959 Porous Silicon-Based Molecular Exchange Membrane

After Lu Zhou returned to Jinling, he did plan on going on another retreat, and he didn’t want to leave his house until he solved Riemann’s hypothesis. However, he had too much responsibility.

Yang Xu, the director of the Institute of Computational Materials, called him for help.

He called about the lithium-air battery project, which was established a couple of years ago.

Lu Zhou was quite surprised. Up until the end of last year, the reports from the Institute of Computational Materials showed that they had been making significant progress in the research of lithium-air batteries.

However, it seemed like everything was going downhill this year?

Wang Peng drove Lu Zhou to the Institute for Advanced Study, and the second Lu Zhou stepped into the laboratory, Yang Xu grabbed his arm and cried for help.

“Please help me! I can’t… do this anymore!”

“Shut up, speak properly. I’m here. It’s not like you’re on your deathbed, tell me what’s wrong, I’ll see if I can help…”

Lu Zhou was shocked at Yang Xu’s mental state.

After becoming the director of the Institute of Computational Materials, he had led many successful projects and solved many materials science research problems.

It wasn’t unusual for a guy like him, who was at the cutting-edge of scientific research, to encounter difficult problems, but this time felt different…

Honestly, Lu Zhou was curious as to what kind of problem could torment this guy to this level.

Yang Xu: “Remember that porous silicon molecular exchange membrane I mentioned in the research progress report a while back?”

Lu Zhou thought back to the report and nodded.

“I think so.”

Yang Xu sighed and said, “Well, according to our experimental analysis, we found that when this kind of porous silicon material is placed under a certain pressure difference, the gas molecules on the high-pressure side slowly transport molecules of a specific diameter to the low-pressure side. Our project team immediately followed up on this research and made an exchange membrane capable of screening gas molecules in the 3.4-3.5A diameter range.”

Lu Zhou: “Isn’t that a good thing?”

The diameter of the oxygen molecule was 3.46A, which happened to be within this range. Even though argon gas molecules had a diameter of 3.4A, which was also within the screening range, argon was rarely found in nature, so it didn’t have a significant effect.

“It’s not good at all.” Yang Xu frowned and shook his head. He then said, “The upper and lower boundaries of the screening range aren’t fixed; they change with pressure… Do you see what I’m trying to say?”

Lu Zhou had an expression of realization.

“Oh, I see, I see where the problem is.”

Basically, this porous silicon-based molecular exchange membrane was like a flexible fishing net. When the fishing net expanded, so did the fishing net holes…

Therefore, the only solution was to maintain constant air pressure on both sides, to ensure only oxygen molecules could pass through the membrane…

But that was obviously impossible.

Yang Xu made it clear that the screening range changed linearly with the pressure difference between the two sides.

Forget about the technical costs of maintaining air pressure to such a precise level, from a safety point of view, it was dangerous to allow a redox reaction to happen in unstable oxygen levels.

Lithium metal was no joke, it could spontaneously explode at any time!

If there was any amount of contamination, they would have a bomb on their hands.

“We’ve been stuck here for half a year.” Yang Xu shook his head and said, “We tried everything we could.”

Lu Zhou thought for a second and said, “Do you have any simulations? Let me see.”

“Follow me.”

Yang Xu walked next to a computer and clicked the mouse. Soon after, a three-dimensional composition image of a silicon-based molecular exchange membrane with a porous network structure was presented on the screen in front of Lu Zhou.

Yang Xu pointed at the picture on the screen and spoke.

“We’ve tried to increase the surface pressure on one side of the exchange membrane, which causes molecules of a certain diameter to pass through the molecular exchange membrane at a constant rate…”

Yang Xu clicked on the mouse again.

Green and red dots appeared on the sides of the molecular exchange membrane, and they began to gather toward the surface of the membrane.

“… When the surface pressure of the membrane reaches level A, oxygen molecules begin to move through the molecular exchange membrane, to the lithium-air battery gas exchange chamber. But when the surface pressure continues to increase, which increases the pressure difference, nitrogen will also start to pass through the exchange membrane…

“However, while the pressure difference changes from A to B, a significant amount of nitrogen molecules have already slowly penetrated through the membrane.”

The red dots on the screen, which represented nitrogen molecules, had gone through the exchange membrane, making contact with the lithium anode.

Lu Zhou looked at Yang Xu’s software demonstration and had a dignified look on his face.

After the demonstration, Yang Xu sighed and sat in the computer chair.

“We have found solutions for water molecules, carbon dioxide, and even carbon monoxide and sulfur dioxide molecules. But nitrogen… is too tricky. They’re like a bunch of flies, they’re impossible to catch.”

Even though nitrogen could be used as a protective gas in most situations, such as the food industry, it wasn’t applicable to lithium-air batteries. Mainly because the nitrogen would react with lithium, forming Li3N.

If the nitrogen gas penetrated into the circulation system of the lithium-air battery, the entire battery would be destroyed within a few cycles.

The reason why lithium-air batteries were so difficult to produce was that lithium was highly reactive. The amount of impurities that needed to be eliminated was extremely high.

Back in the day, IBM’s famous Almaden laboratory tried to research lithium-air batteries. They even used some kind of distributed computing technology, positioning each oxygen atom precisely into the lithium anode…

The final result was obvious. They failed miserably.

Even the wealthy and powerful IBM had to cut off this money-burning project.

Even though the Institute of Computational Materials had found some amount of success with their research, if they couldn’t get rid of the impurities in the gas, their research would become totally useless.

Before asking Lu Zhou for help, Yang Xu and his lithium-air battery project team were stuck at this bottleneck for half a year. They hadn’t been able to make any progress.

Yang Xu knew that if he couldn’t solve this problem himself, no one else in the Institute for Advanced Study could, except the father of computational materials science—Professor Lu.

However, even though Lu Zhou was confident in his own abilities, he wasn’t able to find a solution.

He pondered for a long time and said, “I’ll take a look. If I find anything, I’ll tell you.”

Seeing how even Lu Zhou wasn’t able to think of a solution, Yang Xu gradually lost hope.

“… Thank you.”

Worse came to worst, he would have to give up on this technical route and begin researching other directions.

Lu Zhou didn’t realize how hopeless Yang Xu was, so he awkwardly smiled and spoke.

“You’re welcome…”

This research project could be worth billions, or even trillions!

I’m not interested in money, but this research project is valuable. It’s worth a try…