What are the effects of the particle size distribution of lithium battery anode materials on battery performance?

Lithium batteries are essentially a process of repeated circulation of lithium ions between the positive and negative materials. In this process, lithium ions are continuously embedded in the electrode material, and at the same time, they are continuously deintercalated. It is this kind of swing. The type of embedding and de-embedding process enables lithium batteries to be repeatedly charged and discharged. However, the extraction and insertion of lithium ions are determined by many influencing factors. Among these influencing factors, the particle size of positive and negative materials is undoubtedly very important. The particle size will have a straight impact on the accumulation of materials, and the spatial effect caused by this impact will directly affect the desorption of lithium ions. Embedded, thereby affecting battery performance. In the process of research and development of lithium batteries, the performance of the positive and negative plates has a huge impact on battery performance. Among them, the characteristics of positive and negative electrodes and related production processes are the most important influencing factors. The particle size of the positive and negative materials will directly affect the charging and discharging behavior of the battery, and the rheological properties of the related battery slurry will directly affect the storage, coating and production stability of the slurry. Natural graphite is one of the most important negative electrode materials. The particle size of the powder gradually increases. Its particle size distribution ranges from the standard normal distribution to three different degrees of eccentric distribution. The eccentric distribution of graphite powder is added with different amounts of smaller particle diameters. The type of primary eccentric distribution is leaning toward the smaller particle size. As the particle size increases, the range of the particle size distribution gradually expands. Regarding the irreversible capacity of the carbon anode material in the initial charge and discharge cycle, during the first charge and discharge process of the lithium battery, with the intercalation of Li+ on the surface of the carbon material, the solvent molecules in the electrolyte are co-linked, and a solid is formed on the surface of the carbon material. Only after the entire SEI film is overturned on the surface of the negative electrode in the electrolyte intermediate phase, solvent molecules cannot be embedded. The addition of different amounts of particles with smaller diameters makes the powder present different eccentric distributions. Because the powders with smaller particle diameters have more internal defects, and the graphite powder is easy to change the crystal structure during the mechanical crushing process, From the hexagonal structure to the rhombohedral structure, the number of rhombic crystals in the small particle graphite powder is relatively large, while the rhombohedral graphite has a smaller energy storage capacity, so it affects the overall charge and discharge capacity of the negative electrode material and makes the battery charge The discharge capacity has been reduced. The diffusion of lithium ions between graphite anode materials is directly related to the particle size of carbon crystals. The larger the particle size of the graphite crystallites, the longer the diffusion path of lithium ions. The particle size and distribution of natural graphite have a greater impact on the initial charge and discharge capacity of lithium batteries, while its initial efficiency is relatively small. Natural graphite with a smaller particle size has a larger initial charge and discharge capacity, but also a larger irreversible capacity; medium particle size graphite powder has a higher initial efficiency; an increase in particle size reduces the initial charge and discharge capacity, and a smaller particle size The irreversible capacity of graphite powder is increased for the first time; the particle size distribution is reasonable in a standard normal distribution. The normal distribution of natural graphite anode materials is beneficial to improve the overall performance of lithium batteries. The increase in particle size is beneficial to reduce the irreversible capacity loss of the first charge and discharge. Its particle size distribution range is slightly wider, so that there is a certain smaller powder filling between the larger graphite particles, which can increase the contact area between the particles and reduce the internal It is beneficial to improve the overall performance of the negative electrode to increase the electronic conduction ability. 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 methods for preparing lead-acid battery electrolyte