The importance of cyclic performance to Vape Batteries needs no elaboration; In addition, the longer cycle life means less resource consumption. Therefore, the factors that affect the cycling performance of Vape Batteries are the problems that every person related to the lithium battery industry has to consider. The following article lists several factors that may affect battery cycle performance for your reference.
1. Types of Materials
Material selection is the first factor affecting the performance of Vape Batteries. Selected materials with poor cyclic performance, the process is reasonable, made again perfect, the cycle of the core is also inevitable can not be guaranteed; Select a good material, even if the subsequent preparation has some problems, the cycle performance may not be too bad (once the lithium cobalt acid to play only $number.) 5mah/g around and the Vape Batteries, 1C although Baiyuzh diving but 0.5C, 500 times 90% or more; the cathode has a black graphite particle core and the cyclic performance is normal after the first electric core is disassembled. From the material point of view, the cyclic performance of a whole battery is determined by the poor one of the cyclic performance of the positive and electrolyte matching, the cyclic performance of the cathode and electrolyte. The material has poor cyclic performance, on the one hand may be in the cycle process of crystal structure changes too fast to continue to complete lithium lithium off, on the one hand may be due to the active substance and the corresponding electrolyte can not produce dense uniform sei membrane caused by reactive substances and electrolyte premature adverse reactions to the electrolyte consumption and then affect circulation. In the design of the core, if a very good selection of poor cycle performance of the material, the other pole does not have to choose a better cycle performance of the material, waste.
2. Positive and negative compaction
The positive and negative polarity compaction is too high, although it can improve the energy density of the core, but also to some extent to reduce the material's cyclic performance. From the theoretical analysis, the greater the compaction, the greater the damage to the structure of the material, and the structure of the material is to ensure that Vape Batteries can be recycled to use the basis; In addition, the high positive and negative pressure of the core is difficult to ensure a higher amount of liquid, and the amount of liquid is the core to complete the normal cycle or more cycles of the basis.
Too much water and positive and negative polar active substances occur side effects, damage its structure and then affect the circulation, at the same time too much water is not conducive to the formation of SEI film. But the trace amount of water is difficult to remove at the same time, trace of the amount of moisture can also be to a certain extent to ensure the performance of the core. Unfortunately, man and man's experience in this area is almost nil, and there is not much to say. We are interested to search the forum for information on this topic, or a lot of.
4. Coating film density
It is almost impossible to consider the effect of the membrane density on the cycle of a single variable. Membrane density inconsistency either brings about the difference of capacity, or the difference between the core winding or laminated layer. For the same type of material with the same capacity of the core, the reduction of membrane density is equivalent to the addition of one or more layers of winding or laminated layer, the corresponding increase in the diaphragm can absorb more electrolyte to ensure that the cycle. Considering the thinner membrane density can increase the magnification of the core, the pole and the bare core of baking and water will be easier, of course, too thin film density coating when the error may be more difficult to control, active substances in the large particles may also be coated, rolling negative impact, more layers means more foil and diaphragm, That means higher costs and lower energy densities. Therefore, the evaluation also needs to balance the consideration.
5. Excess of negative electrode
Besides the influence of the first irreversible capacity and the density deviation of the coating film, the effect of the excess of the cathode on the cyclic performance is also considered. For the cobalt-lithium and graphite system, the anode graphite becomes the "short plate" in the cycle process. If the negative electrode is not sufficient, the core may not be in the circulation before the lithium, but after hundreds of times the positive structure of the cycle is very little but the negative structure of the cathode can not fully receive the lithium ions provided by the cathode to analyze lithium, resulting in premature decline in capacity.
6. Electrolyte Quantity
There are three reasons for the effect of insufficient electrolyte quantity on circulation. One is the amount of liquid injection is insufficient, the second is that although the injection volume is sufficient but the aging time is not enough or positive and negative because of compaction too high and other reasons for the leaching is not sufficient, the third is the circulation of the inner electrolyte is consumed. Insufficient injection volume and insufficient liquid volume before writing, "The effect of electrolyte deficiency on the performance of the core" is not covered. For the 3rd, the microscopic manifestation of the matching between anode and cathode and electrolyte is the formation of dense and stable sei, and the visible performance of the right eye is not only the consumption rate of electrolyte in the process of circulation. Incomplete sei membrane on the one hand can not effectively prevent negative reactions with electrolyte and thus consumption of electrolyte, on the other hand in the SEI membrane defective parts will be regenerated with the circulation of the SEI membrane to consume reversible lithium source and electrolyte. Whether the cycle into hundreds or even thousands of cores or for dozens of of times, if the circulation before the electrolyte sufficient and circulation after the electrolyte has been depleted, then increase the electrolyte retention is likely to improve its cyclic performance to some extent.
7. Objective conditions of testing
The testing process of charge and discharge ratio, cut-off voltage, charging cut-off current, the test of overcharge, test room temperature, the test process of sudden interruption, the test point and the contact resistance and other external factors, will more or less affect the cyclic performance test results. In addition, the sensitivity of different materials to the above objective factors varies, the unified test standards and the understanding of the characteristics of common and important materials should be sufficient for daily use.