Unfortunately, this time Chen Yushan guessed wrong.

After returning to Jinling, Lu Zhou was indeed ready to start a new round of retreat, and he did make up his mind to "never take a step out of the room without solving the Riemann conjecture", but there were too many things in reality.

The person who called him for help this time was Yang Xu, director of the Institute of Computational Materials.

As for the content of the distress call......

It is about the lithium-air battery project that was established two or three years ago.

Lu Zhou was also quite surprised to say that until the end of last year, he had been able to see the news of significant progress in lithium-air battery research from the report of the Institute of Computational Materials.

How is it that this year, the whole research has taken a sharp turn?

Let Wang Peng drive himself to the Jinling Institute for Advanced Study, and as soon as he stepped into the laboratory, Lu Zhou, who had just stepped into the laboratory, was grabbed by Yang Xu, who looked pained.

"Do yourself a favor! Big guy! I've ...... No more! ”

"Don't be like this, you have something to say, haven't I come here? Don't make it look like your last words, if you have any problems, I'll see if I can help think of a way......"

Seeing Yang Xu's mentality explode, it really scared Lu Zhou.

Since this guy became the director of the Institute of Computational Materials, he has led many large projects, and has solved many problems in materials science for the Jinling Institute for Advanced Study.

It's not surprising that research in a cutting-edge field like this will encounter problems that can't be solved, but it can torture this guy like this......

To be honest, Lu Zhou was really curious.

Yang Xu: "Do you remember the porous silicon-based molecular exchange membrane I mentioned in my research progress report some time ago?" ”

Lu Zhou thought about it carefully, but recalled some of the contents of the report, nodded and said.

"It's a bit impressive."

Taking a deep breath, Yang Xu continued: "According to the experimental analysis, we found that under a certain air pressure difference, the gas located on the high pressure side of this kind of porous silicon material can slowly transport molecules of a specific diameter and size to the low pressure side. Our project team immediately followed up on this research and successfully fabricated an exchange membrane capable of screening gas molecules in the 3.4-3.5a diameter range. ”

Lu Zhou: "Isn't that good?" ”

The diameter of the oxygen molecule is exactly 3.46a, which is exactly within this range. Although the AR gas molecule is 3.4, it is also next to this screening range, but AR is a rare gas, so it has no effect.

"It's not good at all," the expression on Yang Xu's face was a little bitter, and he shook his head and continued, "The upper and lower boundaries of the screening interval are not a fixed value, but change linearly with the magnitude of the air pressure...... You get the idea. ”

Hearing this, Lu Zhou finally showed a clear expression on his face.

"I see, I understand your question."

In short, this porous silicon-based molecular exchange membrane is like a resilient fishing net, and the larger the net, the larger the mesh will be, and the more fish will slip through the net......

As for whether it is possible to maintain the air pressure on both sides at a constant value to ensure that only oxygen passes through the exchange membrane......

This is also obviously impossible.

Yang Xu has made it clear that the movement of the upper and lower boundaries of the entire screening interval changes linearly with the change of the air pressure difference between the two sides.

Not to mention the technical cost of controlling the air pressure difference to such a precise level, from a safety point of view, it is absolutely impossible for them to allow the redox reaction system in the lithium-air battery to run on such an unstable steel wire.

The liveliness of lithium metal is no joke, it's the Lord who explodes if you don't agree with each other!

If they had put the slightest bit of impurity in, they wouldn't have built a battery, but a bomb.

"We've been stuck on this bottleneck for half a year," Yang Xu shook his head, "We've already tried all the methods we can try......

Lu Zhou thought for a moment and said, "Did you do a simulation?" I'll see. ”

Choking and Strange Novels|w~w~w.

"Follow me."

Walking to the computer with Lu Zhou, Yang Xu held the mouse and clicked twice, and soon a three-dimensional composition of a porous network superimposed silicon-based molecular exchange membrane was presented in front of Lu Zhou.

While pointing to the image on the screen, Yang Xu explained.

"We try to increase the surface air pressure on one side of the exchange membrane, and molecules of a certain diameter will pass through the channels in the molecular exchange membrane at a certain rate......"

As he spoke, Yang Xu held the right hand of the mouse and tapped his index finger twice.

On the screen, the red and green dots on the right side of the molecular exchange membrane begin to gather towards the surface of the molecular exchange membrane, as if they have found an outlet for pouring.

“…… When the surface pressure of the membrane reaches position A in the figure, oxygen begins to move through the molecular exchange membrane to the gas exchange chamber of the lithium-air battery, but when the surface pressure continues to increase with the increase of the pressure difference, and when it reaches position B, nitrogen will also begin to pass through the exchange membrane......"

"But in fact, when the air pressure difference starts to gradually change from A to B, some nitrogen molecules are already penetrating inward at a slow rate."

In the screen, the red dot marking nitrogen has come into contact with the lithium anode through the exchange membrane.

Watching Yang Xu simulate and demonstrate it on the software, a solemn expression appeared on Lu Zhou's face.

After the demonstration, Yang Xu leaned back on the computer chair with a long sigh.

"I can think of a range of impurities including water molecules, carbon dioxide, and even carbon monoxide, and some gases such as sulphur dioxide, which are very weak, but nitrogen is the only ...... It's so hard to do, it's like a swarm of flies that can't be driven away. ”

Even though nitrogen can normally be used as a shielding gas, for example in the food industry, this is not the case for lithium-air batteries, because nitrogen reacts with lithium to form unstable Li3N.

If nitrogen is allowed to enter the circulating system of lithium-air batteries, I am afraid that the entire battery will be discarded after a few runs.

The reason why lithium-air batteries are difficult to do is that lithium metal is too lively. And the impurities that need to be eliminated are too lazy.

IBM didn't believe in this evil at the beginning, and pulled the famous Almaden Research Center to work on this project together, and even used distributed computing technology that now seems to have a bit of black technology elements to locate each oxygen atom that enters the reaction system and accurately distribute it to the lithium anode......

As for the final result, it is also obvious.

Even IBM, which has deep pockets and strength, finally had to believe in this evil, cut down this bottomless pit of the project, and fired the squid of the project leader.

Although the siliceous material of the Institute of Computational Materials has indeed brought a lot of victory to the research in this direction, if it cannot solve the problem of excluding the passage of other impurity gases, this can only be regarded as an interesting phased achievement, and it is not more advanced than the idea of putting an oxygen tank on the outside of the battery.

Before finding Lu Zhou, the research team of the lithium-air battery project led by Yang Xu had been stuck on this bottleneck for almost half a year, and there was no progress at all so far.

His intuition told him that if even he couldn't, who could still hope to solve this problem in the entire Institute for Advanced Study, I am afraid that only Professor Lu, one of the founders of computational materials science, would be left.

However, even if Lu Zhou was still quite confident in his abilities, he couldn't think of any good solution for a while.

After touching his chin and pondering for a long time, in the end he could only give an ambiguous answer.

“…… I'll go back and ponder, and I'll tell you if there's any new development. ”

Seeing that Lu Zhou couldn't come up with a good solution, Yang Xu had gradually begun to sigh without any hope.

“…… Thank you so much! ”

If it really doesn't work, he can only declare this technical route a failure, and think about other possible directions instead.

Hearing Yang Xu's "thank you", Lu Zhou didn't notice the despair in the heart of this "academic leader who has begun to doubt life", but smiled a little embarrassed.

"What is there to thank me for this......"

If this thing can be studied, it will be a market of tens of billions of dollars!

Even if he wasn't very interested in money, the value behind the subject was worth his try......