Explain the maintenance methods of lithium batteries

Lithium battery maintenance When the charging voltage exceeds 4.2v, the lithium battery will begin to appear side-effects. The greater the pressure, the greater the risk. When the voltage of a lithium battery is higher than 4.2V, less than half of the lithium atoms remain in the positive electrode material, and the battery often collapses, resulting in a permanent decrease in battery capacity. If the battery is charged, subsequent lithium metal will accumulate on the surface of the material, because the negative battery is already full of lithium atoms. These lithium atoms grow dendrites from the surface of the cathode toward the lithium ions. These lithium crystals will pass through the diaphragm paper, shorting the anode and cathode. Sometimes the battery explodes before the short circuit occurs. This is because when overcharged, the electrolyte and other substances will decompose to produce gas, causing the battery casing or pressure valve to expand and burst, allowing oxygen to enter and react with the lithium atoms accumulated on the surface of the negative electrode, causing the negative electrode to explode. Therefore, when charging a lithium battery, the upper voltage limit must be set to take into account the battery's life, capacity and safety. The optimal upper limit of the charging voltage is 4.2v. Lithium battery discharge must also have a lower voltage limit. When the battery voltage is lower than 2.4v, some materials begin to be damaged. And because the battery will self-discharge, the longer the voltage, the lower it is. Therefore, it is best not to stop the discharge to 2.4V. During the discharge from 3.0v to 2.4v, the lithium battery can only release about 3% of its capacity. Therefore, 3.0v is the ideal discharge cut-off voltage. When charging and discharging, in addition to voltage limitation, current limitation is also necessary. When the current is too large, lithium ions have no time to enter the storage battery and will accumulate on the surface of the material. When these ions gain electrons, they crystallize lithium atoms on the surface of the material, which is the same risk as overcharging. If the battery box is broken, it will explode. Therefore, the protection of lithium batteries must include at least three parts: the upper limit of the charging voltage, the lower limit of the discharge voltage, and the upper limit of the current. In addition to the lithium battery, the general lithium battery pack will also have a protection board. This protection board is important to provide these three protections. However, the protection of the three protective plates is obviously insufficient, and lithium battery explosion accidents still occur frequently all over the world. In order to ensure the safety of the battery system, the cause of the battery explosion must be analyzed more carefully. 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: What types of low-temperature resistant batteries?