Dry electrode dry slurry molecular phase mixing system
By using organic solvents to dissolve the binder and evaporate it in the dry electrode mixing system of lithium-ion batteries, combined with solvent recycling and dual planetary stirring components, the performance degradation and production complexity of wet and dry mixing methods are solved, and the problem of production complexity of wet and dry mixing methods is achieved. High solids and uniform mixing extend battery life and reduce costs.
Patent Information
- Application Number
- CN202420865265.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-24
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-04-24
AI Technical Summary
The wet and dry mixing methods of existing lithium-ion batteries have problems of performance degradation and production complexity. The wet method leads to large solvent consumption and contamination, and the dry method leads to uneven molecular phases, affecting the battery cycle life.
Using a dry electrode dry slurry molecular phase mixing system, high solid content and uniform mixing are achieved by dissolving the binder in a horizontal stirring tank using organic solvents, and evaporating the solvent by heating, combining solvent recycling and dual planetary stirring components. .
Improves the uniformity of materials and battery performance, extends service life, reduces solvent consumption and pollution, and reduces production costs.
Smart Images
Figure CN222173862U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of lithium ion battery manufacturing and relates to a mixing system, in particular to a dry electrode dry pulp molecular phase mixing system. Background Art
[0002] At present, wet electrode slurry is mostly used in the production of positive and negative plates of lithium-ion batteries at home and abroad. The production equipment is a vertical double planetary mixer. The mixing method is: the positive and negative electrode materials, conductive agents, binders, and solvents of lithium-ion batteries are added to the vertical double planetary mixer in proportion and then stirred in a closed meshing manner. The advantage is that after the binder swells and dissolves in the solvent, it can be fully mixed with the multi-component powder material in molecular phase and smallest particle phase. However, its disadvantages are also obvious, that is, the wet electrode slurry is in a fluid state during the coating process, and the agglomeration of small particles caused by Brownian motion cannot be avoided, resulting in a decrease in battery performance. In addition, the solvent needs to be dried after coating, resulting in a series of problems such as complex and lengthy production lines, large solvent consumption, high energy consumption, and solvent emission pollution, which is not conducive to the development of the battery industry.
[0003] In view of the shortcomings of the above wet mixing, a dry electrode powder mixing method has also been proposed in the prior art, that is, the positive and negative electrode materials, conductive agents, and binders of lithium-ion batteries are prepared according to the process requirements and added to a binder fiberizing mixer. Without using any solvent, the binder fiberizing mixer is heated to about 270°C, and then the powdered binder is pulled into fibers through meshing stirring, and the multi-component powder materials are netted together and directly mixed to form an electrode dry powder with a solid content of 100%. However, the disadvantage is that the fibrous binder cannot achieve full mixing of its molecular phase with the smallest particle phase of the multi-component material, resulting in a significant decrease in battery performance, especially a decrease in battery cycle life.
[0004] Both the wet mixing and dry mixing methods mentioned above have certain disadvantages. Therefore, inventing a new mixing method is an urgent problem to be solved. Utility Model Content
[0005] In order to solve the above deficiencies in the prior art, the utility model aims to provide a dry electrode dry slurry molecular phase mixing system to achieve full mixing of materials, so that small particles of the mixed materials do not agglomerate during the coating process, and the battery prepared using the material has good performance and long service life.
[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:
[0007] A dry electrode dry slurry molecular phase mixing system comprises a stirring kettle and a nitrogen metering tank, a main powder raw material metering tank, and a conductive slurry sol stirring metering tank which are respectively connected to the stirring kettle through pipelines; an organic solvent metering tank and an adhesive conductive agent auxiliary material metering tank are respectively connected to the conductive slurry sol stirring metering tank through pipelines; the conductive slurry sol stirring metering tank is connected to a solvent recycling metering tank through a pipeline, and the stirring kettle is connected to the solvent recycling metering tank through a solvent collecting device; the stirring kettle is provided with a heating system.
[0008] As a limitation of the present utility model, the solvent collection device includes a solvent vapor exhaust device and a solvent condensation recovery heat exchange device which are connected in sequence through pipelines, wherein the solvent vapor exhaust device is connected to the stirring tank through a pipeline, and the solvent condensation recovery heat exchange device is connected to the solvent recycling metering tank through a pipeline; and the solvent condensation recovery heat exchange device is connected to a refrigeration device through a pipeline.
[0009] As a further limitation of the present invention, the conductive slurry sol stirring and metering tank is provided with a heating system.
[0010] As another limitation of the present invention, the stirring kettle is a horizontal structure, including a shell, a left-end stirring assembly and a right-end stirring assembly, and a dry pulp discharge port is provided at the center of the length direction of the shell;
[0011] The left end stirring assembly includes a left power motor, a left planetary gear train and a left-handed planetary propeller which are assembled in sequence;
[0012] The right end stirring assembly comprises a right power motor, a right planetary gear train and a right-hand planetary propeller which are assembled in sequence.
[0013] As a limitation of the present utility model, the dry slurry discharge port of the stirring kettle is connected to a dry slurry buffer tank via a screw conveyor.
[0014] As a further limitation of the present utility model, the dry pulp buffer tank is provided with a weighing device.
[0015] As a further limitation of the present invention, in the mixing system, all connecting pipelines are provided with electromagnetic sealing valves.
[0016] Due to the adoption of the above technical solution, the utility model has the following beneficial effects compared with the prior art:
[0017] (1) The utility model first dissolves the adhesive in the conductive slurry sol stirring and metering tank with an organic solvent, and then mixes the dissolved adhesive with the raw materials. During the mixing process, the heating function of the stirring kettle evaporates the organic solvent, and stores it in the solvent recycling metering tank through a solvent collecting device, so that the solid content of the electrode dry slurry material after mixing reaches 95% to 100%. This not only avoids the agglomeration of small particles caused by Brownian motion of the fluid material after wet mixing during coating, but also avoids the waste and pollution caused by the subsequent setting of a baking system to evaporate the solvent, and also avoids the phenomenon of uneven mixing in dry mixing. It not only improves the uniformity of material mixing, but also improves the coating quality during coating, prolongs the service life of the battery, and the solvent is recycled, which reduces costs and avoids pollution.
[0018] (2) The heating system of the conductive slurry sol stirring and metering tank of the utility model can evaporate the excess organic solvent after mixing into the solvent recycling and metering tank, thereby reducing the pressure of evaporating solvent in the stirring tank, avoiding incomplete evaporation in the stirring tank, and increasing the solid content of the mixed material;
[0019] (3) The horizontal stirring kettle structure of the utility model is provided with stirring components on both sides to improve the uniformity of mixing and the efficiency of stirring.
[0020] In summary, the utility model can improve the solid content of the mixed material while ensuring the uniformity of the mixing, recycling the solvent, reducing the cost, avoiding the pollution caused by the discharge, and is suitable for preparing battery slurry. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The present invention is described in further detail below in conjunction with the accompanying drawings and specific embodiments.
[0022] Figure 1 It is a schematic diagram of the connection structure of each device in an embodiment of the utility model;
[0023] Figure 2 It is a schematic structural diagram of a stirring kettle according to an embodiment of the utility model.
[0024] In the figure: 1. stirring kettle; 2. nitrogen inlet; 3. conductive slurry feed port; 4. main powder feed port; 5. solvent vapor outlet; 6. left power motor; 7. left planetary gear train; 8. left-hand planetary propeller; 9. right power motor; 10. right planetary gear train; 11. right-hand planetary propeller; 12; dry slurry outlet; 13. screw conveyor. DETAILED DESCRIPTION
[0025] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and understand the present invention, and are not used to limit the present invention.
[0026] Embodiment A dry electrode dry pulp molecular phase mixing system
[0027] like Figure 1 As shown, this embodiment includes a stirring kettle 1, a nitrogen metering tank, a main powder raw material metering tank, a conductive slurry sol stirring metering tank, an organic solvent metering tank, an adhesive conductive agent auxiliary material metering tank and a solvent collecting device. Among them, the organic solvent metering tank is used to hold the organic solvent in the electrode material, the adhesive conductive agent auxiliary material metering tank is used to hold the adhesive and conductive agent and other auxiliary materials in the electrode material, and the organic solvent, adhesive and conductive agent are input into the conductive slurry sol stirring metering tank for mixing. The main powder raw material metering tank is used to hold the main raw material of the electrode, and is input into the stirring kettle 1 together with the mixed material in the conductive slurry sol stirring metering tank, and the material is stirred, mixed and heated under the action of nitrogen. The solvent collecting device is used to collect the organic solvent evaporated from the stirring kettle 1 during the mixing process.
[0028] The mixing of the present embodiment is divided into two echelons. The first is the mixing of the organic solvent with the adhesive and the conductive agent. Specifically, the organic solvent metering tank and the adhesive conductive agent auxiliary material metering tank are connected to the conductive slurry sol stirring metering tank through pipelines. The organic solvent metering tank and the adhesive conductive agent auxiliary material metering tank both have metering functions, and the two pipelines are provided with electromagnetic sealing valves. The opening and closing of the two electromagnetic sealing valves respectively control the amount of organic solvent and adhesive conductive agent entering the conductive slurry sol stirring metering tank, and the two are mixed in the conductive slurry sol stirring metering tank. The conductive slurry sol stirring metering tank is provided with a heating system to evaporate a portion of the excess organic solvent after mixing.
[0029] The second stage of mixing is to mix the main powder material with the mixed organic solvent and adhesive conductive agent, specifically: a nitrogen inlet 2, a conductive slurry feed port 3, a main powder feed port 4 and a solvent vapor outlet 5 are provided on the stirring kettle 1, a nitrogen metering tank is connected to the nitrogen inlet 2 of the stirring kettle 1 through a pipeline, a main powder raw material metering tank is connected to the main powder feed port 4 of the stirring kettle 1 through a pipeline, and a conductive slurry sol stirring metering tank is connected to the conductive slurry feed port 3 on the stirring kettle 1 through a pipeline, and electromagnetic sealing valves are provided on the three pipelines, and the opening and closing of the three electromagnetic sealing valves are respectively used to control the amount of nitrogen, main powder raw materials, mixed organic solvent and adhesive conductive agent entering the reactor 1, so as to achieve mixing of materials in the stirring kettle 1 under a nitrogen environment.
[0030] like Figure 2As shown, the stirring kettle 1 is a horizontal structure, including a shell, a left-end stirring assembly and a right-end stirring assembly. The internal left-end stirring assembly and right-end stirring assembly structure in the stirring kettle 1 adopt the existing technology. The left-end stirring assembly includes a left power motor 6, a left planetary gear train 7 and a left-handed planetary propeller 8 assembled in sequence, and the right-end stirring assembly includes a right power motor 9, a right planetary gear train 10 and a right-handed planetary propeller 11 assembled in sequence. Under the action of the left power motor 6 and the right power motor 9, the left-handed planetary propeller 8 and the right-handed planetary propeller 11 are driven to rotate respectively to achieve stirring. A dry pulp discharge port 12 is provided at the center of the length direction of the shell, and a dry pulp buffer tank is connected to the dry pulp discharge port 12 through a screw conveyor 13. The dry pulp buffer tank is provided with a weighing device for measuring the weight of the collected material. A heating system is provided on the shell (the existing technology will not be repeated) to provide a temperature environment for the stirring kettle 1 during the stirring process to evaporate the organic solvent in the material.
[0031] The conductive slurry sol stirring metering tank is connected to a solvent recycling metering tank through a pipeline, and an electromagnetic sealing valve is provided on the pipeline. The conductive slurry sol stirring metering tank has a heating system. During the mixing process, excess organic solvent will evaporate by heating and enter the solvent recycling metering tank for storage through the opening of the electromagnetic control valve. The stirring tank 1 is connected to the solvent recycling metering tank through a solvent collection device, so that the organic solvent heated and evaporated in the stirring tank 1 enters the recycling metering tank.
[0032] The solvent collection device includes a solvent vapor exhaust device and a solvent condensation recovery heat exchange device which are sequentially connected through pipelines, wherein the solvent vapor exhaust device is connected to the solvent vapor outlet 5 of the stirring tank 1 through a pipeline, the solvent condensation recovery heat exchange device is connected to the solvent recycling metering tank through a pipeline, and the solvent condensation recovery heat exchange device is connected to a refrigeration device through a pipeline, and the four pipelines are all provided with electromagnetic sealing valves. In this embodiment, the solvent vapor exhaust device adopts a solvent vapor exhaust fan in the prior art, the solvent condensation heat recovery exchange device adopts a solvent condensation recovery heat exchanger in the prior art, and the refrigeration device adopts a refrigerator.
[0033] When using this embodiment, the electromagnetic sealing valves on the pipelines of the organic solvent metering tank and the adhesive conductive agent auxiliary material metering tank are opened respectively, so that the organic solvent and the adhesive conductive agent enter the conductive slurry sol stirring metering tank according to the process ratio and stir and mix. During the stirring and heating process, the conductive slurry sol stirring metering tank evaporates the excess organic solvent and enters the solvent recycling metering tank through the pipeline. At the same time, the electromagnetic sealing valves on the nitrogen metering tank and the main powder raw material metering tank pipelines are opened respectively, so that the main powder raw material and the mixed organic solvent and adhesive conductive agent enter the stirring tank 1 according to the process ratio, and stir and mix under the nitrogen environment in the stirring tank 1. During the stirring and mixing process, the organic solvent in the stirring tank 1 evaporates and is input into the solvent condensation recovery heat exchange device through the pipeline by the solvent vapor exhaust device. The solvent condensation recovery heat exchanger condenses the organic solvent vapor into liquid through the refrigerant input by the refrigeration device, and the condensed organic solvent liquid enters the solvent recycling metering tank through the pipeline for storage. The solvent stored in the solvent recycling metering tank can be input into the conductive slurry sol stirring metering tank through a pipeline to provide organic solvent for the next mixing, thereby realizing the recycling of organic solvent and overcoming the problem of environmental pollution after discharge. At the same time, the organic solvent in the reactor 1 is evaporated to make the electrode material have a solid content of 95% to 100%.
[0034] It should be noted that the above is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.
Claims
1. A dry electrode dry slurry molecular phase mixing system, comprising a stirring kettle and a nitrogen metering tank, a main powder raw material metering tank, and a conductive slurry sol stirring metering tank connected to the stirring kettle through pipelines, wherein an organic solvent metering tank and an adhesive conductive agent auxiliary material metering tank are connected to the conductive slurry sol stirring metering tank through pipelines, and the characteristics are: The conductive slurry sol stirring and metering tank is connected to a solvent recycling and metering tank through a pipeline, and the stirring kettle is connected to the solvent recycling and metering tank through a solvent collecting device; the stirring kettle is provided with a heating system.
2. The dry electrode dry pulp molecular phase mixing system according to claim 1, characterized in that: The solvent collecting device comprises a solvent vapor exhaust device and a solvent condensation recovery heat exchange device which are connected in sequence through pipelines, wherein the solvent vapor exhaust device is connected to the stirring kettle through a pipeline, and the solvent condensation recovery heat exchange device is connected to the solvent recycling metering tank through a pipeline; the solvent condensation recovery heat exchange device is connected to a refrigeration device through a pipeline.
3. The dry electrode dry pulp molecular phase mixing system according to claim 2, characterized in that: The conductive slurry sol stirring and metering tank is provided with a heating system.
4. A dry electrode dry pulp molecular phase mixing system according to any one of claims 1 to 3, characterized in that: The stirring kettle is a horizontal structure, including a shell, a left-end stirring assembly and a right-end stirring assembly, and a dry pulp discharge port is provided at the center of the length direction of the shell; The left end stirring assembly includes a left power motor, a left planetary gear train and a left-handed planetary propeller which are assembled in sequence; The right end stirring assembly comprises a right power motor, a right planetary gear train and a right-hand planetary propeller which are assembled in sequence.
5. The dry electrode dry pulp molecular phase mixing system according to claim 4, characterized in that: The dry slurry discharge port of the stirring kettle is connected with a dry slurry buffer tank via a screw conveyor.
6. The dry electrode dry pulp molecular phase mixing system according to claim 5, characterized in that: The dry pulp buffer tank is provided with a weighing device.
7. The dry electrode dry pulp molecular phase mixing system according to claim 6, characterized in that: In this mixing system, all connecting pipelines are equipped with electromagnetic sealing valves.