Needless to say, in terms of battery life, electric vehicles have already reached a new level every year, and it is common for NEDC to break 500km. Charging is no longer difficult. 30% to 80% power for half an hour is standard for flagship models; As for safety, it is still an unavoidable difficulty for electric vehicles. Perhaps, the innovation of this car company will solve the ultimate problem of power battery safety hazards.
Blade battery challenge acupuncture test
On the afternoon of March 29th, BYD announced the blade lithium iron phosphate battery (hereinafter referred to as the blade battery) in the form of online conference. At the press conference, BYD showed three videos of battery challenge acupuncture test.
The video content is as follows: Under the same test conditions, the temperature of ternary lithium battery changes dramatically at the moment of acupuncture, and the surface temperature
When the temperature quickly exceeded 500℃, the extreme heat was out of control and began to burn violently, and the eggs on the surface of the battery were blown up; After the traditional lithium iron phosphate battery was broken down, there was no open flame, and the battery pressure relief valve sprayed smoke. The surface temperature reached 200℃~400℃, and the eggs on the surface of the battery were burnt at high temperature. BYD's "blade battery" has no open flame or even smoke after penetration. The surface temperature of the battery is only about 30℃, and the eggs on the battery surface have not changed.
For domestic consumers, acupuncture test should not be a strange test. 2065438+081October 24th, 18, the Ministry of Industry and Information Technology issued three draft mandatory standards, one of which was about GB Safety Requirements for Lithium-ion Power Batteries for Electric Vehicles. In this draft, in addition to canceling all module-level tests, the requirements for single battery needling are also cancelled.
Acupuncture test is a test method to simulate the internal short circuit of lithium ion battery, which leads to thermal runaway and then explosion and fire. As one of the classic battery safety testing methods, why was the acupuncture test cancelled?
At that time, three reasons were given for the preparation of the draft for comment: first, the provisions in the Access Management were not implemented for the time being; Second, the two IEC standards do not use acupuncture; Thirdly, it is considered that acupuncture is not consistent with the actual failure mode.
In the final analysis, it was because ternary lithium batteries occupied the mainstream of the market at that time, but the heating rate of cathode materials (nickel, cobalt and manganese) used in ternary lithium batteries was very high, and the temperature of 200 degrees Celsius would cause thermal runaway. Therefore, due to my natural defects, I can't pass the acupuncture exam. Even now, ternary lithium battery technology is constantly improving. So far, no ternary lithium battery has passed the acupuncture test.
For this reason, in terms of examination standards, acupuncture examination is recognized by the industry as the most difficult examination to pass, and it is at the top of the examination pyramid. In practical sense, it can pass the acupuncture test, which means that the chassis of the electric vehicle can withstand any complicated road conditions. From this point of view, BYD blade battery will lead the global power battery safety to a new height.
Why can "blade battery" conquer acupuncture test?
The blade battery passed the acupuncture test, which can be said to have detonated the network. Power batteries can be safe enough to impress consumers with electric vehicles. Wang Chuanfu, chairman of BYD BYD Company, even directly stated at the press conference that the blade battery will lead the global power battery back to the right track and completely erase "spontaneous combustion" from the dictionary of new energy vehicles.
Why BYD Blade Battery Can Conquer Needle Testing?
The blade battery can overcome the acupuncture test first thanks to the lithium iron phosphate battery itself. Lithium ferrous phosphate has stable structure, high thermal stability and small volume change during use.
BYD uses high-temperature ceramic coating with high temperature resistance and excellent insulation performance in high-risk safety places inside the battery, which greatly improves the safety performance. Even if there is a short circuit inside the battery, there is generally no violent reaction, and in extreme cases, there is only smoke. As can be seen from the video of the test, even acupuncture did not smoke.
Academician Gao commented on the excellent performance of BYD blade battery in acupuncture experiment: "The performance of blade battery in real experiment is excellent. I think there may be two reasons for outstanding performance. On the one hand, because the blade battery is a strip battery, the heat dissipation area is relatively large; On the other hand, when acupuncture, its short circuit will fall back for a long time, so its heat production capacity will decrease relatively. On the one hand, heat production decreases, on the other hand, heat dissipation increases. Of course, the heating rate will be relatively small, so acupuncture performs very well. "
If you want to find an authority in the field of new energy vehicles, Academician Gao must be on the list. Academician Gao has long been engaged in the research on the energy power system of energy-saving and new-energy vehicles, presided over and participated in relevant national and international major scientific and technological plans, and is now the leader of the expert group of the national 863 major project "Energy-saving and new-energy vehicles" and the Chinese chief scientist of the "Clean Vehicles" alliance of the Sino-US Joint Research Center for Clean Energy. 20 17, 165438 10 was elected as an academician of China academy of sciences.
Academician Gao believes that in the future, power batteries should be constantly innovated in design and product engineering. He thinks the blade battery is a good example.
Give consideration to long battery life and long service life.
Safety is the cornerstone of power batteries, but long battery life and long battery life can win the favor of car companies.
As we know, the production of traditional battery pack can be divided into two steps: first, the battery module is composed of batteries; The second assembly module is arranged on the tray to form a battery pack. In the battery module, the space utilization rate of batteries is only 80%, and the rest are structural parts of the module.
From module to battery pack, many beams need to be arranged between modules to ensure the strength of the whole battery pack. Other structural members make the utilization rate of battery modules in the battery pack only 50%. Then the space interest rate of the battery reverse module is 80%, multiplied by the module's utilization rate of the battery pack of 50%, which is equal to 40%.
Byd has found another way. Batteries are not only used as energy components, but also directly made into structural components. BYD directly stretched the battery and fixed it on the frame of the battery pack, so the battery became a structural part, which directly increased the support for the battery pack and solved the problems of fixation and strength.
Compared with the previous iron batteries, due to the intuitive change of shape, the blade batteries can be directly installed into the battery pack shell in a piece-by-piece arrangement mode, without the need for various beams and longitudinal beams to play a fixed role in the module and the battery pack. This scheme can make the space utilization rate of battery pack reach more than 60%.
Blade battery adopts the mode of modular battery pack, which improves the overall space utilization rate of battery pack from 40% in the past to 60%, and directly improves the cruising range of electric vehicles equipped with lithium iron phosphate batteries to the level of ternary lithium battery vehicles.
In the past, lithium iron phosphate battery was famous for its safety, environmental protection and long service life, but the energy density of the battery was not as good as that of ternary lithium battery, and the blade battery solved this problem.
Take BYD Korea EV as an example. The body size of Han EV is 4980×19/kloc-0 ×1495mm, and the wheelbase is 2920mm. As a medium and large car, BYD Han EV is equipped with a large battery of 77kWh, with a curb weight of only 2020kg. This is because the blade battery has a high specific energy, and Korean EV can make the battery big and light.
In addition, lithium ferrous phosphate material has good reversibility, low potential (good stability) and small expansion when charging and discharging. It is understood that BYD's blade battery can be charged and discharged more than 3,000 times, traveling10.2 million kilometers.
Will the power battery pattern change?
Since the emergence of power batteries, lithium ternary and lithium ferrous phosphate have been fighting for hegemony. The two sides are evenly matched and each has its own advantages. However, the breakthrough of blade battery safety pushed the competition situation to a climax. Wang Chuanfu said at the press conference: "Frankly speaking, the unrealistic pursuit of battery energy density completely deviates from the development route of the power battery industry, which makes the safety and reputation of new energy passenger cars pay a very heavy price."
Wang Chuanfu pointed directly at the ternary material itself: "In the past few years, due to the uneven level of technology and quality control of different enterprises in the battery industry, coupled with the characteristics of the ternary material itself, the incidents of spontaneous combustion and even deflagration of electric vehicles have increased significantly, and the safety problems of ternary batteries with high energy density have been exposed. As the saying goes, all glory is lost. What should BYD, as a leading brand in the industry, do about the deviation of the industry? "
As Wang Chuanfu said, the high nickel 8 1 1 ternary battery has been promoted for more than a year, but it has not become the mainstream so far, because the current technology can not solve the explosive nature of high nickel. Once an accident happens, it will bring a devastating blow to the ternary battery. Lithium iron battery has the advantages of high safety, low cost and long life, but its deadly low energy density has been criticized.
Blade battery not only takes safety to the next level, but also directly passes the acupuncture test, and no one is superior to it. Moreover, the volume energy density of the blade battery is close to 8 1 1 ternary lithium battery. With high volume density, a large-capacity battery can be arranged in a small space, and the battery can meet the endurance requirement of 600 kilometers at one charge, which overcomes the weakness of low energy density of lithium-ion batteries.
In 20 19, the national power battery loading capacity totaled 62.2GWh, up 9.2% year-on-year. Among them, the cumulative load of ternary batteries is 40.5GWh, accounting for 65.2% of the total vehicle, with a cumulative year-on-year increase of 22.5%; The cumulative load of lithium iron phosphate battery was 20.2GWh, accounting for 32.5% of the vehicle load, down 9.0% year-on-year. BYD blade battery takes safety as the camp, and takes long battery life and long life as the pioneer. It is not known who the final right to speak in this power battery route dispute belongs to. However, with the entry of blade batteries, the power market pattern in 2020 will change.
Carry out "reform and opening up" with blade batteries
From self-sufficiency to external supply, Wang Chuanfu began to think about this issue in the second half of 20 17. Wang Chuanfu was touched by the domestic automotive power battery Contemporary Amp Technology Co., Ltd., and both the shipment volume and the installed capacity came from behind.
"Wei's lover is sincere" is taken from The Book of Songs, Sang Rou, which means honesty, faithfulness and diligence. BYD set up five Foday companies to further accelerate the foreign cooperation of new energy core components. These five subsidiaries are Foday Battery Co., Ltd., Foday Vision Co., Ltd., Foday Technology Co., Ltd., Foday Power Supply Co., Ltd. and Foday Mould Co., Ltd. ..
Wang Chuanfu compared the relationship between Foday and BYD to the relationship between planets and stars. He hoped that every company in Foday's department would be unique in their respective fields. Coordinate Shenzhen BYD, this "reform and opening up" begins with blade batteries.
Fudi Battery Co., Ltd. was registered on May 5, 20 19, and its predecessor was BYD Lithium Battery Co., Ltd., which was established as early as 1998. According to Wang Chuanfu, this blade battery is only used in BYD Han Chun electric vehicle, and there is no plan to use it in other vehicles.
High safety, long battery life and long service life, He Long, vice president of BYD Co., Ltd. and chairman of Foday Battery Co., Ltd. said, "Almost all automobile brands you can think of are discussing cooperation schemes based on' blade battery' technology with us." The pattern of new energy automobile industry will change.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.