What factors affect the service life of lithium batteries?

The service life of lithium batteries is critically affected by two aspects, one is the external use conditions, and the other is the internal battery cell. From the perspective of external use conditions, the important factors that affect the service life of lithium batteries include the charging and discharging method, the charging and discharging cut-off voltage, the charging and discharging rate, the use temperature, and the shelf conditions. From the perspective of internal cell factors, the use of lithium batteries in RVs is often in the form of battery packs. Generally, the battery packs are connected in series and parallel with hundreds of cells. The consistency of the cells is another important factor that affects the service life. factor. The most important manifestation is the inconsistency of parameters such as voltage, capacity, and internal resistance. The impact of battery external use conditions on the service life of lithium batteries Charge and discharge methods: At present, most of the research on charging methods for lithium batteries is carried out based on the Maas theory, that is, to make the charging current as close as possible to the best charging curve of the Maas theory, which is wrong. The battery causes injury. Some researchers have made a comprehensive comparison of several common charging methods and found that the constant current and constant voltage charging and the stepped constant current charging method overcome the shortcomings of constant current charging and constant voltage charging. This charging method has the lowest damage to the battery. widely used. Charge-discharge rate, charge-discharge cut-off voltage: Under different charge-discharge rates, after the lithium battery is cycled for the same time, the lithium battery capacity decay loss rate is different. After changing the charge-discharge cut-off voltage, it was discovered through detection that the structure of the electrode material has also changed. The change in the structure of the positive electrode material and the thickening of the negative electrode surface film will result in a decrease in the number of lithium ions and blockage of the diffusion channels, which will cause the battery capacity to decline. Operating temperature: Different lithium batteries have different optimal operating temperatures, too high or too low temperatures will affect the battery's service life. Studies have shown that the capacity of cycling batteries at room temperature decays slowly, while at high temperatures of 55°C and 65°C, the batteries show rapid failure behavior. When the temperature is lower than -10°C, the capacity of the battery decreases sharply. At the same time, the performance of the lithium battery will deteriorate at low temperatures, which is related to the decrease of the ionic conductivity of the electrolyte and the electrode material. Shelving conditions: When the lithium battery is left unused, self-discharge, passivation of positive and negative materials, and electrolyte analysis will occur due to the nature of the battery itself. The unstable performance of the negative electrode SEI will cause the negative electrode active material to rapidly decline, and lithium metal is prone to precipitation. At the same time, different electrolyte components have different effects on the decline of the electrode material. The impact of the inconsistency of internal battery cells on the service life of lithium batteries The inconsistency of the monomers is mainly manifested in the inconsistency of parameters such as voltage, capacity, and internal resistance. Inconsistent single batteries are used in series and parallel, and the life of the battery pack is always less than the life of the shortest single battery. Similar to the barrel principle, the life of the battery pack is determined by the single battery with the shortest lifespan. It is very likely that the single battery with the shortest life span is the battery with the smaller capacity. The small capacity battery is fully charged and discharged every time, and the output is too strong, and it is likely to reach the end of life first. The life of a single battery ends, and a group of battery packs welded together will die. 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 post: Comparative analysis of vanadium batteries and lithium batteries