阅读说明：本技术 一种提升复合碳材料电化学性能的方法及电化学装置 (Method for improving electrochemical performance of composite carbon material and electrochemical device ) 是由 赵丽君 郭曼盈 杨晓红 于 2020-06-30 设计创作，主要内容包括：本发明适用于电化学技术领域,提供了一种提升复合碳材料电化学性能的方法及电化学装置,该方法包括以下步骤：将复合碳材料涂敷于集流体上,得到电极片；所述复合碳材料包括氧化石墨烯、碳纳米管和活性炭；将电极片置于磁场强度为0.05～0.25T的磁场中。本发明通过合理调整复合碳材料中各组分的比例,可以使得复合碳材料具有较大的比表面积和较大的比容量；另外,本发明通过对复合碳材料进行外加磁场处理,使得离子和电子在洛伦兹力作用下,由无序变成有序状态,同时运动轨迹发生改变,为此可提供更多的活性位点,从而可以在提高复合碳材料的比电容的同时,又能保持其良好的倍率性能和循环性能。(The invention is suitable for the technical field of electrochemistry, and provides a method for improving the electrochemical performance of a composite carbon material and an electrochemical device, wherein the method comprises the following steps: coating the composite carbon material on a current collector to obtain an electrode plate; the composite carbon material comprises graphene oxide, carbon nanotubes and activated carbon; and placing the electrode slice in a magnetic field with the magnetic field intensity of 0.05-0.25T. According to the invention, the composite carbon material has a larger specific surface area and a larger specific capacity by reasonably adjusting the proportion of each component in the composite carbon material; in addition, the composite carbon material is subjected to external magnetic field treatment, so that ions and electrons are changed into an ordered state from disorder under the action of Lorentz force, and the motion trail is changed, so that more active sites can be provided, the specific capacitance of the composite carbon material can be improved, and the good rate performance and cycle performance of the composite carbon material can be maintained.)

1. A method for improving electrochemical performance of a composite carbon material is characterized by comprising the following steps:

coating the composite carbon material on a current collector to obtain an electrode plate; the composite carbon material comprises graphene oxide, carbon nanotubes and activated carbon; the mass ratio of the graphene oxide to the carbon nano tube to the activated carbon is (40-50) to (2-8) to (42-58);

and placing the electrode slice in a magnetic field with the magnetic field intensity of 0.05-0.25T.

2. The method for improving the electrochemical performance of the composite carbon material as claimed in claim 1, wherein the step of coating the composite carbon material on a current collector to obtain an electrode sheet specifically comprises:

dispersing a composite carbon material, conductive carbon black and an adhesive in a solvent to obtain a dispersion liquid;

and coating the dispersion liquid on a current collector to obtain the electrode plate.

3. The method for improving the electrochemical performance of the composite carbon material as claimed in claim 2, wherein the mass ratio of the composite carbon material, the conductive carbon black and the binder is (70-90): (5-15): 5-15).

4. The method for improving the electrochemical performance of the composite carbon material as claimed in claim 3, wherein the conductive carbon black is acetylene black.

5. The method for improving electrochemical performance of composite carbon material according to claim 3, wherein the binder is polyvinylidene fluoride.

6. The method for improving the electrochemical performance of the composite carbon material as claimed in claim 2, wherein the solvent is N-methylpyrrolidone.

7. The method for improving the electrochemical performance of the composite carbon material as claimed in claim 1, wherein the magnetic field has a magnetic field strength of 0.1-0.2T.

8. An electrochemical device comprises an electrode plate, and is characterized in that a composite carbon material is arranged on the electrode plate, and the composite carbon material comprises graphene oxide, carbon nanotubes and activated carbon; the mass ratio of the graphene oxide to the carbon nano tube to the activated carbon is (40-50) to (2-8) to (42-58); the electrochemical device further includes:

the magnetic field assembly is used for generating a magnetic field with the magnetic field intensity of 0.05-0.25T; the electrode sheet is arranged in the magnetic field generated by the magnetic field assembly.

9. An electrochemical device according to claim 8, wherein said magnetic field assembly comprises two sets of ferrite magnets; the electrode plate is arranged between the two groups of ferrite magnets.

10. The electrochemical device of claim 8, wherein said electrochemical device has a specific capacity of not less than 191F/g.

Technical Field

The invention belongs to the technical field of electrochemistry, and particularly relates to a method for improving the electrochemical performance of a composite carbon material and an electrochemical device.

Background

The twenty-first century is an information technology age, and with the improvement of the performance requirements of people on intelligent electronic equipment, the use and storage of electric energy become the first problems facing people urgently. The super capacitor is a novel electrochemical energy storage device between a traditional capacitor and a battery, has the advantages of high charging and discharging speed, long cycle life, environmental friendliness and the like, and is considered to be an important choice for a novel power supply in the future. At present, the research focus of the electrode material of the super capacitor is always on the research and development of the anode material, and the development of the cathode material is relatively slow. However, the matching of the anode and cathode materials and the overall improvement of the electrochemical performance can only effectively improve the energy density and the power density of the supercapacitor. The negative electrode material is mainly a carbon material, wherein a composite carbon material synthesized by graphene oxide, carbon nanotubes and activated carbon is used as the negative electrode material, so that the negative electrode material has better conductivity, and the capacity, the multiplying power and the cycle performance of the negative electrode material still need to be improved.

At present, the design of novel electrode material structure and adjustment of material types (such as by adding materials with pseudo-capacitive properties) are the main means for improving the electrochemical properties of capacitor electrodes, however, the method for further improving the electrochemical properties of the capacitor electrode materials is close to the bottleneck period, so that the finding of a method capable of generally enhancing the electrochemical properties of the capacitor electrode materials has great significance.

The magnetic field technology is an effective method capable of generally enhancing the electrochemical performance of a capacitor electrode material, and because the magnetic field has the action of Lorentz force on electrons and ions which do Brownian motion, the migration behavior of the electrons and the ions is changed from disorder to order, and the motion path is deflected at a certain angle, so that an effective channel is provided for the transmission of the electrons and the ions; meanwhile, according to different paramagnetic and diamagnetic properties of molecules, the oxygen mass transfer diffusion coefficient, the charge transfer coefficient, the double electric layer capacitance, the charge transfer resistance and the like in the capacitor are influenced to a certain extent, and further the electrochemical performance of the capacitor is influenced.

The patent with the application number CN 201610515270.5 discloses that the magnetic field regulates different phases Co (OH)₂Method for producing materials and use thereof"in" it discloses that the magnetic field is put in the synthesis of material, and the material is phase-changed by the magnetic field, so as to obtain different Co (OH)₂The electrochemical performance is improved; patent application No. CN201910528751.3 discloses a preparation method of magnetic field induced nickel chloride/polyaniline supercapacitor electrode materials, which discloses that the electrochemical performance is changed by changing the shape sequence arrangement of materials by adding a magnetic field in the process of preparing electrodes from the materials. In the above modes, the morphology is changed by an external magnetic field in the material synthesis process to improve the electrochemical performance of the material, but the method of the external magnetic field in the electrochemical performance test is almost not available.

Disclosure of Invention

The embodiment of the invention aims to provide a method for improving the electrochemical performance of a composite carbon material, and aims to solve the problems in the background art.

The embodiment of the invention is realized in such a way that a method for improving the electrochemical performance of a composite carbon material comprises the following steps:

coating the composite carbon material on a current collector to obtain an electrode plate; the composite carbon material comprises graphene oxide, carbon nanotubes and activated carbon; the mass ratio of the graphene oxide to the carbon nano tube to the activated carbon is (40-50) to (2-8) to (42-58);

and placing the electrode slice in a magnetic field with the magnetic field intensity of 0.05-0.25T.

As a preferred scheme of the embodiment of the present invention, the step of coating the composite carbon material on the current collector to obtain the electrode sheet specifically includes:

dispersing a composite carbon material, conductive carbon black and an adhesive in a solvent to obtain a dispersion liquid;

and coating the dispersion liquid on a current collector to obtain the electrode plate.

As another preferable scheme of the embodiment of the invention, the mass ratio of the composite carbon material, the conductive carbon black and the adhesive is (70-90): (5-15): 5-15).

As another preferable mode of the embodiment of the present invention, the conductive carbon black is acetylene black.

As another preferable mode of the embodiment of the present invention, the binder is polyvinylidene fluoride.

As another preferred embodiment of the present invention, the solvent is N-methylpyrrolidone.

As another preferable scheme of the embodiment of the invention, the magnetic field intensity of the magnetic field is 0.1-0.2T.

Another object of an embodiment of the present invention is to provide an electrochemical device, including an electrode sheet, on which a composite carbon material is disposed, the composite carbon material including graphene oxide, carbon nanotubes, and activated carbon; the mass ratio of the graphene oxide to the carbon nano tube to the activated carbon is (40-50) to (2-8) to (42-58); the electrochemical device further includes:

the magnetic field assembly is used for generating a magnetic field with the magnetic field intensity of 0.05-0.25T; the electrode sheet is arranged in the magnetic field generated by the magnetic field assembly.

As another preferable solution of the embodiment of the present invention, the magnetic field component includes two sets of ferrite magnets; the electrode plate is arranged between the two groups of ferrite magnets.

As another preferable scheme of the embodiment of the invention, the specific capacity of the electrochemical device is not lower than 191F/g.

According to the method for improving the electrochemical performance of the composite carbon material, provided by the embodiment of the invention, the proportion of each component in the composite carbon material is reasonably adjusted, so that the stacking of graphene oxide is smaller, the graphene oxide has a larger specific surface area, the activated carbon is less in agglomeration, and meanwhile, a larger specific capacity can be provided; in addition, the composite carbon material is subjected to external magnetic field treatment, so that ions and electrons are changed into an ordered state from disorder under the action of Lorentz force, and the motion trail is changed, so that more active sites can be provided, the specific capacitance of the composite carbon material can be improved, and the good rate performance and cycle performance of the composite carbon material can be maintained.

Drawings

FIG. 1 is an SEM photograph of a composite carbon material obtained in example 1 of the present invention.

FIG. 2 is a CV diagram of the composite carbon material obtained in example 1 of the present invention in a magnetic field of 0.15T.

FIG. 3 is a magnification chart of the composite carbon material obtained in example 1 of the present invention in a magnetic field of 0.15T.

FIG. 4 is a graph showing the cycle performance of the composite carbon material prepared in example 1 of the present invention in a magnetic field of 0.15T.

FIG. 5 is a graph showing the impedance of the composite carbon material obtained in example 1 of the present invention in a magnetic field of 0.15T.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.