What is the cell structure of the 18650 lithium ion battery?

18650 batteries are one of the most commonly used batteries in mobile power supplies and laptop batteries. The common form is a cylindrical cell with a diameter of 18mm and a length of 65mm. The most common lithium-ion battery on the market is a cylindrical (cylindrical) package, which is a widely used battery cell in the field of notebook computers and bright flashlights. The advantage of this kind of packaging is that the specifications are uniform, which is convenient for automation and mass processing. In addition, prismatic (square) flexible packaging is common in mobile phones and tablets. The more direct benefit of this kind of packaging is its lightness and thinness, which makes it easy to control the thickness of the product. The safety valve is the standard configuration of each 18650 battery cell, and it is also a more important explosion-proof barrier. The working principle of the safety valve: When the internal temperature of the battery is abnormal and the air pressure rises to 1.0-1.2Mpa, the safety valve opens to remove the internal gas, so as to avoid explosion due to excessive pressure. Same as the prismatic square flexible packaging battery cell, when the internal pressure is increased, the pregnancy bulge is very common. Here, popular science is the positive electrode inside the battery cell. Now Samsung, Panasonic, Sanyo, LG and other commonly used batteries with 2000-3000mAh capacity, the internal cathode material has been fully upgraded from the first generation of LiCoO2 lithium cobalt oxide to a ternary material, the chemical name is LiNi-Co-MnO2 nickel cobalt manganese. The direct good is: longer service life, safer, and better performance. Speaking of this, the prismatic square soft package mobile phone tablet battery is also made of LiNi-Co-MnO2 nickel cobalt manganese material, but it is different from the 18650 cylindrical package. The 18650 cylindrical lithium-ion battery cell is mainly composed of five parts: a metal shell, a positive electrode, a negative electrode, a thin film and an electrolyte. They each perform their duties to ensure normal charge and discharge. The detailed structure is as follows: Positive electrode: The positive electrode material of the 18650 cylindrical lithium ion battery cell is generally lithium iron phosphate, lithium cobalt oxide, etc. The difference of each cathode material will directly affect the characteristics and cost of the 18650 lithium-ion battery. Negative electrode: 18650 cylindrical lithium ion battery cell anode materials include tin-based anode materials, nano-level anode materials, carbon anode materials, etc. In the battery, the anode material is used for oxidation. The relative potential is low. Electrolyte solution: Taking lithium iron phosphate as an example, it is divided into solute and solvent. Solute: Lithium ion salt is often used, such as lithium perchlorate, lithium hexafluorophosphate, and lithium tetrafluoroborate. Solvent: Lithium ion batteries often use organic solvents, such as ether, ethylene carbonate, propylene carbonate, and diethyl carbonate. 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 theoretical guidelines or methods for lithium-ion battery electrode formulation?