The significance of CR2032 button cell coating

　　The production and processing of lithium-ion batteries is a process closely related to one process step. Generally speaking, the production and manufacturing of lithium batteries includes the production and processing technology of pole pieces, the assembly and processing technology of lithium batteries, and their final filling, precharging, conversion and brittle processing technology. In the process of these three links, each process can be divided into several important processes, and each step is a serious hazard to the final characteristics of the rechargeable battery.

　　In the production and manufacturing process of pole pieces, it can be subdivided into five processing technologies: slurry production, slurry coating, pole plate pressure, pole plate segmentation, and pole plate drying. According to statistics, lithium battery assembly processing technology can be divided into backline machine, shell, welding and other processing technologies according to different rechargeable battery model specifications. The final liquid injection link also includes processing technologies such as liquid injection, exhaust, sealing, pre-filling, formation, and aging.

　　Every process in the manufacturing process of rechargeable batteries is caused by certain consumption. These processes are caused by employee errors, machine equipment errors, natural environment, etc., thus ensuring that the cost rate of goods is good enough and ensuring that every product Every step is a goal.

　　1. The meaning of coating

　　Slurry coating is the next process after slurry preparation. The key is to evenly apply reliable, good viscosity and good fluidity slurry on the positive and negative aggregate liquids. The application of polar films in lithium batteries has important practical significance, which is reflected in the following aspects:

　　1. Critical practical significance for finished battery capacity

　　During the entire sizing process, if the thickness of the positive and negative plasma coatings at the front, middle and rear of the electrode are inconsistent, it is easy to cause the battery to be charged too low or too high, and it is easier to produce lithium during the entire process of the rechargeable battery cycle system, damaging the battery. Cycle Time.

　　2. Important practical significance for battery safety

　　Do 5 seconds of work before applying glue to ensure that there will be no penetrating particles, dirt, smoke, etc. during the entire glue process. If contamination occurs, it will cause micro-short circuit failure inside the battery, or even worse, the battery will ignite and explode.

　　3. Key practical implications for battery performance consistency

　　The li battery factory avoids a batch of rechargeable batteries with large differences in volume and cycle system life. Therefore, during the application process of the diaphragm, the main parameters of the front and rear diaphragms are ensured to be consistent.

　　4. Important practical significance for battery cycle times

　　The electrophotocatalytic performance of the rechargeable battery is related to the left-right difference, the penetration of dust by the electrode, and the uneven thickness of the electrode.

　　Therefore, the processing technology requirements for the slurry coating are: under sufficient and good conditions of the slurry, the relative density of the polar active chemical materials in the front, middle and back is consistent, and the glue crystallization penetrates throughout the process. Of course, the definition of the film is not only determined by the actual effect of the rubber. If the film is serious, does not bend, has milky white bubbles, etc., this is a slurry problem. Return to the first step to deal with it.

　　2. Coating method

　　According to statistics, the coating equipment consists of an expansion module, a feeding module, a tension control system, a screen printing head, an oven, etc. Sizes can be divided into two categories, both with advantages and disadvantages.

　　1. Transfer coating

　　The coating roller rotates to push the slurry, adjusts the slurry migration according to the scraper gap, uses the rear roller or coating roller rotation to transfer the slurry to the plate, controls the coating thickness according to the processing technology, adjusts the net weight, and adjusts the slurry according to dry heat and The heat removes the organic solvent in the slurry, allowing the solid chemical material to bond well with the board. As shown in Figure 1.

　　Its advantage is that the viscosity of the slurry is not high, it is easy to adjust the main parameters of the slurry, and there is no blocking material. The application accuracy in power lithium batteries is not high and the consistency of the polar film cannot be guaranteed. The mud is exposed to the air between the drums, which is detrimental to the performance of the mud.

　　2. Extrusion coating

　　The material system software delivers the paint to the magnetic pump, and then drives the slurry to the extrusion head. According to the extrusion method, the slurry is formed into a liquid film and applied to move the liquid. Its advantages are very uniform coating after coating, high precision, high coating edge plane, airtight computer operating system, which will not be damaged by dirt, and is suitable for mass production. The shortcomings depend on the high precision of the machine, high maintenance, high viscosity slurry, conversion of standard models to replace new seals.

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