Although Shang Yiyun is interested in hydrogen power generation, he also knows in his heart that researching this kind of thing requires strong strength as a backing, and he is now lacking this condition.

Therefore, he attaches great importance to the establishment and development of the company, but the time has not yet come, even if he is in a hurry, it is useless.

At this time, Shang Yiyun was thinking about some things in his mind, and when his thoughts returned to reality, he found that he was still standing on the rostrum.

Faced with this situation, his face also showed embarrassment, and he walked directly off the rostrum.

At this time, there were bursts of applause from the rostrum, and the expressions on the faces of the professors and students of Kyoto University and Huaqing University were very serious.

However, they did not forget to give Shang Yiyun a round of applause, and the speech just now made them gain something.

Shang Yiyun doesn't care about other people's opinions, he believes that as long as he can make achievements, he is better than anything else.

He wasn't the last person to speak, and there were a few people who gave speeches after him, but compared to him, it was somewhat ordinary.

At this moment, the professor sitting in the first row under the rostrum also commented on the previous speech, on the whole, the speeches of the students of the two schools were very exciting, so the strength was also half a catty, but the existence of Shang Yiyun was equivalent to overwhelming the balance and tilting the weight towards Kyoto University.

"Hmph, you are better this time, but there is a powerful student from our Huaqing University who did not come here, if she can come, it is difficult to say whether she will win or lose. ”

As the professors and students of Huaqing University were about to leave, one of the professors said, a little unconvinced.

In this case, the professor of Kyoto University directly chose to ignore it, and no matter what, it was enough that the final winner of this exchange meeting between the two schools was Kyoto University.

Now that the exchange meeting was over, Shang Yiyun felt that there was no need to stay here, so he left quietly, quietly, as if he had never appeared.

When he walked out of the library, he found that it was already five o'clock in the afternoon, and it seemed feasible to go to Huaguo Normal University, but he had looked at the other party's class schedule before and found that there was a class tonight, so he dispelled this idea.

As for devoting himself to research, he had already decided to take a two-day break, and now it is a little inappropriate to temporarily let Cao Xun and Zhang Liu go to the laboratory.

After thinking about it, he finally decided to go back to the dormitory, and after returning to the dormitory, he could turn on the computer to play games and watch movies.

Thinking of this, Shang Yiyun had something to do in his heart, so after walking out of the school library, he sped up his pace, and the journey that originally took ten minutes was reduced to eight minutes.

It was just five o'clock before school ended, and when he returned to the dormitory, he found that there were not many students in and out.

When he returned to the dormitory, he found that his roommate was not in the dormitory, and Shang Yiyun had expected this situation, and he had classes in the afternoon, but in order to participate in the exchange meeting between Kyoto University and Huaqing University, he went to the counselor to ask for leave.

It's only five o'clock, and it's not yet time for school to end, so it's not surprising that his roommate isn't in the dorm.

After figuring out the matter, Shang Yiyun didn't continue to pay attention to this kind of thing, but turned on the computer and started watching movies.

He used to watch those more famous science fiction movies, so now he is aiming at comedy movies, after all, watching movies is to relax, and watching these comedy movies is conducive to relaxing the body and mind.

In the next two days, nothing special happened, I got up, exercised, went to the classroom, ate and went back to the dormitory, went to the classroom again, and finally went back to the dormitory to rest, and the day went by.

It was monotonous and boring, but the thought of starting the research again tomorrow made Shang Yiyun happy in his heart.

Two days of rest was enough, and he was feeling over-energetic and in dire need of something to do.

Before tomorrow arrived, Shang Yiyun contacted Cao Xun and Zhang Liu respectively, explained the situation, and asked the two to arrive at the laboratory on time tomorrow.

Of course, he didn't forget to ask the two of them if they had carefully read the experimental plan for the two of them before, if people understood the knowledge, I believe that tomorrow's experimental process will be simpler.

For this question, Cao Xun and Zhang Liu's answers are very consistent, as for whether they are lying, we will be able to know tomorrow.

Shang Yiyun called Zhang Liu first, and finally Cao Xun.

After saying the matter, he said to Cao Xun. "Okay, there's nothing going on now, as long as you remember to go to the lab tomorrow, and if you're okay, hang up. ”

After saying this, Shang Yiyun waited for the other party's reply, and hung up the phone when he heard that there was nothing to tell him.

Sleep beautifully tonight, and you can continue to study graphene batteries tomorrow.

It's already June, and the temperature is getting muggy, so it's a little hard to sleep, so I toss and turn before falling asleep.

I woke up early the next morning, got dressed, climbed out of bed, and started washing and brushing my teeth.

Because today is Saturday, there are no classes for the whole day, and today's experiment will not be delayed because of other things.

But before that, he had to go to Huaguo Normal University to accompany Chen Feiyun to complete today's exercise task.

After washing, he went to the track and field of Huaguo Normal University, although today is Saturday, but there are many people on the track and field, or running or walking, or doing some push-ups and other exercises, this situation is relatively common before, so he is not too surprised.

After a few casual glances, Shang Yiyun focused on the entrance of the track and field, according to the previous situation, there were still five minutes left, and Chen Feiyun would come here.

Sure enough, after waiting for five minutes, a familiar figure walked in at the entrance of the track and field, it was Chen Feiyun.

When Chen Feiyun approached, Shang Yiyun was amazed by the other party, and insisted on exercising for a long time, which gave Chen Feiyun a youthful and beautiful temperament.

However, Shang Yiyun's gaze soon became the same as usual, and he began to accompany Chen Feiyun to run and exercise.

After exercising, the two of them had breakfast in the school cafeteria, and then went their own way.

At this time, Shang Yiyun was already on his way back to Kyoto University, and today was the first experiment of the new research project, which had extraordinary significance, so he had to arrive at the laboratory in advance.

The agreed time was at 8:00 a.m., but it's only 7:20 a.m., so there's still 40 minutes left.

But when he walked into the laboratory, he found that there were not many people in the laboratory, and it was right to think about it, today is Saturday, which is different from the usual class, and it is understandable that there are fewer people.

Of course, this situation had little to do with him, and after finding a place to sit down, he began to wait for the arrival of Cao Xun and Zhang Liu.

In fact, he can do experiments alone, but it takes more energy, and now that he has two assistants, how can he do experiments alone.

After waiting for 30 minutes, I finally waited for Cao Xun and Zhang Liu, and the two came to the laboratory together.

Now that the members of the three-person research team have arrived, the next time can be devoted to research.

Today, to carry out research on graphene iron phosphate lithium-ion batteries, carbon-coated lithium battery cathode materials are an effective way to improve their electrochemical performance, so he is ready to use this method.

The principle of this method is that the conductivity of the cathode material is improved, and the graphitized carbon material can improve the conductivity of the cathode material to a greater extent due to its higher electrical conductivity.

However, it has been reported in the literature that the diffusion rate of lithium ions is limited when passing through the defect-free graphite sheet, which may reduce the electrochemical performance of the cathode material.

Thinking of this, he began to prepare the materials for the experiment, and then began to do the experiment.

The first step of the experiment is to complete the full coating of graphene: lithium iron phosphate and cetyl trimethylammonium bromide solution are mixed with ultrasonic for 2h, then graphene oxide aqueous solution is slowly added, and hydrochloric acid is added dropwise to adjust the pH value <7, and then hydrazine hydrate is added to reduce, then washed with deionized water, centrifuged and dried, and then heat treated at 600 °C in a nitrogen atmosphere for 2h.

Then the partial coating of graphene is completed: except for the non-introduction of cetyltrimethylammonium bromide, the other steps are the same as those of full graphene coating.

Finally, the amorphous carbon coating was completed: sucrose was used as the carbon source, and lithium iron phosphate was heat treated at 600 °C in a nitrogen atmosphere for 2 hours.

After these steps, the state of the experimental material can be observed and various data can be recorded.

It can be seen that lithium iron phosphate can be fully coated with graphene, and the graphene on its surface is thin and wrinkled, and for amorphous carbon-coated lithium iron phosphate, it can be clearly seen that there is a thin and amorphous carbon layer on its surface.

The structure and microscopic morphology of different carbon-coated materials are different, when the current density of 0.05C is charged and discharged at a constant current of 0.05C, the capacity of the fully coated lithium iron phosphate is only about 40mAh/g, while the capacity of the partially coated graphene is about 150mAh/g, which is mainly because the graphene sheet hinders the transmission and diffusion of lithium ions in lithium iron phosphate into the electrolyte, resulting in the redox reaction of Fe2+/Fe3+ in lithium iron phosphate materials can not be carried out completely.

For the lithium iron phosphate material that is not completely coated, the lithium ions can be transported and diffused through the area that is not coated by graphene, so the redox reaction of Fe2+/Fe3+ in the lithium iron phosphate material can be carried out completely, so that its capacity can be fully utilized.

What needs to be done today is to test the effect of graphene coating on the electrochemical comprehensive properties of lithium iron phosphate cathode materials.

The last step, of course, is to test the electrochemical performance of lithium iron phosphate.

When graphene is partially coated with lithium iron phosphate, it will not obviously block the transmission and diffusion of lithium ions, and its conductivity will be greatly improved, so the electrochemical properties of lithium iron phosphate can be improved, when the lithium iron phosphate cathode material is completely coated with graphene, graphene will block the contact between the active material lithium iron phosphate and the electrolyte, and block the transmission and diffusion of lithium ions。

Follow the steps of the experiment step by step, and complete all the steps, but Shang Yiyun didn't get the answer he wanted, and he was not discouraged in the face of this situation.

Because this is the first time to do an experiment, failure is inevitable, and to do an experiment is to have the awareness of failure, as long as you keep summarizing, strive to reduce the number of experimental failures, and succeed the experiment as soon as possible.

The whole morning was devoted to this experiment, which was carried out several times, but it was still a failure.

For this situation, Shang Yiyun was also helpless, he recalled the steps of the experiment before, but did not find any problems, so he didn't know why the experiment failed.

However, he is very patient because he believes that there will always be a time for success to keep moving forward in the face of failure.

Time passed slowly, the experiment had been carried out nearly ten times, but it had not yet been successful, and he could feel that Cao Xun and Zhang Liu had begun to become impetuous, and in this state, the efficiency of the experiment had decreased a lot.

In this case, he could only dismiss the intention of continuing the experiment, but asked the two to go back first and continue the experiment in the afternoon.

So the morning experiment ended in failure, and after cleaning up the experimental table, Shang Yiyun also left the laboratory and went directly to Huaguo Normal University.

The experiment in the morning failed, and Shang Yiyun wanted to go to Chen Feiyun for comfort.

With this in mind, he came to the campus of Huaguo Normal University, and it was now close to noon, and he believed that Chen Feiyun would soon go to the cafeteria for lunch.

So I made a call to Chen Feiyun.

"Fei Yun, I'm on the campus of your school now, where are you now? I'll look for you. ”

After the phone was connected, Shang Yiyun said his purpose and waited for the other party's reply.

At this time, Chen Feiyun was having lunch in the cafeteria when she suddenly received a call from Shang Yiyun. "Yi Yun, I'm in the school cafeteria now, you can find me if you enter from the main entrance and look on the left. ”

Hearing Chen Feiyun's reply, Shang Yiyun also quickened his pace, he didn't expect that Chen Feiyun was in the cafeteria at this time.

"Okay, it's that you're in the cafeteria now, then I'll go over, it just so happens that I haven't eaten yet, so hang up the phone first." ”

After hanging up the phone, Shang Yiyun put the phone back in his pocket and went to the cafeteria of the Normal University.

It took a few minutes for Shang Yiyun to come to the cafeteria, and according to Chen Feiyun's prompt, he quickly found out where the other party was.

walked directly to the opposite side of Chen Feiyun and spoke.