Analyses the working principle of lithium iron phosphate batteries

Source: 2020 - 04 - 01 15:02 hits: lithium iron phosphate batteries in recent years is analysed, power battery market in China has experienced explosive growth, cell technology is the core of competitiveness. At present power battery mainly including batteries, lithium manganese acid lithium iron phosphate batteries and ternary lithium battery system. Lithium iron phosphate battery for about half of supporting the lithium ion battery material industry in China, and has proper interest for all kinds of battery: the lithium iron phosphate battery cycle relatively long service life, low calorific value, good thermal stability, coupled with the lithium iron phosphate battery also has good environmental security. Lithium iron phosphate batteries because of its low price and safety performance on a large number of electric bus plays an more and more market share. The material good safety, long cycle life, low cost, is the main power and energy storage battery cathode material. Nanoscale carbon coating and surface after the termination of the function of high power discharge and no - carbon coating sample Fe2o3 and Fe3 + impurities, over China's largest international plans to produce. The work mechanism of lithium iron phosphate battery lithium iron phosphate cathode material is olivine structure, hexagonal close packing, the lattice of positive electrode material of lithium iron phosphate, occupied in all directions, P octahedral space orientation by Li Hetie fillers, octahedral crystal and tetrahedron form an integral space framework, different points under the close contact of serrated flat structure. Lithium iron phosphate battery anode composed, olivine structure of LiFePO4 cathode made of graphite, middle the polyolefin PP/PE/PP clearance was used to block the positive and negative, block electronic, let the lithium ions. When charging, lithium ion from the anode from, through anode, electrolyte into the mobile electrons from the external circuit from the positive to the negative terminal, guarantee the balance between the positive and negative charge. Discharging, lithium ion from the cathode, through the electrolyte into the positive. Microstructure make lithium iron phosphate battery voltage, and long service life of good methods: battery charging and discharging process, the anode and the hexagonal system FePO4 lithium iron phosphate in orthorhombic system between the two stages of change, because FePO4 and lithium iron phosphate in 200 ℃ solution coexist, the turning point in the process of charging and discharging no obvious two phase, therefore, lithium iron phosphate battery charging and discharging voltage long and smooth; In addition, after the charging process, the volume of a positive electrode FePO4 reduced only 6. 81%, lithium iron phosphate, and the volume of carbon anode is slim and expanding in the process of charging, scheduling plays an important role in the volume change of the internal structure and support. Therefore, iron phosphate lithium-ion batteries in charging and discharging process with good cycle stability and longer cycle life of lithium iron phosphate cathode material of theoretical capacity of 170 ma/g, the actual capacity of 140 ma/g, vibration density of 0. 9 to 1. 5 / cubic centimeter, working voltage is 3. 4v。