Analyses the shortcoming of the lithium iron phosphate batteries

Source: 2020 - 04 - 10 hits: young man, the disadvantage of the lithium iron phosphate battery is a kind of material has great potential application development, in addition to its advantage, more important is the materials if there is a fundamental flaw. Now in general use lithium iron phosphate as domestic power lithium ion battery cathode material, from the government, scientific research institutions, enterprises and market analysts are optimistic about the material such as securities firms, as the development direction of power lithium ion battery. Analysis its reason, mainly has the following two points: one is influenced by American research direction, valence and the A123 company do the iron phosphate lithium ion battery cathode material of early adoption. Second, there is no one has good high temperature cycle and storage performance of manganese acid lithium materials can be used for dynamic lithium ion battery. But there are some lithium iron phosphate nots allow to ignore the basic defects, summarized as follows: 1. In the sintering process of preparation of lithium iron phosphate, iron oxide may be reduced to elemental iron in high temperature and reducing atmosphere. Simple iron will cause the battery short circuit, is the most taboo in battery materials. This is Japan didn't use the material as the main reason of dynamic lithium ion battery cathode material. 2. Properties of lithium iron phosphate has some defects, such as low density, vibration compaction density low, result in lithium-ion battery energy density is low. Low temperature performance is poor, even nanometer carbon coating is not solve the problem. Argonne national laboratory ( 阿贡国家实验室) Center for energy storage system ( 中心的能源存储系统) Tang Xi lai, director of the brand, 汽油) Dr, low temperature performance of lithium iron phosphate battery is very bad. Of lithium ion battery test results show that the lithium iron phosphate battery at low temperature ( Below 0 ℃) Can't drive, the electric car. Although some manufacturers claim that lithium - Iron phosphate battery at low temperature is still keeps its capacity, but this time with low discharge current, discharge cut-off voltage is low. In this case, the equipment can not start. 3. Cost of material preparation and battery manufacturing cost is high, the battery low yield, poor consistency. Although nanocrysization and lithium iron phosphate material of carbon coating can improve the electrochemical performance, they also bring other problems, such as low energy density, the rising cost of synthesis, the poor processing performance of the electrode and harsh demands on the environment. Lithium iron phosphate in the chemical elements such as lithium, iron, phosphorus content is rich, the cost is low, but the cost of preparation of lithium iron phosphate products is not low. Even with the previous research and development costs, the technology of the material cost and the preparation of the high cost of batteries, the final unit energy storage costs will be higher. 4. Product consistency. At present, China has not a lithium iron phosphate material factory to solve this problem. From the perspective of material preparation, the synthesis of lithium iron phosphate is a complex multiphase reaction, including solid phosphate, ferric oxide and lithium, carbon precursor and reduction of chi. In the process of the complex reaction, it is difficult to ensure consistency of response. 5. The problem of intellectual property rights. The lithium iron phosphate patents held by the university of Texas, the basis of carbon coating by canadians to apply for patent. The two basic patent can't bypass, if costs included royalty, so that the cost of the product