What is the significance of the research on the equalization charging of lithium iron phosphate battery packs

The rated voltage platform of a single-cell lithium iron phosphate battery is 3.2V. It is clear that a single-cell battery is far from meeting the voltage level requirements of electric vehicles for power lithium-ion batteries. On the other hand, currently processed single lithium iron phosphate batteries have a limited rated capacity. Take the cylindrical lithium iron phosphate battery processed by Waterma as an example. As one of the domestic high-quality suppliers of lithium iron phosphate energy processing methods, its critically processed single lithium iron phosphate battery has a rated capacity of no more than 10Ah, which is very clear. The capacity is far from being able to meet the demand for power lithium-ion battery capacity of electric vehicles. Therefore, lithium iron phosphate batteries are often connected in parallel and then in series during use. Lithium iron phosphate battery However, due to the dispersion of performance parameters during the processing of single cells, the capacity dispersion between single cells will gradually increase as the number of charging and discharging increases during the parallel and series use of battery packs. , Resulting in a decrease in the performance of the power lithium-ion battery pack and a shortened cycle life [-1, 17-18]. For this reason, it is necessary to balance the charging of the power lithium-ion battery pack to reduce the impact of the inconsistency of the single battery, improve the performance of the power lithium-ion battery pack, and extend the driving range of electric vehicles. Overcharging of lithium iron phosphate batteries is one of the most dangerous factors leading to unsafe battery behaviors. The unsafe behavior of overcharging of lithium batteries mainly comes from the organic solution electrolyte used. The organic solution electrolyte cannot achieve a reversible process of analysis and recombination like the water in an aqueous battery, which also leads to a strong response to overcharging. In order to ensure the charging safety of the battery pack, the battery pack needs to be equipped with a dedicated protection circuit for charging management in actual use, so as to guard against overcharging of the single battery and to extend the service life of the battery pack as much as possible. The single battery management circuit will continue to consume power when connected to both ends of the single battery. Although the battery management system can reduce power consumption by setting a low power consumption mode when it is working or not working, it will still consume power, and the power consumed at this time will be greater than the self-discharge power of the single battery. Regarding the electric vehicles that have been put on hold for a long time, even if the electric vehicles are not used, because the single battery management circuit is still connected in parallel to the single battery, the battery will continue to be over-discharged until the discharge is damaged. Therefore, in order to guard against battery discharge damage due to the single battery management circuit, a corresponding automatic power-down circuit should be designed. This circuit can automatically disconnect the corresponding single battery management circuit when the battery voltage is lower than the set cut-off voltage. 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: Analysis of 18650 lithium battery repair principles and methods