Lithium ion battery cathode material, preparation method and application thereof
By preparing anthraquinone polymers as cathode materials for lithium-ion batteries, the problems of solubility and poor conductivity of small-molecule organic active materials have been solved, achieving high capacity and high energy density of lithium-ion batteries, which are suitable for power supplies for new energy vehicles.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGXI NON FERROUS METALS GROUP HUIYUANMENGYE
- Filing Date
- 2026-02-03
- Publication Date
- 2026-06-09
AI Technical Summary
Small molecule organic active materials are easily soluble in organic solvents, which leads to a decrease in the capacity retention rate of lithium-ion battery cathode materials and poor conductivity, requiring a large amount of conductive agent to compensate, but reducing energy density.
Anthraquinone polymers were used as positive electrode materials. The polymers were prepared through nucleophilic substitution and Suzuki-Miyaura coupling reaction, introducing a biphenyl backbone to form a high molecular weight active material. Conductive agents and binders were added and then coated onto the current collector.
It effectively suppresses the volume expansion and capacity decay of lithium-ion batteries, improves conductivity, reduces the amount of conductive agent used, and enhances charge transport efficiency.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to a lithium-ion battery cathode material, its preparation method, and its application. Background Technology
[0002] Contemporary lithium-ion battery technology mainly relies on transition metal oxides or phosphates as positive electrode active materials, which depend on rare metals such as cobalt and nickel. Given the increasingly tight supply of rare metal resources, organic active materials have become a research hotspot due to their wide availability and recyclability. Compared to transition metal oxides or phosphates, organic active materials generally have higher specific capacity and energy density. However, small-molecule organic active materials exhibit a significant solubility tendency in commonly used organic electrolytes, which will cause continuous decay of the active material in the positive electrode and volume changes, severely affecting the cycle capacity retention rate of lithium-ion batteries. Furthermore, small-molecule organic active materials are generally non-conductive, with extremely low intrinsic conductivity. When using small-molecule organic active materials as positive electrode active materials, more conductive agents are often required, which will significantly reduce the energy density of the electrode. To address these technical shortcomings, this invention provides a lithium-ion battery positive electrode material, its preparation method, and its application. Summary of the Invention
[0003] The purpose of this invention is to provide a lithium-ion battery cathode material, its preparation method, and its application. An anthraquinone polymer is prepared as an active material in the lithium-ion battery cathode material to solve the problems mentioned in the background art, such as the possible dissolution of small molecule organic active materials in organic solvents and the poor conductivity of small molecule organic active materials.
[0004] The objective of this invention can be achieved through the following technical solutions:
[0005] A method for preparing a lithium-ion battery cathode material includes the following steps:
[0006] Step 1: Using chlororanic acid and barbituric acid as raw materials, polymer units are obtained through nucleophilic substitution reaction;
[0007] Under nitrogen protection, chlorogenic acid, barbituric acid, triethylamine, and dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a reflux condenser, and a rotor. Magnetic stirring was turned on, and the reaction was carried out at a temperature of 75–95 °C for 24–48 h. After the reaction was completed, the mixture was cooled to room temperature and poured into cold deionized water. The solid was separated by filtration, washed with methanol, and dried to obtain the polymerization unit.
[0008]
[0009] The second step involves using polymer units and 4,4′-biphenyl diboronic acid as raw materials to obtain the active substance via a Suzuki-Miyaura coupling reaction.
[0010] Under nitrogen protection, the polymerization unit, 4,4′-biphenyl diboronic acid, potassium carbonate aqueous solution, tetrakis(triphenylphosphine)palladium, and dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a reflux condenser, and a rotor. Magnetic stirring was turned on, and the reaction was carried out at 140–160 °C for 36–48 h. After the reaction was completed, the mixture was cooled to room temperature and poured into deionized water. After filtering to separate the solid, the mixture was washed with dichloromethane and anhydrous ethanol in sequence and then dried to obtain the active substance.
[0011]
[0012] The third step involves mixing the active material, conductive agent, and binder, dissolving them in an organic solvent, coating them onto the surface of the current collector, and drying them to obtain the positive electrode material for lithium-ion batteries.
[0013] Preferably, the conductive agent is at least one of Ketjen Black and acetylene black.
[0014] Preferably, the adhesive is polyvinylidene fluoride.
[0015] Preferably, the organic solvent is at least one of N-methylpyrrolidone and dimethyl sulfoxide.
[0016] Preferably, the current collector is aluminum foil.
[0017] Preferably, in the first step, the mass ratio of chloric acid to barbituric acid is 4.2–6.3:1.3.
[0018] Preferably, in the second step, the mass ratio of the polymerization unit to 4,4′-biphenyldiboronic acid is 2.8–3.6:1.4–1.8.
[0019] Preferably, in the third step, the mass ratio of active material, conductive agent, and binder is 1.48–1.56: 0.24–0.28: 0.2–0.24.
[0020] Preferably, the drying conditions in the third step are drying in a vacuum drying oven at a temperature of 100-120°C for 10-12 hours.
[0021] The present invention also provides a lithium-ion battery cathode material obtained by the above preparation method.
[0022] The lithium-ion battery cathode material provided by this invention is applied in the field of new energy vehicle power supply.
[0023] The beneficial effects of this invention are:
[0024] 1) This invention prepares anthraquinone units into polymers and introduces a rigid biphenyl skeleton into the polymers to obtain active materials, which greatly increases the molecular weight of the anthraquinone units. The active materials of this invention can effectively solve the problems of swelling and loss of organic active materials in organic electrolytes and suppress the volume expansion and capacity decay of lithium-ion batteries during use.
[0025] 2) This invention introduces biphenyl units into the active material, connecting the electron-deficient anthraquinone system and the electron-rich biphenyl system together. This can extend the effective conjugation length of the entire polymer molecule, enhance the degree of electron delocalization, improve the intrinsic conductivity of the polymer molecule, and thus reduce the amount of conductive agent used in the cathode material.
[0026] 3) The lithium-ion battery cathode material of the present invention has a tertiary amine structure. The tertiary amine structure can not only use its own lone pair electrons to form a p-π conjugated network with anthraquinone, enhance the electron delocalization ability within the molecule and improve the intrinsic conductivity of the polymer molecule, but also protonate to form quaternary ammonium cations during use, and use electrostatic interaction to attract anions in the electrolyte, accelerate the migration of lithium ions and improve the charge transport efficiency of the lithium-ion battery. Detailed Implementation
[0027] The technical solutions of the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application.
[0028] The raw materials used in this invention are not particularly restricted in terms of their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.
[0029] Example 1
[0030] A method for preparing a lithium-ion battery cathode material includes the following steps:
[0031] Step 1: Using chlororanic acid and barbituric acid as raw materials, polymer units are obtained through nucleophilic substitution reaction;
[0032] Under nitrogen protection, 4.2 parts by mass of chlororanic acid, 1.3 parts by mass of barbituric acid, 2 parts by mass of triethylamine, and 25 parts by mass of dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a reflux condenser, and a rotor. Magnetic stirring was turned on, and the reaction was carried out at 75°C for 48 hours. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was poured into cold deionized water. After filtering to separate the solid, the mixture was washed with methanol and dried to obtain the polymerization unit.
[0033] The second step involves using polymer units and 4,4′-biphenyl diboronic acid as raw materials to obtain the active substance via a Suzuki-Miyaura coupling reaction.
[0034] Under nitrogen protection, 2.8 parts by mass of polymer units, 1.4 parts by mass of 4,4′-biphenyl diboronic acid, 12 parts by mass of a 2 mol / L potassium carbonate aqueous solution, 0.024 parts by mass of tetra(triphenylphosphine)palladium, and 40 parts by mass of dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a reflux condenser, and a rotor. Magnetic stirring was turned on, and the reaction was carried out at 140℃ for 48 h. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was poured into deionized water. After filtering to separate the solid, the mixture was washed with dichloromethane and anhydrous ethanol in sequence and then dried to obtain the active substance.
[0035] The third step involves mixing 1.48 parts by mass of active material, 0.28 parts by mass of acetylene black, and 0.24 parts by mass of polyvinylidene fluoride, dissolving them with N-methylpyrrolidone, and then coating the mixture onto the surface of aluminum foil. The aluminum foil is then placed in a vacuum drying oven and dried at 110°C for 12 hours to obtain the lithium-ion battery cathode material.
[0036] A lithium-ion battery cathode material, prepared by the above method.
[0037] An application of a lithium-ion battery cathode material, wherein the lithium-ion battery cathode material is applied in the field of power supply for new energy vehicles.
[0038] Example 2
[0039] A method for preparing a lithium-ion battery cathode material includes the following steps:
[0040] Step 1: Using chlororanic acid and barbituric acid as raw materials, polymer units are obtained through nucleophilic substitution reaction;
[0041] Under nitrogen protection, 6.3 parts by mass of chlororanic acid, 1.3 parts by mass of barbituric acid, 2.4 parts by mass of triethylamine, and 35 parts by mass of dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a reflux condenser, and a rotor. Magnetic stirring was turned on, and the reaction was carried out at 95°C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was poured into cold deionized water. After filtering to separate the solid, the mixture was washed with methanol and dried to obtain the polymerization unit.
[0042] The second step involves using polymer units and 4,4′-biphenyl diboronic acid as raw materials to obtain the active substance via a Suzuki-Miyaura coupling reaction.
[0043] Under nitrogen protection, 3.6 parts by mass of polymerization unit, 1.8 parts by mass of 4,4′-biphenyldiboronic acid, 18 parts by mass of 2 mol / L potassium carbonate aqueous solution, 0.040 parts by mass of tetra(triphenylphosphine)palladium, and 50 parts by mass of dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a reflux condenser, and a rotor. Magnetic stirring was turned on, and the reaction was carried out at 160℃ for 36 h. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was poured into deionized water. After filtering to separate the solid, the mixture was washed with dichloromethane and anhydrous ethanol in sequence and then dried to obtain the active substance.
[0044] The third step involves mixing 1.52 parts by mass of active material, 0.26 parts by mass of acetylene black, and 0.22 parts by mass of polyvinylidene fluoride, dissolving them with N-methylpyrrolidone, and then coating the mixture onto the surface of aluminum foil. The aluminum foil is then placed in a vacuum drying oven and dried at 120°C for 11 hours to obtain the lithium-ion battery cathode material.
[0045] A lithium-ion battery cathode material, prepared by the above method.
[0046] An application of a lithium-ion battery cathode material, wherein the lithium-ion battery cathode material is applied in the field of power supply for new energy vehicles.
[0047] Example 3
[0048] A method for preparing a lithium-ion battery cathode material includes the following steps:
[0049] Step 1: Using chlororanic acid and barbituric acid as raw materials, polymer units are obtained through nucleophilic substitution reaction;
[0050] Under nitrogen protection, 5.25 parts by mass of chlororanic acid, 1.3 parts by mass of barbituric acid, 2.2 parts by mass of triethylamine, and 30 parts by mass of dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a reflux condenser, and a rotor. Magnetic stirring was turned on, and the reaction was carried out at 85°C for 36 hours. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was poured into cold deionized water. After filtering to separate the solid, the mixture was washed with methanol and dried to obtain the polymerization unit.
[0051] The second step involves using polymer units and 4,4′-biphenyl diboronic acid as raw materials to obtain the active substance via a Suzuki-Miyaura coupling reaction.
[0052] Under nitrogen protection, 3.2 parts by mass of polymer unit, 1.6 parts by mass of 4,4′-biphenyl diboronic acid, 15 parts by mass of 2 mol / L potassium carbonate aqueous solution, 0.032 parts by mass of tetra(triphenylphosphine)palladium, and 45 parts by mass of dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a reflux condenser, and a rotor. Magnetic stirring was turned on, and the reaction was carried out at 150°C for 42 h. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was poured into deionized water. After filtering to separate the solid, the mixture was washed with dichloromethane and anhydrous ethanol in sequence and then dried to obtain the active substance.
[0053] The third step involves mixing 1.56 parts by weight of active material, 0.24 parts by weight of Ketjen black, and 0.2 parts by weight of polyvinylidene fluoride, dissolving them with dimethyl sulfoxide, and then coating the mixture onto the surface of aluminum foil. The aluminum foil is then placed in a vacuum drying oven and dried at 100°C for 10 hours to obtain the positive electrode material for lithium-ion batteries.
[0054] A lithium-ion battery cathode material, prepared by the above method.
[0055] An application of a lithium-ion battery cathode material, wherein the lithium-ion battery cathode material is applied in the field of power supply for new energy vehicles.
[0056] Comparative Example 1
[0057] The difference between this comparative example and Example 3 is that the active substance is not prepared separately, but instead the small molecule anthraquinone compound 1,4,5,8-tetrahydroxy-9,10-anthraquinone is used to replace the active substance in Example 3.
[0058] A method for preparing a lithium-ion battery cathode material includes the following steps:
[0059] 1.56 parts by weight of 1,4,5,8-tetrahydroxy-9,10-anthraquinone, 0.24 parts by weight of Ketjen black, and 0.2 parts by weight of polyvinylidene fluoride were mixed and dissolved in dimethyl sulfoxide and then coated onto the surface of aluminum foil. The aluminum foil was then placed in a vacuum drying oven and dried at 100°C for 10 h to obtain the lithium-ion battery cathode material.
[0060] A lithium-ion battery cathode material, prepared by the above method.
[0061] An application of a lithium-ion battery cathode material, wherein the lithium-ion battery cathode material is applied in the field of power supply for new energy vehicles.
[0062] Experimental Example 1
[0063] Using the lithium-ion battery cathode materials obtained in Examples 1-3 and Comparative Example 1 as the cathode materials of lithium-ion batteries, lithium metal sheets as counter electrodes, and polypropylene fibers as separators, diethyl carbonate and ethylene carbonate were mixed at a mass ratio of 3:7 as the electrolyte. Lithium-ion batteries were assembled in a nitrogen-protected glove box. The electrochemical performance of each component of the lithium-ion battery was tested and characterized using an electrochemical workstation. The test results are shown in Table 1.
[0064] Table 1
[0065]
[0066] As can be seen from Table 1, the lithium-ion battery cathode materials of the present invention in Examples 1 to 3 have higher specific capacity and energy density, and the cycle capacity retention rate is much better than that of conventional small molecule anthraquinone compounds. Since the anthraquinone compounds in Comparative Example 1 have not been modified, their conductivity is poor. Therefore, the amount of conductive agent added is insufficient to maintain the electron transport network of the battery, and some active materials cannot participate in the electrochemical reaction, which seriously affects the actual capacity of the battery.
[0067] The descriptions of the above embodiments are merely illustrative of the methods and core ideas of the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing a lithium-ion battery cathode material, characterized in that, Includes the following steps: Using chlororanic acid and barbituric acid as raw materials, a polymer unit is obtained through a nucleophilic substitution reaction. Then, using the polymer unit and 4,4′-biphenyl diboronic acid as raw materials, an active material is obtained through a Suzuki-Miyaura coupling reaction. Finally, the active material, conductive agent, and binder are mixed, dissolved in an organic solvent, and coated onto the surface of the current collector. After drying, the positive electrode material for lithium-ion batteries is obtained.
2. The method for preparing a lithium-ion battery cathode material according to claim 1, characterized in that, The conductive agent is at least one of Ketjen Black and acetylene black.
3. The method for preparing a lithium-ion battery cathode material according to claim 1, characterized in that, The adhesive is polyvinylidene fluoride, and the current collector is aluminum foil.
4. The method for preparing a lithium-ion battery cathode material according to claim 1, characterized in that, The organic solvent is at least one of N-methylpyrrolidone and dimethyl sulfoxide.
5. The method for preparing a lithium-ion battery cathode material according to claim 1, characterized in that, The mass ratio of chloric acid to barbituric acid is 4.2–6.3:1.
3.
6. The method for preparing a lithium-ion battery cathode material according to claim 1, characterized in that, The mass ratio of the polymer unit to 4,4′-biphenyldiboronic acid is 2.8–3.6:1.4–1.
8.
7. The method for preparing a lithium-ion battery cathode material according to claim 1, characterized in that, The mass ratio of active material, conductive agent, and binder is 1.48–1.56: 0.24–0.28: 0.2–0.
24.
8. The method for preparing a lithium-ion battery cathode material according to claim 1, characterized in that, The drying conditions are as follows: drying in a vacuum drying oven at a temperature of 100–120°C for 10–12 hours.
9. The lithium-ion battery cathode material obtained by the preparation method according to claim 1.
10. The application of the lithium-ion battery cathode material according to claim 9 in the field of new energy vehicle power supply.