CN115000402B - Organic positive electrode material and preparation method and application thereof - Google Patents

Abstract

The invention provides an organic positive electrode material, a preparation method and application thereof, wherein the preparation method of the organic positive electrode material comprises the following steps: dissolving 2,3,4, 6-tetrachlorobenzoquinone and square amide in a reaction solvent, and then carrying out condensation reaction under the protection of inert gas; after the reaction is finished and cooled, carrying out suction filtration to obtain a filter cake; and washing the filter cake with a washing solvent and then drying to obtain the organic positive electrode material. The preparation method of the organic positive electrode material is simple and feasible, and the prepared organic positive electrode material is a quinone polymer with a specific structure, is difficult to dissolve in electrolyte and effectively inhibits the loss of active substances; meanwhile, the organic positive electrode material has a more stable configuration structure for embedding multivalent ions, has good cycle reversibility, has more stable multiplying power performance, has a first-cycle discharge specific capacity reaching 186mAh g ^‑1 under the current density of 0.02A g ^‑1, and has a capacity retention rate of 89.6 percent after 400 times of charge and discharge.

Description

An organic positive electrode material and its preparation method and application

Technical Field

The present invention relates to the technical field of batteries, and in particular to an organic positive electrode material and a preparation method and application thereof.

Background technique

Organic cathode materials are in line with the concept of sustainable development, and the development of high-performance organic cathode materials is of great significance to the realization of green and clean energy storage. Quinone compounds are a relatively mature type of organic cathode materials. The quinone carbonyl group in their structure has good redox reversibility and is suitable as an active site for ion battery cathode materials. In addition, quinone organic cathode materials have simple synthesis methods and easy structural modification, which is conducive to the development of new structures. Therefore, they show great application potential and have been widely used in energy storage fields such as ion batteries and supercapacitors.

However, in multivalent ion batteries, the electrochemical properties of quinone-based organic cathode materials, such as rate and long cycle, are not ideal. For example, their capacity decays rapidly during continuous charge and discharge, which restricts their high-performance application in ion batteries.

Summary of the invention

In order to solve the above technical problems, the present invention provides an organic positive electrode material and a preparation method and application thereof.

To achieve the above purpose, the technical solution adopted by the present invention is as follows:

The invention provides a method for preparing an organic positive electrode material, which comprises the following steps: dissolving 2,3,4,6-tetrachlorobenzoquinone and squaramide in a reaction solvent, and then carrying out a condensation reaction under the protection of an inert gas; after the reaction is completed and cooled, suction filtering is carried out to obtain a filter cake; and the filter cake is washed with a washing solvent and then dried to obtain an organic positive electrode material.

Furthermore, the method specifically includes the following steps: dissolving 2,3,4,6-tetrachlorobenzoquinone and squaramide in a reaction solvent at a ratio of 0.28 g to 0.64 g of squaramide per gram of 2,3,4,6-tetrachlorobenzoquinone in 10 mL to 150 mL of a reaction solvent, and then reacting at 80° C. to 150° C. for 8 h to 48 h under the protection of an inert gas; after the reaction is completed and cooled, filtering is performed to obtain a filter cake; washing the filter cake with a washing solvent for 2 to 10 times and then drying to obtain a black solid powder, thereby obtaining the organic positive electrode material.

Furthermore, the reaction solvent is ethanol, N,N-dimethylformamide or N-methylpyrrolidone.

Furthermore, the inert gas is nitrogen or argon.

Furthermore, the washing solvent is one or more of methanol, ethanol, isopropanol, tetrahydrofuran and water.

The present invention also provides an organic positive electrode material, such as the organic positive electrode material prepared by the above-mentioned method for preparing the organic positive electrode material.

Furthermore, the structural formula of the organic cathode material is:

Here, n is a natural number greater than or equal to 1.

The present invention also provides the use of the above-mentioned organic positive electrode material in the field of ion batteries.

Compared with the prior art, the technical solution provided by the present invention has at least the following advantages:

The present invention provides an organic positive electrode material and a preparation method and application thereof. The preparation method of the organic positive electrode material is simple and feasible. The prepared organic positive electrode material is a quinone polymer with a specific structure, which is difficult to dissolve in an electrolyte and effectively inhibits the loss of active substances. At the same time, the organic positive electrode material of the present invention has a more stable configuration structure for embedding multivalent ions. Experiments have shown that the organic positive electrode material has good cycle reversibility and more stable rate performance. The long cycle performance has a first-cycle discharge specific capacity of 186 mAh g ^-1 at a current density of 0.02 Ag ^-1 , and a capacity retention rate of 89.6% after 400 charge and discharge cycles.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Unless otherwise stated, the pictures in the drawings do not constitute proportional limitations.

FIG1 is an X-ray diffraction diagram of an organic cathode material prepared in Example 1 of the present invention;

FIG2 is a scanning electron microscope image of the organic cathode material prepared in Example 1 of the present invention;

FIG3 is an infrared spectrum of the organic cathode material prepared in Example 1 of the present invention;

4 is a cyclic ^voltammetry graph of the organic cathode material prepared in Example 1 of the present invention in a zinc ion battery at scan rates of 0.1 mV s ^-1 , 0.2 mV s ^-1 , 0.3 mV s ^-1 , 0.4 mV s ^-1 , 0.5 mV s ^-1 , 0.6 mV s ^-1 , 0.8 mV s ^-1 , 1 mV s ^-1 , 2 mV s -1 , 3 mV s ^-1 , 4 mVs ^-1 , 5 mV s ^-1 , 6 mV s ^-1 , 8 mV s ^-1 , and 10 mV s ^-1 ;

Figure 5 is the rate performance of the organic cathode material prepared in Example 1 of the present invention in a zinc ion battery at current densities of 0.02A g ^-1 , 0.05A g ^-1 , 0.1 A g ^-1 , 0.2A g ^-1 , 0.5A g ^-1 , 1A g ^-1 , 2A g ^-1 and 5A g ^-1 , and the corresponding discharge specific capacities are 188mA hg ^-1 , 150mA hg ^-1 , 111mA hg ^-1 , 83mA hg ^-1 , 55mA hg ^-1 , 44mA hg ^-1 , 39mA hg ^-1 and 32mA hg ^-1 . When the current density drops back to 0.02A g ^-1 , the discharge specific capacity recovers to 166mAh g ^-1 .

FIG6 is a long cycle diagram of the organic cathode material prepared in Example 1 of the present invention after 400 charge and discharge cycles at a current density of 0.02 A g ^-1 in a zinc ion battery.

Detailed ways

The inventors found that in the prior art, ion batteries are assembled with quinone organic positive electrode materials, among which small molecule quinone derivative positive electrode materials are easily dissolved in the electrolyte, which easily causes the loss of positive electrode active substances and the long cycle capacity decays rapidly. In addition, the molecular structure of the organic positive electrode material also plays a key role in the embedding stability of multivalent ions in the material, affecting the cycle performance of the battery. After research, the inventors have developed a new type of quinone polymer organic positive electrode material poly (2,3,4,6-tetrachlorobenzoquinone-square amide), which is a polymer structure and can effectively inhibit the dissolution of active substances in the electrolyte. At the same time, the carbonyl configuration in poly (2,3,4,6-tetrachlorobenzoquinone-square amide) is stably coordinated with multivalent ions, showing good cycle reversibility, and its rate performance is stable in charge and discharge capacity at various current densities, and also shows a high capacity retention rate in long cycle performance.

The invention provides a method for preparing an organic positive electrode material, which comprises the following steps: dissolving 2,3,4,6-tetrachlorobenzoquinone and squaramide in a reaction solvent, and then carrying out a condensation reaction under the protection of an inert gas; after the reaction is completed and cooled, suction filtering is carried out to obtain a filter cake; and the filter cake is washed with a washing solvent and then dried to obtain an organic positive electrode material.

Furthermore, the method specifically includes the following steps: dissolving 2,3,4,6-tetrachlorobenzoquinone and squaramide in a reaction solvent at a ratio of 0.28 g to 0.64 g of squaramide per gram of 2,3,4,6-tetrachlorobenzoquinone in 10 mL to 150 mL of a reaction solvent, and then reacting at 80° C. to 150° C. for 8 h to 48 h under the protection of an inert gas; after the reaction is completed and cooled, filtering is performed to obtain a filter cake; washing the filter cake with a washing solvent for 2 to 10 times and then drying to obtain a black solid powder, thereby obtaining the organic positive electrode material.

The synthetic route of the reaction is as follows:

Furthermore, the reaction solvent is ethanol, N,N-dimethylformamide or N-methylpyrrolidone.

Furthermore, the inert gas is nitrogen or argon.

Furthermore, the washing solvent is one or more of methanol, ethanol, isopropanol, tetrahydrofuran and water.

The present invention also provides an organic positive electrode material, such as the organic positive electrode material prepared by the above-mentioned method for preparing the organic positive electrode material.

Furthermore, the structural formula of the organic cathode material is:

Here, n is a natural number greater than or equal to 1.

The present invention also provides the use of the above-mentioned organic positive electrode material in the field of ion batteries.

The present invention is described in detail below in conjunction with specific implementation modes.

Example 1

0.246 g (i.e. 1 mmol) of 2,3,4,6-tetrachlorobenzoquinone and 0.134 g (i.e. 1.2 mmol) of squaramide were dissolved in 10 mL of N,N-dimethylformamide, and reacted at 120 °C for 12 h under nitrogen protection. After the reaction was completed and cooled, the mixture was filtered and the filter cake was washed twice with ethanol. After drying, the poly (2,3,4,6-tetrachlorobenzoquinone-squaramide) organic cathode material was obtained as a black solid powder.

FIG1 is an X-ray diffraction diagram of the organic cathode material prepared in this embodiment. In the diagram, the main diffraction peak is a broad peak at 25°, and the organic cathode material of the present invention is in an amorphous state.

FIG. 2 is a scanning electron microscope image of the organic positive electrode material prepared in this embodiment, which is distributed in a granular form at the micrometer scale.

FIG3 is an infrared spectrum of the organic cathode material prepared in this example, in which the main absorption peaks are in the range of 745 cm ^-1 , 1378 cm ^-1 , 1456 cm ^-1 , 1620 cm ^-1 and 3100 cm ^-1 to 3330 cm ^-1 .

The organic positive electrode material prepared in this example was used as the active material of the positive electrode of the zinc ion battery. The organic positive electrode material: acetylene black: polyvinylidene fluoride were mixed and ground in a mass ratio of 6:3:1, N-methylpyrrolidone was added dropwise for grinding, and the mixture was coated on a stainless steel mesh and vacuum dried to form a positive electrode sheet. A zinc sheet was used as the negative electrode, a 1 mol·L ^- ₁ ZnSO4 solution was used as the electrolyte, and a glass fiber was used as a separator to assemble a CR2032 coin battery, and the electrochemical performance was tested.

Fig. 4 is a cyclic voltammogram of the organic positive electrode material prepared in Example 1 of the present invention in a zinc ion battery at scan rates of 0.1mV s ^-1 , 0.2mV s ^-1 , 0.3mV s ^-1 , 0.4mV s ^-1 , 0.5mV s ^-1 , 0.6mV s ^-1 , 0.8mV s ^-1 , 1mV s ^-1 , 2mV s ^-1 , 3mV s ^-1 , 4mVs ^-1 , 5mV s ^-1 , 6mV s ^-1 , 8mV s ^-1 , and 10mV s ^-1 . The battery composition is: positive electrode material ‖ZnSO ₄ (1mol L ^-1 )‖Zn, with an oxidation peak at 1.0V and a reduction peak at 0.8V. The redox peaks in the figure are obvious, symmetrical and the peak positions are stable, indicating that the organic positive electrode material of the present invention has good cycle reversibility and almost no polarization phenomenon during the charge and discharge process.

Figure 5 shows the rate performance of the organic cathode material prepared in this example in a zinc ion battery at current densities of 0.02A g ^-1 , 0.05A g ^-1 , 0.1A g ^-1 , 0.2A g ^-1 , 0.5A g ^-1 , 1A g ^-1 , 2A g ^-1 and 5A g ^-1 , and the corresponding discharge specific capacities are 188 mA h g ^-1 , 150 mA h g ^-1 , 111 mA h g ^-1 , 83 mA h g ^-1 , 55 mA h g ^-1 , 44 mA h g ^-1 , 39 mA h g ^-1 and 32 mA h g ^-1 . When the current density drops back to 0.02A g ^-1 , the discharge specific capacity recovers to 166 mAh g ^-1 .

Figure 6 is a long cycle diagram of the organic cathode material prepared in this example after 400 charge and discharge cycles at a current density of 0.02Ag ^-1 in a zinc ion battery. In the figure, the first cycle discharge capacity is 186mAh g ^-1 , and the capacity retention rate after 400 charge and discharge cycles is 89.6%.

The electrochemical properties such as the discharge capacity, rate performance stability, and long cycle capacity retention rate obtained from the above tests are better than those of the positive electrode materials such as naphthoquinone, anthraquinone, poly(quinone-4,4'-diaminobiphenyl), poly(quinone-ethylenediamine), and poly(quinone-urea). For example, the discharge capacity of the first cycle of the poly(quinone-ethylenediamine) positive electrode material at a current density of 0.02A/g is 102mAh g ^-1 , and the capacity retention rate after 250 charge and discharge cycles is 49%. The organic positive electrode material of the present invention has obvious performance advantages.

Example 2

0.246 g (i.e. 1 mmol) of 2,3,4,6-tetrachlorobenzoquinone and 0.090 g (i.e. 0.8 mmol) of squaramide were dissolved in 20 mL of N,N-dimethylformamide, and reacted at 110 °C for 24 h under nitrogen protection. After the reaction was completed and cooled, the mixture was filtered and the filter cake was washed 10 times with ethanol. After drying, the organic positive electrode material poly(2,3,4,6-tetrachlorobenzoquinone-squaramide) was obtained as a black solid powder.

Example 3

0.246 g (i.e. 1 mmol) of 2,3,4,6-tetrachlorobenzoquinone and 0.157 g (i.e. 1.4 mmol) of squaramide were dissolved in 30 mL of N-methylpyrrolidone, and reacted at 150 ° C for 10 h under nitrogen protection. After the reaction was completed and cooled, the filter cake was washed with tetrahydrofuran, ethanol and water for 3 times in sequence, and dried to obtain poly (2,3,4,6-tetrachlorobenzoquinone-squaramide) organic cathode material, which was a black solid powder.

Example 4

0.246 g (i.e. 1 mmol) of 2,3,4,6-tetrachlorobenzoquinone and 0.134 g (i.e. 1.2 mmol) of squaramide were dissolved in 30 mL of N-methylpyrrolidone, and reacted at 80 ° C for 48 h under nitrogen protection. After the reaction was completed and cooled, the filter cake was washed with isopropanol, ethanol and water for 3 times in sequence, and dried to obtain poly (2,3,4,6-tetrachlorobenzoquinone-squaramide) organic cathode material, which was a black solid powder.

Example 5

0.246 g (i.e. 1 mmol) of 2,3,4,6-tetrachlorobenzoquinone and 0.134 g (i.e. 1.2 mmol) of squaramide were dissolved in 10 mL of N,N-dimethylformamide, and reacted at 100 °C for 12 h under nitrogen protection. After the reaction was completed and cooled, the filter cake was filtered and washed twice with ethanol. After drying, the poly (2,3,4,6-tetrachlorobenzoquinone-squaramide) organic cathode material was obtained as a black solid powder.

The poly(2,3,4,6-tetrachlorobenzoquinone-squaramide) organic positive electrode material of the present invention can be applied to calcium ion batteries, magnesium ion batteries, aluminum ion batteries, zinc ion batteries and the like.

Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and in practical applications, various changes may be made to the embodiments in form and detail without departing from the spirit and scope of the present application. Any person skilled in the art may make their own changes and modifications without departing from the spirit and scope of the present application, and therefore the scope of protection of the present application shall be subject to the scope defined in the claims.

Claims (6)

1. A method for preparing an organic positive electrode material, characterized in that the method comprises the following steps: Dissolving 2,3,4,6-tetrachlorobenzoquinone and squaramide in a reaction solvent, and then carrying out a condensation reaction under the protection of an inert gas; after the reaction is completed and cooled, filtering is performed to obtain a filter cake; washing the filter cake with a washing solvent and then drying it to obtain an organic positive electrode material; The structural formula of the organic cathode material is: ; Where n is a natural number greater than or equal to 1; The preparation method specifically comprises the following steps: According to the ratio of 0.28 g to 0.64 g of squaramide per gram of 2,3,4,6-tetrachlorobenzoquinone to 10 mL to 150 mL of reaction solvent, 2,3,4,6-tetrachlorobenzoquinone and squaramide are dissolved in the reaction solvent, and then reacted at 80°C to 150°C for 8 h to 48 h under the protection of inert gas; after the reaction is completed and cooled, the filter is filtered to obtain a filter cake; the filter cake is washed with a washing solvent for 2 to 10 times and then dried to obtain a black solid powder, thereby obtaining the organic positive electrode material. 2. The method for preparing an organic cathode material according to claim 1, wherein the reaction solvent is ethanol, N,N-dimethylformamide or N-methylpyrrolidone. 3. The method for preparing an organic cathode material according to claim 1, wherein the inert gas is nitrogen or argon. 4 . The method for preparing an organic cathode material according to claim 1 , wherein the washing solvent is one or more of methanol, ethanol, isopropanol, tetrahydrofuran, and water. 5. An organic positive electrode material, characterized in that it is an organic positive electrode material prepared by the method for preparing an organic positive electrode material according to any one of claims 1 to 4. 6. Application of the organic cathode material as claimed in claim 5 in the field of ion batteries.