Today we had finished the package of the vacuum planetary mixer for our Russia customer.The mixing machine is used for lithium battery slurry mixing.

The preparation of the battery electrode slurry is the most critical part of the whole process. The quality of the electrode slurry directly affects whether the next step can be performed. Slurry preparation is a non-Newtonian high-viscosity fluid formed by mixing powders and liquids such as living materials, adhesives, solvents, and thickeners. The fluid needs to have a certain viscosity, good fluidity, and a sufficiently small particle size. What kind of equipment does the electrode slurry preparation need to meet the requirements?

Have a good vacuum-tight system

There are three main reasons why a mixer needs a good vacuum-tight system:

① During the whole mixing process, due to frequent collision and friction between materials, and friction between the agitator and the material, more heat will be generated, resulting in temperature rise. Increasing temperature will cause some solvents to be emitted, which will produce great irritating odors, such as NMP, PVDF, etc. Organic gas will cause great harm to human body.

②In the dry powder premixing stage, if the closed system is not good enough, it will cause dust to rise, destroy the working environment, affect product quality and cause harm to employees.

③ There are large voids inside the powder. After mixing with the solvent, there will be many air bubbles inside the slurry. The slurry needs to be defoamed in order to perform electrode coating, otherwise bubbles will break during the coating process, the areal density is different, and even the foil is exposed, which is extremely detrimental to the battery performance.

The material of the mixer has strong corrosion resistance, wear resistance and stable physical and chemical properties

Obviously, regardless of the strong alkalinity of the positive electrode material, the strong corrosion resistance of NMP, etc., the mixer needs to have excellent corrosion resistance. During the stirring process, the continuous stirring of the powder by the agitator requires that it has abrasion resistance and a sufficiently long service life.

The mixing blade structure is reasonable and the design of the stirring speed meets the requirements

In addition to having sufficient stirring power and stirring range in the mixer, the shape and mechanical design of the blades of the mixer have a great influence on the preparation of the slurry. First, it is necessary to ensure that the stirring range of the stirrer is large enough and there is no dead angle in the stirring container. At present, larger-shaft mixers use biaxial or even triaxial planetary agitators to ensure that no powder or agglomerated living materials are not uniformly mixed into the slurry.

Secondly, the shape design of the mixer has an absolute impact on the dispersion, mixing, particle size distribution, and fluidity of the material. At present, the common shapes on the market include paddle type, butterfly type, anchor type, twist type, claw type, frame type, etc. It is best to equip the equipment with high-speed dispersion equipment, because some materials require high-speed shear force to disperse , So there is a certain necessity. The third requirement is that the equipment has the required stirring speed to meet the requirements of high molecular weight and ultra-fine powder dispersion.

In addition to the design of the main stirring shaft and blades, some equipments have scraper design and container rotation design to improve the efficiency of mixing and the degree of mixing of materials.

We are TOB New Energy, we are not only provide the equipment of the battery,but also provide the knowledge of battery.

Contacts: Miss carol(Sales&Engineer)

E-mail:tob.mae@tobmachine.com

Skype:583432443@qq.com

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