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Analysis Of Factors Affecting Cycle Life Of Lithium Ion Power Bank

Jun 26, 2017

With the development of technology and technology mature, Lithium Ion Power Bank applications more and more widely. Lithium Ion Power Bank has a single high voltage, relatively light weight, environmentally friendly, etc., but after a number of cycles of charge and discharge cycle after the battery capacity and other performance degradation. The same conditions, the faster the battery capacity attenuation, the battery quality is relatively poor. Lithium Ion Power Bank cycle performance is an important indicator of its quality, many of the Lithium Ion Power Bank standards have a cycle of life of this project.

The use of Lithium Ion Power Bank charge and discharge cycle of the process, the size of charge and discharge current, charge and discharge cut-off voltage selection and the use of charge and discharge methods such as charge and discharge system for Lithium Ion Power Bank cycle life also has a very important impact. Where the blind increase in battery current, increase the charge cut-off voltage, reduce the discharge cut-off voltage will make the battery performance.

Different electrochemical system of Lithium Ion Power Bank charge and discharge cut-off voltage is different. In the Lithium Ion Power Bank charging process over the charge cut-off voltage that overcharge occurred. K. Maher et al. [24] set the charge cutoff voltage of the LiCoO2 cell from 4.2V to 4.9V, and X-ray diffraction and Raman spectroscopy of the electrode material after the experiment showed that the positive electrode of the graphite anode and the lithium cobalt oxide The structure changes, by testing the different cut-off voltage after charging the electrode of the SOC of the entropy curve, also found that the electrode material has undergone structural changes. When the Lithium Ion Power Bank is overcharged, excess lithium ions exiting from the positive electrode are deposited or embedded on the negative electrode. The deposited active lithium reacts easily with the solvent and releases heat to raise the temperature of the battery. The positive electrode is decomposed by heat to liberate oxygen and make the electrolyte easily decomposed and produce a lot of heat [25]. When the discharge voltage of the lithium battery is lower than the discharge cut-off voltage, an overdischarge is formed. In the process of over-discharge, lithium ions from the negative will be excessive prolapse, the next time to re-insert the charge will be more difficult. Yu Zhongbao [26] on the MCMB as the negative, LiCoO2 as the cathode of the battery over discharge to 0 V, the copper collector is more serious corrosion, the negative SEI film was destroyed, the formation of SEI film performance is poor, so that the negative Impedance increases, polarization enhancement. The battery discharge capacity after the discharge process, the charge and discharge efficiency is greatly reduced.

Li Yan et al [27] 18650 Lithium Ion Power Bank at different magnification of the discharge were studied. The results show that the battery capacity attenuation is almost proportional to the increase in charge and discharge magnification. High capacity cycle of LiCoO2 / graphite Lithium Ion Power Bank capacity attenuation serious. The basic reason for the serious attenuation of the capacity is that the change of the structure of the cathode material and the thickening of the negative electrode surface film lead to the decrease of the number of Li + and the obstruction of the diffusion channel. In the case of high current discharge, the need for rapid ion implantation, out of the positive and negative, the reaction speed quickly. Tang Zhiyuan et al [28] through experimental analysis that: the battery in the high current discharge in a short period of time need to release a large capacity, the electrode reaction is rapid, some lithium ions too late to break or through the anode material discharge process It has ended. In addition, the battery pole may be blown under high current conditions, and the device components may be damaged.

in conclusion

Through the analysis we can see, both in the design and manufacture or use of the process, the impact of Lithium Ion Power Bank cycle life factor is multifaceted. Lithium Ion Power Bank applications more and more widely, the demand for lithium batteries in the number and quality are put forward higher requirements. Cycle life directly affect the use of Lithium Ion Power Bank time and quality, so the producers of its influencing factors is very necessary. Only in the development and production process will affect the cycle of life factors are well grasped, enterprises can compete in the fierce market competition to take the initiative. Consumers should pay attention to the use of Lithium Ion Power Bank during the use of the characteristics, according to the instructions prompted the correct use of the battery.