Seven factors affecting the cycle performance of lithium batteries

These seven factors affect the cycle performance of lithium batteries. The battery we value most is lithium batteries, because the batteries of our mobile phones, pads, and notebooks are lithium batteries, and its battery life capability is also a key direction that the company has been researching. Needless to say, how important the cycling function is to lithium batteries. From a micro point of view, longer riding life means less resource consumption. Therefore, the factors that affect the cycling function of lithium batteries are issues that everyone involved in the lithium battery profession must consider. 1. Too much water. Water will interact with positive and negative reactive substances, destroy its structure, and then affect the circulation. Too much water is not conducive to the composition of the SEI film, but it is difficult to remove with tracking water, and trace water can also be used. To a certain extent, ensure the function of cells. 2. The positive and negative electrode compaction Although the positive and negative electrode compaction is too high, it can increase the energy density of the battery, but it will inevitably reduce the cycle function of the material. From a theoretical analysis, the greater the degree of compaction, the greater the damage to the material structure, and the structure of the material is the basis for ensuring the recycling of lithium batteries; in addition, cells with higher positive and negative compaction cannot guarantee higher liquid Retention, which is the basis for cells to complete normal or more frequent cycles. 3. The objective conditions of the test. During the test, the charge and discharge rate, cut-off voltage, charge cut-off current and overcharge and discharge of the test, at room temperature, sudden interruption in the process of inspection, test points and elements other than the battery, such as contact resistance will be More or less affect the cyclic function test results. On the other hand, the sensitivity of the target elements of different materials is different, consistent inspection specifications, familiar with the characteristics of common and important materials, and meet the daily operation requirements. 4. Excessive negative electrode negative excess in addition to the influence of the first irreversible capacity and the density error of the coating film, the impact on the cycle function is also a consideration factor. For lithium cobalt oxide and graphite systems, negative graphite enters the circulation process. Shortcomings are relatively common. If too many cathodes are unsatisfactory, the lithium battery may be cycled before the analysis, but after hundreds of cycles, the structure of the positive electrode will not change much, and the structure of the negative electrode will be severely damaged and cannot fully receive the positive lithium ions and lithium ions. Supply, the composition capacity drops prematurely. 5. The single variable of coating density considers the influence of film density on the cycle. It is almost a task. It is not a possibility. The film density is inconsistent or brings about the difference in capacity. The difference in battery winding or laminate layer. The same material and battery capacity are equivalent to the falling film density. With the addition of one or more layers or laminate layers, the corresponding new diaphragm can absorb more electrolyte to maintain circulation. Considering the ratio of cell functions to the density of thin film, the pole pieces and bare cells are baked out. Water will be easier, and of course, when the density error of the film coating may be more difficult to control, large particles of active materials may also have a negative impact on the coating and rolling, which means more sheets and film layers, which means more High cost and lower energy density, so the evaluation should also consider balance. 6. Variety of materials The choice of materials is the primary factor affecting the performance of lithium batteries. Choose materials with poor cycle performance. The technology is reasonable and perfect. I chose a better material and made a small problem. Even the subsequent circulation function may not be too far away. From the material point of view, the circulation function of the entire battery is that after the positive electrode and the electrolyte circulation function match, the cathode and the The last two electrolyte circulation functions are matched. The poor people decide. The material circulation function is poor. On the one hand, it may be that the crystal structure changes too fast during the circulation process to continue to end the lithium insertion. On the one hand, this may be the active material and the corresponding electrolysis. The liquid cannot appear fine or even the SEI film, the formation of active substances and electrolytes have side reactions, so the electrolyte is consumed too quickly and blood circulation is affected. In the battery design, if one pole confirms that a material with a poor circulation function is selected, the other pole should not choose a material with a good circulation function, which is wasted. 7. There are three important reasons for the lack of electrolyte in the electrolyte that affect the cycle. One is the insufficient injection volume; the second is that the injection volume is sufficient, but the aging time is impossible; the second is that the positive and negative electrodes are not enough due to over-compaction; the third is that the electrolyte inside the circulating battery is consumed. Third, the positive and negative matching is especially the formation of a close and stable SEI in the microscopic appearance of the cathode and the electrolyte. The right eye is the visible incarnation, which is consumed during the circulation of the electrolyte. On the one hand, an incomplete SEI membrane cannot be effective. To prevent the side-use and consumption of the cathode and electrolyte electrolyte. On the one hand, regarding the defective part, the SEI membrane will regenerate the SEI membrane according to the cycle and consume the reversible lithium source and electrolyte. Cells with hundreds or even thousands of cycles are still about dozens of cells that have already dived. If the electrolyte is satisfied after the cycle cycle and the electrolyte is consumed, then adding electrolyte storage may be a statement to improve the cycle function: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete the previous article: You have to understand these technologies if you want to have a long battery life