; the size of the aluminum foil is 1 cm × 1 cm; the drying refers to drying in an oven at 60°C for 10 min; the rolling temperature is 80°C; the hot pressing refers to hot pressing at 120°C and 10 MPa for 5 min.

[0054] Example 3

[0055] A process for preparing activated carbon electrode material for supercapacitors, the process comprising the following steps:

[0056] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0057] Step 2: After carbonizing the precursor powder with a loose structure, pulse activation, water vapor pore expansion, cooling, and post-treatment are performed to obtain the composite material.

[0058] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0059] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0060] The mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water, and zinc gluconate in step one is 1.1:0.5:11:0.2.

[0061] The mixing described in step one refers to stirring at 100 rpm for 35 minutes in a 60°C water bath.

[0062] The carbonization described in step two refers to heating to 260°C at a heating rate of 5°C / min under a nitrogen atmosphere, holding at that temperature for 30 min, and then heating to 650°C at a heating rate of 10°C / min and holding at that temperature for 1 h.

[0063] The pulse activation described in step two refers to first heating the temperature to 780℃ at a heating rate of 20℃ / min, holding it at that temperature for 10 minutes, then cooling it down to 700℃ and holding it at that temperature for 30 minutes. This heating-holding-cooling-holding operation is repeated twice.

[0064] Step 2, which involves expanding the pores with steam, means heating the temperature to 770°C at 1.5°C, then introducing steam at a flow rate of 60 mL / min for 14 minutes.

[0065] The post-treatment described in step two refers to washing with 0.1 mol / L HCl at room temperature for 20 min, rinsing with deionized water until neutral, and then vacuum drying at 80°C.

[0066] The mass ratio of the composite material, carbon nanofibers, PTFE binder, and anhydrous ethanol in step three is 2.7:0.6:2.4:3.9.

[0067] The ball milling mentioned in step three refers to ball milling at a speed of 140 rpm for 2.2 hours.

[0068] The amount of slurry coated in step four is 1.6 mg; the size of the aluminum foil is 1 cm × 1 cm; the drying refers to drying in an oven at 60°C for 10 min; the rolling temperature is 80°C; the hot pressing refers to hot pressing at 120°C and 10 MPa for 5 min.

[0069] Example 4

[0070] A process for preparing activated carbon electrode material for supercapacitors, the process comprising the following steps:

[0071] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0072] Step 2: After carbonizing the precursor powder with a loose structure, pulse activation, water vapor pore expansion, cooling, and post-treatment are performed to obtain the composite material.

[0073] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0074] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0075] The mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water, and zinc gluconate in step one is 1.13:0.27:11.4:0.22.

[0076] The mixing described in step one refers to stirring at 140 rpm for 38 minutes in a 60°C water bath.

[0077] The carbonization described in step two refers to heating to 270°C at a heating rate of 5.5°C / min under a nitrogen atmosphere, holding at that temperature for 32 min, and then heating to 655°C at a heating rate of 11°C / min and holding at that temperature for 1.1 h.

[0078] The pulse activation described in step two refers to first heating the temperature to 790℃ at a heating rate of 21℃ / min, holding it at that temperature for 11 minutes, then cooling it down to 710℃ and holding it for 33 minutes. This heating-holding-cooling-holding operation is repeated twice.

[0079] Step 2, which involves expanding the pores with steam, means heating the temperature to 775°C by 2°C, then introducing steam at a flow rate of 63 mL / min for 15 minutes.

[0080] The post-treatment described in step two refers to washing with 0.1 mol / L HCl at room temperature for 20 min, rinsing with deionized water until neutral, and then vacuum drying at 80°C.

[0081] The mass ratio of the composite material, carbon nanofibers, PTFE binder, and anhydrous ethanol in step three is 2.8:0.7:2.5:4.

[0082] The ball milling mentioned in step three refers to ball milling at 150 rpm for 2.3 hours.

[0083] The amount of slurry coated in step four is 1.7 mg; the size of the aluminum foil is 1 cm × 1 cm; the drying refers to drying in an oven at 60°C for 10 min; the rolling temperature is 80°C; the hot pressing refers to hot pressing at 120°C and 10 MPa for 5 min.

[0084] Example 5

[0085] A process for preparing activated carbon electrode material for supercapacitors, the process comprising the following steps:

[0086] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0087] Step 2: After carbonizing the precursor powder with a loose structure, pulse activation, water vapor pore expansion, cooling, and post-treatment are performed to obtain the composite material.

[0088] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0089] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0090] The mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water, and zinc gluconate in step one is 1.2:0.3:12:0.25.

[0091] The mixing described in step one refers to stirring at 160 rpm for 40 minutes in a 60°C water bath.

[0092] The carbonization described in step two refers to heating to 280°C at a heating rate of 6°C / min under a nitrogen atmosphere, holding at that temperature for 35 min, and then heating to 660°C at a heating rate of 12°C / min and holding at that temperature for 1.2 h.

[0093] The pulse activation described in step two refers to first heating the temperature to 800℃ at a heating rate of 22℃ / min, holding it at that temperature for 12 minutes, then cooling it down to 720℃ and holding it at that temperature for 35 minutes. This heating-holding-cooling-holding operation is repeated twice.

[0094] Step 2, which involves expanding the pores with steam, means heating the temperature to 780°C by 2°C, then introducing steam at a flow rate of 65 mL / min for 15 minutes.

[0095] The post-treatment described in step two refers to washing with 0.1 mol / L HCl at room temperature for 20 min, rinsing with deionized water until neutral, and then vacuum drying at 80°C.

[0096] The mass ratio of the composite material, carbon nanofibers, PTFE binder, and anhydrous ethanol in step three is 2.9:0.8:2.6:4.2.

[0097] The ball milling mentioned in step three refers to ball milling at 160 rpm for 2.3 hours.

[0098] The amount of slurry coated in step four is 1.8 mg; the size of the aluminum foil is 1 cm × 1 cm; the drying refers to drying in an oven at 60°C for 10 min; the rolling temperature is 80°C; the hot pressing refers to hot pressing at 120°C and 10 MPa for 5 min.

[0099] Example 6

[0100] Based on Example 3, zinc gluconate was removed and replaced with an equal weight of ammonium citrate, while other conditions remained the same as in Example 3.

[0101] Example 7

[0102] Based on Example 3, the mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water, and zinc gluconate in step one was changed to 1.1:0.6:11:0.1.

[0103] Example 8

[0104] Based on Example 3, the mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water, and zinc gluconate in step one is 1.2:0.5:11:0.1.

[0105] Example 9

[0106] Based on Example 3, the mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water, and zinc gluconate in step one is 1.3:0.3:11:0.2.

[0107] Example 10

[0108] Based on Example 3, the mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water, and zinc gluconate in step one is 0.9:0.3:11.55:0.05.

[0109] Example 11

[0110] Based on Example 3, the mass ratio of the composite material, carbon nanofibers, PTFE binder, and anhydrous ethanol described in step three was changed to 2.4:0.9:2.4:3.9.

[0111] Example 12

[0112] Based on Example 3, the mass ratio of the composite material, carbon nanofibers, PTFE binder, and anhydrous ethanol described in step three was changed to 2.9:0.4:2.4:3.9.

[0113] Comparative Example 1

[0114] Based on Example 3, while keeping other conditions the same, the preparation process was changed to the following steps:

[0115] Step 1: After mixing sucrose, ammonium dihydrogen phosphate, and deionized water evenly, add zinc gluconate and mix at 80°C to obtain a mixture;

[0116] Step 2: After carbonizing the mixture, pulse activation, steam pore expansion, cooling, and post-treatment are performed to obtain the composite material.

[0117] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0118] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0119] Comparative Example 2

[0120] Based on Example 3, while keeping other conditions the same, the preparation process was changed to the following steps:

[0121] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0122] Step 2: After carbonizing the precursor powder with a loose structure, pulse activation, water vapor pore expansion, cooling, and post-treatment are performed to obtain the composite material; the carbonization refers to heating to 650℃ at a heating rate of 5℃ / min under a nitrogen atmosphere and holding at that temperature for 1.5h.

[0123] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0124] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0125] Comparative Example 3

[0126] Based on Example 3, while keeping other conditions the same, the preparation process was changed to the following steps:

[0127] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0128] Step 2: After carbonizing the precursor powder with a loose structure, pulse activation, water vapor pore expansion, cooling, and post-treatment are performed to obtain the composite material; the carbonization refers to heating to 650℃ at a heating rate of 10℃ / min under a nitrogen atmosphere and holding at that temperature for 1.5h.

[0129] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0130] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0131] Comparative Example 4

[0132] Based on Example 3, while keeping other conditions the same, the preparation process was changed to the following steps:

[0133] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0134] Step 2: Carbonize and activate the precursor powder with a loose structure, expand the pores with water vapor, cool, and post-process to obtain the composite material; the activation refers to heating to 780℃ at a heating rate of 20℃ / mind and holding at that temperature for 80min.

[0135] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0136] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0137] Comparative Example 5

[0138] Based on Example 3, while keeping other conditions the same, the preparation process was changed to the following steps:

[0139] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0140] Step 2: After carbonizing the precursor powder with a loose structure, pulse activation is performed, followed by steam pore expansion, cooling, and post-treatment to obtain the composite material. The pulse activation refers to heating to 780°C at a heating rate of 20°C / min, holding at that temperature for 20 min, and then cooling to 700°C and holding at that temperature for 60 min.

[0141] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0142] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0143] Comparative Example 6

[0144] Based on Example 3, while keeping other conditions the same, the preparation process was changed to the following steps:

[0145] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0146] Step 2: After carbonizing the precursor powder with a loose structure, pulse activation, cooling, and post-treatment are performed to obtain the composite material.

[0147] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0148] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0149] Comparative Example 7

[0150] Based on Example 3, while keeping other conditions the same, the preparation process was changed to the following steps:

[0151] Step 1: After stirring sucrose, ammonium dihydrogen phosphate and deionized water evenly, add zinc gluconate, mix, and spray dry at 80°C to obtain a precursor powder with a loose structure.

[0152] Step 2: The precursor powder with a loose structure is heated to 650℃ at a heating rate of 10℃ / min, held for 1.5h, then heated to 780℃ at a heating rate of 20℃ / min, held for 20min, then cooled to 700℃, held for 60min, then heated to 770℃ at a heating rate of 1.5℃, and then steam is introduced at a flow rate of 60mL / min for 14min. After cooling and post-treatment, the composite material is obtained.

[0153] Step 3: After mixing the composite material, carbon nanofibers, and PTFE binder evenly, add anhydrous ethanol, ball mill, and allow to stand to remove bubbles to obtain a slurry;

[0154] Step 4: Coat the slurry with aluminum foil, dry, roll, and hot press to form the final product.

[0155] Using the activated carbon electrode materials prepared in Examples 1-12 and Comparative Examples 1-7 as samples, the capacitance value of the samples at a current density of 1 A / g was tested in 6M KOH solution using constant current charge-discharge. The specific results are recorded in Table 1 below.

[0156] Table 1

[0157]

[0158] As shown in Table 1, the activated carbon electrode material for supercapacitors prepared by this invention can effectively improve ion transport efficiency, thereby improving the capacitance performance of the material.

[0159] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any indirect modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A process for the preparation of activated carbon electrode material for supercapacitors, characterized in that: The preparation process comprises the following steps: Step one, after stirring uniformly of sucrose, ammonium dihydrogen phosphate, deionized water, zinc gluconate is added, mixed, 80℃ spray drying to obtain a precursor powder with loose structure; Step two, the precursor powder with loose structure is carbonized, then pulsed activated, water vapor hole expansion, cooling, post-processing to obtain a composite material; Step three, after mixing uniformly of the composite material, carbon nanofiber, PTFE binder, add anhydrous ethanol, ball milling, standing and defoaming to obtain a slurry; Step four, the slurry is coated on aluminum foil, dried, rolled, hot pressed into a shape, and the product is obtained; In step two, the carbonization refers to heating at a rate of 4-6℃ / min to 240-280℃, holding for 25-35min, then heating at a rate of 8-12℃ / min to 640-660℃, holding for 0.8-1.2h under nitrogen atmosphere; In step two, the pulsed activation refers to heating at a rate of 18-22℃ / min to 760-800℃, holding for 8-12min, then cooling to 680-720℃, holding for 25-35min, and repeating the heating-holding-cooling-holding operation for 2 times; In step two, the water vapor hole expansion refers to heating at a rate of 1-2℃ to 760-780℃, then passing water vapor at a flow rate of 55-65mL / min for 13-15min.

2. The process for the preparation of activated carbon electrode material for supercapacitor as claimed in claim 1 wherein: In step one, the mass ratio of sucrose, ammonium dihydrogen phosphate, deionized water and zinc gluconate is 1-1.2:0.2-0.3:10-12:0.15-0.

25.

3. The process for the preparation of activated carbon electrode material for supercapacitor as claimed in claim 1 wherein: In step one, the mixing refers to stirring at a speed of 80-160rpm for 30-40min under 60℃ water bath.

4. The process for preparing activated carbon electrode material for supercapacitor as claimed in claim 1 wherein: In step two, the post-processing refers to washing with 0.1mol / L HCl at room temperature for 20min, then washing with deionized water until neutral, and vacuum drying at 80℃.

5. The process for the preparation of activated carbon electrode material for supercapacitor as claimed in claim 1 wherein: In step three, the mass ratio of the composite material, carbon nanofiber, PTFE binder and anhydrous ethanol is 2.5-2.9:0.4-0.8:2.2-2.6:3.6-4.

2.

6. The process for preparing activated carbon electrode material for supercapacitor as claimed in claim 1 wherein: In step three, the ball milling refers to ball milling at a speed of 120-160rpm for 2.1-2.3h.

7. The process as claimed in claim 1, wherein the process for the preparation of activated carbon electrode material for supercapacitor is characterized by: In step four, the coating amount of the slurry is 1.4-1.8mg; the size of the aluminum foil is 1cm×1cm; the drying refers to drying in an oven at 60℃ for 10min; the rolling temperature is 80℃; the hot pressing refers to hot pressing at 120℃ and 10MPa for 5min.

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