Do you know the structure and working principle of lithium-ion batteries?

There are five important structures of lithium-ion batteries: positive electrode, negative electrode, electrolyte, separator, casing and electrode lead. Currently, the more commonly used lithium-ion battery materials include lithium cobaltate, lithium nickelate, and lithium manganate. The most used material is lithium cobalt oxide, which has good cycle performance and is convenient to manufacture. The disadvantage is that the cobalt compound is more expensive. Lithium nickelate is difficult to manufacture because of its unstable nature. Generally, it is the compound of lithium cobaltate doped with nickel, also known as lithium nickel cobaltate. Lithium manganate is also a very good material. For many reasons, such as the faster attenuation of lithium manganate at high temperatures, most of its applications are still in the laboratory stage. The structure of lithium-ion batteries is mainly divided into two categories: winding type and stacked type. Liquid lithium-ion batteries use a winding structure, while polymer lithium-ion batteries have two types. In the winding type, the positive electrode membrane, the separator, and the negative electrode membrane are placed in sequence and wound into a cylindrical or flat cylindrical shape, mainly represented by SANYO, TOSHIBA, SONY, and ATL. In the stacked type, the positive electrode, the separator, the negative electrode, the separator, and the positive electrode are stacked in multiple layers. Weld all the positive poles together and lead them out, and the negative poles are also welded together and lead out. ATL is the most important representative. In addition, during the process of charging and discharging lithium-ion batteries, they are usually kept under a specific pressure environment or under stable performance conditions. Only when these are all available can the battery permanently maintain stable and continuous performance. And this will greatly extend the service life of the battery. The working principle of lithium-ion batteries uses carbon material as the negative electrode and lithium-containing compounds as the positive electrode. During the charging and discharging process, there is no metal lithium, only lithium ions. This is a lithium-ion battery. When the battery is charged, lithium ions are generated on the positive electrode of the battery, and the generated lithium ions move to the negative electrode through the electrolyte. The carbon as the negative electrode has a layered structure. It has many micropores. The lithium ions reaching the negative electrode 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 (that is, the process we use the battery), the lithium ions embedded in the carbon layer of the negative electrode are released and move back to the positive electrode. The more lithium ions returned to the positive electrode, the higher the discharge capacity. What we usually call battery capacity refers to the discharge capacity. The lack of memory effect is also a prominent advantage of lithium-ion batteries, which other secondary batteries do not have. Before charging the lithium-ion battery, it is not necessary to consider whether the power in it has been used up. The biggest feature of lithium-ion batteries is their high specific energy. 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. 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: How to prevent battery overcharging? What are the possible reasons why the battery or battery pack cannot be charged?