Chapter 249: Even More Like a Cheater
Xu Qingzhou stayed in the laboratory for an hour. After all the samples entered the long charge and discharge test, he left the laboratory and went to the next room to concentrate on his own task.
Although there is a lot of data, Gong Yunfei has already pre-processed it, so he doesn't need to screen the data first like before.
After thinking for a moment, Xu Qingzhou decided to figure out the electrochemical model first.
Of course, since the working principle of the battery involves electrochemical reactions, this topic also involves chemical materials, but the core purpose of the experiment is to use physical means.
For example, electrical testing, thermal analysis, material structure characterization, etc., to study and improve the thermal stability and energy density of lithium-ion batteries.
He has a little knowledge of chemistry, but he can't say he is an expert at it, but he is okay at making models.
First, the solid-phase diffusion equation that describes the process of lithium ion diffusion inside the electrode active material particles is used.
Xu Qingzhou took out the manuscript paper and wrote down the formulas he would use.
【\frac{\partial c_s}{\parti c_s}{\partial r}\right)】
There are also liquid phase diffusion equations, solid phase potential equations, liquid phase potential equations, and electrochemical reaction equations.
The above are the key formulas in the electrochemical model.
In addition to this, it also involves specific formulas for activation polarization overpotential, such as using the Butler-Volmer equation to describe the electrochemical reaction rate on the electrode surface.
Of course, the entire model cannot be completed by simply piecing together a few equations. If it were that simple, Professor Zhao would not have come to him specifically.
These equations are equivalent to the main frame of the building, as well as roofing projects, interior wall painting, etc. Only when all of these are completed can we have a complete building that can be used.
Moreover, in actual experiments, due to the influence of factors such as the complexity and non-uniformity of the internal structure of the battery, these formulas need to be appropriately corrected and adjusted in most cases.
Just talking about the diffusion coefficient, the theoretical diffusion coefficient may not be able to fully reflect the actual diffusion behavior of the material. This requires fitting the experimental data to obtain the effective diffusion coefficient under different conditions and input it into the model.
"Whoo~"
Xu Qingzhou exhaled slowly and clicked on the data chart.
Maximum capacity 4000mAh/g 100μA 16 cycles. Charge and discharge efficiency 92%.
At 4: in the afternoon, the printer next door began to hum, and data charts and diagrams of the internal structure of the battery spit out of the printer.
Wang Wei and Hong Yayu walked out of the laboratory and checked the material structure characterization diagram of the battery in front of the printer.
Xu Qingzhou also put down the calculations at hand and followed Wang Wei and the others to look at the situation of sample No. 138.
Wang Wei pointed to the tree-like scattered shadows in the picture and explained to Xu Qingzhou: "This is lithium dendrites, one of the key factors affecting battery life and safety. Currently, there is no effective way to completely prevent the growth of lithium dendrites."
"However, our current samples have reduced lithium dendrites by 70 percent compared to the original samples."
Xu Qingzhou nodded and said, "But the current growth situation still cannot meet the quality requirements of batteries."
"Yes, that's one of the reasons why we asked you for help. As you said last time, data don't lie. Therefore, we hope to find experimental loopholes in the data and how to control the variables to inhibit the growth of lithium dendrites."
Lithium dendrites. This stuff is pretty challenging.
Xu Qingzhou really wanted to give it a try, but gave up after careful consideration. His main task now was to solve the Polignac conjecture and improve his mathematics level.
Or occasionally participate in experiments in other fields of physics like this, get in touch with new things, and lay the foundation for becoming a pentagon warrior.
Wang Wei sorted out the drawings and said, "Let's go. After we finish the last set of experiments, we can go home from get off work."
"Ah."
Hong Yayu nodded expressionlessly.
At 5 pm, Xu Qingzhou did not stay in the laboratory. He packed up and went to meet Song Yao. Wang Wei and the others wanted to make a concerted effort to finish the experiment today and enjoy the Dragon Boat Festival holiday tomorrow.
The most comfortable thing was the first night before the holiday. Xu Qingzhou and Song Yao also planned to have a sense of ceremony, not eating in the cafeteria, and agreed to go out together to buy some vegetables, some bacon, four dishes and one soup.
After cooking and eating, the two of them sat on the sofa watching TV. In the evening, they called to ask Lao Xu and Lao Song if the rice dumplings they bought for them had arrived.
Friday passed like this.
Saturday.
Xu Qingzhou originally wanted to sleep in, but he couldn't fall asleep after 9 o'clock, so he simply got up with a laugh. As soon as he opened the curtains, the bright sunlight shone through the glass onto his body.
The weather is very good. It is already June. When we enter July, it will be the hottest summer.
Schoolgirl Song also looked like she had just woken up, with a few strands of hair still wet on her forehead. Seeing that she seemed to be planning to go out, Xu Qingzhou asked, "Are you going to buy breakfast?"
"Ah."
"Wait for me, let's go eat outside."
Xu Qingzhou ran to the bathroom to wash up, washed his face and brushed his teeth, and was done in no time.
At 9:, the sun was hanging brightly in the sky, but without the scorching heat of midday. It shone through the leaves on both sides of the road and onto the ground, casting a mottled halo of light.
Xu Qingzhou and Song Yao held hands and walked out slowly. It was different from their usual trip to the library or class, as there was a more leisurely atmosphere.
"This is what life is all about." Xu Qingzhou sighed again and pinched Song Yao's soft little hand. Even though he could touch her legs now, he still liked her hand very much.
He was like that. He used to think he was obsessed with faces, then he thought he was obsessed with legs, and then he suspected he was obsessed with hands. It was not until today that he realized that he was not obsessed with anything and was just simply lustful.
Song Yao glanced at the person next to her. This guy couldn't even walk properly, so she pinched him back.
Xu Qingzhou fought back unconvinced, and Song Yao pinched him back, and the two of them kept pinching each other like this.
This childish fight drew contemptuous looks from the single guys nearby.
Haha, stinky couple.
After coming back from breakfast, the two of them cleaned up first.
According to Xu Qingzhou's previous habit, whenever his friends came over, it would be a general cleaning day. Now that School Beauty Song is here, he cleans much more diligently, but he still picks up a lot of garbage.
After cleaning, the two useless people who wanted to rest all day just curled up on the sofa to take a rest.
Song Yao leaned on the sofa with her legs resting on Xu Qingzhou's thighs, chatting with her younger sister Ding Jiahui, talking about the route to Yandong Garden and what they planned to eat in the evening.
Xu Qingzhou was pinching his leg while checking messages on his phone, only to find out that a big event had happened in the mathematics community during this period, or rather, a competitor of his, a competitor for the Fields Medal, had emerged.
Young mathematician Jonathan Birmingham.
Wow, only 23 years old.
Some time ago, it was announced that the exponential ergodicity of solutions under 1-Wasserstein distance was proved, and a criterion for the exponential ergodicity of Markov semigroups on Banach space under 1-Wasserstein distance was proposed.
In addition, he also founded the theory of regularity structures, which is a generalization of the rough orbit theory of stochastic differential equations, involving modern mathematical theories such as model theory, Hopf algebra, partial differential equations, stochastic analysis, and nonlinear operations of generalized functions.
He has won many international awards including the London Mathematical Society Whitehead Prize, the Philip Leverhulme Prize, and the Froehlich Prize.
He is now a hot candidate for the 18th Fields Medal.
After reading this person's resume, Xu Qingzhou was amazed. It must be said that this person seemed to be even more cheating than him.
The battle between the cheaters.
(End of this chapter)
