Chapter 114： you have to believe in science

As soon as Chen Xiao spoke, everyone was startled, and then his eyes swept over.

"Who are you?" Luo Hao asked.

I'm a freshman, isn't that obvious?

Wearing a camouflage uniform, his face is immature, and at first glance, he looks like a freshman.

Chen Xiao said, "Are you experimenting with lithium batteries?"

Luo Hao said impatiently, "This is the material chemistry laboratory, the freshmen hurry out."

Chen Xiao didn't mind then and said, "If you want to increase the energy density of lithium batteries, there are two ways, one is to change the materials of the positive and negative electrodes, and the other is to optimize the packaging of the battery."

"Are you making lithium cobalt oxide batteries? To the specifications of Sony's 18650 battery?"

The 18650 lithium battery is not a lithium battery of a certain material, but the package size specification of the lithium battery formulated by Sony, 18 is 18mm in diameter, 650 is 65.0mm in height, and 0 is a cylindrical battery.

Everyone originally thought that Chen Xiao was just a freshman who came to watch the fun, but they didn't expect that Chen Xiao could still tell some knowledge about lithium batteries.

Gao Miao asked, "Are you a freshman in the School of Material Chemistry?"

Just when he asked this question, Gao Miao felt something was wrong.

Even if Chen Xiao is a senior student majoring in material and chemical engineering, he should not know too much about lithium batteries, because freshman students generally study basic subjects such as advanced mathematics, physics, and chemistry, and will not be deeply involved in professional knowledge. .

Gao Miao's mood is very depressed now, and her mood is also very low.

Liu Hao's plan was to quickly close the laboratory and then accompany Gao Miao back to the dormitory.

Girls have the lowest defense ability when they are in a bad mood.

Liu Hao wondered if he could hold hands or kiss him when he sent Gao Miao back.

As soon as Chen Xiao came, he talked for a long time, and there must be no more drama.

Chen Xiao said: "I am a freshman, majoring in finance, but I still have some small research on lithium batteries, see if I can discuss it with my brothers and sisters."

After hearing this, the original atmosphere was tense and the graduate students laughed.

Freshman year, or finance major?

Now looking for a graduate student to discuss a graduate thesis?

Liu Hao felt that it was not that he heard it wrong, but that there was something wrong with Chen Xiao's brain.

Liu Hao walked over and said, "This is a laboratory, a postgraduate laboratory. Students without permission are not allowed to enter. Freshman students hurriedly go to the dormitory to sleep and make fun of it."

Liu Hao turned around again and said to Gao Miao and the others, "Okay, everything has been made clear. If you want to quit, quit, and if you don't want to quit, quickly pack up and continue the experiment at nine o'clock tomorrow morning."

Liu Hao said to Gao Miao, "I'll take you back."

Gao Miao glanced at Chen Xiao, and regarded Chen Xiao as a freshman who came to watch the excitement. He never thought about discussing any issues with Chen Xiao.

Chen Xiao smiled helplessly and was speechless. He took the experiment notebook on the table and said, "Currently you are experimenting with lithium cobalt oxide batteries."

"Under the same volume, the energy density of lithium cobalt oxide batteries is indeed high, but its own high temperature resistance is not good, and the safety factor is low! It is easy to BOOM."

"I have browsed your experimental records, and you have blindly changed the stabilizer mix ratio of the positive electrode (negative) of the battery. IMHO, this did not find the key to the problem."

Chen Xiao put down his notebook and said, "You guys are producing according to Sony's 18650 structure. If the external voltage of the 18650 structure battery is lower than 2.7V or higher than 3.3V, symptoms of overheating will occur. If the temperature gradient in the battery is not well controlled, it will cause symptoms of overheating. There is a great risk of fire, and the key to battery technology is voltage current and thermal control…”

"The theoretical density of lithium cobalt oxide is 5.1g/cm3, but due to technical reasons, for battery safety and to prevent battery explosion, we can actually achieve a maximum of 2.0-2.4g/cm3, which is actually not that high. ."

"In addition, the electrothermal peak value of lithium cobalt oxide is around 200, which is much lower than that of other cathode material lithium batteries. Although this kind of battery has high power, high energy density, and high consistency, it has a low safety factor and a high thermal conductivity. Poor characteristics and electrical characteristics…”

Chen Xiao said a lot in one breath, and finally said: "Now, do you know the reason why the batteries you practice have BooM? You must believe in science!"

[Influence +5]

[Influence +3]

[Influence +1]

[Influence +0.01]

…

Chen Xiao received 5 points of influence from Gao Miao, but only 0.01 points of influence from Liu Hao.

Why is there such a big gap?

There is only one reason to explain.

Gao Miao is a scholar who knows his own experiments and papers very well, so he will contribute a wave of influence.

And Liu Hao was just a scumbag who came to make soy sauce. Although he was a graduate student, he didn't know much about his field of study. After Chen Xiao finished speaking, he was confused and didn't know what Chen Xiao was talking about.

Liu Hao opened his mouth and said, "You are talking nonsense! You don't understand."

But Gao Miao knew that what Chen Xiao said was all about dry points is very important knowledge, and the data that was blurted out was something that Gao Miao couldn't find!

Gao Miao didn't believe that Chen Xiao was just a graduate student majoring in finance. She hurriedly asked, "What do you mean, there is something wrong with our cathode material mix ratio?"

Chen Xiao smiled and said, "It's all 16850 batteries. You only know the size of the battery, but you don't know what's inside the battery, how it's packaged, and what kind of separator is used."

"It's not just the positive and negative materials that have problems, but also the packaging."

Chen Xiao said, "I just saw your negative electrode material. It is to apply carbon powder on the copper foil. There is no problem at all, but why use ordinary carbon powder?"

Gao Miao has now completely become a seeker of knowledge, with a longing expression on his face, his big eyes flickering at Chen Xiao, very cute.

Chen Xiao coughed twice, it was hard to imagine that Gao Miao was actually a third-year student. Even if she was 18 years old, she was 24 years old and she was 6 years older than Chen Xiao. Someone believes.

Gao Miao was a little disappointed and said: "There are problems with the positive and negative materials, and there are problems with the packaging..."

Their team has worked hard for about half a year, but they didn't expect to be full of loopholes in the eyes of others.

Although Gao Miao's mentor is guiding the experiment, lithium battery is a frontier subject in the world, and the technology is in the hands of Oriental people. Even Gao Miao's mentor can help Gao Miao find some information at most, and there are not many places to help.

The instructor even asked Gao Miao to change a topic, such as the impact of the environment on the materials of lithium batteries, etc., which is much less difficult.

Gao Miao suddenly said in a somewhat embarrassed and soft voice, "You... can you help me?"