The positive data of lithium-ion batteries is usually composed of lithium active compounds, while the negative electrode is carbon with a special molecular structure. The common important component of positive data is LiCoO2. When charging, the potential on the electrode causes the compound of the positive electrode to release lithium ions, and the negative electrode molecules are embedded in the carbon, forming a sheet structure. When lithium ions are discharged, the lithium ions are separated from the layered carbon and combined with the anode compound. Although the principle of the chemical reaction is very simple, in actual industrial production, there are still many practical issues to be considered: the positive electrode additive of the data must insist on repeated charging activities, and the data of the negative electrode must contain more lithium ions at the molecular structure design level. The electrolyte filled between the positive and negative electrodes, in addition to stability, also has good conductivity, which reduces the resistance of the battery.
Lithium-ion batteries are generally equipped with processing chips and charging control chips. Among them, there are a series of registers in the processing chip, including values such as capacity, temperature, ID, charging status, and discharging time. These values gradually change in use. The important function of charging and discharging about once a month in the application manual is to correct inappropriate values in these registers, so that the charging control and nominal capacity of the battery are in line with the actual situation of the battery. The charging control chip first controls the charging process of the battery. The charging process of lithium-ion batteries is divided into two stages: constant current fast charging stage (battery indicator light is yellow) and constant voltage current drop stage (battery indicator light is green).
In the constant current fast charge stage, the battery voltage is gradually increased to the standard voltage of the battery, and then transferred to the constant voltage stage under the control chip. The voltage is no longer added to ensure that overcharge does not occur. As the battery power increases, the current gradually decreases to zero, and the charging is finally completed. The battery calculation chip samples the power of the battery by recording the discharge curve (voltage, current, time), which is the wh value we read the battery information. However, after repeated use of lithium-ion batteries, the discharge curve will change. If the chip has never had a chance to read a good discharge curve, the calculated power will be inaccurate. So we need a deep charge to calibrate the battery chip.