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What are the key steps in the production process of Polymer Lithium Battery?

Publish Time: 2024-10-24
The production process of Polymer Lithium Battery includes several key steps, which are crucial to the performance, quality and safety of the battery.

The first is electrode preparation. This is a basic and critical step, including the production of positive and negative electrodes. For the positive electrode, the positive electrode active material (such as lithium cobalt oxide, lithium nickel manganese cobalt oxide, etc.), the conductive agent (such as carbon black) and the binder (such as polyvinylidene fluoride) are usually mixed in a certain proportion. These materials are fully stirred in an organic solvent to form a uniform positive electrode slurry. Then, the slurry is evenly coated on a metal foil (such as aluminum foil) by a coating machine, and then dried, rolled and other processes are performed to make the positive electrode material tightly attached to the foil to ensure good conductivity and appropriate thickness. The negative electrode production process is similar, but the active material is generally graphite, etc., and the metal foil is copper foil. The quality of the electrode directly affects the capacity and charge and discharge performance of the battery. For example, uneven coating will lead to inconsistent local capacity and affect the overall performance of the battery.

The second is the preparation and placement of the diaphragm. The diaphragm is a thin film with a porous structure. Its function is to prevent the positive and negative electrodes from directly contacting and short-circuiting, while allowing lithium ions to pass freely during the charging and discharging process. Common diaphragm materials include polyethylene, polypropylene, etc. The preparation of the diaphragm requires precise control of its porosity and pore size to ensure ion conductivity and mechanical strength. During the battery assembly process, the diaphragm must be accurately placed between the positive and negative electrodes. The precision requirements of this link are very high, and any deviation may cause serious problems such as battery short circuit.

Then comes the injection of the electrolyte. The electrolyte is the medium for ion transmission in the battery, generally composed of lithium salts (such as lithium hexafluorophosphate) dissolved in organic solvents (such as ethylene carbonate, dimethyl carbonate, etc.). The injection of the electrolyte needs to be carried out in a dry environment because the electrolyte is very sensitive to moisture. Moisture will react with lithium salts, destroy the chemical stability of the electrolyte, and then affect the battery performance and life. At the same time, it is necessary to ensure that the electrolyte fully infiltrates the electrodes and diaphragms to ensure that ions can be smoothly transmitted between the positive and negative electrodes.

Finally, the battery is packaged. Polymer Lithium Battery can be packaged in various ways, such as aluminum-plastic film packaging. The packaging process must ensure the sealing of the battery to prevent electrolyte leakage and air ingress. Poor packaging quality will lead to problems such as battery bulging and leakage, which will not only affect battery performance but also bring safety hazards. Moreover, after packaging, post-processing processes such as formation and aging are required to activate the battery electrode materials and achieve the best battery performance.
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