Preparation method of graphene composite conductive paste for lithium ion battery

Abstract

The application discloses a graphene composite conductive slurry for lithium ion batteries and a preparation method thereof, and has the following mass percentage composition: graphene 4-7%, molybdenum disulfide 5-10%, water 50-60%, cellulose ether 0.5-1%, conductive carbon black slurry 15-25%, binder 1-2%, dispersing solvent 5-10%, and conductive additive 8-15%. The application has the advantages that the raw materials can be fully broken and extruded and mixed in a way of wind blowing, rapid impact and breaking, and the preparation of water can be automatically completed according to the amount of the raw materials, so that the prepared conductive slurry is more uniform, has higher viscosity and better conductive effect.

Description

Technical Field

[0001] This invention relates to the technical field of conductive paste preparation, and more particularly to a method for preparing graphene composite conductive paste for lithium-ion batteries. Background Technology

[0002] In recent years, with the development of science and technology and the continuous rise in demand for new energy, lithium-ion batteries have become a hot topic in the field of new energy. During the preparation of lithium-ion batteries, conductive paste is usually added to increase the conductivity of the battery, thereby improving the conductivity utilization efficiency of the battery.

[0003] The existing conductive paste preparation process is relatively complex. The raw materials in the conductive paste have low crushing and mixing efficiency and are relatively dispersed, resulting in a low content of raw materials per unit volume, which has certain limitations. Therefore, it is urgent to design a preparation method for graphene composite conductive paste for lithium-ion batteries to solve the above problems.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art and to propose a method for preparing graphene composite conductive paste for lithium-ion batteries.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for preparing graphene composite conductive paste for lithium-ion batteries includes the following steps:

[0008] S1. During the preparation process, graphene raw materials and molybdenum disulfide raw materials are first placed into the impact multi-section tube one and impact multi-section tube two through two feed tubes respectively, thus completing the placement of raw materials.

[0009] S2. After the raw materials are placed, the operator can start the drive motor to make it rotate multiple fan blades. When the fan blades rotate, they will generate airflow, which will be transmitted to the impact multi-section pipe one and impact multi-section pipe two through two air outlet pipes and two air guide pipes.

[0010] S3. The wind and airflow entering the impact multi-section tube one and impact multi-section tube two will impact the graphene raw material and molybdenum disulfide raw material inside, causing them to impact the connecting hose at high speed from both sides. At this time, the graphene raw material and molybdenum disulfide raw material will collide and break at high speed, and will be squeezed and mixed together.

[0011] S4, the mixed raw materials after the collision will fall on the lifting floating plate through the discharge pipe and fixed plate, and will be piled up on it, the raw material will press the lifting floating plate to move down when it is piled up, so that the preparation water at the lower part of the lifting floating plate will be pressed to the upper part of the lifting floating plate through the one-way liquid pipe, and the mixing of the raw materials and the preparation water will be completed;

[0012] S5, the raw materials can be mixed immediately after starting the servo motor to drive the driving roller to rotate, the driving roller will rotate when it will drive a plurality of fixed wheels and a plurality of stirring blades to rotate, the plurality of stirring blades will rotate when it will fully stir and mix the raw materials and the preparation water, so as to complete the preparation of the conductive slurry;

[0013] S6, when the conductive slurry is prepared, the discharge pipe can be opened to take out the conductive slurry for standby, and the liquid supplement pipe is opened to supplement the preparation water, so as to prepare again.

[0014] The mass percentage composition of the graphene composite conductive slurry for lithium ion battery is as follows: graphene 4%-7%, molybdenum disulfide 5%-10%, water 50%-60%, cellulose ether 0.5%-1%, conductive carbon black slurry 15%-25%, binder 1%-2%, dispersing solvent 5%-10%, and conductive additive 8%-15%.

[0015] In the above-mentioned graphene composite conductive slurry for lithium ion battery, the mass percentage composition is as follows: graphene 4%-6%, molybdenum disulfide 5%-8%, water 50%-57%, cellulose ether 0.8%-1%, conductive carbon black slurry 15%-20%, binder 1%-1.5%, dispersing solvent 5%-7%, and conductive additive 8%-13%.

[0016] In the above-mentioned graphene composite conductive slurry for lithium ion battery, the mass percentage composition is as follows: graphene 5%-6%, molybdenum disulfide 5%-7.5%, water 50%-56%, cellulose ether 0.8%-1%, conductive carbon black slurry 16%-20%, binder 1%-1.5%, dispersing solvent 5.5%-7%, and conductive additive 8%-12%.

[0017] In the above-mentioned graphene composite conductive slurry for lithium ion battery, the mass percentage composition is as follows: graphene 4%, molybdenum disulfide 8%, water 53.2%, cellulose ether 0.8%, conductive carbon black slurry 20%, binder 1%, dispersing solvent 5%, and conductive additive 8%.

[0018] In the above-mentioned graphene composite conductive slurry for lithium ion battery, the binder is one or a combination of several of polyvinylidene fluoride, sodium carboxymethyl cellulose, butadiene rubber, epoxy resin, polyvinyl alcohol and polyacrylic acid.

[0019] In the graphene composite conductive slurry for lithium-ion batteries described above, the dispersing solvent is one or a combination of several of N-methylpyrrolidone, deionized water, N,N-dimethylformamide, N,N-dimethylacetamide, anhydrous ethanol, and tetrahydrofuran.

[0020] In the graphene composite conductive slurry for lithium-ion batteries described above, the conductive additive is one or a combination of conductive graphite, conductive carbon black, carbon nanotubes, and vapor-grown carbon fibers.

[0021] Compared with existing technologies, the advantages of this invention are:

[0022] 1. By setting up impact multi-section tubes, graphene raw materials and molybdenum disulfide raw materials are placed in impact multi-section tube one and impact multi-section tube two respectively, and the high-speed impact by wind power can make the two fully crushed and mixed, resulting in a better mixing effect.

[0023] 2. By setting up a lifting float, the lifting float can automatically float down according to the weight of the raw materials to be mixed, thereby automatically pressing out the corresponding amount of preparation water according to the weight, which can make the injection content of preparation water more accurate.

[0024] 3. By setting up stirring blades, after the water preparation is completed, the servo motor will start to drive the drive roller and multiple stirring blades to rotate, so that the water preparation and crushed raw materials are fully mixed and the preparation of the feed slurry can be completed.

[0025] In summary, the present invention uses a wind-powered rapid impact crushing method, which can fully crush and compress the raw materials, and can automatically inject an appropriate amount of water according to the amount of raw materials, so that the prepared conductive slurry is more uniformly mixed, has higher viscosity, and better conductivity. Attached Figure Description

[0026] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0027] Figure 1 This is a schematic diagram of the preparation apparatus used in the preparation method proposed in this invention;

[0028] Figure 2 for Figure 1 Enlarged view of the node at point A in the middle;

[0029] Figure 3 for Figure 1 Enlarged view of the fixed wheel, stirring blades and their upper connection structure;

[0030] Figure 4 for Figure 1 Enlarged view of the connection structure between the middle air box and its upper part;

[0031] Figure 5 For Figure 1 Enlarged view of the inner part connection structure of the feed pipe.

[0032] In the figure: 1 preparation box, 2 air box, 3 impact multi-section pipe one, 4 feed pipe, 5 impact multi-section pipe two, 6 air guide pipe, 7 fixed plate, 8 air exchange pipe, 9 servo motor, 10 drive roller, 11 fixed wheel, 12 lifting floating plate, 13 discharge pipe, 14 one-way liquid pipe, 15 preparation water, 16 liquid supplement pipe, 17 connecting hose, 18 discharge pipe, 19 exhaust pipe, 20 stirring blade, 21 self-resetting rotating shaft, 22 fixed groove, 23 air supplement pipe, 24 drive motor, 25 filter screen, 26 air blade, 27 air outlet pipe, 28 fixed disc, 29 stepped groove, 30 barrier disc, 31 reset spring rod. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0035] Embodiment one: graphene composite conductive paste for lithium ion battery, the mass fraction composition is as follows: graphene 4%-7%, molybdenum disulfide 5%-10%, water 50%-60%, cellulose ether 0.5%-1%, conductive carbon black paste 15%-25%, binder 1%-2%, dispersing solvent 5%-10%, conductive additive 8%-15%.

[0036] The dispersing solvent is one or a combination of several of N-methyl pyrrolidone, deionized water, N,N-dimethylformamide, N,N-dimethylacetamide, anhydrous ethanol and tetrahydrofuran.

[0037] The conductive additive is one or a combination of several of conductive graphite, conductive carbon black, carbon nanotube and vapor grown carbon fiber.

[0038] The binder is one or a combination of several of polyvinylidene fluoride, sodium carboxymethyl cellulose, butadiene rubber, epoxy resin, polyvinyl alcohol and polyacrylic acid.

[0039] Example two: graphene composite conductive paste for lithium ion battery, the mass fraction composition is as follows: graphene 4%-6%, molybdenum disulfide 5%-8%, water 50%-57%, cellulose ether 0.8%-1%, conductive carbon black paste 15%-20%, binder 1%-1.5%, dispersion solvent 5%-7%, conductive additive 8%-13%.

[0040] The uniformity of the conductive paste is increased, the positive electrode conductivity is enhanced, and the viscosity fluctuation range is increased.

[0041] Example three: graphene composite conductive paste for lithium ion battery, the mass fraction composition is as follows: graphene 5%-6%, molybdenum disulfide 5%-7.5%, water 50%-56%, cellulose ether 0.8%-1%, conductive carbon black paste 16%-20%, binder 1%-1.5%, dispersion solvent 5.5%-7%, conductive additive 8%-12%.

[0042] The uniformity of the conductive paste is increased, the positive electrode conductivity is enhanced, and the viscosity fluctuation range is increased.

[0043] Example four: graphene composite conductive paste for lithium ion battery, the mass fraction composition is as follows: graphene 4%, molybdenum disulfide 8%, water 53.2%, cellulose ether 0.8%, conductive carbon black paste 20%, binder 1%, dispersion solvent 5%, conductive additive 8%.

[0044] The uniformity of the conductive paste is increased, the positive electrode conductivity is enhanced, the negative electrode conductivity is enhanced, the viscosity fluctuation range is reduced, and the dispersion fluctuation range is reduced.

[0045]

[0046] Performance comparison chart of conductive paste with different content ratio in examples one to four

[0047] Example five: reference Figures 1-2 and Figures 4-5 The preparation device of the graphene composite conductive paste for lithium ion battery comprises a preparation box 1, impact multi-section pipes one 3 and impact multi-section pipes two 5 are fixedly installed on the preparation box 1, and feed pipes 4 are fixedly installed between the impact multi-section pipes one 3 and the impact multi-section pipes two 5 and the preparation box 1, and blocking mechanisms are installed in the two feed pipes 4, two air outlet pipes 27 are installed in the preparation box 1 through air guide mechanisms, air guide pipes 6 are fixedly installed between the two air outlet pipes 27 and the corresponding impact multi-section pipes one 3 and impact multi-section pipes two 5, and a connecting hose 17 is fixedly installed between the impact multi-section pipes one 3 and the impact multi-section pipes two 5.

[0048] The above notable points are as follows:

[0049] 1. The blocking mechanism includes a fixed plate 28 fixedly installed inside the feed pipe 4. A stepped groove 29 is opened in the fixed plate 28. A blocking plate 30 is slidably installed in the stepped groove 29 through the cooperation of a limiting groove and a limiting block. Multiple return spring rods 31 are fixedly installed between the blocking plate 30 and the inner wall of the stepped groove 29. The blocking mechanism serves to block the feed pipe 4, so that the feed pipe 4 can only be connected in one direction and the backflow of material will not occur.

[0050] 2. The air guiding mechanism includes a wind box 2 fixedly installed on the preparation box 1, and two air outlet pipes 27 are fixedly installed on the wind box 2. A drive motor 24 and a filter screen 25 are fixedly installed inside the wind box 2, and multiple fan blades 26 are rotatably installed between the drive motor 24 and the filter screen 25. Multiple air supply pipes 23 are fixedly installed on the wind box 2.

[0051] 3. The graphene raw material and the molybdenum disulfide raw material are placed in the impact multi-section tube 3 and the impact multi-section tube 5 respectively, and the high-speed impact by wind blowing can make the two fully crushed and mixed, resulting in a better mixing effect.

[0052] Reference Figures 1-3 A fixed plate 7 is fixedly installed inside the preparation box 1, and a discharge pipe 18 is fixedly installed between the fixed plate 7 and the connecting hose 17. Multiple exhaust pipes 19 are fixedly installed on the discharge pipe 18. A lifting float 12 is installed inside the preparation box 1 through a sliding mechanism, and the lower part of the lifting float 12 is filled with preparation water 15. Multiple one-way liquid pipes 14 are fixedly installed on the lifting float 12. Multiple stirring blades 20 are installed inside the preparation box 1 through a rotating mechanism.

[0053] The following points are worth noting:

[0054] The sliding mechanism includes a trapezoidal slider fixedly installed on the lifting float 12. A trapezoidal groove is provided in the preparation box 1, and the trapezoidal slider is engaged in the trapezoidal groove. The sliding mechanism is used to ensure that the lifting float 12 can only slide up and down within the preparation box 1, without shifting or separating from the preparation box 1.

[0055] The rotating mechanism includes a servo motor 9 fixedly installed in the preparation box 1. Multiple fixed wheels 11 are fixedly installed on the drive end of the servo motor 9 via a drive roller 10. A self-resetting shaft 21 is rotatably installed in each fixed wheel 11, and multiple stirring blades 20 are respectively fixedly installed on the self-resetting shaft 21.

[0056] Each stirring blade 20 has a fixing groove 22, a liquid replenishment pipe 16 is fixedly installed on the preparation box 1, and the upper surface of the lifting float 12 is triangularly inclined.

[0057] Control valves are installed in both the replenishment pipe 16 and the discharge pipe 13, and multiple conical pipes are installed in both the impact multi-section pipe 1 3 and the impact multi-section pipe 2 5.

[0058] Embodiment six: a method for preparing a graphene composite conductive slurry for lithium ion batteries, comprising the following steps:

[0059] S1, when preparing, first put the graphene raw materials and molybdenum disulfide raw materials into the impact multi-section pipe one 3 and the impact multi-section pipe two 5 through two feeding pipes 4 respectively, which can complete the placement of the raw materials;

[0060] S2, after the raw materials are placed, the operator can start the drive motor 24 to drive the multiple fan blades 26 to rotate, and the fan blades 26 will generate wind power flow when rotating, which will be conducted to the impact multi-section pipe one 3 and the impact multi-section pipe two 5 through two air outlet pipes 27 and two air ducts 6;

[0061] S3, the wind power flow entering the impact multi-section pipe one 3 and the impact multi-section pipe two 5 will impact the graphene raw materials and the molybdenum disulfide raw materials inside, so that they are impacted at high speed from both sides to the connecting hose 17, at this time the graphene raw materials and the molybdenum disulfide raw materials will collide and break at high speed, and will be extruded and mixed with each other;

[0062] S4, the raw materials after collision and mixing will fall on the lifting floating plate 12 through the discharging pipe 18 and the fixed plate 7, and will be stacked thereon, and the lifting floating plate 12 will be driven downward when the raw materials are stacked, so as to press the preparation water 15 at the lower part of the lifting floating plate 12 to the upper part of the lifting floating plate 12 through the one-way liquid inlet pipe 14, and complete the mixing of the raw materials and the preparation water 15;

[0063] S5, after the raw materials are mixed, the servo motor 9 can be started to drive the drive roller 10 to rotate, and the drive roller 10 will drive the multiple fixed wheels 11 and the multiple stirring blades 20 to rotate when rotating, and the multiple stirring blades 20 will fully stir and mix the raw materials and the preparation water 15 when rotating, which can complete the preparation of the conductive slurry;

[0064] S6, when the conductive slurry is prepared, the discharge pipe 13 can be opened to take out the conductive slurry for standby, and the liquid supplement pipe 16 is opened to supplement the preparation water 15, so as to prepare again.

[0065] Further, the above-mentioned fixed connection should be understood in a broad sense unless otherwise specified and limited, for example, it can be welding, or gluing, or integrally formed, etc. The skilled in the art is familiar with the conventional means.

[0066] It is to be noted that, in the present text, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0067] The above description is only the preferred embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacements or changes according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered by the protection scope of the present application.

Claims

1. A method for preparing graphene composite conductive paste for lithium-ion batteries, characterized in that, Includes the following steps: S1. During preparation, graphene raw material and molybdenum disulfide raw material are first placed into impact multi-section tube one (3) and impact multi-section tube two (5) through two feed pipes (4) respectively, and the placement of raw materials can be completed. S2. After the raw materials are placed, the operator can start the drive motor (24) to drive multiple fan blades (26) to rotate. When the fan blades (26) rotate, they will generate airflow, which will be transmitted to the impact multi-section pipe one (3) and the impact multi-section pipe two (5) through two air outlet pipes (27) and two air guide pipes (6). S3. The wind and airflow entering the impact multi-section tube one (3) and the impact multi-section tube two (5) will impact the graphene raw material and molybdenum disulfide raw material inside, causing them to impact the connecting hose (17) at high speed from both sides. At this time, the graphene raw material and molybdenum disulfide raw material will collide and break at high speed, and will be squeezed and mixed together. S4. The raw materials after collision and mixing will fall onto the lifting float (12) through the feed pipe (18) and the fixed plate (7), and will accumulate on it. When the raw materials accumulate, they will press the lifting float (12) down, thereby pressing the preparation water (15) at the bottom of the lifting float (12) to the top of the lifting float (12) through the one-way liquid pipe (14), thus completing the mixing of raw materials and preparation water (15). S5. After the raw materials are mixed, the servo motor (9) can be started to drive the drive roller (10) to rotate. When the drive roller (10) rotates, it will drive multiple fixed wheels (11) and multiple stirring blades (20) to rotate. When the multiple stirring blades (20) rotate, they will fully stir and mix the raw materials and the preparation water (15), and the preparation of the conductive paste can be completed. S6. After the conductive slurry is prepared, the discharge pipe (13) can be opened to take out the conductive slurry for later use, and the replenishment pipe (16) can be opened to replenish the preparation water (15) so that it can be prepared again.

2. The method for preparing the graphene composite conductive paste for lithium-ion batteries according to claim 1, characterized in that, The conductive paste has the following composition by mass fraction: graphene 4%-7%, molybdenum disulfide 5%-10%, water 50%-60%, cellulose ether 0.5%-1%, conductive carbon black paste 15%-25%, binder 1%-2%, dispersion solvent 5%-10%, and conductive additives 8%-15%.

3. The method for preparing the graphene composite conductive paste for lithium-ion batteries according to claim 2, characterized in that, The conductive paste has the following composition by mass fraction: graphene 4%-6%, molybdenum disulfide 5%-8%, water 50%-57%, cellulose ether 0.8%-1%, conductive carbon black paste 15%-20%, binder 1%-1.5%, dispersing solvent 5%-7%, and conductive additives 8%-13%.

4. The method for preparing the graphene composite conductive paste for lithium-ion batteries according to claim 2, characterized in that, The conductive paste has the following composition by mass fraction: graphene 5%-6%, molybdenum disulfide 5%-7.5%, water 50%-56%, cellulose ether 0.8%-1%, conductive carbon black paste 16%-20%, binder 1%-1.5%, dispersant 5.5%-7%, and conductive additives 8%-12%.

5. The method for preparing the graphene composite conductive paste for lithium-ion batteries according to claim 2, characterized in that, The conductive paste has the following composition by mass fraction: graphene 4%, molybdenum disulfide 8%, water 53.2%, cellulose ether 0.8%, conductive carbon black paste 20%, binder 1%, dispersing solvent 5%, and conductive additive 8%.

6. The method for preparing the graphene composite conductive paste for lithium-ion batteries according to any one of claims 2-5, characterized in that, The adhesive is one or a combination of several of the following: polyvinylidene fluoride, sodium carboxymethyl cellulose, styrene-butadiene rubber, epoxy resin, polyvinyl alcohol, and polyacrylic acid.

7. The method for preparing the graphene composite conductive paste for lithium-ion batteries according to any one of claims 2-5, characterized in that, The dispersing solvent is one or a combination of several of N-methylpyrrolidone, deionized water, N,N-dimethylformamide, N,N-dimethylacetamide, anhydrous ethanol, and tetrahydrofuran.

8. The method for preparing the graphene composite conductive paste for lithium-ion batteries according to any one of claims 2-5, characterized in that, The conductive additive is one or a combination of several of conductive graphite, conductive carbon black, carbon nanotubes, and vapor-grown carbon fibers.

Images