What to Consider in the Production of Lithium-Ion Batteries
To successfully produce lithium-ion batteries, it’s vital to pay attention to these 5 crucial steps, from selecting the right materials to testing the final product:
First, improve the physical and chemical structure of the positive and negative active materials, which is the basic link of the lithium-ion battery production process:
- Appropriate ion doping of the material.
- improve the particle size dispersion of the active material, to prevent the particle size dispersion of the active material is too wide.
- Use materials with disordered layer structure or thin layer structure as far as possible.
- Improve the appearance structure of the electrode material.
Second, the high bonding strength of the electrode coating is conducive to reducing the cycle capacity decline rate, which is the most technical process in the production process of lithium-ion batteries, to which attention should be paid to:
- the binder and solvent that constitute the adhesive material should be pure, and the coated electrode sheet should not be stored for too long.
- positive and negative electrode coating in the mix of adhesive and the active material is used in the appropriate ratio to ensure that the coating does not fall off the powder, no powder.
Third, the optimization of electrolyte composition, lithium-ion battery production process requirements related to the electrolyte is to adhere to the capacity, and extend the life of the battery: 1, after the lithium salt, solvent, and solvent and the battery life:
- through the optimization of lithium salts, solvents, and additives, to improve electrolyte conductivity, reduce polarization
- Inhibit the reaction between cathode material and electrolyte
- through the control of the appropriate specific surface area and carbon anode material for coating, film formation, and appearance of chemical reactions and other exterior treatments, to improve the appearance of the negative electrode material structure.
Fourth, after the battery material preparation is completed, the lithium-ion battery production process will enter the assembly process, at which time attention should be paid to:
- the capacity of the negative electrode is slightly larger than the capacity of the positive electrode.
- after winding the positive and negative electrode and the divider, the gap between the positive and negative electrode sheets and the divider is not larger than 0.5mm, and the deviation between the top and bottom is not more than 0.5mm.
Fifth, the sub-capacity test, in accordance with national standards, with low rate charging is appropriate, generally 0.2C.
In general, the following proportional relationships should be emphasized in the process production stage: pole surface and pole compaction density, negative excess rate, formulation process, electrolyte, and positive and negative electrode blending applicable amount.
Each step in the production process of lithium-ion batteries has a different moment, in general, the ingredients, baking, into a long moment, less than 10 hours or so, more than two days and two nights; other processes are faster, even 5, 6 hours. The entire lithium-ion battery production process takes about 15 days.
