As the originator of automobile batteries, BYD's lithium iron phosphate battery is their special skill. Under the impact of ternary lithium battery, they have tried to use it. But this time, the black technology-blade battery seems to be well prepared, which solves three problems at once, safety, battery life and energy density of battery system. Today, battery technology has not advanced by leaps and bounds, this blade-type lithium ferrous phosphate has found another way to skillfully return electric vehicles to a rational level. ?
Ternary lithium battery VS lithium iron phosphate battery?
Because of the high energy density of the battery system, ternary lithium battery meets the needs of consumers for long mileage and state subsidies, and because the cathode material contains nickel, cobalt, aluminum or nickel, cobalt and manganese, it is widely used in pure electric vehicles, but it is only called ternary battery. Among these cathode materials, cobalt is a precious metal, and electric vehicles all over the world have developed to varying degrees, and the price has soared in recent years. ?
Lithium iron phosphate battery is low-key because of the appearance of ternary battery. The main material of the positive electrode is lithium ferrous phosphate, which is slightly cheaper because no precious metal is used. According to the data at the end of 20 19, the domestic price of lithium iron phosphate batteries is 1.05 yuan /Wh, and that of lithium iron phosphate batteries is 0.8 yuan /Wh. When subsidies are crazy, this part of the price difference may not be so prominent. With the withdrawal of subsidies, the cost difference of nearly 20% is significant. ?
Expensive. The energy density of ternary lithium battery is higher than that of lithium iron phosphate battery, but its high temperature resistance is not as good as the latter, especially in breakdown test. In order to make electric vehicles reach high mileage and meet the needs of consumers, puncture test is not mandatory. Relatively speaking, lithium iron phosphate battery is indeed safer, and the pass rate of breakdown test is extremely high, that is to say, even if the battery is seriously short-circuited, it is not easy to explode and catch fire. Then the problem is coming. How do manufacturers and users of lithium iron phosphate battery based on BYD solve the battery life problem? Black technology-blade battery. ?
Blade battery life?
There are several ways to increase the cruising range. First, the battery capacity is piled up, but it takes up a lot of space. Second, the use of high energy density batteries has hidden concerns about safety performance; Third, optimize the battery layout and improve the battery capacity under the same volume. BYD's blade battery belongs to the last type. ?
A conventional battery pack has a battery module composed of a plurality of batteries, which are fixed on a bracket by bolts to form a large battery of an electric vehicle. Because the horizontal and vertical brackets occupy a lot of space and contribute weight, the space utilization rate of the battery pack is about 40%. The invention is ingenious in that the battery module, the transverse beam and the bolt are omitted, and the battery core is directly installed in the battery pack shell, so that the space utilization rate in the battery pack shell is improved, and the total capacity and energy density of the battery system are improved. In contrast, the utilization rate of blade battery is about 60% under the same volume casing. If the external conditions remain unchanged, lithium iron phosphate battery will be used to replace the original cruising range of 500 kilometers with blade battery, and the cruising range will reach 600 kilometers. ?
BYD Han is the flagship medium and large RV to be launched soon, and it is also the first model to use blade batteries. At present, three models of Hanche series have been listed in the promotion catalogue of new energy vehicles of the Ministry of Industry and Information Technology. The pure electric cruising range of the predecessor version NEDC is 605 kilometers, and the acceleration of the four-wheel drive version is 3.9 seconds. This will be a strong competitor of Tucki P7, and they will touch the price ceiling of pure electric self-owned brand cars. ?
Blade battery invincible? ?
The blade battery is safe because of the lithium iron phosphate battery, and the cruising range is guaranteed because of the structural optimization. The charging cycle life reaches more than 3500-5000 times, which is much longer than the cycle life of 2500 times of ternary lithium battery. So, can the blade battery be used every second? ?
The safety of battery is exactly what consumers need, and it is also the source of confidence for the long-term development of pure electric vehicles. Although the blade battery improves the utilization rate and cruising range of the battery pack, it cannot be compared with the ternary lithium battery system with the same volume due to data limitations. According to the second batch of new energy products of Ministry of Industry and Information Technology in 2020, the highest energy density of battery system using lithium iron phosphate battery is 140 Wh/kg, and the highest energy density of ternary lithium battery system is 180. Wh/Kg, from the perspective of energy density, the blade battery will not kill the ternary lithium battery, but the safety performance is really invincible. ?
In addition, ternary lithium batteries still have advantages in low temperature resistance, especially in extremely cold conditions, the capacity of lithium iron phosphate batteries is more serious than ternary lithium batteries at MINUS 20 degrees Celsius. If you live at this temperature, don't touch the electric car. If you want to save fuel and protect the environment, BYD Korea's hybrid power is also a good choice. ?
Summary?
In a word, BYD's newly released blade battery is really a big brain opening, which not only knows the performance characteristics of lithium iron phosphate battery, but also takes into account the cruising range of the general trend. Although it is not a revolution, it is a new way for the battery industry to return to the lowest logic of automobiles-safety. After all, endurance anxiety, charging anxiety and low temperature anxiety are all superficial use levels, and safety anxiety is the biggest obstacle to the development of electric vehicles. I hope, as Mr. Wang Chuanfu, chairman of BYD, said, "the word' spontaneous combustion' can be completely erased from the dictionary of new energy vehicles."
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.