Forums > General Discussion > What should I do if Lithium-ion battery cathode material moisture exceeds the standard?
| What should I do if Lithium-ion battery cathode material moisture exceeds the standard? | |
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| Posted: 11 Jul 2022 03:17 UTC | Post #1 |
| winshinepower Deck & Engine |
Registered Total Posts: 8 |
| Lithium-ion battery cathode materials are mostly micro or nano-scale particles, which can easily absorb moisture in the air, especially ternary materials with high Ni content. When preparing the cathode slurry, if the lithium-ion battery cathode material has high moisture content, the solubility of PVDF will decrease after NMP absorbs water during the slurry stirring process, resulting in a jelly-like slurry gel, which affects the processing performance. After the battery is made, its capacity, internal resistance, cycle, and rate will be affected. Therefore, the moisture of the positive electrode material of lithium-ion batteries should be regarded as a key control item like foreign metal objects. The higher the automation of the production line equipment, the shorter the time the powder is exposed to the air, and the less moisture is introduced. Promoting lithium-ion battery material suppliers to improve the degree of automation of equipment, such as the realization of full pipeline transportation, monitoring of pipeline dew point, and the installation of manipulators to achieve automatic charging and unloading contribute greatly to preventing the introduction of moisture. However, some material suppliers are limited by plant design or cost pressure, and the degree of automation of equipment is not high, and when there are many breakpoints in the manufacturing process, it is necessary to strictly control the exposure time of powder materials. The temperature and humidity of the lithium-ion battery production workshop is also key control indicator. In theory, the lower the dew point, the better. Most lithium-ion battery material suppliers will focus on moisture control after the sintering process. They believe that the sintering temperature of about 1000 degrees can remove most of the moisture in the powder. As long as the introduction of moisture from the sintering process to the packaging stage is strictly controlled, the basic It can ensure that the moisture content of the material does not exceed the standard. Of course, this does not mean that there is no need to control moisture before the sintering process because if too much moisture is introduced in the previous process, the sintering efficiency and the microscopic morphology of the material will be affected. In addition, the packaging method of lithium-ion batteries is also very important. Most material suppliers use the aluminum-plastic bag vacuum packaging method, which seems to be the most economical and effective method at present. Of course, the design of lithium-ion battery materials is different, and the water absorption will also be quite different. For example, differences in coating materials and differences in specific surface area will affect its water absorption. Although some lithium-ion battery material suppliers prevent the introduction of moisture during the manufacturing process, the material itself has the characteristics of easy water absorption, and it is extremely difficult to bake out the moisture after the pole piece is made, which causes trouble for battery manufacturers. Therefore, the problem of water absorption should be considered when developing new materials, and the development of materials with higher universality is of great benefit to both the supply and demand sides of lithium-ion batteries. lithium- ion batteries：https:// www.winshinepower.co m/LFP-12-8V-42AH-Bat tery.html | |
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