Introduction to the working principle of lithium ion battery and the activation method of lithium ion battery

The working principle of lithium-ion batteries Lithium-ion batteries have five important structures in terms of structure: positive electrode, negative electrode, electrolyte, separator, casing and electrode lead. Lithium ion battery is a kind of secondary battery, which mainly depends on the movement of lithium ions between the positive electrode and the negative electrode to work. During charging and discharging, Li+ intercalates and deintercalates back and forth between the two electrodes: during charging, Li+ deintercalates from the positive electrode and inserts into the negative electrode through the electrolyte, the negative electrode is in a lithium-rich state; the opposite is true during discharge. The charging and discharging process of lithium-ion batteries is the process of Li+ intercalation and deintercalation in the positive and negative materials accompanied by the absorption and release of energy. Charge the lithium-ion battery: Li+ is deintercalated from the positive electrode material, reaches the negative electrode through the electrolyte, absorbs electrons, and is embedded in the negative electrode material to form a higher energy intercalation compound. 1. Lithium ions are extracted from the positive electrode crystal lattice under the drive of an electric field during charging, pass through the electrolyte, and are inserted into the negative electrode crystal lattice. At the beginning of charging, the voltage of the battery to be charged should be detected first. If the voltage is lower than 3V, pre-charge should be carried out first. The charging current is 1/10 of the set current, generally about 0.05C. 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. 2. When discharging, the process is just the opposite. Lithium ions return to the positive electrode, and the electrons pass through the electrical appliances from the external circuit to the positive electrode to recombine with the lithium ions. The greater the discharge current of a lithium-ion battery, the smaller the discharge capacity and the faster the voltage drop. 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 electrons equivalent to lithium ions (usually the positive electrode is represented by insertion or deintercalation, and the negative electrode is represented by insertion or deintercalation). During the charging and discharging process, lithium ions are intercalated/deintercalated and intercalated/deintercalated back and forth between the positive and negative electrodes, which is vividly called the rocking chair battery. Regarding the activation of lithium-ion batteries, many claims are: the charging time must be more than 12 hours, repeated three times in order to activate the battery. The statement that the first three charges should be charged for more than 12 hours is obviously a continuation of the statement that nickel batteries (such as nickel-cadmium and nickel-metal hydride). So this statement can be said to be misinformation at the beginning. The charging and discharging characteristics of lithium-ion batteries and nickel batteries are very different, and I can tell you very clearly that all the serious official technical materials I have consulted emphasize that overcharge and overdischarge will affect lithium-ion batteries, especially Liquid lithium-ion batteries cause huge damage. Therefore, it is best to charge according to the standard time and standard method, especially not to charge more than 12 hours. Usually, the charging method described in the instruction manual is the standard charging method. At the same time, long-term charging takes a long time and is often carried out at night. According to the situation of my country's power grid, the voltage at night in many places is relatively high and fluctuates greatly. As mentioned earlier, lithium-ion batteries are very delicate, and their ability to withstand fluctuations in charging and discharging is much worse than that of nickel batteries, so this brings additional dangers. In addition, another aspect that cannot be ignored is that lithium-ion batteries are also not suitable for over-discharge, and over-discharge is also detrimental to lithium-ion batteries. Disclaimer: Some pictures and content of the articles published on this site are from the Internet, if there is any infringement, please contact to delete. Previous post: Introduction to battery capacity knowledge