Chapter 959: Porous silicon-based molecular exchange membrane

Shuwulou, the latest chapter of the black technology system of Xueba will be updated as soon as possible!
Unfortunately, Chen Yushan was wrong this time.
After returning to Jinling, Lu Zhou did make a plan to start a new round of retreat, and indeed made a determination to "not solve the Riemann conjecture and never step out of the door", but the reality Too much.
Yang Xu, the director of the Institute of Computing Materials, called him for help this time.
As for the help ...
It is about the lithium-air battery project that was established two or three years ago.
Speaking of Lu Zhou, he was also surprised. Until the end of last year, he has been able to see the major progress in the research of lithium air batteries from the report of the Institute of Computing Materials.
How come this year, but the whole research has turned sharply?
Wang Peng was asked to drive himself to the Jinling Institute of Advanced Research. As soon as he stepped into the laboratory's land boat, Yang Xu grabbed his arm with painful expression.
"Do me a favor! Big brother! I'm already ... not good!"
"Don't do this. There is something to say. Am I all here? Don't make it look like a last word. If there is any problem, let me see if I can help you find a way ..."
Watching Yang Xu's mentality explode, he really startled Lu Zhou.
Since this guy became the director of the Institute of Computing Materials, he has also led many large projects, and has solved many material science problems for the Jinling Institute of Advanced Research.
It is not surprising that the research in such frontier fields will encounter uncertainties, but the problem that can torture this guy into this way ...
To be honest, Lu Zhou was really curious.
Yang Xu: "Remember the porous silicon-based molecular exchange membrane I mentioned in the research progress report some time ago?"
Lu Zhou thought about it, but recalled the contents of some reports, nodded and said.
"Some impression."
Taking a deep breath, Yang Xu continued, "Based on experimental analysis, we found that under certain pressure differences, the gas on the high pressure side can slowly transport molecules of a specific diameter to the low pressure side. Our The project team immediately followed up this research and successfully made an exchange membrane that can screen 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 happens to be in an unbiased range. Although the Ar gas molecule is 3.4, it is next to this screening interval, but Ar is a rare gas, so it has no effect.
"It's not good at all," Yang Xu said with a bitter expression on his face, shaking his head and continuing to say, "The upper and lower boundaries of the screening interval are not a fixed value, but change linearly with the pressure ... you get it."
Hearing this sentence, Lu Zhou's face finally showed a clear expression.
"That's it, I understand your problem."
In short, this porous silicon-based molecular exchange membrane is like a fishing net full of elasticity. The larger the net, the larger the net, and the more fish that miss the net ...
As for whether the air pressure on both sides can be maintained at a constant value to ensure that only oxygen passes through the exchange membrane ...
This is 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 in air pressure difference on both sides.
Not to mention the technical cost of controlling the pressure difference to such a precise degree, from the perspective of safety, it is absolutely impossible for them to allow the redox reaction system in the lithium-air battery to run on such unstable steel wires. .
The liveliness of lithium metal is not a joke, it is the master who explodes without a word!
If a little bit of foreign matter comes in, they will not make a battery, but a bomb.
"We have been stuck on this bottleneck for half a year," Yang Xu shook his head, "We have tried the methods that can be tried ..."
Lu Zhou thought for a moment and said, "Are there any simulations? I'll see."
"follow me."
Walked to the computer with the landing boat, Yang Xu held the mouse and clicked twice. Soon, a three-dimensional composition of a porous network superimposed silicon-based molecular exchange membrane was presented in front of Lu Zhou.
Pointing at the image on the screen, Yang Xu explained.
"We try to increase the surface pressure on one side of this exchange membrane, and molecules of a certain diameter will pass through the channels in the molecular exchange membrane at a certain rate ..."
Speaking, Yang Xu held the right hand of the mouse and tapped his index finger twice.
In the screen, the red dots and green dots distributed to the right of the molecular exchange membrane seemed to have found a pouring outlet and began to gather toward the surface of the molecular exchange membrane.
"... When the surface pressure of the membrane reaches the position A in the figure, oxygen starts to move through the molecular exchange membrane and toward the gas exchange chamber of the lithium air battery. At that time, nitrogen will also begin to pass through the exchange membrane ... "
"But in fact, when the pressure difference started to change from A to B, some nitrogen molecules had penetrated inward at a slow rate."
In the screen, the red dot marked with nitrogen has contacted the lithium negative electrode through the exchange membrane.
Looking at Yang Xu's simulation on the software, a dignified expression appeared on Lu Zhou's face.
After the demonstration, Yang Xu sighed and leaned against the computer chair.
"I can think of a series of impurities including water molecules, carbon dioxide, and even carbon monoxide. There are also some gases such as sulphur dioxide that are very weak in content, but nitrogen alone ... it is too difficult. It's almost like a bunch of flies that can't be driven away. "
Even though nitrogen can be used as a protective gas under normal circumstances, such as in the food industry, it is not suitable for lithium air batteries, because nitrogen will react with lithium to form unstable Li3N.
If nitrogen is allowed to enter the circulation system of a lithium-air battery, I am afraid that the entire battery will be discarded within a few runs.
The key to the difficulty of lithium air batteries is that lithium metal is too lively. The impurities that need to be eliminated are too lazy.
At first, IBM did not believe in this evil, and pulled on the famous Almaden Research Center to work on this project. It even used distributed computing technology that now seems to have dark technology elements to locate each one into the reaction system. Oxygen atom and accurately assign it to the lithium anode ...
As for the final result, it is also obvious.
Even the wealthy and powerful IBM eventually had to believe in this evil ~ EbookFREE.me ~ to cut down this bottomless pit-like project and fire the project leader.
Although the siliceous material of the Institute of Computational Materials has indeed brought a great deal of victory to the research in this direction, but if the problem of passing other impurity gases cannot be solved, this can only be regarded as an interesting phase achievement. , Not more advanced than the idea of ​​putting an oxygen tank outside the battery.
Prior to finding Lu Zhou, the research team of the lithium air battery project brought by Yang Xu had been stuck on this bottleneck for almost half a year, and so far no progress has been made.
Intuition tells him that if he can't even do it, who in the entire advanced research institute has hope to solve this problem, I am afraid that only one of the founders of computational materials science-Professor Lu.
However, even though Lu Zhou was quite confident in his abilities, he couldn't think of a good solution for a while.
After touching his chin for a long time, he finally gave only an ambiguous answer.
"... I'll go back and think, if there's new progress, I'll tell you."
Seeing Lu Zhou couldn't think of a good solution, Yang Xu had gradually started to sigh without any hope.
"... I thank you!"
If that 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 realize the deep despair of this "academic leader who has begun to doubt life", but was a little embarrassed and smiled.
"What's so thankful to me ..."
If this thing can be researched, it will be a market with thousands of trillions!
Even if he is not very interested in money, the value behind this subject is worth trying.