Lithium-ion Battery Manufacturing Process – Cathode and Anode Material Preparation and Slurry Mixing

I. Composition of Cathode Material

1. Active Material: Such as lithium cobalt oxide, it is the cathode active material and the source of lithium ions, providing the lithium source for the battery.

2. Conductive Agent: To improve the electrical conductivity of the cathode, compensating for the electronic conductivity of the cathode active material.

3. PVDF Binder: To bind the active material, conductive agent, and aluminum foil or mesh together.

4. Raw Material Pre-treatment: Pre-treatment of active material, conductive agent, and binder, such as dehydration, drying, and screening, to remove impurities and moisture, improving the purity and uniformity of the raw materials.

II. Cathode Material Preparation and Slurry Mixing

1. Mixing Ratio: According to the battery formulation requirements, accurately weigh the ratio of active material, conductive agent, and binder. This ratio is usually optimized to balance the battery’s capacity, cycle life, and safety performance.

2. Solvent Selection: Choose an appropriate solvent, such as N-Methyl-2-pyrrolidone (NMP), to dissolve the binder and form the slurry. The selection of solvents should consider their solubility for raw materials, volatility, and environmental impact.

3. Slurry Preparation: Add the active material, conductive agent, and binder in a certain ratio to the solvent, and mix and disperse them in a vacuum mixer. Control parameters such as stirring speed, stirring time, and vacuum degree during this process to obtain a uniform and stable cathode slurry.

4. Slurry Inspection: Inspect the particle size and viscosity of the prepared cathode slurry. The particle size directly affects the uniformity of the coating and the performance of the battery; while viscosity determines the fluidity and coatability of the slurry. If the inspection results do not meet the requirements, adjust the slurry until it meets the process requirements.

III. Composition of Anode Material

1. Active Material: Such as graphite, it is the anode active material and the main substance of the anode reaction. Graphite is divided into two major categories: natural graphite and artificial graphite.

2. Conductive Agent: To improve the electrical conductivity of the anode, compensating for the electronic conductivity of the anode active material.

3. Binder: Such as SBR and CMC, they bind the active material, conductive agent, and copper foil or mesh together.

4. Solvent: Deionized water, used as the solvent for the aqueous mixture.

5. Raw Material Selection and Treatment: Based on the battery performance requirements, select the appropriate anode active material. For graphite-type anode materials, carbonization treatment is required to improve their conductivity. At the same time, pre-treat conductive agents, additives, and binders, such as drying and screening, to ensure their quality and uniformity.

IV. Anode Material Preparation and Slurry Mixing

1. Mixing Ratio: According to the battery formulation, accurately weigh the ratio of active material, conductive agent, additives, and binder. This ratio is optimized to balance the battery’s capacity, cycle stability, and safety performance.

2. Solvent and Dispersant: Choose an appropriate solvent (such as deionized water) and dispersant to mix the raw materials into a uniform slurry. The selection of solvents and dispersants should consider their solubility, dispersibility for raw materials, and environmental impact.

3. Slurry Preparation: Add the active material, conductive agent, additives, and binder in a certain ratio to the solvent and dispersant, and mix and disperse them. Control parameters such as stirring speed, stirring time, and temperature during this process to obtain a uniform and stable anode slurry.

4. Slurry Inspection and Adjustment: Inspect the particle size and viscosity of the prepared anode slurry. Adjust the slurry according to the inspection results to meet the process requirements. The particle size and viscosity directly affect the uniformity of the coating and the performance of the battery.

V. Precautions

1. Raw Material Quality: Ensure that the quality of all raw materials meets the production process requirements, and avoid using expired or substandard raw materials.

2. Environmental Control: During the material preparation and slurry preparation process, strictly control the temperature and humidity of the environment to prevent the raw materials from getting damp or deteriorating. For some anode materials, such as artificial graphite, special graphitization treatment may also be required to improve their performance.

3. Equipment Maintenance: Regularly maintain and service the mixing equipment to ensure it is in good working condition. The use of efficient mixing equipment can improve the uniformity and stability of the slurry.

4. Safe Operation: During the operation, wear appropriate protective equipment to prevent harm to operators from harmful substances. At the same time, be careful to prevent slurry splashing and the mixing of other impurities.