What are the general methods for delaying the decline of lithium-ion battery capacity?

1. Deposition of metal lithium Through the previous clarification, we know that lithium-ion batteries should not exist in the form of lithium. Lithium is either in the form of metal oxides, carbon-lithium compounds, or in the form of ions. . The deposition of metallic lithium generally occurs on the appearance of the negative electrode. For inevitable reasons, when lithium ions migrate to the appearance of the negative electrode, some lithium ions do not enter the negative electrode active material to form an unchanging compound, but get electrons and deposit on the negative electrode surface to become metallic lithium, and no longer participate in the subsequent cycle process. Resulting in a decrease in capacity. This kind of environment is generally caused by several reasons: charging is higher than the cut-off voltage; charging at a high rate; and the material of the negative electrode is insufficient. When overcharging or the material of the negative electrode is insufficient, the negative electrode cannot accommodate the lithium ions migrated from the positive electrode, resulting in the deposition of metal lithium. When charging at a high rate, the amount of lithium ions reaching the negative electrode in a short time is too much, causing clogging and deposition. The deposition of metallic lithium will not only cause a decrease in the life of the cycle, but also cause a short circuit of the positive and negative electrodes in severe cases, causing serious safety problems. To deal with this problem, it is necessary to have a fair ratio of positive and negative materials, and at the same time strictly limit the utilization conditions of lithium-ion batteries to prevent environments that exceed the utilization limit. Although, starting from the magnification function, it is also possible to partially improve the cycle life. 2. Analysis of the positive electrode material The lithium-containing metal oxide as the positive electrode material has sufficient invariance, but in the long-term use process, it will still be analyzed continuously, showing some electrochemical inert substances (such as Co3O4, Mn2O3, etc.) ) And some combustible gases, which smashed the balance of capacity between the electrodes, causing irreversible loss of capacity. This kind of environment is particularly obvious in the overcharging environment, and sometimes even a violent release of the analytical body will be produced, which not only affects the battery capacity, but also causes serious safety risks. 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 important reasons for the expansion of lithium-ion battery mobile phones?