Each lithium industry personnel have had to consider the lithium-ion battery cycle performance, and longer cycle life means less consumption of resources. So what exactly determines the performance of lithium-ion batteries that cycle? 
 
Material Type: choice of materials is the first factor affecting the performance of lithium-ion batteries. Select a poor cycle performance materials, processes and then reasonable to prepare for further improvement, batteries can not be guaranteed circulation is bound; choose a better material, even made ​​a slight problem follow the cycle of poor performance may not too outrageous (once played grams of lithium cobalt oxide is only about 135.5mAh / g and analysis of lithium batteries, 1C although hundreds of times diving but 0.5C, 500 times more than 90%; anode batteries have open after a black graphite particles batteries, the cycle performance of normal). From the material point of view, the performance of a full cycle of the battery, the positive electrode and the electrolyte solution cycle characteristics after the match, the cycle properties of the electrolyte and the negative electrode after the two match, the less one to decide. Poor cycling performance, one may change the crystal structure of the cycle can not proceed so fast lithium deintercalation one hand, since the active substance may be unable to generate the corresponding electrolyte membrane caused by dense, homogeneous active substance SEI side reactions with the electrolyte leaving prematurely excessive consumption thereby affecting electrolyte circulation. In the design of the batteries, if the material is poor cycle performance of a selection electrode is recognized, the other electrode is preferably no need to select the cycle performance material waste. 
Compaction is negative: positive and negative high compaction, although the energy density of batteries, but also reduces the cycle performance of the material to some extent. From the theoretical analysis, the greater the compaction, the greater the equivalent structural damage to the material, the structure of the material is the basis for a lithium-ion battery can be used; addition, the positive and negative high compaction is difficult to ensure than the batteries the high liquid retention amount, and the amount of fluid is guaranteed to complete the normal cycle batteries or more cyclic basis. 
Moisture: Excessive moisture will occur with the positive electrode active material side reactions, thereby affecting its structure destruction cycle, while too much water is not conducive to the formation of the SEI film. However, while difficult to remove traces of water, traces of water can be guaranteed to some extent, the performance of batteries. Unfortunately, this aspect of civil and military personal experience almost zero, can not say too many things. We are interested can search a search inside information forum on this topic, or a lot. 
Coated film density: the density of a single variable consider the impact of the film on the cycle is almost an impossible task. Film density inconsistencies or differences in the capacity to bring either batteries or winding difference laminated layers. With the same capacity of the same material type batteries, the lower the density of the film corresponds to an increase or a wound layer or layers laminated layers, corresponding to the increase of the electrolyte membrane can absorb more to ensure circulation. Considering the thinner the film density can be increased rate performance of batteries, and the bare core pole piece of baking will be easier to remove water, of course, the density of the coating film is too thin, the error may be difficult to control when the active substance large particles may also be coated, rolled a negative impact, more layers means more foil and diaphragm, in turn means higher costs and lower energy density. Therefore, when assessing the need to balance considerations. 
Negative excess: excessive negative reasons in addition to consider for the first time beyond the capacity of irreversible effects and coating film density deviation, the impact on cycling performance is also a consideration. For lithium cobalt oxide and graphite system, the negative cycle of graphite become "short board" one of the more common. If negative excess is not sufficient, batteries may not analyzed before cycling lithium, but hundreds of times the loop structure is minimal but the positive and negative changes in the structure was severely damaged but not completely positive reception thus providing lithium-ion analysis of lithium, resulting in over-capacity early fall. 
Electrolyte volume: lack of impact on the amount of electrolyte circulation for three main reasons, one less than the amount of fluid injection, the second injection fluid volume is adequate, but despite the lack of time or aging infusion due to the positive and negative high compaction and other causes not full, three batteries, with the loop inside the electrolyte is consumed. Note inadequate fluid volume and wrote "electrolyte deficiencies on performance batteries" before Paul Wenwu thus insufficient amount of fluid will not go. On the third point, the negative electrode and the positive and negative electrolyte particular microscopic matching dense and stable performance of SEI formation and performance of the visible eye, both for circulation of the electrolyte during the consumption rate. Incomplete SEI film on the one hand and the electrolyte can not effectively prevent the occurrence of negative side effects and thus consume the electrolyte, while the SEI film with defective parts will be re-circulated in order to generate the SEI film and electrolyte depletion reversible lithium source . Whether circulating hundreds or even thousands of times the batteries or both diving for dozens of batteries, the electrolyte is sufficient and if the first cycle after cycle has been consumed electrolyte, the electrolyte increased ownership is likely to be some enhance the cycle performance degree. 
The objective conditions of the test: the test during charge-discharge rate, cut-off voltage, the charging cut-off current, tests overcharge and over discharge, test room temperature, the sudden interruption during the test, the test point and the contact resistance of batteries and other external factors will more or less affect the cycle performance test results. In addition, the sensitivity of different materials to the above objective factors varies, uniform testing standards and understand the characteristics of the common and important materials should be sufficient daily use. 
Summary: As casks principles as factors that affect the performance of batteries circulation among many, the ultimate decisive factor is a number of factors in the shortest board. Meanwhile, among these factors, but also have a reciprocal influence. In the same materials and made ​​capacity, the higher the circulation, often means lower energy density, to find exactly the point of integration to meet customer needs, try to ensure the consistency of batteries made ​​of party is the most important task lies .