Analysis of the cycle performance of lithium iron phosphate batteries

The cycle performance (experimental results) of lithium iron phosphate batteries is one of the key components of electric vehicles, and its cost even accounts for half of the cost of electric vehicles, so the battery life directly determines the cost of using electric vehicles. Due to the stable chemical properties of the positive and negative electrode materials of lithium iron phosphate power lithium-ion batteries, the volume and stress change little during the charging and discharging process, so the cycle life is very long. As can be seen from Figure 1, the 2OAh lithium iron phosphate battery is charged to 3.65v with a C multiplier current, and then becomes a constant voltage until the current drops to 0.02c. Discharge current 1c, cut-off voltage 2.0V (charge and discharge depth 100%) cycle life. It can be seen from Figure 1 that after more than 1600 cycles, the remaining capacity of the battery is still more than 80% of the original capacity. Although the current cost of lithium iron phosphate batteries is still relatively high, the extension of battery life will significantly reduce the use and maintenance costs of electric vehicles. Abstract of experimental research on the performance of lithium iron phosphate batteries: Compared with traditional lead-acid, nickel-hydrogen, nickel-cadmium and other aqueous secondary batteries, lithium iron phosphate batteries have the advantages of long cycle life, high energy density and high safety. Among various battery systems, lithium iron phosphate battery is the most promising battery system. Therefore, lithium iron phosphate batteries have been widely used in electric vehicle power supplies, large-scale energy storage, communication base stations, electric bicycles and other fields. Although the same electrochemical system is used, the performance of the battery varies greatly due to the different structural design of the battery. The performance of the thin liquid flexible packaging structure is better. During the processing of this battery, the excess electrolyte is extracted after the battery formation process is completed. The remaining electrolyte in the battery is stored in the diaphragm and the micropores L of the positive and negative plates, and it hardly flows, but it ensures the normal use of the battery and minimizes the potential burning hazard caused by the electrolyte. When the battery is overcharged, the electrolyte dissolves and very little gas appears. Due to the flexible packaging design, the battery is only slightly convex, preventing the risk of explosion. This structure also further increases the energy density of the battery. This paper studies the cycle life, high-rate charge-discharge performance, acupuncture safety, weight and energy density of lithium iron phosphate batteries, which lays a theoretical foundation for the further application of lithium iron phosphate batteries. Experimental process: lithium iron phosphate cathode material (Xinxiang, Henan Huanyu Group), Ks-l5 conductive graphite (Switzerland) and polyvinylidene fluoride (Jiangsu, 99.9%), according to the mass ratio of 89:4:7 and an appropriate amount of N Base pyrrolidone (Nanjing, 99.9%), electrode paste, and then applied to 20m thick aluminum foil (made in Shenzhen, 99.9%), and dry cuttings and active plates at 110°C; graphite (Xinxiang, Henan Huanyu Group) and Ks-15 conductive graphite ( Switzerland) and polyvinylidene fluoride (Jiangsu, 99.9%), according to the mass ratio of 92:3:5 and an appropriate amount of N-methylpyrrolidone (Nanjing, 99.9%), mixed uniformly on a 12-meter thick copper foil (Hunan, 99.99) %), the cathode block 110 is then dried; the membrane is made of Celgard2400 film made in the United States, and the electrolyte is made of LB3564 made in Zhangjiagang. 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 article: Five common problems in the use of lithium batteries