How does the voltage and current affect the life of the ternary lithium battery during the charging process?

How does voltage and current affect battery life? Generally, we often say that the first three elements refer to NMC data, and it also includes the ability of NCA information to layer material structure stability, because the chemical stability of Ni3+ is more affected than finite elements, so the charging of NMC data More lees will appear in the process, and the new capacity of data will make a greater progress. With the advancement of lithium battery energy density, traditional lithium cobalt oxide materials have gradually replaced ternary information with higher capacity, and the layered structure of ternary materials is similar to LCO, but in contrast, the data of LCO ternary materials is not only obtained in information capacity Great progress has been made, and the thermal stability is significantly better than the LCO information. Generally speaking, we often say that the first of three elements refers to NMC data, and also includes the ability of NCA information to layer material structure stability, because the chemical stability of Ni3+ is more affected than finite elements, so more will appear in the process of charging NMC data. Li, the new capacity of the data has improved from a larger one. On the other hand, the structural stability of the oxidized layered anode data is also affected by the amount of de-li, and excessive de-li will cause the data layered structure to collapse. Therefore, in order to ensure the structural stability of the NMC data, it is necessary to restrict the charging cut-off voltage of the data to ensure the long-term cycle stability of the data. Johannes Kasnatscheew of the University of Munster in Germany and others studied the impact of the charging system on the cycle life and structural stability of NCM111 and NCM532 (two BMW Group models), NCM622 and NCA (Customcell two models) and NCM811 (cedartechnology two models). The impact of the charge cut-off voltage The amount of lithium removed from the NMC data is proportional to the charge cut-off voltage. In other words, the higher the charge cutoff voltage, the greater the amount of lithium removed from the NMC data, and the more unstable the data structure. The figure below shows the cyclic function curve of NCM811 data under different charge cut-off voltages. It can be seen that after the improved cut-off voltage, the data capacity has been significantly improved, but the rate of data decline is therefore accelerated. By comparing the cycle data under different cut-off voltages, it is found that although the specific capacity of the 4.6v cut-off voltage is the highest at the fifth discharge, after 53 cycles, its capacity quickly drops below 4.5v and 4.4v cut-off voltage NMC111 Capacity. This shows that only the charging cut-off voltage is improved. Although the data capacity will be greatly improved, the cycle stability of the data will be significantly reduced. Therefore, it is necessary to select the charging cut-off voltage reasonably according to the planned life of the battery. Below NMC111, NMC532, NMC622, NMC811 and NCA materials are cycled 53 times according to different cut-off voltages, and the discharge energy and discharge rate curves can be seen from the figure. It can be seen from the figure that the discharge energy density is not the highest voltage of the battery after 53 cycles. NMC811 has the highest data. 4.3V cut-off voltage obtains the highest discharge energy density, NMC622NMC532, NCA data obtains the highest charge cut-off voltage 4.4V discharge energy density, NMC111 data obtains the highest energy density at 4.5v. This is only the data after 53 cycles. As the number of cycles increases, the higher the cut-off voltage, the faster the data decrease. According to the trend of the above cycle curve, when the cut-off voltage is the lowest, the discharge energy density is the largest. In addition, it can be seen from the figure below that no matter what kind of data is added with the increase of the charging cut-off voltage, it will cause the acceleration of the capacity drop. In particular, the data of NMC111, NMC532, and NMC622 with lower Ni content are more affected by the cut-off voltage, indicating that the data structure with lower Ni content is less stable. In the actual application of lithium batteries, the influence of environmental temperature must also consider the stability of data at high temperatures. JohannesKasnatscheew studied the cycling function of NMC622, NMC811 and NCA data at room temperature and 60°C, and the results are shown in the figure below. Generally speaking, the increase of temperature can improve the internal dynamic conditions of the battery to improve the function of the battery, which can be significant from the battery capacity of 60℃, but the high temperature will have some influence on the cycle stability data. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Analysis of the advantages and disadvantages of 18650 lithium batteries