1. Two days ago in committee of 100, Wang Chuanfu, chairman of BYD, revealed some information about "blade battery": "Will it be this year? 3? It was mass-produced for the first time in Chongqing factory in June, and the volume specific energy density of the newly introduced "blade battery" is higher than that of the traditional iron battery? 50%, with high safety, long life and other characteristics, the life of the whole vehicle can reach more than one million kilometers. The first model of "Blade Battery" will be BYD "Han" which went on sale this year. 6? Monthly listing, endurance? 600? Kilometers. 」
2. Also at the committee of 100, Shu Youxing, general manager of BYD's international cooperation division, revealed that BYD owns this "blade battery"? 300? A number of "core technologies".
3. In the following days, due to the good news of blade battery, BYD shares rose sharply.
Why is this battery technology so concerned? In fact, in the final analysis, it is because the battery of pure electric vehicles is very heavy. This quantity is not only weight, but also cost. Does the battery cost account for the cost of the whole vehicle? 1/3- 1/2。 That's why. EV？ One of the reasons why it can't be popularized on a large scale-the cost of the whole vehicle is difficult to be greatly reduced, which leads to high price, and naturally it can't compete with traditional fuel vehicles.
The blade battery technology, in BYD's view, is likely to reduce the battery cost on a large scale, which is undoubtedly a big plus for them and can also enhance the competitiveness of products to a certain extent. BYD's stock soared, probably because the capital market saw these potential "values" behind the blade battery technology.
Then the question is, is the blade battery technology really that strong? How is its performance? According to the information we have at present, this paper makes some interpretations on the technology of "blade battery".
What is a "blade battery"?
BYD's "blade battery" technology can be found in the following patent applications of the State Patent Office:
BYD's battery patent is a battery pack design patent. In this battery pack, the design of long single cells is innovatively adopted, and a plurality of long single cells are assembled into a battery array, thus improving the capacity of the battery pack. At the same time, the single battery has its specific size, and the overall rigidity of the battery pack is improved by the battery itself.
Specifically, BYD improved the battery cell, because the battery cell looks like a blade, so it is named "blade battery cell", which allows more batteries to be arranged in the battery pack. At the same time, because the use of beams or longitudinal beams in the battery pack is reduced, even beams or longitudinal beams can not be used, the space utilization rate of the battery pack is improved, and then the capacity, voltage and endurance of the whole battery pack are improved.
What is the specific effect? BYD cited an example in its patent:? In electric vehicles, this design can change the original space utilization rate? About 40%, at most? More than 60% or even higher, such as? 80%。
At the same time, due to the use of fewer beams and longitudinal beams, it also makes? Simplifies the manufacturing process of the battery pack, reduces the assembly complexity of the single battery, and reduces the production cost; On the other hand, the weight of the battery pack can also be reduced to some extent. ? Theoretically, the electric vehicle using this battery pack can realize light weight and improve endurance. In addition, because the single battery is hard shell (aluminum shell or steel shell) and the size is very long, there is no need to reinforce the structure, and the structural strength of the battery pack can be ensured directly by the single battery itself? So as to ensure that the battery pack is not easy to deform under the action of external force.
Before, our power battery packaging was divided into three parts: battery core-battery module-battery? Packaging. that is, packaging single batteries into battery modules, and then packaging battery modules into batteries? Pack, also known as "battery pack". According to Gao's explanation, BYD's "blade battery" actually removes the intermediate link and directly assembles the battery cells into a battery pack. "The battery can be as wide as a car. In the past, the battery was very short, but now it is as long as a blade, but its height is still so high. Cooling ducts, explosion-proof valves and other configurations are placed on both sides, and then long batteries are stacked one by one. Stiffness and strength are still very good, and they can also be used as structural parts. This is a very important innovation. The manufacturing cost of battery cells will be further reduced, and this technology is highly appreciated.
For lithium iron phosphate batteries, it is not the weight specific energy, but the volume specific energy. The volume is smaller than energy because its material is dense and airtight. BYD's blade battery can solve this problem well. According to relevant sources, "? Does the new battery volume increase the energy density? About 50%, can the cost be reduced? Wang Chuanfu said that the "blade battery" will be carried on BYD "Han" first. What is the cruising range? 600? Kilometers (should be? NEDC？ Working conditions). In this way, this blade battery technology is really exciting.
That's all we know about the blade battery.
Why does BYD use iron batteries?
BYD's blade battery will be reused as lithium iron phosphate battery.
Why is this?
At present, there are mainly two kinds of lithium-ion batteries used in passenger car power batteries: one is lithium iron phosphate battery, and the other is ternary lithium battery. Driven by the subsidy policy, mainstream manufacturers are currently using ternary lithium batteries. Lithium iron phosphate battery has the advantages of many cycles, high safety and stability; The disadvantage is that the specific energy of the battery is low, which is also the reason why everyone turned to the ternary lithium battery route later, because the ternary lithium battery has a high specific energy and is easier to meet the national subsidy policy. Subsidized slope retreat will make the influence of policy factors on the development route of battery technology less and less.
How to choose the appropriate battery technology route after the subsidy is withdrawn? BYD gave its own answer: "Returning to the old business (using lithium iron phosphate battery)" is the direction they are considering.
In addition, although the energy density of lithium iron phosphate battery is relatively low, the upper limit of specific energy of iron battery is very low, which is easy to enter the bottleneck, which is also related to the current lithium ion battery material system. At this time, we must make a balance: safety? Or? Cost. If you want to increase the specific energy of a battery cell, then the safety of the battery cannot be guaranteed (spontaneous combustion will occur, etc.). ), but also need to add a lot of things (such as battery management system) to maintain the consistency of the battery. These are all costs.
Gao said, 20 19? Did the cost of China power battery come true in? 0.6? Yuan-1? Yuan /Wh, in which lithium iron phosphate battery can reach? 0.6? Yuan /Wh, that is to say, the cost of lithium iron phosphate battery can be achieved? 100? Dollar/kWh? Below, and this target value, in the eyes of many people, is a watershed in the competition between electric vehicles and fuel vehicles. This is definitely one of the reasons why BYD wants to use lithium iron phosphate battery to come back; In addition, compared with ternary lithium batteries, BYD has accumulated more in the field of lithium iron phosphate batteries, and it is reasonable to make a technological breakthrough from this point.
On the whole? BYD's "blade battery" is not the technological innovation of the battery itself, but more the innovation of the battery pack. ? The official information disclosed by BYD also confirms this point. The official said that the battery itself will be improved to some extent. The improvement of energy density of blade battery is not only from the size and dimension of battery core. Packing? Optimization, but also battery and internal design and production process innovation? . 」
Where to? Is it? Go on ...
But things are not over. There are still many questions about the blade battery: What specific improvements have it made on the battery? What is the final performance (such as discharge capacity and attenuation)? And most importantly, what impact will it have on BYD's own open battery business?
This year? 3? The first mass production of "Blade Battery" will be realized in BYD's Chongqing factory in May, when the truth will come out.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.