阅读说明：本技术 吡咯并吡咯衍生物在锂离子电池上的应用 (Application of pyrrolopyrrole derivative in lithium ion battery ) 是由 蔺红桃 张志强 柳玉英 许子琛 侯圣贤 于 2019-11-07 设计创作，主要内容包括：本发明属于锂离子电池制备技术领域,具体涉及一种吡咯并吡咯衍生物在锂离子电池上的应用。采用有机电极制备锂离子电池,将吡咯并吡咯衍生物作为制备有机电极的材料。按照电池外壳、锂片、电解质溶液、隔膜、有机电极、垫片、弹片的顺序组装,即得锂离子电池。本发明吡咯并吡咯衍生物锂离子电池获得高比电容、高循环稳定性,显著地改善了因为羰基本身特性受限导致电压较低以及小分子结构易分解带来的稳定性差的缺点,为低成本的高容量、高稳定性的电极材料制备提供了思路。(The invention belongs to the technical field of lithium ion battery preparation, and particularly relates to an application of a pyrrolopyrrole derivative in a lithium ion battery. The lithium ion battery is prepared by adopting an organic electrode, and the pyrrolopyrrole derivative is used as a material for preparing the organic electrode. And assembling the battery shell, the lithium sheet, the electrolyte solution, the diaphragm, the organic electrode, the gasket and the elastic sheet in sequence to obtain the lithium ion battery. The pyrrolo-pyrrole derivative lithium ion battery has high specific capacitance and high cycle stability, remarkably overcomes the defects of low voltage caused by the limited characteristics of carbonyl and poor stability caused by easy decomposition of a small molecular structure, and provides an idea for preparing a low-cost high-capacity and high-stability electrode material.)

1. the application of the pyrrolopyrrole derivative in the lithium ion battery comprises the step of preparing the lithium ion battery by adopting an organic electrode, and is characterized in that the pyrrolopyrrole derivative is used as a material for preparing the organic electrode.

2. Use of a pyrrolopyrrole derivative according to claim 1 in a lithium ion battery, characterized in that the material of the organic electrode comprises the pyrrolopyrrole derivative, a conductive additive and a binder.

3. The use of a pyrrolopyrrole derivative according to claim 1 in a lithium ion battery, wherein the molecular formula of the pyrrolopyrrole derivative is as follows:

wherein R is-CH₂COOC(CH₃)₃、-(CH₂)₅CH₃or-CH (CH)₂CH₃)(CH₂)₃CH₃In the above-mentioned manner, the first and second substrates are,

ar is one of the following structural formulas:

4. use of a pyrrolopyrrole derivative according to claim 2 in a lithium ion battery, characterized in that the conductive additive is carbon black and the binder is polytetrafluoroethylene.

5. The use of a pyrrolopyrrole derivative according to claim 2 for lithium ion batteries, characterized in that the mass ratio of the pyrrolopyrrole derivative, the conductive additive and the binder is 5-8:1-4: 1.

6. The application of the pyrrolopyrrole derivative to the lithium ion battery according to claim 1, further comprising preparing the lithium ion battery by using a battery shell, a lithium sheet, an electrolyte solution, a diaphragm, a gasket and a spring sheet.

7. The use of pyrrolopyrrole derivatives according to claim 6 in lithium ion batteries, characterized in that the electrolyte solution is LiPF₆The solution and the membrane are glass fiber.

8. Use of a pyrrolopyrrole derivative according to any one of claims 1 to 7 in a lithium ion battery, characterized by comprising the steps of:

(1) respectively adding the pyrrolopyrrole derivative, the conductive additive, the binder and the solvent into a mortar which is continuously ground, continuously grinding to obtain uniform slurry, coating the slurry on a metal foil to obtain an organic electrode, drying in vacuum, cooling, and slicing the organic electrode for later use;

(2) and under the condition of nitrogen, assembling the battery shell, the lithium sheet, the electrolyte solution, the diaphragm, the organic electrode, the gasket and the elastic sheet in the glove box in sequence to obtain the lithium ion battery.

9. Use of a pyrrolopyrrole derivative according to claim 8 in a lithium ion battery, characterized in that the solvent in step (1) is N-methylpyrrolidone.

10. The use of the pyrrolopyrrole derivative according to claim 8 for lithium ion batteries, wherein the metal foil in step (1) is aluminum foil or copper foil.

Technical Field

The invention belongs to the technical field of lithium ion battery preparation, and particularly relates to an application of a pyrrolopyrrole derivative in a lithium ion battery.

Background

The traditional energy resources such as coal, petroleum, natural gas and the like face the problems of shortage of reserves, bad influence on the environment and the like. In recent years, there has been a strong demand for the research of a high-capacity, environmentally friendly energy storage device. The lithium ion battery has the advantages of high voltage, high capacitance, long cycle life, high rate performance and the like, can meet the energy supply requirements of people in the aspects of travel, daily life and the like, and is relatively low in damage to the environment. Currently, the research on lithium ion batteries mainly can be divided into two aspects: one is an inorganic material used as an electrode material, and the other is an organic material used as an electrode material.

The inorganic material has been rapidly developed in the last two decades as the electrode material of lithium ion battery, and has attracted much attention and application in the excellent comprehensive battery performance compared with lead, nickel and nickel-hydrogen battery. Inorganic materials are commonly used as the positive electrode of lithium ion batteries, but are limited by their theoretical capacity and structural stability, making it difficult to further increase their energy density, such as LiCoO₂And LiFePO₄. Secondly, the large-scale use of transition metal complexes such as Fe, Co, Ni, Mn and the like is not only expensive, but also unfavorable for environmental protection.

Subsequently, the related art has synthesized and studied various organic disulfide compounds such as cyclic disulfide polyamide, copolymer of 2, 2-dithiodiphenylamine and aniline, phenyl polyorganodisulfide, etc., and studied electrochemical properties. The research on the battery electrode material aiming at the organic sulfur mainly aims at sulfur dichloride and thioether bonds, but the characteristics of high theoretical capacity and low voltage are ubiquitous. The compound composed of free radicals is mainly researched by oxynitride, but the compound is generally low in capacitance and low in practical application value, but the voltage of the compound serving as a positive electrode material is high. The third is carbonyl compounds, which generally contain two or more redox active sites and provide larger theoretical capacitance, but generally have lower voltage. Currently, research on carbonyl compounds has focused mainly on benzoquinone derivatives, naphthalimides, pyrroles and the like, and carbonyl compounds attract much interest due to their high theoretical capacity, high reversibility.

Therefore, the development of an organic electrode material with considerable theoretical capacity, long stability, low price and environmental friendliness is a work with great scientific research significance. Although many researches on organic electrode materials have been conducted, the kinds of organic electrode materials are still limited and electrochemical properties are not ideal, and it is very necessary to develop a novel high-performance conjugated carbonyl organic material.

Disclosure of Invention

The invention aims to provide an application of a pyrrolopyrrole derivative in a lithium ion battery, wherein the pyrrolopyrrole derivative is firstly used as an electrode material of the lithium ion battery, and the prepared electrode material has the characteristics of high specific capacitance and high cycle stability, and the defects of low voltage and poor stability caused by easy decomposition of a small molecular structure due to the limited characteristics of carbonyl are obviously overcome.

The application of the pyrrolopyrrole derivative in the lithium ion battery comprises the steps of preparing the lithium ion battery by adopting an organic electrode and taking the pyrrolopyrrole derivative as a material for preparing the organic electrode.

The material of the organic electrode includes a pyrrolopyrrole derivative, a conductive additive, and a binder.

The organic electrode is an organic positive electrode or an organic negative electrode, preferably an organic negative electrode.

The molecular structural formula of the pyrrolopyrrole derivative is as follows:

wherein R is-CH₂COOC(CH₃)₃、-(CH₂)₅CH₃or-CH (CH)₂CH₃)(CH₂)₃CH₃In the above-mentioned manner, the first and second substrates are,

ar is one of the following structural formulas:

the conductive additive is carbon black (SP), and the binder is Polytetrafluoroethylene (PVDF).

The mass ratio of the pyrrolopyrrole derivative to the conductive additive to the binder is 5-8:1-4: 1.

The application of the pyrrolopyrrole derivative in the lithium ion battery also comprises the step of preparing the lithium ion battery by adopting a battery shell, a lithium sheet, an electrolyte solution, a diaphragm, a gasket and a spring sheet.

The lithium sheet serves as a counter electrode.

The electrolyte solution is LiPF₆The concentration of the solution and the electrolyte solution is 1 mol/L.

The diaphragm is made of glass fiber.

The application of the pyrrolopyrrole derivative in the lithium ion battery comprises the following steps:

(1) respectively adding the pyrrolopyrrole derivative, the conductive additive, the binder and the solvent into a mortar which is continuously ground, continuously grinding to obtain uniform slurry, coating the slurry on a metal foil to obtain an organic electrode, drying in vacuum, cooling, and slicing the organic electrode for later use;

(2) and under the condition of nitrogen, assembling the battery shell, the lithium sheet, the electrolyte solution, the diaphragm, the organic electrode, the gasket and the elastic sheet in the glove box in sequence to obtain the lithium ion battery.

In the step (1), the solvent is N-methylpyrrolidone (NMP), and 5mLNMP is required to be added for every 100mg of the pyrrolopyrrole derivative.

The viscosity of the slurry in the step (1) is 3900-.

The metal foil in the step (1) is an aluminum foil or a copper foil; when the organic electrode is an organic cathode, the metal foil is a copper foil.

The diameter of the organic electrode slice in the step (1) is 12 mm.

The invention provides a novel organic lithium ion battery material, the main body of which is a pyrrolopyrrole derivative, the interior of which is provided with a plurality of redox active sites, the voltage and the stability of which are researched through different substitutes and branched chains, and the novel organic lithium ion battery material has good electrochemical performance. The molecular structure of the pyrrolopyrrole derivative mainly researched by the invention is shown as follows:

wherein R is-CH₂COOC(CH₃)₃、-(CH₂)₅CH₃or-CH (CH)₂CH₃)(CH₂)₃CH₃One kind of (1).

The application of the pyrrolopyrrole derivative in the lithium ion battery comprises the following specific steps:

(1) the preparation process of the organic electrode is as follows: since the pyrrolopyrrole derivatives are poor in conductivity, it is necessary to add a conductive additive, carbon black (SP), to enhance the conductivity of the electrode when it is prepared into an organic electrode. The pyrrole and pyrrole derivative, the conductive additive and the binder are respectively added into a mortar for continuous grinding, and a proper amount of solvent (a small amount is added for a plurality of times and slowly dropped) is added for mixing and grinding, so as to prepare the slurry with the viscosity of 3900-. And uniformly coating the ground slurry on a metal foil by using a medical scraper, then putting the metal foil into a vacuum oven, drying the metal foil overnight at 90 ℃ under a vacuum condition, and cooling. The cooled organic electrode was finally removed, sliced with a microtome (12 mm diameter) and weighed for subsequent button cell assembly.

(2) Assembling the battery: the organic electrode does not need to be pretreated, and the organic electrode can be assembled in a glove box filled with nitrogen according to the sequence of a battery shell, a lithium sheet, an electrolyte solution, a diaphragm, the organic electrode, a gasket and a shrapnel.

When the battery is measured, the quality of the pyrrolopyrrole derivatives in the organic electrode is calculated by the formula a.

Formula a: the mass of the pyrrolopyrrole derivative in the organic electrode (mass of organic electrode-mass of metal foil) x the percentage of the pyrrolopyrrole derivative to the total mass of the pyrrolopyrrole derivative, the conductive additive, and the binder.

The mass of the copper foil with a diameter of 12mm in the present invention was 9.8 mg.

The invention can prepare the lithium ion battery with high capacity and environmental protection.

The invention has an innovative work that the commonly used pyrrolopyrrole derivative containing heterocyclic aromatic hydrocarbon thiophene, furan, pyridine and benzene ring in the photoelectric material is firstly used for the organic electrode of the lithium ion battery, and obtains very considerable performance. For example, a lithium battery prepared from the pyrrolopyrrole Thiophene Dihexane (TDPP) has the reversible specific capacity of more than or equal to 250mAh/g and the charge-discharge cycle number of more than or equal to 70 circles under the current density of 100mA/g, and the capacitance can be increased to 400mA/g after 70 circles of circulation.

The invention has the following beneficial effects:

the pyrrolo-pyrrole derivative lithium ion battery has high specific capacitance and high cycle stability, remarkably overcomes the defects of low voltage caused by the limited characteristics of carbonyl and poor stability caused by easy decomposition of a small molecular structure, and provides an idea for preparing a low-cost high-capacity and high-stability electrode material.

Drawings

FIG. 1 is a cyclic voltammogram of a lithium ion battery prepared in example 1 using pyrrolopyrrole Thiophene Dihexane (TDPP); wherein the scanning rate is 0.1mV/s, and the voltage range is 0-3.5V.

FIG. 2 is a graph of the cycling performance of the lithium ion battery of example 1 prepared with pyrrolopyrrolethiophenedihexane (TDPP) at current densities of 100mA/g and 200 mA/g.

FIG. 3 is a GCD curve for cycles 1, 5, 10, 25, 50 at a current density of 100mA/g for a lithium ion battery prepared in example 1 using pyrrolopyrrolethiophenedihexane (TDPP).

FIG. 4 is a cyclic voltammogram of a lithium ion battery prepared in example 2 using pyrrolopyrrole Furan Dihexane (FDPP); wherein the scanning speed is 0.1mV/s, and the voltage range is 0-3V.

FIG. 5 is a graph of the cycling performance of the lithium ion battery of example 2 prepared with pyrrolopyrrole Furan Dihexane (FDPP) at current densities of 100mA/g, 200mA/g, 500mA/g and 1000 mA/g.

FIG. 6 is a GCD curve for cycles 1, 5, 10, 25, 50 at a current density of 100mA/g for a lithium ion battery prepared in example 2 using pyrrolopyrrole Furanbishexane (FDPP).

Fig. 7 is a graph of the rate at 100, 200, 500, 1000mA/g current density for the lithium ion battery prepared with pyrrolopyrrole thiophene bis-hexane (TDPP) in example 1 and the lithium ion battery prepared with pyrrolopyrrole furan bis-hexane (FDPP) in example 2, respectively.

Detailed Description

The present invention is further described below with reference to examples.