On the fast charging technology of lithium iron phosphate battery

　　Some people say that lithium iron phosphate is not suitable for fast charging, because its conductivity is not good enough, and it is easy to generate heat during fast charging. But this is only for pure-phase lithium iron phosphate materials, which have good ion and electron migration rates after grain refinement, surface carbon coating, and unit cell element doping, which is suitable for fast charging. The high safety, high thermal stability and long cycle life of lithium iron phosphate phosphate make it a good choice for fast charging.

　　Fast charging is the most important technological path for the development of new energy vehicles. It has significant effects on alleviating cruising range anxiety and reducing charging time. Therefore, it has become the market choice of many car companies and battery companies. In the new energy vehicle subsidy adjustment plan released at the end of 2016, the fast-charging pure electric bus was regarded as a separate subdivision product, and detailed subsidy standards were given: according to the electric capacity of the passenger car, a subsidy of 3000 yuan/Kwh was obtained. The three grades of "3C-5C, 5C-15C, 15C+" fast charge rates received 0.8 times, 1 times, and 1.4 times subsidies respectively.　　 In this context, mainstream car companies including Beiqi Foton, Yutong, Xiamen Kinglong and other power battery companies such as Ningde Times, Watermark, Meguli, and Weihong Power have begun to increase their layout in the field of fast charging. From a technical point of view, despite the fact that certain research or new materials can greatly increase the energy density of batteries in the scientific community, in actual production and application, due to cost, technology, process and safety considerations, battery life is still It is a major factor restricting the development of new energy vehicles. Before the battery technology has made a revolutionary breakthrough, choosing fast charging to alleviate the shortcomings of new energy vehicles' insufficient cruising range is a good way to find another way.　　 In fact, the application of fast charging to power batteries has already blossomed everywhere. But in terms of technology, in fact, different routes have the same goal. The core of fast charging technology is to accelerate the speed of lithium ions moving between the positive and negative electrodes through chemical system and design optimization without affecting the life and safety of the battery.