Preparation method of oxygen-containing functional group modified activated carbon material and application of oxygen-containing functional group modified activated carbon material as ammonium ion battery electrode material
By generating oxygen-containing functional groups on the surface of activated carbon, the problem of poor pore connectivity of carbon materials in ammonium ion batteries is solved, the ion transmission path is optimized, and the electrochemical performance and material utilization of electrode materials are improved.
Patent Information
- Application Number
- CN202510664782.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-22
- Publication Date
- 2025-08-15
AI Technical Summary
In ammonium ion batteries, existing carbon materials have poor channel connectivity, low specific surface area and few active sites, resulting in low battery capacity and poor rate performance.
A large number of oxygen-containing functional groups are generated on the surface of activated carbon, increasing hydrogen bonding sites, optimizing the ion transport path and improving the ion diffusion rate. The activated carbon is treated with strong oxidation solutions of concentrated sulfuric acid, concentrated nitric acid and potassium permanganate to form oxygen-containing functional groups such as carbonyl and carboxyl groups.
It improves the electrochemical performance of the electrode material, increases hydrogen bonding sites, provides rich ammonium ion storage sites and spacious ion diffusion pathways, and improves the utilization rate of the material.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of novel electrode materials and can be applied to the field of ammonium ion battery electrodes. It specifically relates to a preparation method of an activated carbon material modified with oxygen-containing functional groups and its application as an ammonium ion battery electrode material. Background Art
[0002] In recent years, aqueous non-metallic ion batteries, which use non-metallic ions as charge carriers, have become a research hotspot due to their advantages such as high safety, low cost, and fast charging. Among them, ammonium ion batteries have rapidly developed in aqueous energy storage systems due to their abundant resources and small hydrated ion radius. However, the development of aqueous ammonium ion battery electrode materials with excellent conductivity, good ammonium ion storage performance, and ultrafast reaction kinetics is still in the exploratory stage. Carbon materials are considered to be one of the most promising electrode materials due to their low cost, long cycle life, and excellent chemical stability. However, pure carbon materials have poor pore connectivity, low specific surface area, and relatively few active sites, resulting in low capacity and poor rate performance of assembled batteries. Therefore, developing an activated carbon material modified with oxygen-containing functional groups to increase the number of hydrogen bonding sites on the activated carbon surface, thereby optimizing ion transport pathways and increasing ion diffusion rates, and enhancing the reaction kinetics of the electrode material, will greatly promote the practical application of this material in the field of energy storage. Summary of the Invention
[0003] The purpose of the present invention is to provide a method for preparing an activated carbon material modified with oxygen-containing functional groups and its application as an electrode material for ammonium ion batteries. The present invention generates a large number of oxygen-containing functional groups on the surface of the activated carbon, increases the binding sites for the activated carbon to form hydrogen bonds with ammonium ions, thereby optimizing the ion transmission path and increasing the ion diffusion rate, thereby improving the electrochemical performance of the electrode material.
[0004] The technical solution adopted in the present invention is:
[0005] An activated carbon material modified with oxygen-containing functional groups is obtained by oxidizing the activated carbon with a strong oxidizing solution of concentrated nitric acid, concentrated sulfuric acid, and potassium permanganate. In this strong oxidizing system, the C atoms of the activated carbon and some of the previously formed hydroxyl groups (-OH) can be oxidized into carbonyl groups (C=O) and carboxyl groups (OC=O), generating a large number of oxygen-containing functional groups on the surface of the activated carbon. The activated carbon material is then washed, filtered, and vacuum dried to obtain an activated carbon material modified with carbonyl@carboxyl@hydroxyloxy functional groups.
[0006] The preparation method of the above-mentioned activated carbon material modified with oxygen-containing functional groups comprises the following steps:
[0007] 1) Add activated carbon powder to concentrated sulfuric acid and stir thoroughly;
[0008] 2) slowly adding concentrated nitric acid to the solution obtained in step 1) under continuous stirring;
[0009] 3) adding potassium permanganate to the solution obtained in step 2) and stirring to obtain a mixed solution;
[0010] 4) The mixed solution obtained in step 3) is washed with anhydrous ethanol and deionized water and filtered, and the collected gray-black precipitate is vacuum-dried to obtain an activated carbon material modified with oxygen-containing functional groups.
[0011] Furthermore, in the above preparation method, in step 1), according to the solid-liquid ratio, activated carbon powder: concentrated sulfuric acid = 1g: 15-20mL.
[0012] Furthermore, in the above preparation method, according to the solid-liquid ratio, activated carbon powder: concentrated nitric acid = 1g: 10-15mL.
[0013] Furthermore, in the above preparation method, the mass ratio of activated carbon powder to potassium permanganate is 1:3.
[0014] Furthermore, in the above preparation method, in step 3), the stirring treatment time is 0-5h.
[0015] Furthermore, in the above preparation method, in step 4), the vacuum drying condition is: vacuum drying at 60° C. for 24 hours.
[0016] Application of the above-mentioned activated carbon material modified with oxygen-containing functional groups as an electrode material for ammonium ion batteries.
[0017] Furthermore, the above application method is as follows: the activated carbon material modified with oxygen-containing functional groups is mixed with polyvinylidene fluoride, superconducting carbon black and N-methylpyrrolidone, and after sufficient grinding, it is evenly coated on the surface of the carbon cloth current collector material to obtain an electrode material.
[0018] Furthermore, in the above application, the mass ratio of activated carbon material modified with oxygen-containing functional groups: polyvinylidene fluoride: superconducting carbon black is 8:1:1.
[0019] The beneficial effects of the present invention are as follows: the surface of the activated carbon material modified with oxygen-containing functional groups provided by the present invention has increased hydrogen bonding sites, which can achieve highly reversible insertion and extraction of ammonium ions, provide abundant ammonium ion storage sites and spacious ion diffusion pathways, and improve the utilization rate of the material. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is the cyclic voltammetry curve of the OAC-0.5 material prepared in Example 1.
[0021] Figure 2 The charge-discharge curves (a) and specific capacitance curves (b) of the OAC-0.5 material prepared in Example 1 at different current densities.
[0022] Figure 3 This is the cyclic voltammetry curve of the OAC-1 material prepared in Example 2.
[0023] Figure 4 The charge-discharge curves (a) and specific capacitance curves (b) of the OAC-1 material prepared in Example 2 at different current densities.
[0024] Figure 5 This is the cyclic voltammetry curve of the OAC-2.5 material prepared in Example 3.
[0025] Figure 6 The charge-discharge curves (a) and specific capacitance curves (b) of the OAC-2.5 material prepared in Example 3 at different current densities.
[0026] Figure 7 2. The charge and discharge curves of the OAC-2.5@OAC-2.5 symmetrical battery prepared in Example 3 at different current densities.
[0027] Figure 8 This is the cyclic voltammetry curve of the OAC-5 material prepared in Example 4.
[0028] Figure 9 The charge-discharge curves (a) and specific capacitance curves (b) of the OAC-5 material prepared in Example 4 at different current densities. DETAILED DESCRIPTION
[0029] Example 1
[0030] (1) The preparation method of activated carbon material modified with oxygen-containing functional groups is as follows:
[0031] 1) Place 1g of commercial activated carbon powder in a beaker, slowly add 15mL of concentrated sulfuric acid to the beaker and stir thoroughly to obtain a uniformly dispersed suspension.
[0032] 2) Add 10 mL of concentrated nitric acid to the suspension obtained in step 1) and stir thoroughly to obtain a gray-black suspension.
[0033] 3) Add 3 g of potassium permanganate to the suspension obtained in step 2) and stir for 30 min. After the reaction is complete, cool to room temperature.
[0034] 4) washing with anhydrous ethanol and deionized water, filtering and collecting the gray-black precipitate, and then vacuum drying at 60° C. for 24 h to obtain an activated carbon material modified with oxygen-containing functional groups (OAC-0.5).
[0035] (2) Application
[0036] 1. Preparation of electrode materials: 2 mg of OAC-0.5 material was thoroughly ground with 0.25 mg of polyvinylidene fluoride and 0.25 mg of superconducting carbon black, and then 0.0125 mL of N-methylpyrrolidone was added. After further grinding, the resulting slurry was evenly applied to the surface of the carbon cloth current collector to obtain the electrode material.
[0037] 2. Electrochemical analysis results:
[0038] Methods: At room temperature and pressure, using carbon cloth current collector electrode material coated with OAC-0.5 material as the working electrode, graphite foil as the counter electrode, saturated calomel electrode as the reference electrode, 2.5M NH4Cl as the electrolyte, and cyclic voltammetry sweep test and constant current charge-discharge test of OAC-0.5 electrode material in the potential range of -1 to 1V (vs.SCE) were carried out to study its specific capacitance and energy storage rate performance.
[0039] Figure 1 The OAC-0.5 electrode material prepared in Example 1 was scanned at a rate of 20 mV s -1 The cyclic voltammogram under Figure 1 It can be seen that in 2.5M NH4Cl electrolyte, when the scan rate is 20mV s -1 The OAC-0.5 electrode material exhibits a much larger integrated area under the curve than the AC electrode material, confirming a significant enhancement in its specific capacitance. Furthermore, the redox peak from -1 to 1 V in the CV curve of OAC-0.5 is sharper, and the current density is higher, indicating that the OAC-0.5 electrode material has more electroactive sites and faster reaction kinetics.
[0040] Figure 2 The constant current charge-discharge curve (a) and specific capacitance curve (b) of the OAC-0.5 electrode material prepared in Example 1 are shown in FIG. Figure 2 It can be seen that when the current density is 1A g -1 Its specific capacitance can reach up to 149mAh g -1 When the current density increases from 1A g -1 Increased to 10A g -1 When the specific capacitance is 64% of the initial specific capacitance, it shows a better rate performance.
[0041] Example 2
[0042] (1) The preparation method of activated carbon material modified with oxygen-containing functional groups is as follows:
[0043] 1) Place 1g of commercial activated carbon powder in a beaker, slowly add 15mL of concentrated sulfuric acid to the beaker and stir thoroughly to obtain a uniformly dispersed suspension.
[0044] 2) Add 10 mL of concentrated nitric acid to the suspension obtained in step 1) and stir thoroughly to obtain a gray-black suspension.
[0045] 3) Add 3 g of potassium permanganate to the suspension obtained in step 2) and stir for 1 h. After the reaction is complete, cool to room temperature.
[0046] 4) washing with anhydrous ethanol and deionized water, filtering and collecting the gray-black precipitate, and then vacuum drying at 60° C. for 24 h to obtain an activated carbon material modified with oxygen-containing functional groups (OAC-1).
[0047] (2) Application
[0048] 1. Preparation of electrode materials: At room temperature and pressure, using a carbon cloth current collector electrode material coated with OAC-1 material as the working electrode, graphite foil as the counter electrode, a saturated calomel electrode as the reference electrode, and 2.5 M NH4Cl as the electrolyte, the OAC-1 electrode material was subjected to cyclic voltammetry and constant current charge-discharge tests in the potential range of -1 to 1 V (vs. SCE) to study its specific capacitance and energy storage rate performance.
[0049] 2. Electrochemical analysis results:
[0050] Methods: At room temperature and pressure, using carbon cloth current collector electrode material coated with OAC-1 material as the working electrode, graphite foil as the counter electrode, saturated calomel electrode as the reference electrode, 2.5M NH4Cl as the electrolyte, and cyclic voltammetry and constant current charge-discharge tests on the OAC-1 electrode material in the potential range of -1 to 1 V (vs. SCE) were carried out to study its specific capacitance and energy storage rate performance.
[0051] Figure 3 The OAC-1 electrode material prepared in Example 2 was scanned at a rate of 20 mV s -1 The cyclic voltammogram of Figure 3 It can be seen that in 2.5M NH4Cl electrolyte, when the scan rate is 20mV s -1 The OAC-1 electrode material exhibits a much larger integrated area under the curve than the AC electrode material, indicating a significant increase in specific capacitance. Furthermore, the OAC-1 CV curve exhibits a sharper redox peak from -1 to 1 V and a higher current density, indicating that the OAC-1 electrode material has more electroactive sites and faster reaction kinetics. Its integrated area under the curve, current density, and redox peak also increase compared to Example 1.
[0052] Figure 4 The constant current charge-discharge curve (a) and specific capacitance curve (b) of the OAC-1 electrode material prepared in Example 2 are shown in FIG. Figure 4 It can be seen that when the current density is 1A g -1Its specific capacitance can reach up to 185mAh g -1 , when the current density increases from 1Ag -1 Increased to 10A g -1 When the specific capacitance is 54% of the initial specific capacitance, it shows a better rate performance.
[0053] Example 3
[0054] (1) The preparation method of activated carbon material modified with oxygen-containing functional groups is as follows:
[0055] 1) Place 1g of commercial activated carbon powder in a beaker, slowly add 15mL of concentrated sulfuric acid to the beaker and stir thoroughly to obtain a uniformly dispersed suspension.
[0056] 2) Add 10 mL of concentrated nitric acid to the suspension obtained in step 1) and stir thoroughly to obtain a gray-black suspension.
[0057] 3) Add 3 g of potassium permanganate to the suspension obtained in step 2) and stir for 2.5 h. After the reaction is complete, cool to room temperature.
[0058] 4) washing with anhydrous ethanol and deionized water, filtering and collecting the gray-black precipitate, and then vacuum drying at 60° C. for 24 h to obtain an activated carbon material modified with oxygen-containing functional groups (OAC-2.5).
[0059] (2) Application
[0060] 1. Preparation of electrode materials: At room temperature and pressure, using a carbon cloth current collector electrode material coated with OAC-2.5 material as the working electrode, graphite foil as the counter electrode, a saturated calomel electrode as the reference electrode, and 2.5M NH4Cl as the electrolyte, the OAC-2.5 electrode material was subjected to cyclic voltammetry and constant current charge-discharge tests in the potential range of -1 to 1 V (vs. SCE) to study its specific capacitance and energy storage rate performance.
[0061] 2. Electrochemical analysis results:
[0062] Methods: At room temperature and pressure, using carbon cloth current collector electrode material coated with OAC-2.5 material as the working electrode, graphite foil as the counter electrode, saturated calomel electrode as the reference electrode, 2.5M NH4Cl as the electrolyte, and the potential range of -1 to 1V (vs. SCE), cyclic voltammetry sweep test and constant current charge-discharge test of the OAC-2.5 electrode material were carried out to study its specific capacitance and energy storage rate performance.
[0063] Figure 5 The OAC-2.5 electrode material prepared in Example 3 was scanned at a rate of 20 mV s -1 The cyclic voltammogram of Figure 5It can be seen that in 2.5M NH4Cl electrolyte, when the scan rate is 20mV s -1 The OAC-2.5 electrode material exhibits a much larger integrated area of the curve than the AC electrode material, confirming a significant enhancement in its specific capacitance. Its integrated area of the curve is higher than that of Examples 1 and 2. In contrast, the redox peak from -1 to 1 V in the CV curve of OAC-2.5 is sharper than that of Examples 1 and 2, and the current density is higher. This indicates that the OAC-2.5 electrode material has a significantly increased number of electroactive sites and a significantly improved reaction kinetics.
[0064] Figure 6 The constant current charge-discharge curve (a) and specific capacitance curve (b) of the OAC-2.5 electrode material prepared in Example 3 are shown in FIG. Figure 6 It can be seen that when the current density is 1A g -1 When the specific capacitance is as high as 321mAh g -1 When the current density increases from 1A g -1 Increased to 10Ag -1 When , the specific capacitance is 67% of the initial specific capacitance, showing the best rate performance.
[0065] Figure 7 The charge and discharge curves of the OAC-2.5@OAC-2.5 symmetrical battery prepared in Example 3 at different current densities are shown in Figure 3. Figure 7 It can be seen that when the current density is 1Ag -1 Its specific capacitance can reach up to 80.2mAh g -1 , showing excellent energy storage performance.
[0066] Example 4
[0067] (1) The preparation method of activated carbon material modified with oxygen-containing functional groups is as follows:
[0068] 1) Place 1g of commercial activated carbon powder in a beaker, slowly add 15mL of concentrated sulfuric acid to the beaker and stir thoroughly to obtain a uniformly dispersed suspension.
[0069] 2) Add 10 mL of concentrated nitric acid to the suspension obtained in step 1) and stir thoroughly to obtain a gray-black suspension.
[0070] 3) Add 3 g of potassium permanganate to the suspension obtained in step 2) and stir for 5 h. After the reaction is complete, cool to room temperature.
[0071] 4) washing with anhydrous ethanol and deionized water, filtering and collecting the gray-black precipitate, and then vacuum drying at 60° C. for 24 h to obtain an activated carbon material modified with oxygen-containing functional groups (OAC-5).
[0072] (2) Application
[0073] 1. Preparation of electrode materials: At room temperature and pressure, using a carbon cloth current collector electrode material coated with OAC-5 material as the working electrode, graphite foil as the counter electrode, a saturated calomel electrode as the reference electrode, and 2.5 M NH4Cl as the electrolyte, the OAC-5 electrode material was subjected to cyclic voltammetry and constant current charge-discharge tests in the potential range of -1 to 1 V (vs. SCE) to study its specific capacitance and energy storage rate performance.
[0074] 2. Electrochemical analysis results:
[0075] Methods: At room temperature and pressure, using carbon cloth current collector electrode material coated with OAC-5 material as working electrode, graphite foil as counter electrode, saturated calomel electrode as reference electrode, 2.5M NH4Cl as electrolyte, and potential range of -1 to 1V (vs. SCE), cyclic voltammetry sweep test and constant current charge-discharge test of OAC-5 electrode material were carried out to study its specific capacitance and energy storage rate performance.
[0076] Figure 8 The OAC-5 electrode material prepared in Example 4 was scanned at a rate of 20 mV s -1 The cyclic voltammogram of Figure 8 It can be seen that in 2.5M NH4Cl electrolyte, when the scan rate is 20mV s -1 When , the OAC-5 electrode material shows a much larger curve integral area than the AC electrode material, confirming that its specific capacitance has been greatly enhanced, but its curve integral area is smaller than that of Example 3, and the current density from -1 to 1 V in the CV curve of OAC-5 is lower than that of Example 3.
[0077] Figure 9 The constant current charge-discharge curve (a) and specific capacitance curve (b) of the OAC-5 electrode material prepared in Example 4 are shown in FIG. Figure 9 It can be seen that when the current density is 1Ag -1 When the specific capacitance is as high as 222mAh g -1 When the current density increases from 1A g -1 Increased to 10Ag -1 When the specific capacitance is 44% of the initial specific capacitance, it shows a better rate performance.
Claims
1. An activated carbon material modified with oxygen-containing functional groups, characterized in that: The activated carbon material modified with oxygen-containing functional groups is obtained by oxidizing the activated carbon with a strong oxidizing solution of concentrated nitric acid, concentrated sulfuric acid and potassium permanganate, and then washing, filtering and vacuum drying to obtain the activated carbon material modified with carbonyl, carboxyl and hydroxyl oxygen functional groups.
2. The method for preparing an activated carbon material modified with an oxygen-containing functional group according to claim 1, wherein: The steps include: 1) Add activated carbon powder to concentrated sulfuric acid and stir thoroughly; 2) slowly adding concentrated nitric acid to the solution obtained in step 1) under continuous stirring; 3) adding potassium permanganate to the solution obtained in step 2) and stirring to obtain a mixed solution; 4) The mixed solution obtained in step 3) is washed with anhydrous ethanol and deionized water and filtered, and the collected gray-black precipitate is vacuum-dried to obtain an activated carbon material modified with oxygen-containing functional groups.
3. The preparation method according to claim 2, characterized in that In step 1), according to the solid-liquid ratio, activated carbon powder: concentrated sulfuric acid = 1g: 15-20mL.
4. The preparation method according to claim 3, characterized in that According to the solid-liquid ratio, activated carbon powder: concentrated nitric acid = 1g: 10-15mL.
5. The preparation method according to claim 4, characterized in that By mass ratio, activated carbon powder: potassium permanganate = 1:
3.
6. The preparation method according to claim 2, characterized in that In step 3), the stirring treatment time is 0-5h.
7. The preparation method according to claim 2, characterized in that In step 4), the vacuum drying condition is: vacuum drying at 60° C. for 24 h.
8. Use of the activated carbon material modified with oxygen-containing functional groups according to claim 1 as an electrode material for ammonium ion batteries.
9. The use according to claim 8, characterized in that The method is as follows: an activated carbon material modified with oxygen-containing functional groups is mixed with polyvinylidene fluoride, superconducting carbon black and N-methylpyrrolidone, and after being fully ground, the mixture is evenly coated on the surface of a carbon cloth current collector material to obtain an electrode material.
10. The use according to claim 9, characterized in that By mass ratio, activated carbon material modified with oxygen-containing functional groups: polyvinylidene fluoride: superconducting carbon black = 8:1:1.