Hand rubbing nuclear fusion live in the wilderness

Chapter 262 Don't play with your phone while eating

Compared with 'propylene carbonate solution', it is simpler to configure mixed electrolyte lithium salt.

Of course, this simplicity is only relative, and the purification of electrolyte lithium salt is still a bit troublesome.

After all, the electrolyte lithium salt cannot be purified by the method of refining salt with saturated sodium chloride. In addition, it is necessary to pay attention to the temperature of the solution for purification.

Once the temperature exceeds a predetermined value, as the chloride ions in the chloride lithium salt of perchlorate are easily decomposed, the lithium salt solution prepared at that time will be wasted.

In addition to purifying the electrolyte lithium salt, there is a slightly more difficult point is the stabilizing additive.

This is a brand-new compound material: '1-3 propanesultone', which belongs to a kind of organic additives.

The link between its molecules is like the nerve cells of the human brain. With the macromolecule of propanesulfone as the core cell, the stretched out nerve tentacles can effectively stick to other electrolyte lithium salt ions, so as to achieve stable electrolyte lithium salt without affecting the conductivity. Effect.

It requires a lot of sulfur and propionic acid to prepare, and the temperature is quite unpleasant.

However, the finished product after preparation has only a faint sulfur smell, which smells pretty good.

Although the above things are troublesome, for an excellent old chemical engineer who is still running, he will not be knocked down by these things. After a busy day, Won successfully prepared a qualified electrolyte solution.

This step is completed, which is equivalent to the completion of more than one-third of the preparation of lithium-sulfur batteries.

What remains to be dealt with is the cathode and anode of the lithium-sulfur battery and the most critical artificial SEI film.

Yin and Yang are extremely easy to deal with, and there is still some time left, and Han Yuan plans to deal with it today.

Typical lithium-sulfur batteries generally use elemental sulfur as the positive electrode and metal lithium sheets as the negative electrode.

Its reaction mechanism is different from the ion deintercalation mechanism of lithium-ion batteries, but an electrochemical mechanism.

During discharge, the negative electrode reaction is that lithium loses electrons and becomes lithium ions, and the positive electrode reaction is that sulfur reacts with lithium ions and electrons to form sulfide.

The potential difference between the positive electrode and the negative electrode reaction is the discharge voltage provided by the lithium-sulfur battery.

When charging, under the action of an external voltage, the positive and negative reactions of the lithium-sulfur battery proceed in reverse, which is the charging process.

However, there is a fatal problem here.

The lithium metal negative electrode will change in volume during the charging and discharging process, and it is easy to form dendrites. This is the beautiful but deadly 'lithium dendrite'.

It is also a key issue that has plagued the development of lithium-ion batteries.

In order to solve this problem, humans have been researching for decades, but they still haven't come up with any good solutions.

These scientific research scholars have studied and studied, and finally found that in addition to the problem of lithium dendrite formation that cannot be solved, they have also found a "bunch" of brand new problems.

For example, when studying the growth of lithium dendrites, they found that no matter how the electrolyte was changed, pure sulfur was not suitable as an anode for lithium-sulfur batteries.

Because of the poor electronic and ionic conductivity of elemental sulfur, the conductivity of sulfur materials at room temperature is extremely low.

Another example is that during the charge and discharge process of sulfur, the volume expands and shrinks very much, which may cause battery damage.

But decades of hard work have not been in vain.

At least in the use of anodes of sulfur materials, scientists have found some sulfur compounds that can effectively solve the problem of sulfur anodes in lithium-sulfur batteries.

This time, the anode material used by South Korean Won is a sulfur mesoporous carbon composite material upgraded on the basis of the sulfur carbon composite material developed by Hua Guo scientists.

It can solve the problem of non-conductivity and volume expansion of sulfur.

The other cathode is naturally lithium metal.

As for the formation of lithium dendrites, this is the key, and the Korean won will be left for tomorrow to deal with.

There is nothing to deal with the metal lithium cathode material. There is a lot of lithium metal sealed in paraffin in the storage room, which can be used as cathode material after treatment.

The key point lies in the sulfur mesoporous carbon composite material.

This is a composite material prepared by upgrading the carbon material based on the ordinary sulfur-carbon composite material studied by Huaguo scientists.

Facts have proved that Huaguo is at the forefront of the world in the research of lithium-sulfur batteries.

At least in terms of anode materials, it is estimated that in a period of time, Huaguo will be able to develop composite sulfur-carbon materials suitable for lithium-sulfur batteries.

Of course, no one can tell how long this so-called period of time is.

It may be a month, it may be a year, or it may be developed in a day, or it may not be done in five or six years.

After all, scientific research is a thing that requires experience and inspiration.

Experience accounts for 90.00%, but often that one percent of inspiration is the key to advancing technological progress.

No, when the experts who had been studying sulfur-carbon composites before saw Korean Won preparing sulfur-mesoporous carbon composites, they suddenly realized.

It was as if an expert had opened up the eight extraordinary meridians, and understood what was going on.

Mesoporous materials are materials with extremely high specific surface area, regular and ordered pore structure, narrow pore size distribution, and continuously adjustable pore size.

It is precisely because of these characteristics that it can complete the adsorption, separation, and catalysis of macromolecules.

Moreover, the ordered pores of this material can be used as "microreactors".

Using mesoporous carbon as the carbon material in sulfur-carbon composites can transport lithium ions more effectively than pure carbon materials or graphene or polymer nanocarbon tubes.

In other words, mesoporous carbon is like a magnet that can attract charged ions in the electrolyte.

Seeing that Won is dealing with sulfur mesoporous carbon materials, the faces of scientific researchers and experts who study this industry are somewhat complicated.

This should be the closest they got to this anchor.

Sulfur-carbon composites for anodes in lithium-sulfur batteries is something they've been working on.

But what they consider more is to use carbon materials such as graphene, polymer carbon materials or carbon nanotubes with better conductivity and more stable performance to compound sulfur.

Mesoporous carbons do not perform very well in comparison.

But the anchor in front of him told them with practical actions that not only the best and the top are suitable.

But the most suitable is the most suitable.

This is a lamp lit by the pioneers walking on the road ahead, which is thought-provoking.

In the dust-free studio, Han Yuan was already busy like a spinning top, and he never expected that his actions would bring a new mentality to the scientists in Huaguo.

Sulfur mesoporous carbon composite is a mesoporous material with a cage structure, which is composed of macromolecular sulfur as the base and mesoporous carbon as the branch.

In the process of preparation, it is necessary to control the temperature of the solution to keep constant, and at the same time, it needs constant high-speed stirring, and it also needs to continuously add new materials.

In fact, the laboratory preparation of this material is usually done by two or three people.

For industrial preparation, intelligent automatic assembly lines are used to control production, which is not suitable for one person to carry out production processing.

But the Korean won has no choice but to bite the bullet.

And the result of daring to bite the bullet is naturally a failure.

The first failure, the second failure, and the third failure followed.

This should be the most times he failed to produce something after injecting the genetic medicine.

But as the number of failures increased, Won began to feel as if he could multitask.

He didn't wake up from this state until the sulfur mesoporous carbon composite was prepared.

After stopping work, Han Yuan recalled this state of multi-tasking, and immediately understood that this should be the human body development drug at work.

This feeling is very strange, like drawing a circle with one hand and a square with the other, but he can sense and control more events.

Multitasking means doing several things at the same time, which is difficult for most people.

Ordinary people draw circles with one hand and squares with one hand, and the result is basically that they all draw circles or squares in the end.

But in fact this ability can be cultivated.

For a person with a normal mind and body, "one mind" can be "dual-purpose" or even "multiple-purpose".

However, in many cases, dual-purpose or multi-tasking is useless, or even half the effort, and in severe cases, it will affect the intellectual development of the brain.

This is not nonsense, but a conclusion drawn by human scientists after research on the brain.

For example, a doctoral professor named Alan Keane from the University of Queensland in Australia found through research that talking while walking can damage health.

This is because speaking and breathing are controlled by the same area of ​​the brain. Talking while walking will cause the brain to "dual-task", resulting in the interruption of the transmission of nerve signals in the central nervous system, weakening the activity of abdominal muscles, and reducing the protective effect on the spine.

Similarly, if you eat while thinking about problems; or eat while reading or watching TV, a lot of blood will be supplied to the brain, which will directly affect the blood supply of the gastrointestinal tract.

If things go on like this, it will inevitably affect the function of the stomach and lead to stomach problems.

There is also the potential to trigger a range of dangerous mental health problems, such as intense stress and mania in adults, or learning disabilities and autism in children.

So it's really right not to play with mobile phones or watch TV while eating.

It's just that for most people, this is farting.

　Sorry for the late update, I was busy with other things today, and I didn't go home until [-] pm.

　　
　
(End of this chapter)