Analysis of the influencing factors of aging and decay of lithium battery materials

The influence of aging and decay of lithium battery materials 1. Before customizing lithium batteries, the process of charging and discharging cycles is the process of lithium ions tripping and moving back and forth between the positive and negative materials through the electrolyte. In the cycle of lithium batteries, in addition to the oxidation-reduction reaction of the positive electrode and the negative electrode, there are a large number of side reactions. If the side reaction of the lithium battery can be reduced to a lower level, so that the lithium ions can always flow smoothly through the electrolyte between the positive electrode and the negative electrode material, and the cycle life of the lithium battery can be improved. 2. According to the analysis by the engineers of the lithium battery manufacturer, when the lithium battery is overcharged, the excess lithium ions released from the positive electrode will be deposited or embedded in the negative electrode. The deposited active lithium reacts easily with the solvent to release heat and increase the battery temperature. The cathode of a lithium battery releases oxygen through thermal separation, which makes the electrolyte easy to decompose and a large amount of heat appears [25]. When the discharge voltage of the lithium battery is lower than the discharge cut-off voltage, overdischarge will occur. During the over-discharge process, lithium ions will escape excessively from the negative electrode, and the next insertion and charging of the lithium battery will be more difficult. Yu Zhongbao [26] MCMB is used as the anode, the LiCoO2 cathode battery is discharged at 0V, the copper foil current collector is more severely corroded, the cathode SEI film is damaged, the performance of the SEI film is poor, and the negative impedance is added, and the polarization is improved. , After discharging during the cycle of discharge capacity of lithium battery, the charging and discharging efficiency is greatly reduced. Lithium battery custom design and manufacturing process 1. Lithium battery customization In the battery design process, the choice of materials is the most important factor. Different materials have different performance characteristics, and there are gaps in the performance of the developed batteries. The cycle life of the battery is longer only when the cycle performance of the positive electrode material and the negative electrode material are well matched. The electrolyte is also an important factor in the reversible capacity of the battery. 2. The disconnection and insertion process of lithium ion and lithium battery electrode material is always a process of mutual use with the electrolyte, which has an important influence on the change of the interface condition and internal structure of the electrode material. The electrolyte is lost during the interaction with the positive and negative materials. In addition, when the battery forms an SEI film and is precharged, part of the electrolyte is also consumed. Therefore, the type of electrolyte and the amount of injection also affect the life of the battery. 3. In terms of ingredients, pay attention to the amount of positive and negative materials added. Generally speaking, in the design and assembly process, the capacity of the negative electrode is generally required to be greater than the capacity of the positive electrode. Otherwise, lithium will precipitate from the negative electrode during charging, forming lithium dendrites, which will affect safety. The negative electrode is too much relative to the positive electrode, and there may be too much lithium dihydrogen in the positive electrode, resulting in structural damage. The processing technology of lithium battery mainly includes: positive and negative electrode ingredients, coating, film making, winding, upper shell, liquid injection, and sealing synthesis. In the process of battery processing, every step of the process is very strict. If any process is not well controlled, it may affect the cycle performance of the battery. 4. During the charging process of the positive and negative electrodes, attention should be paid to the amount of binder added, stirring speed, slurry concentration, temperature and humidity, and to ensure that the material can be evenly dispersed. 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 post: Analysis of the impact of light on polymer solar cells