On March 29, BYD officially announced the launch of the "Blade Battery", which we can understand as a new generation of "lithium iron phosphate" batteries, not the ternary lithium batteries we often heard before. So, what are the advantages of blade batteries?
In 2015, China’s electric vehicle industry suddenly accelerated. At that time, most electric vehicles were equipped with lithium iron phosphate batteries. As the battery energy density stipulated by the state is getting higher and higher, and at the same time, within the limited volume, manufacturers are more willing to maximize battery life, so as to meet consumers' demand for battery life. Therefore, after 2016, most car companies gradually switched to ternary lithium batteries with higher energy density and can carry more electric energy in the same volume.
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What are the advantages of ternary lithium batteries? Under the same volume, ternary lithium batteries can store more electrical energy than lithium iron phosphate batteries due to their natural advantage of high energy density. In other words, if the same car is equipped with a ternary lithium battery and a lithium iron phosphate battery, the cruising range of the ternary lithium battery will definitely be higher than that of the lithium iron phosphate battery.
Not only that, the ternary lithium battery can support output and input power, which is also stronger. Because, from a chemical point of view, ternary lithium batteries are more active than lithium iron phosphate batteries. How to understand it? In short, we prepare two bags respectively, one of which has a larger mouth (ternary lithium), while the other bag has a smaller mouth (lithium iron phosphate), then relatively speaking, the bag with a larger mouth The more rice the pocket can hold, the more rice can be poured out at a greater or faster speed.
When it comes to electric vehicles, we can understand that the charging efficiency of ternary lithium batteries is higher. In addition, the maximum power data in vehicle performance can also be higher. Seeing this, we can't help but ask, do ternary lithium batteries have no shortcomings?
Indeed, under normal circumstances, everything has two sides. Subsidies for new energy vehicles in my country are declining year by year, and there are increasingly strict regulations on the batteries used in vehicles that can receive subsidies. Among these increasingly stringent regulations, the most important consideration is the "energy density" of the battery, which is the energy contained in the unit volume. Therefore, major car companies in my country are more willing to use ternary lithium batteries. However, as the energy density becomes higher and higher, the disadvantages of ternary lithium batteries are becoming more and more exposed.
The picture comes from the Internet
Due to its higher activity, the stability and safety performance of ternary lithium batteries are relatively poor. As the cruising range continues to increase, the NEDC range of mainstream electric vehicles at this stage generally exceeds 400 kilometers, and has even reached 500 kilometers or 600 kilometers. However, consumers all know that the so-called NEDC battery life promoted by manufacturers is difficult to achieve in our daily driving. Although the battery pack has a large capacity, the ternary lithium battery is relatively more active and unstable, which results in its faster power output.
Another disadvantage or drawback caused by an active battery is "unsafe". Previously, the editor had interviewed the then technical engineer of BAIC New Energy. According to him, the batteries of electric vehicles generally do not explode, so although we often pay attention to the battery safety of electric vehicles because of the explosion of power batteries, if we think about it carefully, we will find that the natural total amount of electric vehicles Compared with gasoline vehicles, the number is smaller.
As mentioned earlier, the engineer said at the time that spontaneous combustion would not occur under normal circumstances, but there are buts. Once an electric vehicle spontaneously ignites, it is likely to cause an explosion. Therefore, the engineer said that if an electric vehicle is found to be smoking and has a tendency to spontaneously ignite, we should try our best not to use a fire extinguisher to put out the fire. Instead, we should focus on ensuring our own personal safety and stay away from the vehicle as soon as possible.
In 2019, a video of a Tesla car suddenly exploding in the basement went viral on the Internet, which seemed to once again confirm what the engineer said at that time was true. Therefore, it is understandable that we consumers are concerned about the safety of power batteries, because chemical changes will cause explosions, rather than simple combustion.
So, lithium iron phosphate batteries don’t have these problems? To be honest, there still are! It's just relatively safe. There are also many comparisons between lithium iron phosphate batteries and ternary lithium batteries on the Internet.
Let me briefly list the advantages and disadvantages of both parties, as shown in the table below:
So, we can see that large electric vehicles on the market, such as buses and freight vehicles, are still equipped with relatively more stable iron phosphate Lithium battery.
So, is there a third possibility? At this point, the focus of this article comes. BYD Batteries started out, and its unique battery technology has made it among the top five in global power battery production many times. It is also unrivaled in technology. The core of BYD's batteries is lithium iron phosphate batteries.
In recent years, as the energy density of energy batteries installed in passenger cars has become higher and higher, BYD has had no choice but to replace ternary lithium batteries. It turns out that BYD, which briefly used ternary lithium batteries, was "holding back its big move." From last year, Wang Chuanfu made it clear at the China Electric Vehicle Forum of 100 people that he would launch blade batteries, to BYD's official "puncture" experimental video of three power batteries released recently, we finally learned that what "technical madman" Wang Chuanfu said was true. BYD, which is well-known for its R&D and technology, did not disappoint consumers.
The so-called blade battery actually uses the same internal raw materials as lithium iron phosphate batteries, but BYD has made comprehensive updates in terms of the shape, internal structure and assembly method of the power battery. Of course, BYD has not yet opened up its blade battery patents, and we can only understand it from the analysis of some experts and the videos and data released by BYD.
Currently, what we know is that the energy density of the blade battery has broken through the bottleneck of the original lithium iron phosphate battery. Based on BYD's original lithium iron phosphate battery, the energy density has increased by 50%. In addition, due to multi-dimensional technological updates such as internal structure and separator materials, blade batteries are more stable and safer than lithium iron phosphate batteries.
In the words of BYD Chairman Wang Chuanfu, who is known as a technology geek: BYD will use blade batteries to completely erase the word "spontaneous combustion" from the dictionary of new energy vehicles! With technical confidence and the belief that seeing is believing, we have reason to believe that the emergence of BYD blade batteries may make consumers feel more confident and safe when buying electric vehicles. Let’s talk about BYD’s puncture test again.
What is a puncture test? What is the purpose and necessity of side-to-side testing?
The so-called puncture test is actually a literal meaning. Use a 3~5mm heat-resistant steel needle to vertically penetrate a power battery. We can still see the specific test process clearly through the video uploaded by BYD. In fact, in the early days, my country's electric vehicle power batteries were required to undergo puncture testing. However, due to the interests of many parties, my country has canceled the puncture testing in its regulations in recent years. However, we should not place too much emphasis on the results of the puncture test. Because under normal conditions, there is a protective shell on the outside of the power battery, making it extremely difficult for a real environment similar to a puncture test to occur. The puncture test only focuses on the safety of power batteries under the most extreme circumstances.
But it doesn’t matter. This does not prevent car companies from conducting separate tests. At the same time, puncture test is also a "standard feature" of almost every manufacturer or battery manufacturer. Judging from the video results displayed, the ternary lithium battery sold on the market smoked, caught fire and then exploded within a few seconds after passing the puncture test. This reflects the common ternary lithium battery on the market today. Unsafe and unstable during puncture test.
When the lithium iron phosphate battery is subjected to a puncture test, the reaction is obviously not as large as that of the ternary lithium battery, but it is still affected by the puncture. The battery has an internal short circuit and the battery temperature gradually increases.
For a long time after the puncture test, the battery temperature of the blade battery remained normal and the battery continued to output voltage, which highlighted its safety. Having said this, some friends may ask, why can blade batteries be so safe? To be honest, I don't know. Because this technology is now in the hands of BYD, and they don’t reveal the secret, I’m afraid it will be difficult for us to fully understand it. However, we can still make assumptions.
Due to its battery structure, as shown in the video, the volume of the blade battery is relatively flat. In the acupuncture laboratory, after the steel needle penetrates the battery, its internal structure is relatively "isolated", that is, the punctured The battery core cannot form an effective skiing reaction with other battery cells, thereby avoiding internal short circuit. Of course, this possibility is possible, but the final results and answers still need to be informed by BYD.
BYD announced that the blade battery will be installed in BYD’s new sedan, BYD Han, and will be installed in more BYD models in the future. Relatively speaking, the research and development of new technologies needs to be cautious, so I am afraid that BYD is currently unable to mass-produce blade batteries on a large scale. In addition to R&D issues, there are also cost issues. As we all know, BYD's technological advantages in the field of new energy are achieved through real money. High R&D expenses have always been BYD's advantage. However, after the successful development of new technologies, how to recover costs and increase profits is what every company faces. problem.
The editor analyzed that blade batteries will be put into large-scale mass production as early as the end of 2021. They may cooperate with other automobile manufacturers in 2022, and it will be difficult to start large-scale mass production this year. Wang Chuanfu once revealed that the birth of the blade battery was actually to "correct" the development route of my country's power batteries. Through his point of view, we can also believe that Wang Chuanfu wants to use blade batteries to break the current situation of ternary lithium batteries dominating the market. At the same time, the emergence of blade batteries will gradually affect consumers' thinking about the safety of power batteries.
Safety issues can never be ignored, and as a relatively emerging field of electric vehicles, they are even more important. Whether autonomous driving causes death or power batteries cause death, all sophistry is abhorrent in the face of life. For issues related to safety, relevant departments and manufacturers should take precautions before they occur to ensure nothing goes wrong. Doing our best to protect the safety of consumers' lives and property is the most normal and important thing.
This article comes from the author of Autohome Chejiahao and does not represent the views and positions of Autohome.