Chapter 959

Unfortunately, Chen Yushan guessed wrong this time.

After returning to Jinling, Lu Zhou did plan to start a new round of closures, and indeed made up his mind to "never step out of the house without solving Riemann's conjecture". However, there are so many things in reality.

This time, Yang Xu, director of the Institute of computational materials, called for help.

As for the contents of the rescue

It's about the lithium air battery project that was approved two or three years ago.

Lu Zhou was also surprised. Until the end of last year, he had been able to read about the significant progress made in the research of lithium-air batteries from the report of the Institute of computational materials.

How come this year, the whole research is turning down?

Wang Peng drove himself to the Jinling Institute of higher learning. As soon as he stepped into the lab's boat, he was grabbed by Yang Xu, who was in agony.

"Do me a favor! Big man! I have No way! "

"Don't do that. I have something to say. Haven't I come here? Don't make it look like the last words. If you have any questions, I'll see if I can help you find a way... "

Seeing Yang Xu's state of mind exploding, he really scared Lu Zhou.

Since he became the director of the Institute of computational materials, he has led many major projects and solved many problems in materials science for Jinling Institute of higher learning.

It's not surprising that research in such cutting-edge fields will encounter uncertain problems, but it can torture this guy like this

To be honest, Lu Zhou is really curious.

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

After thinking about it carefully, Lu Zhou recalled some contents of the report and nodded.

"A little impression."

Taking a deep breath, Yang Xu continued: "according to the experimental analysis, we found that under a certain pressure difference, the gas at the high pressure side can slowly transport molecules of a certain diameter to the low pressure side. Our project team immediately followed up this research and successfully made an exchange membrane capable of screening gas molecules in the diameter range of 3.4-3.5a. "

Lu Zhou: "isn't that good?"

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

"It's not good at all," Yang Xu continued, shaking his head. "The upper and lower boundary of the screening range is not a fixed value, but changes linearly with the pressure You get it. "

Hearing this, Lu Zhou's face finally showed a clear expression.

"I see. I understand your question."

In short, this porous silicon-based molecular exchange membrane is like a fishing net full of elasticity. The larger the net is, the larger the mesh will be, and the more fish will escape

As for whether the air pressure on both sides can be maintained at a constant value to ensure that there is only oxygen passing through the exchange membrane

This is clearly impossible.

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

Not to mention the technical cost of controlling the air pressure difference to such an accurate level, from the perspective of safety, they are absolutely impossible to allow the redox reaction system in lithium air battery to run on such unstable steel wire.

The liveliness of lithium metal is not a joke, but it's the one who can't say a word and explode!

If a little impurity is put in, what they make is not a battery, but a bomb.

"We've been stuck in this bottleneck for half a year," Yang said, shaking his head. "We've tried all the ways we can..."

The boat thought for a moment and said, "is there a simulation? Let me see. "

"Follow me."

Taking the boat to the computer, Yang Xu holds the mouse and clicks twice. Soon, a three-dimensional composition of the porous network overlay silicon-based molecular exchange membrane appears in front of the boat.

Pointing to the image on the screen, Yang Xu explains.

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

With that, Yang Xu holds the right hand of the mouse and knocks his index finger twice.

In the screen, the red and green spots on the right side of the molecular exchange membrane begin to gather towards the surface of the membrane, just like finding the outlet of 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. However, when the surface pressure continues to rise with the increase of the pressure difference, and reaches position B, nitrogen also begins to pass through the exchange membrane... ""But in fact, when the pressure difference starts to change from a to B, some nitrogen molecules have already infiltrated in at a slow rate."

In the screen, the red dot of nitrogen has been contacted with lithium anode through the exchange membrane.

Looking at Yang Xu's simulation demonstration on the software, a solemn expression appeared on the face of Lu Zhou.

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

"I can think of ways to deal with a series of impurities, including water molecules, carbon dioxide, and even carbon monoxide. There are also some weak sulfur dioxide and other gases that are well handled, but only nitrogen It's so hard to do it. It's like a group of flies that can't be driven away. "

Even though nitrogen can be used as a protective gas in general, such as in the food industry, it can not be used for lithium-air batteries, because nitrogen will react with lithium to generate unstable Li3N.

If nitrogen is allowed to enter the circulation system of lithium-air battery, the whole battery will be wasted if it can not be operated several times.

The key to the difficulty of lithium air battery is that the lithium metal is too active. The impurities that need to be removed are too lazy.

At the beginning, IBM didn't believe in this evil. It took the famous Almaden research center to carry out this project together, and even used the distributed computing technology with a little black technology elements, positioning each oxygen atom entering the reaction system and accurately allocating it to the lithium cathode

As for the final result, it is also obvious.

Even the rich and powerful IBM finally had to believe in this evil, cut down this bottomless project and fired the project leader.

Although the silicon material of the Institute of computational materials has indeed brought great success to the research in this direction, if the problem of other impurities passing through cannot be solved, it can only be regarded as an interesting stage achievement, not more advanced than the idea of putting an oxygen tank on the outside of the battery.

Before Lu Zhou was found, Yang Xu's research team of lithium air battery project had been stuck in this bottleneck for nearly half a year, and so far, there has been no progress.

Intuition told him that if he could not even solve this problem, Professor Lu, one of the founders of Computational Materials Science, would be the only one who could hope to solve this problem in the whole Institute of higher learning.

However, even though the land boat is quite confident in its ability, it can't think of any good solution for a while.

He felt his chin for a long time, and finally he could only give an ambiguous answer.

“…… I'll go back and think about it. If there's any new progress, I'll let you know. "

Seeing that Lu Zhou couldn't come up with a good solution, Yang Xu began to sigh with no hope.

“…… I thank you! "

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

Hearing Yang Xu's "thank you", Lu Zhou didn't realize the deep despair of the "academic leader who has begun to doubt his life". Instead, he was embarrassed to smile.

"What can I do for you..."

If this thing can be studied out, it will be a market of thousands and trillions!

Even if he is not very interested in money, the value behind this topic is worth his try