The top student must be diligent.

Chapter 198 Electron-Interface Reaction Migration Model
After all, it is impossible to easily develop a solid-state lithium-sulfur battery.

As far as the current scientific theories are concerned, there are still quite a lot of things that are not understood about solid electrolytes.

Especially some processes that occur on the interface.

And "interface" is also a common concept in chemistry and physics.

An interface usually refers to the boundary or contact area between two different phases, such as the area where any different phases, substances or materials come into contact.

This concept exists between various combinations of solids, liquids, and gases.

Especially in the field of batteries, electrodes and electrolytes are made of different materials, and different materials inevitably have different properties.

At the interface, these differences will lead to gradient changes in physical and chemical properties, such as differences in potential, concentration, structure, etc.

Naturally, the interfaces between different materials bring different problems.

"However, although these materials may seem different, the ultimate problem is just reflected in the electrons."

In the office, Xiao Yi lowered his head and thought.

Just like the principle of absolute electronicity that he once worked out.

Weak force, strong force, and gravity have little to do with materials. In daily life and under conventional experimental conditions, the essence of materials is electromagnetic interaction.

“It is quite appropriate to use the absolute electronic principle to calculate the migration of electrons and ions on the interface, but it lacks some specificity.”

The pen in his hand kept writing on the draft paper until Xiao Yi finally shook his head.

"The original calculation of absolute electronic properties only considered relatively simple cases, mainly focusing on the same material. It is indeed somewhat incapable of addressing the interface problem between two complex materials."

"There is a lack of a theory that can simply simplify interface problems..."

"Well, there is a theory of space charge layers, but it is not perfect yet."

“In addition, there are some related concepts.”

Xiao Yi narrowed his eyes slightly, and then wrote various related concepts on the draft paper.

Space charge layer, interface resistance, interface capacitance, interface interdiffusion model...

How to combine various concepts?
Suddenly Xiao Yi's eyes moved and he focused on the interface mutual diffusion model.

"Oh, right, the reaction-diffusion equation!"

【u/t=D^2u+R(u)】

I wrote down this formula on a piece of scratch paper.

This is a partial differential equation, similar to the NS equation, which can describe the various behaviors of molecules in the fluid, while the reaction-diffusion equation is used to describe the diffusion and reaction processes of chemical substances in the system.

Similarly, it can also describe the ion migration process occurring on the interface very well.

Xiao Yi's eyes lit up slightly, and he began to deduce on the draft paper.

"Now suppose there is an interfacial reaction system in which substance A is transformed into substance B by diffusion and reaction at the interface..."

【For the concentration CA(x, t) of substance A, the reaction-diffusion equation is: CA/t=DA^2CA-kCA. 】

[For substance B...]

As the entire sheet of draft paper was filled with his writing, the pen in his hand finally stopped.

"So, using this process, I can start to build a model that can describe the relationship between the electrode and the electrolyte!"

[For each ion i, the following reaction-diffusion equation can be written: Ci/t=Di^2CiJi+Ri(Ci,)]

[Here, Ji is the flux of the i-th ion, which can be expressed by the Nester-Planck equation: Ji=Di(Ci+(ziF/RT)Ci)]

"Well... the distribution of electric potential can be solved by Poisson's equation."

"Then there are the interface conditions. For the electrode and solid electrolyte that I am currently studying... Now let's assume that the reaction at the interface is..."

As Xiao Yi continued to deduce, an increasingly complete model gradually appeared on the draft paper.

Until finally, he derived the complete model.

"Well, this should only be considered a preliminary model. There are still quite a lot of things that have not been taken into consideration."

"If we can also incorporate the principle of absolute electronicity, perhaps we can make this model more complete."

"But it still lacks a bit of specificity..."

Targetedness, that is, the targeting of interface reactions. The current model has a relatively large scope of application and is not precise enough.

Just like the NS equations, there are also extensions to describe the Hagen-Poiseuille flow in pipes and the Couette flow between two parallel plates.

However, this problem is not a problem for Xiao Yi.

He began to recall the scenes when he used materials to study solid electrolytes.

Think carefully about the differences in that microscopic world.

Suddenly, his eyes lit up, and he immediately took out a new piece of draft paper and began to continue his new deduction on it.

Time passed gradually.

It was not until several hours later, when the sky gradually darkened, that Xiao Yi raised his head again and smiled slightly.

"Well...it's almost done."

"As I thought before, even the reaction of the interface is ultimately the behavior of electrons."

"In a battery, whether it is an oxidation reaction or a reduction reaction, it is nothing more than a process of gaining and losing electrons."

"so……"

Xiao Yi smiled indifferently.

Borrowing some inspiration from the calculation of absolute electronicity, he further optimized the reaction-diffusion equation that he had originally improved.

The traditional reaction-diffusion equation cannot fully describe the quantum migration behavior of electrons. For this reason, he spent a considerable amount of time solving the Schrödinger equation for electrons at the interface and finally obtained a sufficiently accurate solution.

According to this exact solution, it is equivalent to obtaining the fine structure of electron wave functions, which describe the state and spatial distribution of electrons at different energy levels.

Using such a fine structure, he reconstructed the reaction-diffusion model and improved it to the point where it could accurately describe the quantum tunneling effect and Coulomb interaction of electrons. This way, he could perform a more complete simulation of the actual interface reaction process.

"But this is not enough..."

Xiao Yi took a look at the remaining part.

The state density at the interface is also a key factor affecting electron migration. If the state density can be included, this model can incorporate the core part of the principle of absolute electronicity.

"But to calculate the density of states, you need a computational model."

This is not something Xiao Yi can calculate on his own - of course, he can calculate it, but the process that can be handed over to the computer should be handed over to the computer.

"As for this conclusion... let's name it the electron-interface reaction migration model."

Xiao Yi smiled slightly, and then he was about to go to the computer room.

The calculation of state density requires the use of computers, and of course their laboratory also has servers.

But at this moment, there was a knock on the office door.

His assistant Wang Hao walked in.

"Director Xiao, Director Zhao from the plasma research institute next door just called and said he wants to meet you tomorrow."

"Plasma Institute?"

Xiao Yi was stunned.

Why did the people from the Plasma Institute come to see him?

But he nodded first and said, "I understand."

"Also, is there anyone using the computer room? I need to use it now."

"Not available now." said Wang Hao.

"That's fine. I'm going to use the server now."

Xiao Yi nodded.

"Okay, I'll prepare it for you now." Wang Hao said respectfully, and then he left the office.

Looking at Wang Hao's diligent figure, Xiao Yi couldn't help but sigh, no wonder everyone likes to be a leader, even if you go to the computer room to turn on a machine, there will be someone to help you. But...

“I always feel that this laboratory is a bit small.”

He rubbed his chin.

As the laboratory began to recruit staff, it naturally began to look smaller.

The most important thing is that when various function rooms are in use, if he wants to use them, he also needs to see the arrangements.

Of course, as the director of the laboratory, he still has some privileges. At least when others need to use it, they need to apply and see how it is allocated, but as long as no one is using it, he can go in and use it directly.

However, he began to feel that the laboratory was not enough.

“Is it time to prepare for expansion?”

Xiao Yi looked outside from the office window.

Well, what you can see is the view of Shushan Lake. Of course, the laboratory is quite some distance away from Shushan Lake, so there is a large open space.

In addition to the side he could see, there was also a lot of open space around the laboratory.

These open spaces were left intentionally, specifically for the future expansion of the Science Island Laboratory.

All in all, there are more than a hundred acres of land.

As for why it was not allocated to the laboratory at the beginning, it was because people wanted to see how much value the Science Island Laboratory could achieve under the leadership of Xiao Yi.

It's waiting to be sold at a price.

However, for now, the achievement of high-temperature superconductors is basically enough.

The leaders of Fei City talked to him about this matter some time ago.

Now, he really had this idea in mind again.

"From now on, this building will be used exclusively as a condensed matter laboratory."

“Then we’ll build a specialized materials laboratory over there.”

"Build another mathematics and mathematical physics laboratory over there."

"Well...there are also administrative buildings and dormitories."

The plan and layout of the future Science Island Laboratory seemed to emerge in Xiao Yi's mind.

Of course, all this requires money.

"Well...then wait for me to get this battery out."

Once the battery is developed, he will have even more reason to ask for money.

By then, the Science Island laboratory upgrade plan will probably be officially implemented.

At this time, Wang Hao came in again and said to Xiao Yi: "The computer room is ready, you can go now."

Xiao Yi nodded, then temporarily stopped imagining in his mind, went to the computer room, and began to prepare to calculate the state density required in the electron-interface reaction migration model.

……

In the following period of time, Xiao Yi began to devote all his energy to the task of perfecting the electron-interface reaction migration model.

For now, this model can only be regarded as a framework structure. If we want to make it closer to perfection, we need to make continuous adjustments and add some factors that have not been considered before.

Including the solution he solved for the Schrödinger equation for electrons at the interface, there is still room for improvement. Using computers, a better solution can be found.

In this way, time passed slowly and it was the next day.

……

Today is the day that the director of the Plasma Institute has an appointment to meet with Xiao Yi.

After some discussion, Xiao Yi was finally invited to visit the Plasma Institute.

"This is EAST, the Eastern Super-Anatomical Ring."

Standing in front of a huge experimental equipment, Director Zhao Zhanyou introduced it to Xiao Yi.

Xiao Yi couldn't help but marvel at the huge facility in front of him.

“It’s really big enough.”

Among the most expensive and largest experimental equipment in the world, particle accelerators may rank first, but the next second must be controlled nuclear fusion facilities.

The Eastern Super Ring in front of us is called the Fully Superconducting Tokamak Nuclear Fusion Experimental Device. It is the world's first fully superconducting non-circular cross-section nuclear fusion experimental device put into operation.

The main engine is 11 meters high, 8 meters in diameter and weighs about 400 tons.
Zhao Zhanyou said with a smile: "How is it? Do you like it?"

Xiao Yi raised his eyebrows: "I like it, of course I like it, but if I like it, can you give it to our Science Island Laboratory?"

Zhao Zhanyou burst into laughter and waved his hand: "No, that won't do. If I send it out, hundreds of people in our institute will probably scold me."

"But if the Science Island Laboratory wants a better tokamak than this one, we can definitely help."

Xiao Yi looked at Zhao Zhanyou with a half-smile and said, "As expected, I knew Director Zhao specially invited me to visit here, so he must have something to say."

Zhao Zhanyou was not embarrassed at all. He shrugged and said, "Well, Director Xiao, the high-temperature superconductor you developed has excited all of us in the institute. We have been discussing it for more than a month, and now I am here to see you."

Xiao Yi nodded. He had heard from President Bao Hexin that the Plasma Institute played a role in the smooth development of the Science Island Laboratory.

Of course, this is mainly due to the attraction brought by high-temperature superconductors.

Now it seems that the people at the Institute of Plasma Physics have not been disappointed.

However, after all, he had spoken for him in the beginning, so Xiao Yi said, "Then I'm all ears. What do you think, Director Zhao?"

Seeing that Xiao Yi did not refuse, Zhao Zhanyou chuckled, rubbed his hands, and said: "Hey, you see, our EAST is a device from many years ago, and it has not been upgraded much until now."

"Now that we have a high-temperature superconductor like HTSC-1, we thought maybe it's time to start over."

Xiao Yi couldn't help but laugh and said, "Then your stove is really big."

And it's a bit hot.

When it burns, the temperature will be over 100 million degrees.

If this is baked, it will be black and red in parts.

Zhao Zhanyou said helplessly: "There is nothing we can do. The things used in EAST are a bit outdated. For example, the superconducting coils use technology from a long time ago."

"I don't know if you've heard of this, but recently a company called Energy Singularity has come up with a tokamak called Honghuang 70. Damn, they made it with yttrium barium copper oxide, which makes us really jealous."

“I’ve heard of this.”

Xiao Yi nodded.

But at this time, Zhao Zhanyou said gloatingly: "But fortunately, you announced the completion of HTSC-1 when they had just completed the construction. I guess they were dumbfounded when they heard the news."

Looking at Zhao Zhanyou's expression, Xiao Yi couldn't help but laugh or cry.

Is this a colleague?

At this time, a voice came: "Okay, Zhan You, why do you have to gloat over other people's misfortunes? It's already good enough that they are willing to invest money in nuclear fusion research."

Hearing this voice, Zhao Zhanyou immediately stopped smiling, looked at the person who came, and said, "Academician Li."

Xiao Yi also turned and looked at the person who came.

Li Jiangan, an academician, is also a veteran of the Institute of Plasma Physics. EAST was built with the support of this veteran academician.

It was he who spoke for Xiao Yi at the meeting at HKUST.

"Hello, Professor Xiao, welcome to our Plasma Research Institute."

Li Jiangan walked up to Xiao Yi and shook hands with him.

"Hello, Academician Li." Xiao Yi nodded.
Li Jiangan nodded and said, "The plan Director Zhao told you about was also my suggestion. Let me tell you my thoughts in detail."

Xiao Yi smiled and said, "Of course."

……

(End of this chapter)