The traditional process of making button cell battery cr2025 slurry

　　button cell battery cr2025 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. It is the most important link in the entire production process.

　　In the electrode manufacturing of lithium-ion batteries, the positive electrode slurry is composed of binders, conductive agents, positive electrode materials, etc.; the negative electrode slurry is composed of binders, graphite carbon powder, etc. The preparation of positive and negative electrode slurries includes a series of processes such as mutual mixing, dissolution, and dispersion of liquids and liquids, liquids and solid materials, and this process is accompanied by changes in temperature, viscosity, environment, etc. In the positive and negative electrode slurries, the dispersion and uniformity of the granular active materials directly affect the movement of lithium ions between the two electrodes of the battery. Therefore, the mixing and dispersion of the slurry of each electrode material is crucial in the production of lithium-ion batteries. , the quality of slurry dispersion directly affects the quality of subsequent lithium-ion battery production and the performance of the product.

　　Ultra-fine dispersion is carried out based on traditional technology. This is because traditional mixing and stirring equipment can only break up large powder groups in the solution and distribute them evenly; however, the powder form is in the form of fine powder groups. In solution, only the processing requirements of macroscopic dispersion are met. The slurry after macroscopic stirring and dispersion can further disperse and homogenize the fine powder or solid particle agglomerates in the solution under the strong mechanical cutting force of the ultra-fine dispersion and homogenization equipment to obtain sufficiently fine solids. The particles are evenly distributed in the solution to achieve microscopic and ultra-fine dispersion and homogeneity, which can significantly improve the comprehensive performance of the slurry.

　　The current traditional slurry process is:

　　(1) Ingredients:

　　1. Solution preparation:

　　a) Mixing ratio and weighing of PVDF (or CMC) and solvent NMP (or deionized water);

　　b) Stirring time, stirring frequency and times of the solution (and solution surface temperature);

　　c) After the solution is prepared, inspect the solution: viscosity (test), degree of dissolution (visual inspection) and storage time;

　　d) Negative electrode: SBR+CMC solution, stirring time and frequency.

　　2. Active substances:

　　a) Monitor whether the mixing ratio and quantity are correct when weighing and mixing;

　　b) Ball milling: the ball milling time of the positive and negative electrodes; the ratio of agate beads to the mixture in the ball mill barrel; the ratio of large balls to small balls in the agate ball;

　　c) Baking: Setting of baking temperature and time; test the temperature after cooling after baking is completed.

　　d) Mixing and stirring of active substances and solutions: stirring method, stirring time and frequency.

　　e) Sieve: pass through 100 mesh (or 150 mesh) molecular sieve.

　　f) Testing and inspection:

　　Conduct the following tests on slurries and mixtures: solid content, viscosity, mixture fineness, tap density, and slurry density.

　　In addition to clarifying the traditional manufacturing process, it is also necessary to understand the basic principles of lithium battery slurry.

　　colloid theory

　　The main factor that causes the agglomeration of colloidal particles is the van der Waals force between particles. To increase the stability of colloidal particles, there are two ways. One is to increase the electrostatic repulsion between colloidal particles, and the other is to create steric positions between powders. Block the agglomeration of powder in these two ways.

　　The simplest colloidal system consists of a dispersed phase and a phase dispersion medium, where the size of the dispersed phase ranges from 10-9 to 10-6m. Substances in colloids must have a certain degree of dispersion ability to exist in the system. A variety of different colloidal forms can be produced depending on the solvent and dispersed phase. For example, mist is an aerosol in which droplets are dispersed in gas, and toothpaste is a sol in which solid polymer particles are dispersed in liquid.

　　The applications of colloids abound in life, and the physical properties of colloids vary depending on the dispersed phase and dispersion medium. Observing colloids from a microscopic perspective, the colloidal particles are not in a constant state, but move randomly within the medium. This is what we call Brownian motion. Above absolute zero, colloidal particles will undergo Brownian motion due to thermal motion. This is the dynamic characteristic of microscopic colloids. The collision of colloidal particles due to Brownian motion is an opportunity for aggregation. Colloidal particles are in a thermodynamically unstable state, so the interaction force between particles is one of the key factors in dispersion.

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