Interpretation of preparation equipment scheme of different slurry for lithium batteries

The electrode manufacture of lithium-ion battery consists of binder, conductive agent, positive electrode material, etc.. The negative slurry consists of binder, graphite carbon powder and so on. The preparation of positive and negative plasma materials includes a series of process processes such as mixing, dissolving, and dispersing between liquid and liquid, liquid and solid materials, and in this process, it is accompanied by changes in temperature, viscosity, and environment. In the positive and negative plasma, the dispersion and uniformity of granular active substances directly ring to the movement of lithium ions between the two poles of the battery. Therefore, the mixing and dispersion of the slurry materials of each electrode material is of great importance in the production of lithium ion batteries. The quality of dispersion directly affects the quality of subsequent lithium ion battery production and the performance of its products.

Double planet mixer

When the planetary frame rotates, it can drive the machine's stirring shaft around the reaction bucket. At the same time, the mixing axis of the two planets rotates at a high speed. This kind of revolution rotation can simultaneously promote the material to be strongly cut and squeezed by the machinery. The effect, In order to achieve the goal of full emulsification, dispersion and mixing of materials, the mixing effect of this structure equipment is several times that of ordinary mixers. At the same time, a group of scrappers was set up on the planetary frame of the dual-planet mixer to rotate with the planetary frame, and the continuous seamless scraping of the wall bucket to make the bucket non-stranded battery slurry improved the mixing effect. The dual-planet mixer is a vacuum resistant machine that can be vacuumed, heated, and cooled. It can meet the demand of wet mixing process of lithium battery slurry.

Advantages:

1. Low clearance. The gap between pulp and pulp, between pulp and barrel wall, between pulp and barrel bottom is low, and the precise gaps between the mixing pulp and the mixing tank make the mixing tank have no dead angle, and have a high degree of squeezing effect, so that the materials can quickly penetrate and squeeze each other in a short period of time.

2. Efficient. The unique design of mixed and dispersed mixing structure has greatly improved the production capacity of lithium battery production equipment and can be efficiently produced.

3. The material does not stick to the wall, and the material is clean.

360-Degree non-dead angle design to ensure that the material is evenly stirred. The scraper on the planetary shelf of the dual-planet mixer can easily make the bucket wall free of retention material. At the same time supplemented with scraping type mixing paddle, can scratch the bottom of the drum, avoid stirring dead corner, greatly improve the mixing effect of the material, ensure the quality of the finished product.

4. High dispersion / low shear noise. The line speed of dispersed/emulsified parts can reach more than 23M/S, parts processing, professional equipment, parts with high compatibility, small wear, and smooth and low noise. Under full load operation, create a low-noise work space.

5. Resistance to corrosion and zero leakage. The anti-corrosion mechanical seal plus soft, static and other seals, the planetary transmission box adopts a fully sealed structure, and the all-round sealing concept improves the sealing performance on the traditional basis by 50 %; And high vacuum retention, ensure that the stirring process is zero pollution.

6. High intensity. According to different mixing processes(dry mixing, wet mixing), after strict strength calculation, suitable for high viscosity, high solid content battery positive and negative slurry, binder use.

7. Set Cheng Hua Gao. Pre-mixing, stirring, turning, and filtering are seamless and quickly disassembled, with no contact with the air. PLC fully automatic control, speed, temperature, lift, vacuum system, can be integrated in a panel control.

Disadvantages:

There are also many problems with dual-planet stirring during the operation:

1. Batch dispersion process, long mixing dispersion time, energy consumption.

2. The electrode powder material is added from the top of the planetary mixer, and the dust is easy to fly and float. More importantly, the mixture of powder and liquid is very easy to reunite.

3. The material is easy to remain on the lid, wall and paddle of the planetary mixer, and it is difficult to clean and operate.

4. The air is easy to remain in the dispersed mixing tank, and the bubble has an impact on the dispersion effect.

5. Batch processes result in restrictions on mass production, production lines occupy the ground, and maintenance costs are high.

Battery slurry twin screw stirring

The screw stirring system is generally composed of a measuring bucket, a weighing and conveying system, a storage tank, a rubber tank, a transfer tank, a feeding machine, a high-speed mixing machine, a supercharged pump, a magnetic filter, a high-speed homogenizing machine, auxiliary equipment, and a DCS central control system. The positive and negative material(powder and liquid) of the lithium battery is automatically and continuously transported to the spiral mixer through an accurate measurement system, and the mixing, dispersion, grinding, vacuum extraction and other operations are completed in the spiral mixer to form a slurry. Then the slurry is continuously output from the screw mixer into the next production process.

The double screw stirring automatic production line has the advantages of high production efficiency, closed production, low material and energy consumption, etc.. At present, it is also recognized in the industry.

Advantages:

1, strong production continuity. The continuous mixing process is based on a twin screw extruder, and the basic operations such as continuous raw material feeding, pre-stirring, fine dispersion, and degassing are concentrated in a single device. The continuous stirring process includes the continuous feeding of all liquid and solid components and the microscopic distribution of solid particles in the liquid phase.

2, less equipment investment. With high production efficiency, the continuous mixing process can replace multiple batch blenders with one operating production line. As a result, the investment required for mass production of devices can be significantly reduced.

3, with energy conservation, automation Chengdu Gaohe needs less human resources, reduce operating costs.

4, enhance the repeatability and controllability of product performance.

5, online quality control to achieve more stable product quality. Full automation of raw material feeding(powder and liquid), stirring, dispersing and venting to improve formulation accuracy, process control and traceability.

Disadvantages:

1, it is difficult to ensure the accuracy of the weight loss scale. Because the proportion of additives and raw materials is quite different, under the non-stacking feed mode, a higher precision weight loss scale should be used to ensure the accuracy of feed measurement and to ensure that all types of particles can enter the equipment continuously and accurately according to the formula ratio. In order to improve the uniformity of the mixture, the quality of the battery is improved.

2, the material consistency is poor, double screw design should adopt the reasonable screw design combination, to ensure the material enters the continuity and the mixing uniformity.

A plough mixer

The plough-type mixer consists of a transmission component, a blender, a circular barrel body, and a high-speed flying knife. When the ploughhead of the blender is running at high speed, in addition to the axial dispersion of the material, it can also drive the material to flow around the circular cylinder. Effectively solve the problem of material stratification, The high speed flying knife in the middle carries on the auxiliary mixing and the dispersing of the agglomeration material. The material can be evenly mixed in a short time under the dual action of the plow and the flying knife.

Advantages:

1, mixing speed. The application of the core technology of the new concept of ploughknife stirring mechanism, coupled with the discrete stirring of the high-speed rotary knife head, according to the different formulations of the product, the host stirring time is 90-180s.

The mixing precision of the mixing host is high. The compatibility and evenness of various materials are good. When mixing, segregation is not produced. The mixing ratio of mixing can be as high as 1:10,000, which can meet the construction requirements to the greatest extent.

3, unloading material adopts pneumatic opening, unique opening method so that unloading material can be completed within 10 seconds;

4, flying knife made of manganese steel, equipped with a hard-tooth gear reducer, can start at full load;

5, the plow head, flying blade wear can be replaced, on the basis of dry powder mixing can be added spray function, so that the solid liquid mixing effect is better.

Disadvantages:

1, poor production continuity. With too much loading, the material will affect the mixing effect and prolong the mixing time and increase the power consumption because there is not enough active space in the ploughfork mixer. Too little loading will also cause too little material in the ploughfork mixer to form enough resistance, thus weakening the mixing effect and prolonging the mixing time.

2, easy to cause the accumulation of materials, after the use of residue is not easy to clean.

Different pulp preparation schemes have been applied in various companies in the industry. There is no conclusion as to the superiority or inferiority. Beifanghua is committed to the research and development of pulp preparation technology, and has created an advanced slurry preparation system to provide better pulp preparation solutions for industry customers..

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