BYD released the "Blade Battery" on March 29, and its stock price rose sharply in the following two trading days (up 2.65 on the 30th and 6.65 on the 31st). And all major platforms are rushing to report related news, and some even call the release of the "Blade Battery" a battery revolution. So in this issue of "Tram Things" let's talk about the "Blade Battery"?
On March 29, BYD officially launched the "Blade Battery", and the battery has already rolled off the production line at the Chongqing Fudi Battery Factory. Wang Chuanfu, chairman and president of BYD Group, also said that this battery will be the first to be sold in BYD. Equipped on Han pure electric models. It should be noted that the official name of this battery is not "Blade Battery", but "Super Iron Lithium Battery". Because its single cells are relatively flat in shape and are inserted side by side into the battery pack in an array, they are called "blade batteries."
In terms of safety, BYD Battery Laboratory conducted acupuncture experiments on ordinary lithium iron phosphate batteries, ternary lithium-ion batteries and "blade batteries".
Let’s talk about the ternary lithium-ion battery first. After the steel needle pierced the ternary lithium-ion battery, the battery case expanded rapidly, and then the pressure relief valve opened, and then the battery caught fire and exploded. After an ordinary lithium iron phosphate battery was pierced by a steel needle, the battery case expanded to a certain extent, and then the pressure relief valve opened. However, it did not catch fire and explode like a ternary lithium-ion battery, and the overall degree of thermal runaway was low. . The "blade battery" did not expand or catch fire after being pierced by the steel needle, and the battery shell temperature stabilized at around 30 degrees Celsius during the experiment. Generally speaking, the "blade battery" showed extremely high safety in the acupuncture test and has very strong resistance to thermal runaway and thermal diffusion.
Paike believes that the term "battery revolution" is too strong. For this reason, Paike consulted with senior technical personnel in the battery industry, and he provided technical answers to some "questions".
1. Which one is the future, blade battery or ternary battery?
Answer: The core of "Blade Battery" is lithium iron phosphate, which is a mature and stable technology. "Blade" redesigns the shape of the battery pack and does not change the characteristics of lithium iron phosphate. Therefore, the "scalability" of lithium iron phosphate batteries is not as high as that of ternary lithium-ion batteries. In other words, the upper limit of performance of lithium iron phosphate batteries is still lower than that of ternary lithium batteries. "Blade battery" is more of a technological improvement than a technological revolution.
Two: "Blade Battery" adopts CTP (Cell to Pack) packaging mode. What are its advantages and disadvantages?
Answer: Compared with traditional ternary lithium battery packs that use cell-module-Pack mode, the structure of the "blade battery" is simpler. The space utilization rate of traditional battery packs is around 40. Structural parts must be arranged between modules to ensure the strength of the battery pack. "Blade batteries" can eliminate structural parts through module-free packaging. "Blade batteries" are directly packaged and fixed in the battery pack. On the frame, more batteries can be used in the same area, which is beneficial to enhancing battery life.
It is worth noting that although space utilization has been improved, the module-less design may have potential risks, which is to deal with external impacts. When the module battery is hit, one or more modules may be damaged, which can be dealt with by disassembling and replacing them. However, the CTP design does not have the protection of modular structural parts, and external impact may cause internal damage and the damage area will be larger.
However, the "Blade Battery" should have anti-impact requirements at the beginning of its development, such as a stronger frame. In addition, the characteristics of the battery mean that it will not spontaneously ignite and explode in a short period of time, leaving time for the occupants to escape.
Three: Why choose lithium iron phosphate battery?
Answer: At this stage, lithium iron phosphate batteries seem to have become popular. Both Tesla (the specific model is still uncertain) and BYD are considering developing in this direction.
However, as far as the current car companies are concerned, the use of lithium iron phosphate batteries is more of a compromise for companies to cope with the complete withdrawal of subsidies.
The cost of ternary lithium-ion batteries is too high. If subsidies are completely withdrawn, new energy vehicles will still suffer losses. This is the last result that companies want to see. As a power battery solution, lithium iron phosphate batteries can be regarded as one of the means for car companies to control costs.
At the same time, when costs are controlled, new car prices can also be lowered. Taking Tesla as an example, consumers care about price and battery life. If it can provide a battery life that is acceptable to consumers (such as 400 kilometers) and the price is reasonable, then it does not matter the type of battery.
Four: How to manage thermal management of lithium iron phosphate batteries?
Answer: Since BYD has only released a small amount of data information so far, we can only assume that we will know more about it after BYD completes the release of its new car. Battery thermal management should be achieved by heating/cooling the aluminum alloy frame.
Five: How versatile is the "blade battery"?
Answer: "Blade battery" may not be applied to currently launched models because the previous battery design is incompatible with new technologies, and previous model plans have a large part of the production capacity, making direct switching difficult. The scope of future applications depends on market feedback and cannot be “one size fits all”. As for BYD's announcement to open up its "blade battery" technology to peers, this is more like a PR method. For new energy companies, how can batteries, as the core technology, be leaked to competing products?
In short, although the "blade battery" has extremely high safety performance, its core is still lithium iron phosphate. This is a new technology, but it is not a revolutionary product. Talking about "blade battery" alone, it is more like a "patch" of lithium iron phosphate battery technology, obtaining an "advanced enhancement package" in terms of safety.
At the end of last month, BYD announced that it would launch the DM-i platform, which has the advantages of ultra-low fuel consumption, rich battery life of 50 kilometers, and improved NVH. The models it adopts are more economical. At this time, BYD launched the "blade battery" technology, and Paike believes that it does not rule out the possibility of applying it to DM-i platform models. In addition, Li Yunfei, deputy general manager of BYD Sales Company, said that "Blade Battery" has a large number of partners in talks.
This article comes from the author of Autohome Chejiahao and does not represent the views and positions of Autohome.