PT-based azo conjugated polymer for battery positive electrode material and preparation method of PT-based azo conjugated polymer

Abstract

The invention discloses a PT-based azo conjugated polymer for a battery positive electrode material and a preparation method of the PT-based azo conjugated polymer, and the PT-based azo conjugated polymer is an extended conjugated system formed by azo connection and contains rich carbonyl (C = O) and azo (N = N) sites. According to the preparation method of the PT-based azo conjugated polymer, nitration of a conjugated precursor PT and subsequent nitro polymerization reaction are utilized to obtain the PT-based azo polymer PTAP, the PT-based azo polymer PTAP has high-density oxidation-reduction active sites, the electronic conductivity is greatly enhanced and reaches 4.26 * 10 <-3 > S / m, and the PT-based azo polymer PTAP also has excellent solubility resistance and rate capability.

Description

Technical Field

[0001] The invention relates to the technical field of compounds with high electronic conductivity and preparation methods thereof, and in particular to a PT-based azo conjugated polymer used for battery positive electrode materials and a preparation method thereof. Background Art

[0002] The booming development of rechargeable aqueous zinc-ion batteries, which are resource-rich, safe, environmentally friendly, and have a high theoretical capacity (820 mAh / g), has aroused a wave of exploration of high-performance cathode materials among researchers. In particular, organic molecules have been favored as cathode materials in recent years due to their strong structural adjustability, environmental friendliness, and abundant and low-cost raw materials. However, the inherent structural characteristics of organic molecules and the random stacking distribution of molecules result in limited electronic conductivity and low energy density of organic cathode materials.

[0003] The electron transport of organic molecules is closely related to their molecular structure. The π electrons in the conjugated system are no longer confined to a single atom, but can move freely throughout the system to form a delocalized π electron cloud. Organic molecules with conjugated structures usually have good electrical conductivity. The longer the conjugated system, the larger the range of electron movement and the higher the conductivity.

[0004] However, the reported extended conjugated systems always involve some inactive components, which inevitably reduce the energy density of the battery. In addition, small organic molecules have a strong tendency to dissolve electrolytes during electrochemical reactions, which seriously threatens the stable storage and efficient conversion of energy in zinc-organic batteries. Summary of the invention

[0005] The present invention provides a PT-based azo conjugated polymer for anode materials of a battery and a preparation method thereof, so as to solve the problem in the prior art that the conjugated system reduces the energy density of the battery and has a negative impact on the ability of the zinc organic battery to stably store and efficiently convert energy. The PT-based azo conjugated polymer has a high density of redox active sites, which greatly enhances the electronic conductivity and reaches 4.26×10- 3 S / m, and also has excellent anti-dissolution and rate performance, realizing the ability of stable storage and efficient conversion of zinc-organic battery energy.

[0006] A PT-based azo conjugated polymer for a positive electrode material of a battery, wherein the PT-based azo conjugated polymer is an extended conjugated system formed by azo connection, wherein the carbonyl site is as follows:

[0007]

[0008] The electronic conductivity of the PT-based azo conjugated polymer is 4.26×10- 3 S / m.

[0009] The present application embodiment provides a method for preparing a PT-based azo conjugated polymer, the steps comprising:

[0010] Step 1: Synthesize dinitro-4,5,9,10-pyrenetetraone DNPT using pyrene-4,5,9,10-tetraone and fuming nitric acid as raw materials;

[0011] Step 2: Directly synthesize PT-based azo polymer PTAP using a reductive coupling reaction.

[0012] Preferably, the specific preparation method of step 2 is:

[0013] Dissolve dinitro-4,5,9,10-pyrenetetraone DNPT and iodine particles in methanol at room temperature, slowly add magnesium powder, stir evenly at room temperature, add magnesium powder again, heat, pour the obtained liquid into ice water while hot and stir continuously, neutralize with glacial acetic acid to pH 4-5, filter and wash with a small amount of ice water, and recrystallize with ethanol to obtain PT-based azo polymer PTAP.

[0014] A technical solution provided in the embodiments of the present application has at least the following technical effects:

[0015] 1. PT-based azo polymer PTAP is obtained by nitration of conjugated precursor PT and subsequent nitro polymerization reaction. PT-based azo polymer PTAP is connected by conjugated molecules through azo groups, which expands the conjugated structure and realizes the long-range delocalization of π electrons. At the same time, the azo group can also serve as an active site to avoid the introduction of inactive components, giving PTAP the characteristics of high capacity of the electrode. The strong conjugation effect also produces a small energy band gap, so that PTAP has high electronic conductivity. Therefore, the problem of the conjugated system reducing the energy density of the battery and having a negative impact on the ability of zinc organic battery to stably store and efficiently convert energy in the prior art is solved. The conductivity of azo polymer PTAP reaches 4.26×10 -3 S / m, and also has excellent solvent resistance and rate performance.

[0016] 2. The strong interaction between the macromolecular chains of PTAP-based azo polymers also gives the PTAP cathode a strong anti-dissolution property in aqueous electrolytes, effectively overcoming the problem of poor cycle stability of zinc-organic batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural diagram of a PT-based azo polymer PTAP according to Example 1 of the present application;

[0018] Figure 2 The SEM and HRTEM images of the PT-based azo polymer PTAP of Example 1 of the present application;

[0019] Figure 3 This is the structural characterization of the PT-based azo polymer PTAP of Example 1 of the present application. 3a is the infrared curve diagram of PTAP, and 3b is the XRD diagram of PTAP. DETAILED DESCRIPTION

[0020] The present invention provides a PT-based azo conjugated polymer for a positive electrode material of a battery and a preparation method thereof, which solves the problem in the prior art that the conjugated system reduces the energy density of the battery and has a negative impact on the ability of the zinc organic battery to stably store and efficiently convert energy. The PT-based azo conjugated polymer improves the conductivity of the organic compound itself, and the PT-based azo conjugated polymer has a high density of redox active sites, and the electronic conductivity is greatly enhanced, reaching 4.26×10- 3 S / m, and also has excellent solvent resistance and rate performance.

[0021] The technical solution in the embodiment of the present application is to solve the above problems, and the overall idea is as follows:

[0022] First, 2,7-dinitro-4,5,9,10-pyrenetetraone (DNPT) is synthesized, and then a PT-based azo polymer is directly synthesized by a reduction coupling reaction. The synthesized PT-based azo polymer breaks the mutual constraint between the active site density and electronic conductivity of the organic positive electrode through molecular structure design, thereby achieving the function of simultaneously improving the battery's specific capacity and rate performance.

[0023] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0024] Embodiment 1

[0025] Raw materials: pyrene-4,5,9,10-tetraone (PT), 98% concentrated sulfuric acid, 95% fuming nitric acid, 99.9% iodine, 99.5% magnesium powder, 99.9% methanol, 99.9% glacial acetic acid.

[0026] Step 1: Synthesis of 2,7-dinitro-4,5,9,10-pyrenetetraone (DNPT)

[0027] 2mM, 524mg PT was added to a 4:1 v / v mixture of sulfuric acid and 20mL nitric acid, then heated at 90°C for 2h. After the reaction was completed, the mixture was poured into 200mL deionized water. The resulting yellow precipitate was filtered, washed several times with saturated 200mL NaHCO3 and water, and dried under vacuum at 65°C for 24h to obtain yellow DNPT.

[0028] Step 2: Synthesis of PT-based azo polymer (PTAP)

[0029] Dissolve 176.1 mg, 0.5 mmol DNPT and I2 iodine particles in 20 mL methanol at room temperature, then gradually add 75 mg magnesium powder. After stirring at room temperature for 30 minutes, add 75 mg magnesium powder again and heat at 80°C for 2 hours. Pour the resulting liquid into ice water while hot and stir continuously, carefully neutralize with glacial acetic acid to a pH of 4-5, filter and wash with a small amount of ice water, and finally recrystallize with ethanol to obtain PT-based azo polymer.

[0030] Please refer to Figure 1-Figure 3 , Figure 1 It is the structural diagram of PTAP. PTAP is an extended conjugated system formed by azo linkages and contains abundant carbonyl (C=O) and azo (N=N) sites.

[0031] Depend on Figure 2 The SEM and HRTEM images of PTAP show that PTAP is a bulk structure composed of irregular nanosheets with a π-π lattice spacing of 0.35 nm.

[0032] Figure 3 Figure 3a is the infrared curve of PTAP, which proves the existence of C=O and N=N groups.

[0033] 3b is the XRD pattern of PTAP, which proves that it is an azo polymer with a crystalline structure.

[0034] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0035] Since the azo polymer PTAP is obtained by nitration of the conjugated precursor PT and subsequent nitro polymerization reaction, the azo polymer PTAP is connected by azo groups, which expands the conjugated structure and realizes the long-range delocalization of π electrons. At the same time, the azo group can also serve as an active site, avoiding the introduction of inactive components, giving the PTAP electrode the characteristics of high capacity. The strong conjugation effect also produces a small energy band gap, so that PTAP has high electronic conductivity. Therefore, the problem of the conjugated system reducing the energy density of the battery and having a negative impact on the ability of the zinc organic battery to stably store and efficiently convert energy in the prior art is solved. The conductivity of the azo polymer PTAP reaches 4.26×10 -3 S / m, and also has excellent rate performance.

[0036] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0037] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A PT-based azo conjugated polymer for a positive electrode material of a battery, wherein: The PT-based azo conjugated polymer is an extended conjugated system formed by azo connection, wherein the carbonyl site is as follows: The electronic conductivity of the PT-based azo conjugated polymer is 4.26×10 -3 S / m.

2. A PT-based azo conjugated polymer as claimed in claim 1, wherein: A method for preparing a PT-based azo conjugated polymer, comprising the steps of: Step 1: Synthesize dinitro-4,5,9,10-pyrenetetraone DNPT using pyrene-4,5,9,10-tetraone and fuming nitric acid as raw materials; Step 2: Directly synthesize PT-based azo polymer PTAP using a reductive coupling reaction.

3. The preparation method according to claim 1, wherein The specific preparation method of step 2: Dissolve dinitro-4,5,9,10-pyrenetetraone DNPT and iodine particles in methanol at room temperature, slowly add magnesium powder, stir evenly at room temperature, add magnesium powder again, heat, pour the obtained liquid into ice water while hot and stir continuously, neutralize with glacial acetic acid to pH 4-5, filter and wash with a small amount of ice water, and recrystallize with ethanol to obtain PT-based azo polymer PTAP.

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