What are the ways to test the 'slightly less' electrolyte injection volume of lithium-ion batteries?

What are the ways to test the slightly smaller amount of electrolyte injection for lithium-ion batteries? The performance of lithium-ion batteries is closely related to the electrolyte, and the amount of electrolyte has a greater impact on the electrochemical and safety performance of the battery. The proper amount of electrolyte injection is not only beneficial to increase energy density and reduce costs, but also has important uses for improving the cycle life of lithium-ion batteries. What are the ways to test the slightly smaller amount of electrolyte injection for lithium-ion batteries? Since the electrolyte will continue to undergo oxidation and reduction reactions on the positive and negative electrodes during the operation of the lithium-ion battery, the injection volume is too small. The cycle life of the battery is unfavorable. At the same time, if the amount of electrolyte is too small, some active materials will not be infiltrated, which is not conducive to the capacity of the lithium-ion battery. However, too much liquid injection will also cause the energy density of the lithium-ion battery to decrease, and the cost Therefore, the balance between performance and cost of lithium-ion batteries is particularly important as to how to determine the appropriate injection volume. 'Slightly less, less, and less severely' the electrolyte injection volume of lithium-ion batteries is a general statement, and there is no strict requirement. Even if the electrolyte is slightly less, the lithium-ion battery is already a defective product. Cells with slightly less electrolyte are not easy to be found. At this time, the capacity and internal resistance of the cells are normal. There are three methods for testing lithium-ion batteries with less electrolyte: removing the cells, weighing, Detection. 1. Disassembly of the battery core is a destructive test and only one battery core can be tested at a time. Although the problem can be determined intuitively and accurately, the actual use of this method to screen the battery is basically unnecessary. 2. The weighing method is less accurate, because the pole piece, aluminum plastic film, etc. will also have weight differences; since the electrolyte of the lithium ion battery is 'slightly lessThe difference will not be large, so the weight difference of other materials is likely to be greater than the difference in electrolyte weight. Of course, you can accurately and timely know the problem cell by measuring the injection volume or retention volume of each cell during injection. However, instead of weighing the full cell, it is better to add the accuracy of the injection equipment And optimize the process, so as to cure the symptoms. 3. Detecting this is the focus of the problem. What kind of detection method can be used to screen out cells with 'slightly less' electrolyte, which is equivalent to what kind of abnormalities will occur in cells with 'slightly less' electrolyte. At present, only two methods are known to measure cells with normal capacity and internal resistance, but with slightly less electrolyte. These two methods are: cycle, rate discharge platform. What effect does the electrolyte injection volume have on the performance of lithium-ion batteries? ①The influence of electrolyte volume on the capacity of lithium-ion batteries The capacity of lithium-ion batteries increases with the increase in electrolyte content. The optimal capacity of a lithium-ion battery is that the separator will wet out. It can be seen that the amount of electrolyte is insufficient, the positive electrode plate is not fully wetted, and the separator is not wetted, resulting in large internal resistance and low capacity. The addition of electrolyte is conducive to making full use of the capacity of the active material. This shows that the capacity of a lithium-ion battery has a great relationship with the amount of electrolyte. The capacity of lithium-ion batteries increases as the amount of electrolyte increases, but eventually tends to be constant. ②The amount of electrolyte affects the cycle performance of lithium-ion batteries. The electrolyte is less, and the conductivity is low. The internal resistance increases faster after cycling. Accelerating the decomposition or volatilization of the local electrolyte of lithium-ion batteries is the rate of decline in battery cycle performance. Too much electrolyte will cause side reactions and increased gas production, which will lead to a decrease in cycle performance. Moreover, too much electrolyte is wasted. It can be seen that the amount of electrolyte has a significant impact on the cycle performance of the lithium ion battery. Too little or too much electrolyte is not conducive to the cycle performance of the battery. ③The influence of electrolyte volume on the safety performance of lithium-ion batteries One of the reasons for the explosion of lithium-ion batteries is that the injection volume cannot meet the process requirements. When the amount of electrolyte is too small, the internal resistance of the battery is large and the heat generation is large. An increase in temperature will cause the electrolyte to quickly decompose and produce gas, and the separator will melt, which will cause the lithium-ion battery to expand and short-circuit explosion. When the amount of electrolyte is too much, the amount of gas that appears during charging and discharging is large, the internal pressure of the battery is large, and the case is broken, causing electrolyte leakage. When the electrolyte temperature is high, it will catch fire when it encounters air. Electrolyte is used as a medium for lithium migration and charge transfer. In order to ensure that the active material is fully used, each void area of u200bu200bthe battery core is required to be filled with electrolyte. Therefore, the internal space volume of the battery can also be used to roughly determine the battery's demand for electrolyte. . It can be seen that the amount of electrolyte of a lithium ion battery has a significant impact on the cycle performance of the battery. Too much or too little electrolyte is not conducive to the cycle performance of the lithium ion battery. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous article: Lithium-ion batteries for electric vehicles are gaining momentum. Who will be the biggest winner?