The working principle and discharge of lithium ion battery

Lithium-ion batteries use carbon materials as the negative and lithium-containing compounds as the positive. There is no metal lithium, only lithium ions. This is a lithium-ion battery. Lithium ion battery refers to the general term for batteries with lithium ion intercalation compounds as positive materials. The charging and discharging process of lithium ion batteries is the process of intercalation and deintercalation of lithium ions. In the process of intercalation and deintercalation of lithium ions, it is accompanied by the intercalation and deintercalation of the equivalent electrons of lithium ions (the positive term is used to represent the insertion or deintercalation, and the negative is represented by the insertion or deintercalation). In the process of charging and discharging, lithium ions are inserted/de-intercalated and inserted/de-intercalated back and forth between positive and negative, which is vividly called the rocking chair battery. When the battery is charged, lithium ions are generated on the positive side of the battery, and the generated lithium ions move to negative through the electrolyte. As negative carbon has a layered structure, it has many micropores, and the negative lithium ions are embedded in the micropores of the carbon layer. The more lithium ions are inserted, the higher the charging capacity. Similarly, when the battery is discharged (the process we use the battery), the lithium ions embedded in the negative carbon layer are released and move back to positive. The more lithium ions return to the positive, the higher the discharge capacity. Generally, the charging current of lithium-ion batteries is set between 0.2C and 1C. The larger the current, the faster the charging and the greater the heat generated by the battery. Moreover, charging with an excessive current will result in insufficient capacity because the electrochemical reaction inside the battery takes time. It's the same as pouring beer. If you pour it too fast, foam will appear, but you will be dissatisfied. Precautions for use (discharge), for the battery, normal use is the process of discharging. There are several points to pay attention to when discharging lithium-ion batteries: First, the discharge current should not be too large. Excessive current will cause the internal heating of the battery, which may cause damage. On mobile phones, this is not a problem, so you don't need to consider it. Two, can't over discharge! The internal storage of electric energy in lithium-ion batteries is achieved by a reversible chemical change in electrochemistry. Excessive discharge will cause irreversible reactions in this chemical change. Therefore, lithium-ion batteries are afraid of overdischarge. Once the discharge voltage is lower than 2.7V, It may cause the battery to be scrapped. Fortunately, a protection circuit has been installed inside the battery of the mobile phone, and the voltage is not low enough to damage the battery, the protection circuit will be used to stop the discharge. 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 are the methods for lithium-ion battery safety performance testing?