Points to note when discharging lithium batteries

The working principle of lithium batteries Lithium batteries use carbon material as the negative electrode and lithium-containing compounds as the positive electrode. There is no metal lithium, only lithium ions. This is a lithium battery. Lithium batteries refer to batteries that use lithium ion intercalation compounds as negative electrode materials. The charging and discharging process of lithium batteries is the intercalation and deintercalation process of lithium ions. In the process of lithium ion embedding and de-embedding, it is accompanied by the embedding and de-embedding of electrons equivalent to lithium ions. During the charging and discharging process, lithium ions are inserted/pulled out between the positive electrode and the negative electrode, and lithium ions are inserted/pulled out. This is what we know as the rocking chair battery. When the battery is charged, lithium ions are formed at the positive electrode of the battery, and the resulting lithium ions pass through the electrolyte to reach the negative electrode. The carbon as the negative electrode has a layered structure with many pores. Lithium ions reaching the negative electrode are embedded in the pores of the carbon layer. The more lithium ions, the greater the charging capacity. Similarly, when the battery is discharged (as we did with the battery), the lithium ions embedded in the carbon layer of the negative electrode escape and return to the positive electrode. The more lithium ions that return to the positive electrode, the greater the discharge capacity. The charging current of lithium batteries is generally set between 0.2c and 1C. The greater the current, the faster the charging and the greater the heat of the battery. In addition, since the electrochemical reaction inside the battery takes a certain time, too much current cannot be charged with the maximum capacity. Just like pouring beer, if it is poured too quickly, it will foam and cause dissatisfaction. Application (discharge) preventive measures: the normal use of the battery is the process of discharging. Pay attention to the following points when discharging lithium batteries: First, the discharge current should not be too large. Excessive current will cause the battery to heat up and may cause permanent damage. On mobile phones, this is not a problem and cannot be considered. The greater the discharge current of the battery, the smaller the discharge capacity and the faster the voltage drop. Second, never over-discharge! The electric energy stored in lithium batteries is through electrochemical reversible chemical changes. Over-discharge will cause this chemical change to have irreversible consequences. Therefore, lithium batteries are most afraid of over-discharge, and the discharge voltage is lower than 2.7v, may cause the battery to be scrapped. Fortunately, the mobile phone battery has been installed inside the protection circuit, and the voltage is not low enough. If the battery is damaged, the protection circuit will work and stop discharging. 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 article: Value and realization of battery management system