Scholar's Advanced Technological System - Chapter 153
Chapter 153: Beautiful And Deadly Tree
Lu Zhou replied, “Let me do it.”
The system did not specify who must do the experiment, only that he must collect the data. However, for the purpose of learning, Lu Zhou decided to do it himself.
After all, he had to have hands-on experience in order to become a legendary high tech master.
When Lu Zhou wore the white coat, he felt like a little scientist. He then took a deep breath before he reached for the sample box containing the experiment materials.
However, his hand was pushed away by Brother Qian.
“Let me do it, just watch.”
Brother Qian took the initiative for the experiment while Lu Zhou watched from aside.
Lu Zhou looked at Liu Bo who merely shrugged.
“Don’t take it to heart, he’s just like this. The equipment here is like his wife. It’s more important than his life… Just watch him do it.”
Brother Qian then said, “Doing experiments isn’t like mathematics, you can’t make any mistakes. Of course, I was afraid that you’ll break the equipment… Show me your experiment design.”
Lu Zhou took out the A4 paper and said, “It’s right here.”
The experimental steps and data required by the system were written on there.
Brother Qian brother took the A4 paper and nodded as he said, “The design is quite professional.”
Emm…
It’s designed by the system.
Lu Zhou did not say anything.
…
The experiment flow was simple. They should start with the battery and observe the phenomenon.
95.7% of graphite was used as the negative electrode material, and the binder was sodium carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR). The current collector was a copper foil. The graphite layer had a thickness of 90 μm, the positive electrode active material used LiFePO 4, and the current collector was aluminum foil.
As for the separator, a three-layer separator of Celgard 2325 was used, and the thickness was about 25 μm.
To prevent oxidation of the material, everything was done in an argon-filled glove box.
Of course, it was 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.
Even high school students knew about hydrofluoric acid.
The stuff was dangerous. If it got on someone’s hand, the hand would be destroyed beyond recognition.
Brother Qian did the experiment professionally.
Soon after, the sample was made.
In order to prevent the sample from being damaged, the side-to-side assembly method was used. Brother Qian completely covered the LiFePO4 material with a layer of the separator, and carefully left the free end of the positive and negative electrodes at a distance of 2 mm.
This step was crucial.
Brother Qian took out the sample and exhaled a long breath.
“Done.”
As Lu Zhou looked at the sample in Qian brother’s hand, he asked, “This is the battery?”
Brother Qian brother replied in a concise manner, “A simple and unsafe lithium-ion battery.”
Lu Zhou asked nervously, “Will it explode?”
Brother Qian shook his head, “It won’t explode, but it might ignite.”
A fire would cause big trouble.
Not only would the sample be destroyed, but the digital microscope would also be burned.
Lu Zhou guessed that this was one of the reasons why Brother Qian did not let him touch the equipment.
The sample was connected to the BK-6808 rechargeable battery tester and then placed on a digital microscope. Brother Qian set several parameters to the computer and said, “The data collection frequency is 1 Hz, and the battery is discharged to the cut-off voltage. Wait for it to be charged for 400 minutes… ”
Now, all they had to do was wait.
Lu Zhou looked at the instrument and asked, “Do we have to wait that long?”
400 minutes was almost seven hours.
Brother Qian pushed his glasses and said, “7 hours is the basic operation. Sometimes it takes days to see the results. Normally one person will stay in the lab. I’ll usually take turns with Liu Bo.”
Liu Bo replied, “That’s right, last year I watched more than 40 TV shows while waiting in the lab. Do you want me to recommend you some?”
Lu Zhou, “There’s… No need for that.”
He did not have time to watch TV shows.
After doing the necessary steps, Brother Qian briefly taught Lu Zhou about what to do in an emergency.
For example, what do to when the sample was smoking or smelled weird, how to clean the damaged sample, and most importantly how to protect himself.
No matter how expensive the equipment was, it was not as valuable as one’s own life.
Of course, the experiment was not that dangerous, so Brother Qian was confident to give Lu Zhou the key.
He still had some stuff to do with Liu Bo, so they could not stay here.
Lu Zhou sat next to the digital microscope and pulled out a quantum physics book. He would study quantum physics and occasionally looked at the digital microscope.
Later, he found out that he did not have to be so careful. The sample under the microscope did not change at all.
It seemed that Brother Qian’s experimental skills were quite reliable.
Lu Zhou stayed in the lab all day, and he even called delivery for lunch.
Finally, the time was up. The discharge time was over. Lu Zhou waited for 10 minutes and kept the circuit open before he cut off the power.
He was almost finished with the experiment when he suddenly heard footsteps outside the lab. Liu Bo had just eaten dinner at the cafeteria before he returned to the lab.
As Liu Bo looked at the sample, he asked, “Done?”
He then skillfully operated the computer and said, “Then let’s collect the data.”
The printer started to hum.
Soon after, Lu Zhou received 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 required him to collect.
Liu Bo started chatting to him.
“… Lithium is the most ideal anode material, but it’s also the most difficult to charge. When charging, the lithium ion that returns to the negative pole will never change to a flat lithium metal layer. Like a flower, it’ll form a beautiful and deadly tree.”
Lu Zhou looked at the printer and asked, “Is it fatal?”
“Yes, once this kind of dendritic thing is formed, it’ll continue to grow with constant charge. It’ll eventually puncture the diaphragm and contact the positive electrode like a fork.”
Liu Bo paused for a moment before he said in a joking manner, “Imagine if you connected the positive and negative poles of a battery, it would short circuit. Have you heard of the Moli company?”
“No… Why?”
Liu Bo shrugged and handed the printed A4 paper to Lu Zhou as he said, “Their products almost created history, but because of the use of lithium as the negative electrode, a major accident occurred. The NTT mobile phones were recalled. Finally, the company went bankrupt and was acquired. In contrast, Sony was very smart. They used graphite directly as a negative electrode, and the introduction of lithium-ion batteries quickly took over the market.”
Lu Zhou could not help but ask, “Did they not do a safety test?”
Liu Bo sighed and said, “Yeah, everyone asked that. But things are not that simple. Maybe they didn’t find any problems at all? Or maybe they thought they found a perfect solution? Who knows?”
