What are the ways to improve the performance of lithium iron phosphate batteries?

Ways to improve the performance of lithium iron phosphate batteries Although lithium iron phosphate (LiFePO) is safer, more environmentally friendly, and cheaper than other lithium battery cathode materials, it still has fatal weaknesses: first, low conductivity and poor high-current discharge performance ; The second is low vibration density, low battery capacity and energy density. So how to improve the performance of lithium iron phosphate batteries? Lithium iron phosphate batteries 1. Carbon has excellent conductivity. In the synthesis of lithium iron phosphate, doping or coating conductive carbon is a simple and effective way to improve the conductivity of lithium iron phosphate. Adding a small amount of carbon, on the one hand, through the direct contact between carbon and LifePO; enhances the electronic conductivity between particles, and improves the conductivity of lithium iron phosphate. On the other hand, it can inhibit the growth of LiFePO and particles to a certain extent, reduce the particle size, shorten the diffusion path of Lit during charge and discharge, and indirectly improve the multiplier characteristics of lithium iron phosphate. Carbon sources used for doping or coating carbon can be divided into inorganic carbon sources and organic carbon sources. Inorganic carbon sources include various forms of carbon materials such as acetylene black, graphite, and SP, and organic carbon sources include organic compounds and polymers such as glucose, sucrose, citric acid, polypropylene, and polyvinyl alcohol. The low density of carbon can not only increase the conductivity of lithium iron phosphate, but also reduce its vibration density. Therefore, while ensuring the conductivity, the less carbon is added, the better. 2. Doping metal ions in lithium iron phosphate is one of the effective means to improve the internal conductivity of lithium iron phosphate particles. When the doped metal ions enter the crystal, it will cause lattice defects of the material, thereby fundamentally improving the conductivity of the material. Compared with carbon doping or carbon coating, metal ion doping does not reduce the vibration density of the material, which is beneficial to increase the energy density of lithium iron phosphate batteries. Reducing the particle size to nanometer level, improving the reversible capacity and cycle performance, and introducing rare earth ions are an effective way to improve the electrochemical performance of lithium iron phosphate. 3. Reducing the particle size of lithium iron phosphate is beneficial to shorten the diffusion path of lithium ions during the charge and discharge process, increase the diffusion rate of lithium ions, and improve the high-current charge and discharge performance. The use of liquid phase chemical synthesis (such as co-precipitation method, sol-gel method, etc.) is conducive to reducing the particle size. However, if the particle size is too small, it will reduce the vibration density of the material and increase the specific surface area of u200bu200bthe material, which is not conducive to the production of electrodes and the improvement of battery energy density. Reasonable control of particle size is one of the key technologies to optimize the overall performance of materials. Modification methods include doping conductive carbon or coated carbon on the surface of lithium iron phosphate particles, metal coating, metal ion doping and particle size control. At present, carbon doping (or coating) and metal ion doping are still research hotspots. The coating can increase the electrical conductivity to about 10-s/cm, and the doping can increase the electrical conductivity by 8 times, improve the charging and discharging performance, and the multiplier has high performance, which suppresses the capacity attenuation to a certain extent. The industrialization of lithium iron phosphate has also proved that carbon doping (or coating) and metal ion doping can solve the problem of low conductivity of lithium iron phosphate. 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: How to classify lithium batteries?