Great Country Academician

Ethylene carbonate, also known as ethylene carbonate, 1,3-dioxolane-2-one, 1,3-dioxolane ethylene carbonate.

Its chemical molecular formula is 'C3H4O3', which is a crystalline solid at room temperature, but becomes a transparent colorless liquid when the temperature exceeds 35°C. It is an organic solvent with excellent performance, which can dissolve many kinds of polymers. Used in fertilizer, fiber, pharmaceutical and organic synthesis industries.

As a material researcher, Xu Chuan has some knowledge about the compound ethylene carbonate, but not much.

After all, his materials research in his previous life mainly focused on physical materials, while ethylene carbonate belongs to the category of chemical materials.

However, it is not difficult for him to understand the properties of a material and find another additive that can control it.

All things generate and restrain each other, and so do materials.

Different materials have different chemical and physical properties. The blending between molecules, looking for order in disorder, looking for simplicity and beauty in complexity, or destruction, or new life.

For example, the amorphous alloy material looks extremely hard, but it has no absolute order. In the never-ending flow, it is like Van Gogh's "Starry Night". If you look carefully, it seems to be forever in motion. move.

This is the charm of material science.

"Ethylene carbonate: the molecular formula is C3H4O3, the molar refractive index in the molecular structure is 17.17, the surface tension is 37.3, the dipole moment is 10-cm3, and the polarizability is 6.80"

"Number of hydrogen bond donors: 0, number of hydrogen bond acceptors: 3, number of rotatable chemical bonds: 0, number of tautomers: none, topological molecule polar surface area 35.5, number of covalent bond units: 1"

"Miscible with hot water above 40°C, alcohol, benzene, chloroform, ethyl acetate, acetic acid, etc. Insoluble in dry ether, carbon disulfide, carbon tetrachloride, petroleum ether, etc."

In the laboratory, Xu Chuan listed all the information about ethylene carbonate bit by bit.

Whether it is its chemical and physical properties, or various previous studies.

These things are of great help in finding materials to control ethylene carbonate.

In fact, to find a material to control ethylene carbonate, he can ask other chemical researchers for help.

For those chemical materials researchers who have been immersed in this field for many years, it is not too difficult to find several materials that meet the requirements.

But Xu Chuan has another idea. He wants to try it out to see if mathematics can be integrated into material science calculations.

Just as others speculate that his development of anti-radiation materials and lithium battery materials relies on strong mathematical ability.

Only he himself knows it's not.

Today, what Xu Chuan wants to do is to take this step and use mathematics to help him complete this task.

For a chemical reaction, it is the transformation of chemical formulas line by line in the textbook, and the breaking of old chemical bonds and the formation of new chemical bonds in the laboratory.

For example, the essence of redox reaction is the gain and loss of electrons outside the nucleus, and the structure of the atom itself changes.

The essence of the metathesis reaction is atomic rearrangement, that is, the arrangement and combination of multiple atoms changes.

But in fact, its deeper essence is the flow of electron clouds.

To judge whether a chemical reaction can occur, it must be confirmed from various aspects such as thermodynamics, kinetics, enthalpy change, entropy change, free energy (Gibbs free energy), and activation energy.

In fact, strictly speaking, the current development of chemistry is not perfect.

Because we often cannot even explain the simplest chemical reactions clearly with theories, many theories are phenomenological.

If we go back along the chemical explanation chain, we will eventually return to the explanation of physics.

Therefore physics is the most basic subject in the natural sciences (mathematics is not a natural subject!).

Many people mistakenly think that chemistry is the most basic, because the chemical bond is essentially an electrical interaction, which belongs to the electromagnetic interaction among the four fundamental forces. The progress of chemical reactions is also related to the movement and collision of molecules.

Of course, the potential of chemistry is very deep, and it is of great value to dig deeper.

And if we look at the deep nature of chemistry, there is no doubt that mathematics can be applied.

For example, the rate of the most common chemical reactions can be described by calculus equations. Mathematical equations can be solved using numerical methods to determine reaction rate constants and other parameters.

For example, wave function theory, group theory, etc. are used to describe electronic structures and reaction mechanisms.

Or molecular dynamics simulation, which uses a kind of computer mathematics to simulate and study the laws of material motion. It involves a lot of knowledge in calculus, probability statistics, and optimization algorithms.

In addition, there are thermodynamics, analytical chemistry and other aspects, which can be done through mathematics.

Theoretically speaking, if the relevant information and conditions of the materials required for the chemical reaction are known, it is completely possible to simulate the whole process of the entire reaction through mathematics.

It sounds incredible, but it works in theory.

Of course, in practice this is an impossible thing, at least not for now.

And what Xu Chuan wanted to do was to take the first step towards this impossible thing.

Ethylene carbonate is a good test target.

"Considering the polymer solvent and positive and negative electrode materials used in the electrolyte, there are not many options for additives to control ethylene carbonate."

"Most of the alkali compounds and alcohol compounds can basically be eliminated. These compounds will react with ethylene carbonate to generate various substances harmful to the battery. Not to mention the corrosion of the positive and negative electrodes, they cannot be recycled."

"Then there are not many options left, and some materials such as ketones, fluorides, and rings can be considered."

"After screening based on the reversibility conditions, the ketone compound with a carbonyl group connected to two hydrocarbon groups is a good choice."

"However, the range of ketones is still too large and needs to be narrowed."

In the laboratory, Xu Chuan muttered to himself non-stop, and the ballpoint pen in his hand was also constantly recording item by item data on the A4 manuscript paper.

He is doing a rough screening of available additives based on some basic chemical reactions, and then simulates and selects them through mathematics.

This is a very challenging road. Although it is not untrodden, it is not deep; the path that can see the end is full of thorns in the unknown fog, and one needs to muster up the courage to move forward.

Fortunately, he has never lacked the courage to explore and face difficulties.

In the laboratory, Xu Chuan is constantly improving his theory and data.

On the other hand, tests for new artificial SEI films and ethylene carbonate content are also in progress.

Five or six days passed in the blink of an eye.

While Xu Chuan was still looking for suitable materials, the tests at the Chuanhai Materials Laboratory had basically been completed.

"Director Fan, this is the experiment and test data of these days. Judging from the experiments these days, it is most appropriate to reduce the content of ethylene carbonate to about 67.3% of the original basis without changing other materials and additives. a number of

In the laboratory, Yu Zhen, the official researcher who was originally in charge of the research on artificial SEI thin films, handed over a thick plate of report materials.

Fan Pengyue nodded and reached out to take it: "Thank you for your hard work."

Yu Zhen shook his head and replied, "I am ashamed to say that we have not played any role in the research and development of lithium battery materials this time."

"From the very beginning of the theoretical and experimental process, to the solution of the artificial SEI thin film problem, and the discovery of ethylene carbonate interference with lithium dendrites and the discovery of lithium separation, everything is done by the boss."

"We just conducted the experiment according to his requirements. This kind of experiment can be done by any master student who has done lithium battery experiment."

Hearing this, Fan Pengyue also sighed.

"He is indeed perverted. At the age of 21, he won the highest honors in the mathematics and physics worlds at the same time. This is no longer a person in the same world as us."

"I believe that no matter which industry field he is in, he can show the most terrifying ability."

After a pause, Fan Pengyue continued: "You know what? When I was still a Ph.D. student, I followed my mentor to do a tungsten diselenide material project. I encountered a problem and almost made my mentor give up that project."

"The younger junior student not only helped to solve this problem, but also used mathematics to discover the root cause of the problem and find a solution."

"And the results of that project are worth billions of dollars!"

"More importantly, he was still in his freshman year at the time."

Hearing this, Yu Zhen gasped.

He knew who Fan Pengyue's mentor was.

After all, several months have passed, and the usual chats and conversations are enough for everyone to get to know each other.

Not only their boss, but the airborne executive in front of him is actually not bad. A disciple of an academician of the Academy of Sciences, this interpersonal relationship and status are not comparable to those of them.

And the project that even an academician almost gave up, must have encountered fatal problems.

Although I know that the Nobel Prize winners and Fields Medal winners are not from the same world as them, but when I was a freshman, I was able to participate in a project worth billions of dollars and solve fatal problems.

This talent is indescribable.

But looking back, Yu Zhen suddenly felt reasonable again.

If it weren't for such a monstrosity, how could he solve problems that even academicians could not solve, and win the Nobel Prize and Fields Medal at the age of 21? These are the two most authoritative awards in academia.

Although shocked, this mathematical ability also made Yu Zhen a little curious.

He couldn't help asking: "You said, is it really that good if you are good at mathematics? Can materials, a field of mathematics that is difficult to apply, be solved through mathematics?"

Hearing this question, Fan Pengyue was silent for a while, and after thinking for a while, he replied in confusion: "I don't know. Maybe it is for him?"

After a pause, he added cautiously: "However, I have never seen this level of application of mathematics in other mathematics professors."

"Maybe he's special."

On the other side, in the office, Xu Chuan was prostrate at the desk, writing with the ballpoint pen in his hand.

".EC, (c) DEC, (d) DMC, (e) EMC, (f) EC/DEC = 1/1, (g) EC/DMC = 1/1, .(j) ECO/EMC = 1 /2."

"."

Staring at the data on the manuscript paper, Xu Chuan fell into deep thought.

"From the data point of view, methyl ethyl ketone is a good choice. According to the chemical properties, it can play a certain role in inhibiting ethylene carbonate."

"As we all know, the reason why ethylene carbonate plays a great role in promoting lithium-ion batteries is that it can form a tightly ordered Li+-EC solvation configuration with Li+ through solvation, so that the electrolyte containing EC It is more stable during cycling."

"Since the 'Li+-ethylene carbonate solvent' configuration is more stable than other solvated lithium ions, such as ethyl methyl carbonate and other materials, the 'Li+-ethylene carbonate solvent' is added to the electrolyte After adding components, the cycle performance and voltage polarization of the battery can be significantly improved."

"This not only improves the stability of the electrolyte, but at the same time, the reduction product of ethylene carbonate helps to form a stable solid electrolyte interfacial film, making the electrolyte more stable during the cycle."

"And methyl ethyl ketone can be inside, through the lithium ion deposition/extraction behavior, thus weakening the lithium precipitation phenomenon of the negative electrode to a certain extent."

"As for the specific situation, experiments are still needed. After all, there must be some differences between the calculated data and the actual application."

Thinking about it, Xu Chuan shook his head again, looked at the manuscript paper on the table and let out a long sigh of relief.

These days, he let go of other projects and concentrated on researching this problem. In terms of progress, there is indeed some progress, but not much.

Up to now, he has only found out one possible suitable material.

He underestimated all kinds of joint phenomena that may occur in chemical reactions. These things can be calculated to exhaust a person.

"Maybe, I should come up with a mathematical model?"

In his mind, Xu Chuan turned his thoughts to another side.

Although a mathematical model cannot accurately predict the properties of untested material samples and possible chemical joint phenomena, it can provide certain references for users.

For example, narrowing the scope of the experiment in the sense of probability or something.

A long time ago, when he was still a freshman, he made a mathematical model for his mentor Chen Zhengping on a tungsten diselenide material project, and quickly helped to find the problems in the experimental process and locked the best reducing substance concentration.

It can be said that in the process of material research and development, a mathematical model still plays a very important role.

It's just that he doesn't have that much time to do this right now.

It should be possible to make a mathematical model for the research of chemical materials, but in terms of difficulty, it is definitely much more difficult than the one he made for his mentor Chen Zhengping before.

It can even be said that it is one day and one place.

After all, the tungsten diselenide material project is only aimed at one material, even if there are conditions such as reducing agent, temperature, and air pressure, it is not very complicated.

But chemistry is different. The complexity of this kind of mathematical model for the exploration of chemical materials has simply broken through the sky.

Even if he brings a team of more than a dozen people to write, it may take several months.

Of course, if successful, it will bring great convenience to his future chemical experiments.