Scholar’s Advanced Technological System

Lu Zhou replied: "I am coming."

The system does not specify who must do the experiment, just do the experiment and collect the data that needs to be collected. However, for the purpose of learning, Lu Zhou still wants to do it himself.

After all, the end of the paper is shallow, and the book is handed to him is a theory, only the implementation of the hand, can turn the legendary black technology into a real guy.

Very ceremonially replaced with a white coat, Lu Zhou took out a little scientist's momentum, took a deep breath and reached for the sample box containing the experimental materials.

However, his hand had not been touched, and he was taken over by the money-stricken brother.

"I still come, look at it."

Apart from anything else, the money brother took over the initiative of the experiment and left the sturdy land boat to the side.

Looking at Liu’s brother, Liu’s brother, holding his arms, shrugged his shoulders.

"Don't mind, the old money is like this. The instrument here is like his wife, it is more important than his life... The first time you still watch him do it again."

Qian Shixiong did not return, and then said: "Doing experiments is not about mathematics. If you make a mistake, you can change the decimal point and change it. The experiment is wrong with a small detail, which may cause the whole experiment to be abolished. Of course, I am more afraid. You have to abolish the experimental equipment... Show me the experimental flow of your design."

"Here." Lu Zhou quickly took out the a4 paper.

The experimental steps required by the system and the experimental data that needs to be collected are written on it.

Qian Shixi took a glance at the a4 paper and nodded: "The design is quite professional."

Emmm...

After all, it is system design.

Lu Zhou had a subtle expression and did not speak.

......

The flow of the experiment is very simple, starting with the battery and observing the phenomenon.

95.7% of graphite was used as a negative electrode material, and the binder was sodium carboxymethylcellulose (cmc) and styrene-butadiene rubber (sbr), and the current collector was copper foil. The thickness of the graphite layer is 90 m, the positive active material is lifepo4, and the current collector is aluminum foil.

As for the diaphragm, a three-layer diaphragm of celgard 2325 is used, and the thickness is about 25 m.

To prevent oxidation of the material, everything is done in an argon-filled glove box.

Of course, not only to prevent oxidation of the material, but also to prevent the lipf6 component in the electrolyte from reacting with water in the air to form hydrofluoric acid.

Hydrofluoric acid is known to anyone who has studied high school chemistry.

And how dangerous this thing is, people who have been in the silicon-based microelectronics lab should be very clear. Which hand is used to wipe a little, this hand basically can't see anyone.

Judging from the operation process of Qian’s brother, it is obviously more professional than Lu Zhou’s theorist.

Soon, the sample was made.

In order to prevent the sample from being damaged, the side-to-side assembly method is used. Brother Qian completely covered the lifepo4 material with a layer of diaphragm in the glove box, and carefully left the free ends of the positive and negative electrodes at a distance of 2 mm.

This step is critical and is about the safety of the experiment.

The sample was taken out of the glove box, and the money brother closed the valves and gave a breath.

"Get it done."

Looking at the sample in the hands of Qian’s brother, Lu Zhou asked: "Is this a battery?"

“A simple and unsafe lithium-ion battery,” Qian’s brother said in a concise manner.

Lu Zhou was nervous: "Can it explode?"

Qian Shixiong shook his head: "The explosion will not happen, but improper operation may lead to fire."

Moreover, it is a fire on a digital microscope.

It’s a trivial matter to burn out the sample. It’s too much trouble to bake the lens of the digital microscope.

Lu Zhou estimates that this is one of the reasons why Qian’s brother does not let his newbie touch the experiment.

The sample was connected to the bk-6808 rechargeable battery tester, and then placed on a digital microscope. Qian Shixiong set several parameters to the computer, and said to himself whispering the steps on the paper: "2min The image is collected once, the data data collection frequency is 1hz, and the battery is discharged to the cut-off voltage after the first charge to 400min...ok."

The rest is a long wait.

Looking at the instrument that has not changed, Lu Zhou couldn't help but ask: "Do you have to wait for this battery material test for so long?"

For four hundred minutes, it was almost seven hours.

Qian Shixiong pushed the glasses and said: "Seven hours is the basic operation. Sometimes it takes a few days to see the results. Under normal circumstances, individuals will be on duty in the laboratory. Basically, I and Liu Bo take turns. ”

“Yes,” Liu Bo said with a smile. “I brushed more than forty dramas last year, which was brushed when I was on duty in the lab. Would you like me to recommend it to you?”

Lu Zhou: "This is still not needed."

Even if it is recommended, he probably has no time to look at it.

After all the operations that need to be done are done, Qian Shixiong simply taught Lu Zhou some methods to deal with emergencies.

For example, see the sample smoke, smell the wrong smell, how to clean the damaged sample, how to protect the instrument, and how to protect yourself.

No matter how expensive the instrument is, it is not as important as people.

Of course, this experiment is not so dangerous, so the money brother is very confident to throw the key to Lu Zhou.

He and Mr. Liu have something to do, it is impossible to stay here all the time, and Lu Zhou is also embarrassed to trouble people. After all, doing this experiment has delayed them for quite some time.

Taking out the book of quantum chromodynamics, Lu Zhou sat next to the digital microscope, and on the other hand, he used the knowledge of theoretical physics to squint the situation on the digital microscope from time to time.

Later, he found that he didn't have to be so careful at all. The sample stayed under the microscope for so long, and there seemed to be no change at all.

It can be seen that the skill of Qian’s brother to do the experiment is still quite reliable.

Starting from 10:00 in the morning, I stayed at the laboratory for six o'clock in the evening. During the period, Lu Zhou also called a takeaway and ate lunch.

Finally, the set time is up, the charge and discharge is over, Lu Zhou, according to Qian Shixiong, waited for 10 minutes while keeping the open circuit, and then cut off the power.

Almost after he had finished the finishing work, there was a footstep outside the lab. Mr. Liu, who had just had dinner in the cafeteria, almost stepped into the lab.

“Get it?” Looking at the sample, Mr. Liu skillfully operated the computer and clicked the button to print. “Then collect the data.”

The printer rang.

Soon, Lu Zhou got what he wanted.

A set of pictures showing the growth of lithium dendrites under microscopic conditions, as well as graphs such as cyclic voltage curves that the system requires to collect, and so on.

While collecting these data, Liu brother said in a chattering tone.

"...Lithium is the most ideal anode material, but it is also the most difficult to serve. When charging, the lithium ion that returns to the negative pole will never change to a flat lithium metal layer as you wish. Like a flower, it will form a beautiful and deadly tree."

Waiting for the printer to print the chart, Lu Zhou asked casually: "Fatal?"

"Yes, once this kind of dendritic thing is formed, it will continue to grow with constant charging, and will eventually puncture the diaphragm and contact the positive electrode like a fork."

Speaking of this, Master Liu paused and said in a joking tone: "Imagine if you use a wire with the positive and negative poles of the battery. Yes, it is a short circuit. The organic electrolyte is easy. Burning things, have you heard of moli company?"

"no, what happened?"

Liu Shixi shrugged and handed the printed a4 paper to Lu Zhou’s hand. “Their products almost created history, but because of the use of lithium as the negative electrode, a major safety accident occurred, resulting in a ntt mobile phone. Was recalled, and finally the company went bankrupt and was acquired. In contrast, Sony was very smart, using graphite directly as a negative electrode, and the introduction of lithium-ion batteries quickly occupied the market."

Lu Zhou couldn't help but ask: "Did they not do a safety test?"

Liu Shixiong sighed: "Yeah, it is personally asked, but things may not be so simple. Maybe they have not found any problems at all? Maybe they think they have found the perfect solution? Who knows? Sometimes The reality is such a magic."