The working principle of lithium battery The structure of lithium battery

Lithium batteries are rechargeable batteries that rely heavily on lithium ions to move between the positive and negative electrodes. During the charging and discharging process, the Li+ intercalation layer is deintercalated between the two electrodes: in the rechargeable battery, Li+ is debited from the positive electrode and inserted into the negative electrode through the electrolyte, the negative electrode is in a lithium-rich state; during the discharge process, in contrast. The material with lithium as the electrode is representative of modern high-performance batteries. The working principle of lithium batteries is the principle of charge and discharge. When a lithium battery is discharged, the electrons and Li+ are used at the same time, in the same direction, but in different paths. The electrons pass through the external circuit from the negative to the positive electrode; the lithium ion Li+ jumps from the negative electrode into the electrolyte and flows out. Combine together. During the charging and discharging process of lithium batteries, lithium ions are in a moving state from the positive electrode to the negative electrode and then to the positive electrode. If we compare a lithium-ion battery to a rocking chair, the two ends of the rocking chair are the two poles of the battery. Lithium ion is like an excellent athlete running back and forth on both ends of the rocking chair. So experts gave the battery a cute name, rocking chair battery. The structure of the lithium battery The structure of the lithium battery consists of five parts: positive electrode, negative electrode, electrolyte, separator, casing and electrode lead. The structure of lithium batteries can be divided into two categories: winding type and stacking type. Liquid lithium batteries have a winding structure, while polymer lithium batteries also have a winding structure. Cathode material: active material, conductive agent, solvent, binder, matrix. Among the lithium batteries, the positive material market has the largest capacity and higher added value, accounting for about 30% of the cost of lithium batteries, with a low gross profit rate of 15% and a high level of more than 70%. At present, materials have been used in batches for lithium batteries, including lithium cobalt oxide, lithium manganese oxide, lithium nickel nickel manganese oxide, lithium cobalt nickel manganese oxide and lithium iron phosphate. Anode material: active material (graphite, MCMB, CMS), binder, solvent and matrix. Negative electrode materials account for a relatively low proportion of the cost of lithium batteries, including carbon anode materials and non-carbon anode materials. Separator: Separator is placed between the two poles as a device to isolate the electrodes, so as to prevent the direct contact of the active materials between the two poles, which will cause the internal short circuit of the lithium battery. The diaphragm still needs to be able to allow charged ions to pass through and form a path. Important lithium battery separator materials include single-layer PP, PE, PP+ceramic coating, PE+ceramic coating, double PP/PP and three-layer PP/PE/PP. Electrolyte: The better electrolyte for shell hardware (steel shell, aluminum shell, cover plate, ears, insulating sheet, insulating tape) is LiPF6, but it is expensive; others have LiAsF6, but are highly toxic; LiClQ, which has strong oxidizing properties; Organic solvents include DEC, DMC, DME, etc. Battery case: It is divided into steel case (square shape is rarely used), aluminum case, nickel-plated iron case (for cylindrical battery), aluminum plastic film (soft packaging), etc., and battery cover, which is also the positive and negative terminal of the battery. 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 explosion-proof technologies for explosion-proof lithium batteries?