Three aspects to understand the principle of lithium-ion battery

　　 Lithium batteries, lithium ion batteries, lithium polymer batteries, people are often confused by these 'lithium' batteries. The necessary explanation of the principle of lithium ion batteries becomes the key to solving this puzzle, because in all Among these battery theories involving 'lithium

　　 First of all, we must clarify the three concepts we put forward at the beginning. In the history of the development of lithium batteries, the first stage is a lithium primary battery. The negative electrode of this battery is lithium metal. On this basis, the second stage has developed a rechargeable lithium battery, that is, a lithium ion battery in the theoretical sense. The rechargeable lithium battery is a battery with no metal lithium, only lithium ion. Since the lithium-containing compounds and electrolytes used as positive electrode materials are different, there are principles of lithium-ion batteries based on different materials. In recent years, the lithium polymer battery that people often say is developed on the basis of liquid lithium ion battery. Its appearance makes the lithium battery enter the third stage. Because the lithium polymer battery is composed of lithium ion battery electrolyte The battery is improved from the liquid state to the solid state or the gel state. Therefore, its working mechanism does not deviate from the principle system of the lithium ion battery, but only improves the principle of the lithium ion battery.

　　Secondly, it is necessary to understand the principle of lithium-ion battery in structure. Generally speaking, lithium-ion batteries have five parts: positive electrode, negative electrode, separator, organic electrolyte, and casing. In the principle of lithium-ion batteries, the separator is the most technical manufacturing link, while the electrolyte is liquid or polymerized. Things are different.

　　 Third, understand the principle of lithium-ion batteries from the mechanism of action. Lithium-ion battery is a general term for batteries in which lithium-ion intercalation compounds are used as cathode materials. In this sense, as long as it is a lithium-ion battery with this working mechanism, whether it is liquid or polymer, and many battery manufacturers are working hard to create power batteries , Are applicable to the universal lithium-ion battery principle. Under the principle of lithium ion batteries, the battery charging process is the process of insertion and extraction of lithium ions. During charging, lithium ions are extracted and inserted into the negative electrode from the positive electrode through the electrolyte. The opposite is true when discharging.

　　 understand the above principle of lithium-ion battery, and finally can use an image metaphor as a conclusion, people generally use 'rocking chair battery' as the description of the principle of lithium-ion battery, that is, lithium ion is always in ' In the state of positive-negative-positive' movement, the lithium-ion battery is like a rocking chair. The two ends of the rocking chair are the positive and negative electrodes of the battery, and the lithium ion is the 'person' moving at both ends. This metaphor is based on the mechanism of action. To illustrate the principle of lithium-ion batteries.

　　 Article source: Lithium battery technology