Pure electric vehicle power battery matching problem

Source: 2020 - 03 - 28 clicks, at a time, why the ternary material were dominant in the pure electric vehicle logistics? In our country, in the field of pure electric vehicle logistics, three yuan is the most used lithium battery technology, the second is the lithium iron phosphate batteries. Tesla and LG, for example, choose the ternary material. Whether in the quality of battery, battery life, cycle life and battery energy density, parameters are different. And some parameters, it is along with the advance of technology, also in constant change. Many parameters, there is only one absolute value. Let's compare the advantages and disadvantages of all kinds of power battery anode materials, then answer why ternary material occupies the main process of logistics vehicles. The interests of high capacity, long life, low price, good safety performance under low temperature and long cycle life, avirulent environmental protection, stable structure, circulation function good, iron resources rich in resources, low cost and good security. A simple preparation high voltage, stable discharge voltage, applied to large current charge and discharge, than can be high, high conductivity faults with low size, the lower the initial charge and discharge power, poor safety, many single cells need combination, so the size of the battery pack is very big function at low temperature, low theoretical capacity, low room temperature conductivity high prices, poor work at high temperature circulating function poor resistance to overcharge and safety performance is poor, is heavily polluted general function, the optimal well poor second, for pure electric vehicle logistics, stroke of concave and convex, affect the logistics operation of the vehicle and power. Pure electric car logistics, mainly used for 'fine decoration logistics distribution, urban transit, such as home delivery store. Delivery task requires the ability to finish in a day, especially in the 'double tenth of a business such as a busy period of time, the need for continuous journey. Travel endurance of concave and convex, however, was mainly affected by the number of cells, and the influence of power system matching. Third, now, tilt state subsidies, land compensation fees are declining, many local subsidies even as low as 400 yuan per KWH of electricity, such as jiangsu, hangzhou and other places, pure electric car logistics operators, said so low subsidies, cannot play. For car companies, seeking reasonably cost-effective technology, the journey of a car, the cost of power battery is the highest, and now many places subsidies is to promote business, logistics car production technology is not as high as other vehicles. Ternary lithium battery costs less than the lithium iron phosphate batteries, technical requirements are not as high as the lithium iron phosphate. This greatly save the social resources and production capital. Fourth, lithium iron phosphate is one of the biggest drawback is the low temperature performance is poor, even after nanoparticlization and carbon coated cannot solve. Discussion shows that a capacity of 3500 mah battery, if the - 10 ℃ under the environment of running, after less than 100 times of charging and discharging circulation, electricity will decay rapidly to 500 mah, the toilet. And three yuan material has good low temperature performance, attenuation 1 ~ 2%. Under low temperature, the decrease rate than the lithium iron phosphate (faster. Fifth, the ternary material accounted for the mainstream, a large part of the reason is by foreign car companies. Most foreign car companies of new energy vehicles using ternary lithium batteries, mostly produced in 18650. From the 286 new vehicles can also be seen in the announcement, most of the pure electric vehicle logistics USES a 18650 ternary lithium battery. A single 18650 lithium ion battery of the nominal voltage is commonly 3. 6 v or 3. 7v。 The minimum discharge termination voltage generally to 2. 5 ~ 2. 75V。 General capacity of 1200 ~ 3300 mah. 18650 battery but very consistent; Cascade battery capacity is big, 20 Ah ~ 60 Ah) , monomer quantity can be reduced, but the poor consistency. With battery supplier, by contrast, invest a lot of manpower and resources to improve the cascade battery production process is very difficult. Sixth, because the subsidy programs have strict requirements of energy consumption of 100 km, electric vehicle logistics should be lightweight, and the corresponding lithium battery also need to reduce weight, and high specific energy density batteries ternary material advantage of falling weight.