Influence the properties of lithium battery cycle seven points for attention

Source: 2020 - 03 - 26 hits: remained time influence the properties of lithium battery cycle seven note we care about most of the battery is lithium battery, because of our mobile phone, pad, notebook battery is lithium battery, its life is also a key enterprise constantly research direction. Needless to say, circulation function is very important for the lithium battery. From the microcosmic point of view, longer cycle life means less resource consumption. As a result, the influencing factors of lithium ion battery cycle function is everyone in the lithium battery industry must be thinking of problem. 1, water too much water will cause the positive and negative side effects of active material and its structure, thus affecting circulation. At the same time, excess water is bad for the composition of the SEI, but I can't remove the trace of water at the same time, the trace of water also can guarantee the function of the cells in a certain extent. 2. Is compacted and negative pressure if the positive and negative of compaction through high, battery energy density increases, but the material circulation function can also drop on the horizontal. Theoretically, the greater the degree of compaction, the greater the damage to the structure of the material, the structure of the material is to guarantee the foundation of the lithium ion battery recycling. In addition, cells are negative pressure the higher the degree of compaction, the more difficult to guarantee the high fluid retention, this is complete normal cells or the basis of more frequent circulation. 3. Test the objective conditions of the test in the process of charging and discharging rate, cut-off voltage, charge cut-off current charge discharge, test, test at room temperature, infix suddenly in the process of test, test points and battery outside elements, such as contact resistance will be more or less affects the cycle of other functions, test results, different materials of different sensitive level of the target element, a unified test specification, understand common and important characteristics, use should be able to meet the daily work. 4. Too much cathode negative reasons in addition to the need to consider too many for the first time the irreversible capacity and the density of coating film of bias, the influence of the circulating function is also a factor, the influence of the cobalt acid lithium and graphite system, negative electrode graphite into the 'short' is relatively common in the process of circulation, if negative excess is not enough, lithium-ion batteries, perhaps before the cycle analysis, but the positive structural change effect cycle has destroyed the structure of the anode after hundreds of times, and not good to accept lithium ion and lithium ion anode, constitutes the capacity of the early fall. 5, coating density variable density affected the cycle of a single thought is a task, could not bring the ability of different membrane density, or laminated battery winding layer is different, and the type of battery and size and material, falling film density is equivalent to add a layer or multilayer or laminated layer, add the gap can absorb more electrolyte, to ensure that the circulation and think thin film density than function, can increase the battery pole piece and bare battery baked in addition to water will be more easy, also, of course, when the thin-film coating may be more difficult to control the density of the errors, large particles in the active material may also produce negative influence coating and rolling. More layer means more foil and separation, that means higher costs and lower energy density. 6. The choice of material types are primary factors influencing the performances of lithium ion batteries. Choose circular function material with poor, no matter how reasonable technology, perfect production, there is no guarantee that the cycle of the battery. Choose a good material, by a small problem, even if the subsequent poor circulation function may not too far away, from the perspective of materials, the whole function of the cell cycle, is by the positive electrode and the electrolyte circulation function, one after another game in the cathode and the electrolyte after two of periodic function, the poor man, material circulation function is poor, on the one hand may be crystal structure change in the process of circulation quickly, so can't continue to complete the intercalated-li lithium, on the one hand, it may be active material and the corresponding electrolyte can't form an average density of SEI, which constitute the active material and electrolyte early side effects, so the electrolyte consumption too fast, which affects the circulation of the blood. In battery design, if one allows you to select with poor circulation function material, then the other don't need to choose better circulation function materials, namely the waste. 7. Lack of electrolyte electrolyte influence cycle there are three main reasons, one is the lack of injected fluid, another is, of course, injecting liquid is enough but aging time enough or positive and negative electrodes, because the cause of the high compaction immersion is not enough, the third is a cycle of the consumption of the electrolyte in the cell. Third, the positive and negative match especially in microscopic embodied in SEI formation of cathode and the electrolyte density, stable, the embodiment of right eye is visible, the consumption in the process of circulation of electrolyte, incomplete SEI film on the one hand, can not effectively prevent the cathode and the electrolyte electrolyte, side effects and consumption on the one hand, the SEI film has its own shortcomings, can produce a large number of cyclic stop as the site SEI source and reversible lithium electrolyte membrane and consumption. Both cells have been circulating hundreds or thousands of times or have been diving dozens of times, if before the electrolyte is fully before the circulation and consumption in circular electrolyte electrolyte additives on circular level may be necessary.