This article is reproduced from the negative review
In the past two days, Ouyang Minggao, an academician of the Chinese Academy of Sciences, angered the exaggerated news of GAC New Energy Vehicles, and once again brought this magical and magical material-graphene, back to the sight of netizens.
As usual, let's sort out the ins and outs of this matter to our friends.
At an electric vehicle forum held last Saturday, Ouyang Minggao, an academician of the Chinese Academy of Sciences, said publicly: "If someone tells you, this car can run 1,000 kilometers, it can be fully charged in a few minutes, it is safe, and the cost is very low. Technically speaking, he must be a liar."
Coincidentally, on the poster of GAC’s press conference last Friday, GAC used a huge slogan to show GAC’s big muscles in the battery field: The tram we are about to release, that’s awesome, it’s 80% full in 8 minutes, and it has a battery life It has reached 1,000 kilometers.
This became interesting all at once. At the press conference held by GAC on Friday, Academician Ouyang made such a speech on Saturday.
In fact, if we simply think about it, we know that GAC’s promotion is impossible.
Want to charge a battery with a battery life of 1,000 kilometers in 8 minutes, the State Grid was the first to refuse.
The bad reviewer simply calculates an account for the bad friend. Now 80% of the 1000 kilometers of the electric car in 8 minutes, the power required for charging is about 900 kilowatts. If the common charging pile is 380V DC voltage, the current must reach 2400 amps.
At present, the fast charging piles of the State Grid can only support 30 kilowatts. If you take a step back, even if you build a 900 kilowatt charging pile, you can’t power off the entire community in order to charge an electric car. Got it.
Then some friends would like to ask. Putting aside the question of power, is this "80% full in 8 minutes, and battery life reaching 1,000 kilometers" graphene battery may appear?
It is estimated that many friends have not figured out what graphene is. Is graphene really so amazing?
Friends who have gone to junior high school chemistry should all know that there is a kind of allotrope in chemical elements. They are all composed of a single element, but because of the different arrangement, they have completely different characteristic.
Graphene, diamond, graphite and fullerene are all allotropes of carbon.
As we all know, we live in a three-dimensional space, and before the advent of graphene, all known elements also existed in a three-dimensional structure.
The structure of graphene is surprisingly weird. To put it bluntly, it is a single-layer graphite, a material that exists in two-dimensional space.
In fact, the discovery of graphene is far simpler than the friends imagined. These two scientists used extremely simple tools: tape!
They attached the tape to the surface of the graphite, and then uncovered the tape again and again to obtain a single-layer graphite structure.
Therefore, graphene, the magical material "demonized" by these unscrupulous manufacturers in recent years, is far from being as mysterious as everyone imagined.
However, graphene has become a valuable material due to its unique two-dimensional structure.
The first is that it is unimaginably light, but extremely strong. Its strength is 300 times that of steel, but it has good flexibility.
And graphene is also a nearly perfect thermal conductivity material, with a thermal conductivity of 3000W/m·K~5000W/m·K, which can almost kill the thermal conductivity of almost all metals.
In addition, due to the special structure of graphene, it has a very high electron mobility, that is, electrons on the graphene can move freely if they enter no one's environment, so the conductivity of graphene is also very good, and the heat is small.
With so many outstanding characteristics appearing on a material, graphene has instantly become a sweet bun for major manufacturers and materials research fields.
The discovery of graphene also naturally won the Nobel Prize in physics.
After understanding graphene, it is easy for us to think that using the high conductivity of graphene can indeed greatly increase the charging speed.
Yes, the idea is very good.
Unfortunately, on the one hand, graphene is too expensive. Tear with tape, you can indeed get observable graphene. But to get usable graphene, I am afraid that it will not work if it is stuck on tape. For example, chemical oxidation, crystal epitaxial growth, chemical vapor deposition, etc. are used to prepare it.
However, graphene is a two-dimensional material, which is prone to wrinkles and deformation. Once deformed, the characteristics of graphene will change. Therefore, the cost of good graphene has not been reduced, and it is called "black gold".
On the other hand, the surface properties of graphene are greatly affected by the chemical state, it is difficult to maintain the stability between each batch of graphene, and the low cycle life of pure graphene is a problem.
Therefore, in actual use now, the graphene in the graphene battery often appears as a dopant of the electrode material, and it is good to improve the conductivity and heat dissipation problems slightly.
To completely break through the bottleneck of today's batteries, we are still far away.
Just as the major mobile phone manufacturers have long known that graphene batteries are sweet and pastry, they have made the layout very early. After a few years of investment, none of them have been able to produce mass-produced products.
Is graphene really useless? No, because low-cost graphene batteries are useless, and useful graphene batteries are too expensive to be used in laboratories.
Not to mention, in fact, this time GAC’s advertising is actually a first-hand word game.
After the academician smashed GAC, GAC hurriedly stated that "graphene super fast charge battery" and "long-life silicon anode battery" are two types of batteries.
The full name of GAC's graphene battery is "graphene-based super fast rechargeable battery" and it is not a real graphene battery. In addition, the graphene-based super fast rechargeable battery is charged fast, and the silicon negative electrode battery is the long battery life.
Two different technologies have been put into a long picture, which is indeed very easy to misunderstand.
To be reasonable, just look at the "80% full charge in 8 minutes". Many batteries can achieve this without adding graphene.
Regardless of battery capacity and battery energy density, just talk about charging rate, which is no different from "discussing toxicity without dosage".
Recall that the academic community generally believes that graphene batteries are still in the laboratory stage at this stage, so the amount of moisture in the graphene battery of GAC is still unknown.
What makes the bad reviewer feel paradoxical is that it seems that all new-born technologies carry a kind of "curse." Whether it is graphene or quantum mechanics, some unscrupulous manufacturers will use people's curiosity and ignorance of new technologies to harvest a wave of IQ taxes.
It is estimated that friends have heard of graphene more or less in some exaggerated advertisements of manufacturers.
For example, graphene underwear that can be antibacterial, absorb sweat, have low-temperature far-infrared function, and even self-heat.
In addition, there are "graphene mask", "graphene power bank", "graphene floor" and so on. That is called one: graphene can be used in everything.
As long as you add a little graphene to any product, you can instantly get the blessing of "high-tech". You don't have to doubt what bizarre effects can be produced.
What kind of high-tech material is this? It is simply the gold of technology products. Underpants are underdeveloped technology, and graphene must be added! With graphene on the mask, one sheet can hold 100 sheets!
Is this reasonable?
You must know that high-purity graphene is much more expensive than gold. The cheap products with graphene on the Internet are graphene oxide at best, or graphite at all, and graphene is not the same thing .
Even if real graphene is added, because of the purity and quality of graphene, it is harder to say how much it can play.
Maybe you now spend several times the price of a graphene panties, the antibacterial properties might as well buy a few more modal panties and wear them well.
Yes, the material of graphene is amazing, and people are constantly advancing on the way to explore graphene.
However, many characteristics of graphene can only be achieved under the premise of high purity and high proportion, or very strict chemical structure design.
Current graphene products are more of a "high-tech placebo", and apart from being more expensive, they have very limited benefits.
Wait for graphene to become practical? Let's talk about reducing the cost of single-layer graphene by 100 times.
And "graphene" has also become the hardest hit area of the IQ tax along with high-tech terms such as "quantum", "negative ions" and "nano materials", making a lot of contributions to the advertising and marketing industry.
Let these technologies frequently appear in some negative news, and even give birth to some famous stalks, so that consumers will not consciously raise their vigilance when they hear these words. Is this reasonable?
Even in academia, the reputation of graphene is almost stinking, because too many people use graphene to write papers.
Last year, there was an out-of-the-loop joke. In order to satirize the phenomenon of graphene paper irrigation, a scholar seriously wrote a paper about whether the electrocatalytic effect of bird droppings would increase if graphene was added to bird droppings.
Unexpectedly, it was also listed in the top academic journal ACS NANO in the American materials industry.
The discovery of graphene was originally a great thing, but under the abuse of some unscrupulous manufacturers and scholars, it has gradually changed its taste, and it has reached the point of "talking about the color change of graphene."
The bad reviewer popularizes graphene, a super material, to his friends. He just hopes to be able to make the original source clear, so that everyone can have their own judgment when facing these false announcements.