Lithium battery manufacturers talk about the formation principle and working principle of lithium-ion battery. Lithium-ion battery is a kind of secondary battery which is composed of two compounds which can embed and deinter lithium ions reversibly. People call this kind of lithium-ion battery with unique mechanism as "rocking chair battery", commonly known as "lithium battery". Next, the lithium battery manufacturers talk about the formation principle and working principle of lithium-ion batteries.
Formation principle of lithium ion battery
The formation of Li-ion battery is a very complex process, and it is also an important process that affects the battery performance. Because the first time Li + is charged, the first time Li + is inserted into graphite, an electrochemical reaction will take place in the battery. In the first charging process of the battery, it is inevitable to form a passivation covering the surface of the carbon electrode on the interface between the carbon anode and the electrolyte Thin layer is called solid electrolyte phase interface or SEI membrane.
The positive electrode material of lithium-ion battery usually consists of active compounds of lithium, while the negative electrode is carbon with special molecular structure. The main component of the common positive electrode material is lico2. When charging, the potential added to the two poles of the battery forces the compounds of the positive electrode to release lithium ion, which is embedded in the carbon with the negative electrode molecules arranged in a lamellar structure. When discharging, the lithium ion is separated from the carbon with the lamellar structure, and is reconstituted The compounds of the poles combine, and the movement of lithium ions creates an electric current.
The main role in the formation of lithium ion batteries
The formation of lithium-ion battery has two functions: one is to make the active substance in the battery change into the substance with normal electrochemical action by means of the first charge; the other is to make the electrode form an effective passivation film or SEI film mainly on the negative electrode. In order to make the surface of the negative carbon material form a uniform SEI film, the step charging and discharging method is usually adopted. In different stages, charging and discharging The time of using is different with different electric current. It should be controlled according to the material and process route. Generally, the formation time is controlled around 24 hours.
Working principle of lithium ion battery
The lithium-ion battery has a spiral structure inside. The positive electrode and the negative electrode are separated by a thin film paper with many tiny holes. Lithium ion battery is a new type of battery energy. It does not contain lithium metal. In the process of charging and discharging, only lithium ion moves between the positive and negative electrodes, and the electrode and electrolyte do not participate in the reaction.
When the battery is charged, lithium ions are generated in the positive electrode of the battery. The lithium ions move to the negative electrode through the electrolyte, and are combined with the electrons that have already run to the negative electrode through the external circuit. However, as a negative electrode, the carbon has many micropores with layered structure, and the lithium ions that reach the negative electrode are embedded in the micropores of the carbon layer, and the more the lithium ions embedded, the higher the charging capacity. During the discharge, the electrons and Li + both act at the same time, with the same direction but different paths. The electrons run from the negative electrode to the positive electrode through the external circuit; the lithium ions move from the negative electrode to the positive electrode through the electrolyte, and are combined with the electrons that have run for a long time. Generally speaking, the battery capacity refers to the discharge capacity.
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