Novel organic material for aqueous ammonium ion battery as well as preparation method and application of novel organic material

Abstract

The invention discloses a novel organic material for an aqueous ammonium ion battery as well as a preparation method and application of the novel organic material, and belongs to the technical field of novel organic energy storage materials. According to the preparation method, the novel organic material PHAT-HKH is prepared by carrying out dehydration condensation reaction on cyclohexanehexone hydrate and 2, 4, 6-tri (1, 2-phenylenediamine)-1, 3, 5-triazine. The PHAT-HKH material prepared by the invention is rich in pyridine nitrogen, so that the oxidation-reduction activity of the material is improved. Meanwhile, a constructed hydrogen bond network enhances the structural stability of the material, and the ammonium ion energy storage performance of the material is improved under a synergistic mechanism.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of new organic energy storage materials, and particularly relates to a new organic material for aqueous ammonium ion batteries and a preparation method and application thereof. BACKGROUND

[0002] In the face of today's fossil energy crisis, aqueous batteries with ammonium ions as charge carriers are widely considered as a promising energy storage technology. Compared with commercial lithium ion batteries, they have higher sealing and lower fire risk. As a representative non-metallic cation, NH4 + exhibits unique energy storage characteristics, including high sustainability, low molar mass and small hydration radius. However, NH4 + and the hydrogen bond formed by the material is weak, which hinders the diffusion of NH4 + and slows down the kinetics. Therefore, it is crucial to develop suitable ammonium storage electrode materials to realize the stable operation of ammonium ion energy storage systems. Commonly used organic materials can provide satisfactory storage capacity, but most of them have the problem of insufficient cycle stability, which is attributed to their small size, easy dissolution in aqueous electrolyte and low conductivity. In order to cope with these challenges, it is promising to polymerize organic small molecules into covalent organic framework materials with larger molecular size, ordered stacking and higher conjugation. SUMMARY

[0003] In order to solve the above-mentioned technical problems, the application utilizes the dehydration condensation reaction between the carbonyl carbon atoms in cyclohexanehexone hydrate and the amino groups in 2,4,6-tris(1,2-phenylenediamine)-1,3,5-triazine to prepare a new organic material PHAT-HKH of covalent organic framework, effectively solving the problems of structural instability, high solubility in electrolyte and low conductivity encountered by traditional organic materials.

[0004] To achieve the above-mentioned application purposes, the technical solution adopted by the application is: a new organic material for aqueous ammonium ion batteries, the preparation method comprising: adding cyclohexanehexone hydrate and 2,4,6-tris(1,2-phenylenediamine)-1,3,5-triazine into N,N-dimethylacetamide and ultrasonic dispersion; then adding o-dichlorobenzene and glacial acetic acid, and reacting in an argon atmosphere in an oil bath at 100-120 DEG C for 48-50 hours; after cooling to room temperature, the product is washed and collected and placed in a vacuum drying box for drying, to obtain the new organic material PHAT-HKH for aqueous ammonium ion batteries.

[0005] Further, according to the solid-liquid ratio, cyclohexanehexone hydrate: 2,4,6-tris(1,2-phenylenediamine)-1,3,5-triazine: N,N-dimethylacetamide = (110mg-130mg): (230mg-240mg): (2mL-5mL).

[0006] Further, the volume ratio of o-dichlorobenzene: glacial acetic acid is (15 mL-20 mL):(0.1 mL-0.5 mL).

[0007] Further, the argon atmosphere refers to 5 min-10 min of continuous purging with argon after vacuumizing through a three-way valve.

[0008] The application provides application of the novel organic material PHAT-HKH as an electrode material in a water-based ammonium ion battery.

[0009] Further, the method is as follows: PHAT-HKH is mixed with polyvinylidene fluoride, superconducting carbon black and N-methylpyrrolidone, and after being fully ground, the mixture is uniformly coated on the surface of a functionalized carbon cloth current collector material to obtain an electrode material.

[0010] Further, the mass ratio of PHAT-HKH: polyvinylidene fluoride: superconducting carbon black is 8:1:1.

[0011] The application has the following beneficial effects:

[0012] The application utilizes the dehydration condensation reaction between the carbonyl carbon atoms in cyclohexanehexone hydrate and the amino groups in 2,4,6-tris(1,2-phenylenediamine)-1,3,5-triazine to prepare a novel covalent organic framework material PHAT-HKH with high redox activity. The high conductivity, structural stability and order of the covalent organic framework structure solve the problems of low conductivity, structural instability and easy agglomeration of organic small molecules. Meanwhile, the carbon-nitrogen double bond in the material is an excellent redox center, which solves the problem of insufficient redox activity of organic small molecules, and the synergistic effect realizes the improvement of the comprehensive electrochemical performance of the material in the ammonium ion battery. The PHAT-HKH material prepared in the application contains rich pyridine nitrogen, which improves the redox activity of the material. Meanwhile, the hydrogen bond network constructed enhances the structural stability of the material, and the synergistic mechanism improves the ammonium ion storage performance of the material. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a SEM image of PHAT-HKH synthesized in Example 1.

[0014] Figure 2 is a cyclic voltammogram of the PHAT-HKH electrode at a scan rate of 50 mV s -1 .

[0015] Figure 3 is a charge-discharge curve of the PHAT-HKH electrode at a current density of 1 A g -1 .

[0016] Figure 4is the charge-discharge curve of PHAT-HKH electrode at a current density of 10 A g -1

[0017] Figure 5 is the cycle curve of PHAT-HKH electrode at a current density of 10 A g -1 DETAILED DESCRIPTION

[0018] Example 1 A new organic material PHAT-HKH for aqueous ammonium-ion battery

[0019] I. Preparation method is as follows:

[0020] 120 mg of cyclohexanehexone hydrate and 235 mg of 2,4,6-tris(1,2-phenylenediamine)-1,3,5-triazine were added into 2 mL of N,N-dimethylacetamide and ultrasonically dispersed. Then 15 mL of o-dichlorobenzene and 0.2 mL of glacial acetic acid were added, and after vacuumizing with a three-way valve, argon was continuously passed for 5 min. The reaction was carried out in an argon atmosphere at 110°C in an oil bath for 48 h, cooled to room temperature, and the product was collected after washing and placed in a vacuum drying box for drying, obtaining a dark black solid product, which is the organic material PHAT-HKH.

[0021] The synthesis reaction formula of PHAT-HKH is as follows:

[0022]

[0023] II. Characterization

[0024] Figure 1 is the SEM image of the synthesized PHAT-HKH. It can be seen fromthat the covalent organic framework of PHAT-HKH presents long ordered channel structure, which is conducive to the migration of ammonium ions. Figure 1 Example 2 Application of new organic material PHAT-HKH as electrode material in aqueous ammonium-ion battery

[0025] I. Preparation of electrode material

[0026] After 2 mg of PHAT-HKH material prepared in Example 1 was fully ground with 0.25 mg of polyvinylidene fluoride and 0.25 mg of superconducting carbon black, 0.0125 mL of N-methyl pyrrolidone was added, and after grinding again, the obtained slurry was uniformly coated on the surface of the functionalized carbon cloth current collector material, obtaining the electrode material.

[0027] II. Electrochemical analysis

[0028] 1. Cyclic voltammetry scanning test

[0029]

[0030] ​​Method: In normal temperature and pressure, with carbon cloth current collector coated with PHAT-HKH material as working electrode, graphite foil as counter electrode, saturated calomel electrode as reference electrode, 2M (NH4) 2SO4 as electrolyte, in the potential range of-1V (vs. SCE) ~ 0.2V (vs. SCE), cyclic voltammetry scanning test was carried out on PHAT-HKH electrode material at 50mV s -1 .

[0031] Figure 2 is the cyclic voltammetry curve of PHAT-HKH battery electrode at 50mV s -1 Figure 2 It can be seen that when the scanning rate is 50mV s -1 , the CV curve integral area of PHAT-HKH is large, which shows good energy storage performance.

[0032] 2, constant current charge-discharge test at 1A g -1 current density

[0033] Method: In normal temperature and pressure, with carbon cloth current collector coated with PHAT-HKH material as working electrode, graphite foil as counter electrode, saturated calomel electrode as reference electrode, 2M (NH4) 2SO4 as electrolyte, in the potential range of-1V (vs. SCE) ~ 0.2V (vs. SCE), constant current charge-discharge test was carried out on PHAT-HKH electrode material at 1A g -1 current density.

[0034] Figure 3 is the charge-discharge curve of PHAT-HKH battery electrode at 1A g -1 current density. From the charge-discharge curve, it can be seen that the capacity of PHAT-HKH can reach 287mAh g -1 at 1A g -1 current density, which proves that the method improves the storage performance of ammonium ions of organic materials.

[0035] 3, constant current charge-discharge test at 10A g -1 current density

[0036] Method: In normal temperature and pressure, with carbon cloth current collector coated with PHAT-HKH material as working electrode, graphite foil as counter electrode, saturated calomel electrode as reference electrode, 2M (NH4) 2SO4 as electrolyte, in the potential range of-1V (vs. SCE) ~ 0.2V (vs. SCE), constant current charge-discharge test was carried out on PHAT-HKH electrode material at 10A g -1 current density.

[0037] ​Figure 4 is the charge-discharge curve of PHAT-HKH battery electrode at 10A g -1 Current density. It can be observed that PHAT-HKH has a capacity of 168mAh g -1 at 10A g -1 Current density, showing excellent rate performance.

[0038] 4, 10A g -1 Current density cycle stability test

[0039] Method: At room temperature and normal pressure, carbon cloth current collector electrode material coated with PHAT-HKH material as working electrode, graphite foil as counter electrode, saturated calomel electrode as reference electrode, 2M (NH4) 2SO4 as electrolyte, in the potential range of-1V (vs. SCE) ~ 0.2V (vs. SCE), 10A g -1 Current density cycle stability test of PHAT-HKH electrode material.

[0040] Figure 5 is the cycle stability diagram of PHAT-HKH battery electrode at 10A g -1 Current density. After 9000 cycles of charge-discharge, the capacity retention rate of PHAT-HKH is 91.8%, which verifies that the structure of the new organic material is beneficial to the improvement of cycle stability.

Claims

1. A novel organic material for aqueous ammonium ion batteries, characterized in that: The preparation method includes: adding cyclohexanone hexaketone hydrate and 2,4,6-tris(1,2-phenylenediamine)-1,3,5-triazine to N,N-dimethylacetamide and ultrasonically dispersing; then adding o-dichlorobenzene and glacial acetic acid, reacting in an oil bath at 100°C-120°C under an argon atmosphere for 48h-50h; after cooling to room temperature, washing and collecting the product, and drying it in a vacuum drying oven to obtain a new organic material PHAT-HKH for aqueous ammonium ion batteries.

2. A novel organic material for aqueous ammonium ion batteries according to claim 1, characterized in that: According to the solid-liquid ratio, cyclohexanone hydrate: 2,4,6-tris(1,2-phenylenediamine)-1,3,5-triazine: N,N-dimethylacetamide = (110mg-130mg): (230mg-240mg): (2mL-5mL).

3. A novel organic material for aqueous ammonium ion batteries according to claim 2, characterized in that: By volume ratio, o-dichlorobenzene: glacial acetic acid = (15 mL - 20 mL): (0.1 mL - 0.5 mL).

4. A novel organic material for aqueous ammonium ion batteries according to claim 1, 2 or 3, characterized in that: The argon atmosphere refers to the process of purging with argon for 5-10 minutes after vacuuming through a three-way valve.

5. Use of the novel organic material PHAT-HKH according to any one of claims 1 to 4 as an electrode material in an aqueous ammonium ion battery.

6. The use according to claim 5, characterized in that The method is as follows: PHAT-HKH is mixed with polyvinylidene fluoride, superconducting carbon black and N-methylpyrrolidone, and after being fully ground, it is evenly coated on the surface of the functionalized carbon cloth current collector material to obtain the electrode material.

7. The use according to claim 6, characterized in that By mass ratio, PHAT-HKH: polyvinylidene fluoride: superconducting carbon black = 8:1:1.

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