Uniform feeding device for electrode slurry

Abstract

The utility model relates to a uniform feeding device of electrode slurry, which comprises a stirring tank, an upper cover, a stirrer, a storage tank and a base, the upper cover is hermetically connected with the stirring tank, the upper cover is provided with a solid auxiliary material feed opening, a main material feed opening and a liquid auxiliary material feed opening, a main material storage tank is arranged above the main material feed opening, and the liquid auxiliary material feed opening is connected with the stirrer. A sand clock type throttling valve is arranged between the main material storage tank and the main material discharging port, a feeding port of the main material storage tank is connected with a dry nitrogen conveying mechanism, the solid auxiliary material discharging port and the liquid auxiliary material discharging port are respectively connected with the stirring tank through pipelines, and the sand clock type throttling valve is connected with the stirring tank. According to the utility model, the stirring operation of the current electrode slurry can be upgraded, so that the stirring process operation is more standardized, a time sequence parameter basis is provided for the uniformity and consistency of the stirred slurry, and the uniformity and consistency of the slurry in each pot are ensured. The electrode slurry is slowly fed according to the time sequence during stirring, and the uniformity of the slurry is evaluated according to the feeding time sequence.

Description

Technical Field

[0001] The utility model belongs to the field of lithium ion battery manufacturing, and in particular relates to a uniform feeding device for electrode slurry. Background Art

[0002] Lithium battery cell slurry stirring is a mixing and dispersion process that affects product quality by more than 30% in the entire production process of lithium-ion batteries and is the most important link in the entire production process.

[0003] In the manufacture of lithium-ion battery electrodes, the positive electrode slurry is composed of a binder, a conductive agent, a positive electrode material, etc.; the negative electrode slurry is composed of a binder, graphite powder, etc. The preparation of positive and negative electrode slurries includes a series of process steps such as mixing, dissolving, and dispersing between liquid and liquid, and between liquid and solid materials, and this process is accompanied by changes in temperature, viscosity, and environment. In the positive and negative electrode slurries, the dispersion and uniformity of the granular active substances directly affect the movement of lithium ions between the two poles of the battery. Therefore, the mixing and dispersion of the slurries of various pole sheet materials is crucial in the production of lithium-ion batteries. The quality of the slurry dispersion directly affects the quality of subsequent lithium-ion battery production and the performance of its products.

[0004] The current preparation of lithium-ion battery slurry is completed in a double planetary dispersion device. Although the production technology of small batteries has become increasingly mature, the consistency control of batteries in the production process of lithium-ion batteries is still a technical difficulty in the production of lithium-ion batteries, especially for large-capacity and high-power power lithium-ion batteries. In addition, with the continuous advancement of lithium-ion battery materials, the particle size of raw material particles is getting smaller and smaller, which not only improves the performance of lithium-ion batteries, but also easily forms secondary agglomerates, thereby increasing the difficulty of the mixing and dispersion process. In the production process of lithium-ion batteries, the control of the battery electrode structure is the key. The self-discharge rate, cyclability, capacity, consistency, etc. of batteries produced by lithium-ion manufacturers using electrode sheets with different structures are different. How to control the microstructure inside the electrode sheet is the key technology in the production process of lithium-ion batteries. Therefore, in the process of preparing electrode sheets, the mixing and dispersion quality of lithium-ion battery slurry must be controlled to improve the uniformity and dispersion stability of battery slurry.

[0005] In the current production process, due to insufficient stirring of some slurries, slurry agglomeration will occur, affecting the uniformity and consistency of the slurry. In order to solve this problem. For example, the patent document with the authorization announcement number CN 215996250U discloses a battery slurry production equipment and a coating device. The battery slurry production equipment includes a continuous dispersion device, a transfer device and a filtering device. The filter screen in the filtering device can filter the slurry, and the scraper can move relative to the filter screen to clean the filter residue on the filter screen. The continuous dispersion device, the filtering device and the transfer device are connected in turn through pipelines, and the transfer device is connected to the continuous dispersion device through pipelines. The battery slurry production equipment of the present application can produce slurry by slurry circulation, which can increase the dispersion speed of the powder and reduce the difficulty of stirring. The patent document with the authorization announcement number CN 208742019U discloses a slurry filtering device for lithium battery production, including a stirring chamber, a feed hopper is arranged on the top of the stirring chamber, and a motor is installed on one side of the feed hopper, a protective cover shell is wrapped on the outside of the motor, and the motor is rotatably connected to the stirring rod through a rotating shaft, the bottom of the stirring chamber is connected to the pipeline through a separating funnel, and a control valve is arranged inside the pipeline, a filter chamber is arranged below the stirring chamber, and a card slot is arranged on the inner side wall of both ends of the filter chamber, a sliding block is installed on the card slot, and a limit block is arranged on the upper and lower ends of the sliding block, and a coarse-pore filter screen plate and a fine-pore filter screen plate are respectively arranged between the sliding blocks, and the fine-pore filter screen plate is located directly below the coarse-pore filter screen plate. By fully stirring the slurry for lithium battery production, a double-layer filter screen plate is arranged to filter impurities therein. The patent document with the authorization announcement number CN 213528241 U discloses an automatic feeding device for battery slurry production, including a bottom plate, a controller fixedly installed on the front of the bottom plate, a stirring tank fixedly installed on the top left side of the bottom plate, a driving motor fixedly installed on the top of the stirring tank, a connecting shaft fixedly connected to the bottom of the driving motor, and a stirring rod fixedly connected to the bottom of the connecting shaft. The driving motor is set to drive the stirring rod to continuously stir the slurry to be fed, so that the slurry will not condense into lumps due to standing, and the condensed lumps are filtered through the filter screen of the filtering device, so that the lumps are blocked, which indirectly improves the quality of the slurry.

[0006] In the lithium battery slurry manufacturing process, it is urgent to introduce a feeding device that can meet the time sequence and feed evenly, so as to solve the slurry agglomeration phenomenon after feeding, so as to improve the dispersion stability and uniformity of the electrode slurry. Utility Model Content

[0007] The utility model aims to overcome the deficiencies in the prior art and provides a uniform feeding device for electrode slurry. The utility model adopts an hourglass throttling mechanism to control the feeding time of main materials and auxiliary materials and ensure the dispersion stability and uniformity of each pot of slurry.

[0008] In order to achieve the above-mentioned purpose, the utility model is realized through the following technical scheme: a uniform feeding device for electrode slurry, comprising a stirring tank, an upper cover, an agitator, a storage tank and a base, the upper cover is sealed and connected to the stirring tank, the upper cover is provided with a solid auxiliary material discharge port, a main material discharge port and a liquid auxiliary material discharge port, a main material storage tank is provided above the main material discharge port, an hourglass type throttle valve is provided between the main material storage tank and the main material discharge port, the main material storage tank feed port is connected to a dry nitrogen gas transmission mechanism, the solid auxiliary material discharge port and the liquid auxiliary material discharge port are respectively connected to the stirring tank through pipelines, and the hourglass type throttle valve is connected to the stirring tank.

[0009] Furthermore, the hourglass type throttle valve comprises a powder feeding chamber, a powder hourglass chamber and a powder discharging chamber connected from top to bottom, and the cross-sectional shapes of the powder feeding chamber, the powder hourglass chamber and the powder discharging chamber are respectively isosceles trapezoidal.

[0010] Furthermore, the isosceles trapezoidal shape of the powder hourglass cavity is an inverted bucket shape, with an upper opening size of 10-20cm×10-20cm, a lower opening size of 1-2cm×1-2cm, and a height of 10-15cm.

[0011] Furthermore, the number of the powder hourglass cavities is 1-2, and the main material flow rate is controlled to be 100g / s-200g / s.

[0012] Furthermore, the dry nitrogen gas delivery mechanism is connected to a plurality of nitrogen gas outlets through dispersed pipelines, the nitrogen gas outlets are distributed at the upper part of the powder feed chamber, and the air pressure value of the dry nitrogen gas delivery mechanism is 0.4Mpa.

[0013] Furthermore, a mesh screen is fixedly connected to the lower opening of the powder feeding cavity.

[0014] Furthermore, the mesh diameter of the mesh screen is 0.5 mm-1 mm.

[0015] Furthermore, a sealing ring is provided at the connection between the upper cover and the stirring tank.

[0016] Beneficial effects: Compared with the prior art, the utility model can upgrade the current stirring operation of electrode slurry, make the stirring process more standardized, provide a time series parameter basis for the uniformity of the stirred slurry, and ensure the uniformity of each pot of slurry. The electrode slurry stirring is realized by slowly adding it in time sequence, and the uniformity of the slurry is evaluated by the time sequence of feeding. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] Figure 2 It is a structural schematic diagram of an hourglass type throttle valve structure;

[0019] Figure 3 It is a schematic diagram of the structure of the upper cover.

[0020] In the figure: 1. mixing tank, 2. upper cover, 2-1. solid auxiliary material discharge port, 2-2. main material discharge port, 2-3. liquid auxiliary material discharge port, 3. agitator, 4. storage tank, 5. base, 6. hourglass throttle valve, 6-1. powder feeding chamber, 6-2. powder hourglass chamber, 6-3. powder discharge chamber, 7. pipeline, 8. main material storage tank, 9. solid auxiliary material storage tank, 10. liquid auxiliary material storage tank, 11. dry nitrogen gas transmission mechanism, 11-1. nitrogen gas outlet, 12. mesh screen, 13. sealing ring. DETAILED DESCRIPTION

[0021] The following is a detailed description of the specific implementation method provided according to the utility model in combination with the preferred embodiment: See the accompanying drawings for details. This embodiment provides a uniform feeding device for electrode slurry, including a stirring tank 1, an upper cover 2, an agitator 3, a storage tank 4 and a base 5. The upper cover is sealed with the stirring tank, and the upper cover is provided with a solid auxiliary material discharge port 2-1, a main material discharge port 2-2 and a liquid auxiliary material discharge port 2-3. A main material storage tank 8 is provided above the main material discharge port, and an hourglass throttle valve 6 is provided between the main material storage tank and the main material discharge port. The feed port of the main material storage tank is connected to a dry nitrogen gas delivery mechanism 11, and the solid auxiliary material discharge port and the liquid auxiliary material discharge port are respectively connected to the stirring tank through a pipeline 7, and the hourglass throttle valve is connected to the stirring tank.

[0022] In the preferred embodiment of the present invention, the hourglass throttle valve comprises a powder feeding chamber 6-1, a powder hourglass chamber 6-2 and a powder discharge chamber 6-3 connected from top to bottom, and the cross-sectional shapes of the powder feeding chamber, the powder hourglass chamber and the powder discharge chamber are respectively isosceles trapezoidal. The shape of the powder feeding chamber is convenient for matching the hourglass throttling discharge.

[0023] In the preferred embodiment of the present invention, the isosceles trapezoidal shape of the powder hourglass cavity is an inverted bucket shape, with an upper opening size of 10-20cm×10-20cm, a lower opening size of 1-2cm×1-2cm, and a height of 10-15cm. The inverted bucket shape facilitates the spraying of the main material into the mixing tank.

[0024] In the preferred embodiment of the present invention, the number of the powder hourglass cavities is 1-2, and the main material flow rate is controlled to be 100g / s-200g / s. In the present embodiment, the number of the powder hourglass cavities is 2.

[0025] In a preferred embodiment of the present invention, the dry nitrogen gas delivery mechanism is connected to a plurality of nitrogen gas outlets 11-1 through dispersed pipelines, the nitrogen gas outlets are distributed at the upper part of the powder feed chamber, and the air pressure value of the dry nitrogen gas delivery mechanism is 0.4Mpa.

[0026] In the preferred embodiment of the present invention, the lower opening of the powder feeding cavity is fixedly connected with a mesh screen 12. The function of the mesh screen is to evenly disperse the main material after passing through the mesh screen.

[0027] In a preferred embodiment of the present invention, the mesh diameter of the mesh is 0.5 mm to 1 mm.

[0028] In a preferred solution of this embodiment, a sealing ring is provided at the connection between the upper cover and the stirring tank.

[0029] The solid auxiliary material storage tank, the main material storage tank and the liquid auxiliary material storage tank of this embodiment are respectively connected to a weighing mechanism (not shown in the figure). The weighing mechanism adopts existing production equipment.

[0030] The pipelines of the solid auxiliary material discharge port and the liquid auxiliary material discharge port are respectively provided with valve switches, adopting the structure of the existing production equipment. (not shown in the figure)

[0031] In a preferred solution of this embodiment, a sealing ring 13 is provided at the connection between the upper cover and the stirring tank.

[0032] Working process and principle

[0033] 1. Main material discharge port: weigh the powder to be mixed to confirm the accuracy of the formula. Since the amount of solid and liquid auxiliary materials is small, they can be used in combination with the main materials according to the formula;

[0034] 2. Hourglass type throttle valve structure: it will not start feeding before the powder is weighed, and is used to turn on and off the feeding of the main material, to control the flow rate of the main material, and to ensure that the main material can be evenly scattered;

[0035] 3. Powder sealing chamber: After the initial powder is weighed, it is put into the main material storage tank; dry nitrogen mechanism: by turning on the nitrogen blowing mode, the impact force of the gas is used to disperse the powder to be mixed (air pressure value: 0.4Mpa, 3 air outlets are set); powder feeding chamber: timed and quantitative feeding is carried out through the designed bipolar hourglass; (the size of the hourglass is designed as: lower end aperture 1-2cm, height 10-15cm, upper end aperture 10-20cm); powder feeding chamber: the feeding area is directly connected to the slurry mixing tank;

[0036] 4. Net drying and feeding: the main material powder pushed by ultrasonic wave is further evenly dispersed and dropped into the mixing tank;

[0037] 5. Self-rotation of the mixing tank: The tank body of the mixing tank rotates synchronously with the upper cover (existing technology), so that the material is discharged and stirred simultaneously, and the discharged material is further evenly dispersed.

[0038] Combine the above 5 steps to complete the mixing process setting of the powder, and the process is: feeding - weighing - feeding through the hourglass throttle valve - opening the dry nitrogen gas supply mechanism - mesh screen to disperse the feeding - tank body to rotate and disperse the feeding - stirring - setting the corresponding stirring parameters - completing the slurry production.

[0039] Mixing tank cover structure: multiple dispersing and unloading windows are synchronously set at the feeding end of the cover. The number of these unloading ports can be additionally increased according to the types of main and auxiliary materials in the process. Its function is to evenly disperse and unload the main material while also dispersing and unloading the auxiliary material, so that it can be better integrated into the main material structure system.

[0040] The hourglass throttle valve needs to be equipped with a corresponding speed-limiting screen to feed the main material powder uniformly at a limited speed;

[0041] The mesh size of the speed-limiting screen needs to be selected in combination with the time requirements of the feeding process, that is, it needs to meet the weight of the powder that can pass through within a fixed time;

[0042]

[0043] The above-mentioned detailed description of a uniform feeding device for electrode slurry with reference to the embodiment is illustrative rather than restrictive, and several embodiments can be listed according to the limited scope. Therefore, changes and modifications without departing from the overall concept of the utility model should fall within the scope of protection of the utility model.

Claims

1. A uniform feeding device for electrode slurry, characterized by: It includes a stirring tank, an upper cover, an agitator, a storage tank and a base. The upper cover is sealed with the stirring tank. The upper cover is provided with a solid auxiliary material discharge port, a main material discharge port and a liquid auxiliary material discharge port. A main material storage tank is provided above the main material discharge port. An hourglass-type throttle valve is provided between the main material storage tank and the main material discharge port. A dry nitrogen gas transmission mechanism is connected to the feed port of the main material storage tank. The solid auxiliary material discharge port and the liquid auxiliary material discharge port are respectively connected to the stirring tank through pipelines, and the hourglass-type throttle valve is connected to the stirring tank.

2. The uniform feeding device for electrode slurry according to claim 1, characterized in that: The hourglass throttle valve comprises a powder feeding chamber, a powder hourglass chamber and a powder discharging chamber connected from top to bottom, and the cross-sectional shapes of the powder feeding chamber, the powder hourglass chamber and the powder discharging chamber are respectively isosceles trapezoidal.

3. The uniform feeding device for electrode slurry according to claim 2, characterized in that: The isosceles trapezoidal shape of the powder hourglass cavity is an inverted bucket shape, with an upper opening size of 10-20cm×10-20cm, a lower opening size of 1-2cm×1-2cm, and a height of 10-15cm.

4. The uniform feeding device for electrode slurry according to claim 2 or 3, characterized in that: The number of the powder hourglass cavities is 1-2, and the main material flow rate is controlled to be 100g / s-200g / s.

5. The uniform feeding device for electrode slurry according to claim 1, characterized in that: The dry nitrogen gas delivery mechanism is connected to a plurality of nitrogen gas outlets through a dispersed pipeline, and the nitrogen gas outlets are distributed at the upper part of the powder feeding chamber. The air pressure value of the dry nitrogen gas delivery mechanism is 0.4Mpa.

6. The uniform feeding device for electrode slurry according to claim 2, characterized in that: A mesh screen is fixedly connected to the lower opening of the powder feeding cavity.

7. The uniform feeding device for electrode slurry according to claim 6, characterized in that: The mesh diameter of the mesh screen is 0.5 mm-1 mm.

8. The uniform feeding device for electrode slurry according to claim 1, characterized in that: A sealing ring is provided at the connection between the upper cover and the stirring tank.

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