Talk about the process production flow of 14250 battery

Common 18650 lithium batteries are divided into lithium-ion batteries and lithium iron phosphate batteries. The nominal voltage of lithium-ion batteries is 3.7v, the charging cut-off voltage is 4.2v, the nominal voltage of lithium iron phosphate batteries is 3.2V, the charging cut-off voltage is 3.6v, the capacity is usually 1200mAh-3350mAh, and the common capacity is 2200mAh-2600mAh. The process production flow of 18650 lithium batteries 18650 lithium batteries are commonly used lithium batteries in electronic products, and are often used as batteries in laptop batteries. The definition rule of its model is: such as 18650 type, which means that the battery has a diameter of 18mm, a length of 65mm, and a cylindrical battery. The production process of 18650 lithium batteries: coating First of all, let's understand the coating process. In this process, you can see large rolls of copper foil (yellow) and aluminum foil (silver). Aluminum foil is used to coat nickel-cobalt-manganese NCM ternary materials; conversely, copper foil is used to coat graphite, the negative electrode active material; the white one is the separator. The global lithium battery separator is mainly occupied by manufacturers such as Asahi, Celgard, SK, Toray, and W-SCOP, and these foreign companies hold nearly 70% of the market share. The market share of Chinese separator companies is about 30%, and the independent localization of lithium battery separators is constantly breaking through. The capacity of the battery cell is obtained according to the proportion and area of these formulas. A whole roll of coated positive and negative electrode materials is about 126mm wide, and then it needs to be cut into 7 small rolls with a width of about 18mm. Each roll will be evenly divided into several sections, and each section represents the materials required for a battery cell. According to Xu Gong, an engineer at the battery cell factory, the current price of ternary positive electrode materials is 120,000 yuan per ton, and each ton of materials can be used to produce 50,000 battery cells; the current battery cell production capacity is 500,000 per day, and 10 tons of ternary positive electrode materials are needed. This expense alone requires 600,000 yuan per day. The automated machine stamps each section with a nickel strip and an insulating and high-temperature resistant Mylar sheet. The next step is to weigh it in five levels, namely, heavy, A1, A2, A3, and light. This is the same as the selection of CPU wafers. The same batch of cutting processes will also have different physiques. According to the different physiques, the corresponding capacity will be divided and shipped in pairs. The second production process of 18650 lithium batteries: the positive and negative electrodes that have been assembled and classified will be fully automatically rolled here. The white material is the diaphragm. The 14250 battery cannot work properly in this way. Electrolyte needs to be added as a medium to allow the positive and negative electrodes to react chemically. Only then can lithium ions migrate between the positive and negative electrodes, generate charge ions to output energy, and lithium batteries can be charged and discharged. After the automatic rolling is completed, it rolls directly onto the assembly line and enters the next assembly step to be loaded into the steel shell. The steel shell is stamped in one piece with a thickness of less than 1mm, so the strength and quality of the steel are very high. This 14250 battery factory uses imported Korean steel materials. In this step, the negative electrode ear is connected to the bottom of the steel shell by spot welding. The spot welding accuracy and product quality are ensured. The spot welding machine cannot weld the bottom of the steel shell. The assembly girl has a copper nail in her hand. First, insert it into the bottom through the reserved small hole, and then put it into the spot welding machine. With a click, the negative electrode is connected to the bottom of the steel shell with a nickel strip. The electrolyte is injected into the glove box filled with inert gas argon in the sealed box. The oxygen concentration in the sealed box gloves must be lower than 10ppm to prevent electrode oxidation. The electrolyte argon is input into the sealed box through a circulating purification device. There are catalysts and reducing agents hydrogen in the device. The water generated by the hydrogen-oxygen reaction can remove oxygen. At the same time, the desiccant in the device absorbs moisture to ensure the dryness of the atmosphere in the box. After the electrolyte is injected, the cap of the battery cell has been connected to the steel shell by laser welding. Rows of neat and orderly stacked, ready to go. A new 14250 battery cell was born. Each battery cell needs to wear a "new clothes" PVC casing classified by capacity. Different capacities correspond to different PVC sleeves. Production process of 14250 battery cell 3: First charging and testing After the electrolyte is injected into the 14250 battery cell, it is not actually charged, and the state of the positive and negative electrode surfaces has not reached stability at this time. It must be charged for the first time before it can be used normally. This first charge is called "formation". Extra electricity needs to be charged during the first charge to produce a protective film on the electrode surface. This protective film is the secret of the low self-discharge of lithium-ion batteries. At the same time, the properties of the protective film also affect the performance and life of the battery. Therefore, the formation process is very important. The formation is completed in a capacity cabinet. The battery cell is a chemical. In order to ensure safety and life, it needs to be paired and packed in boxes before leaving the factory, with 200 cells per box. Ensure three consistency: consistent capacity, consistent internal resistance, and consistent voltage. Only in this way can it be shipped normally, otherwise it will be put into the cold palace and become a B-level or C-level battery cell. Internal structure of 14250 battery cell Lithium battery cell positive electrode 14250 battery is wrapped by metal shell outside, and the negative electrode of lithium battery cell can be seen by breaking the shell. The negative electrode of lithium battery cell has blue plastic insulating gasket like the positive electrode. After disassembling it, we found that the cylindrical 18650 battery cell is wrapped by full metal shell, which can provide good protection for the internal substances and prevent leakage. Inside the battery cell, the film is soaked in electrolyte. The inside of the 14250 battery cell is a roll of film, and the positive and negative electrodes are designed at both ends of the battery cell. The internal film is a specially formed polymer film. The film adopts a microporous structure design, which allows lithium ions to shuttle freely. How to judge the quality of 14250 battery cell? 1. Use the multimeter DC gear greater than the rated voltage of the battery to test. For example: test dry battery 9V, 1.5V with DC10V, DC2V gear. 2. After selecting the gear according to the rated voltage of the lithium battery, use the test lead to connect the positive and negative electrodes of the battery respectively. When the test voltage is greater than or equal to the rated voltage marked on the battery. The battery is intact. When the test voltage is 10% lower than the rated voltage, the battery can be used in electrical appliances with a low depth of discharge. 3. It should be noted that the voltage of rechargeable batteries is generally 15%-25% lower than that of similar batteries. For example, the voltage of 5# battery is 1.5V, while the rechargeable battery is generally only 1.2-1.3V. Therefore, the rated value marked on the battery should be carefully confirmed. At present, the cycle life of 3.7V 18650 lithium batteries can generally reach about 500~1000 times, and the life of 3.2V 18650 can generally reach more than 2000 times. Of course, the premise is that the battery is produced by a regular manufacturer. If it is a defective or counterfeit battery, the life will be very short.

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