Hand rubbing nuclear fusion live in the wilderness

Chapter 251 Lithium Dendrite

(Chapter 249 is at the back. I was screened twice because I wrote something before, and reissued after editing and deleting some.)
In the simulation space, Han Yuan checked the power remaining and walked towards the chemical laboratory.

The speculations made by experts and scientific researchers from China and the United States based on the live broadcast are really correct.

For him at present, it is almost impossible to produce a nanoscale lithography machine.

Because there are no conditions, whether it is an ultra-high-grade dust-free workshop or a processing machine tool, they are not equipped to process nano-level or even micron-level chips.

This time, Han Yuan never thought of making nano-scale chips at one time when making a lithography machine.

He just wanted to upgrade the transistor computing core to increase its computing power, and then reduce the original huge operating core to a few levels so that it can be installed on the aircraft.

But compared with modern chips, there is still a big gap.

The chip computing power of modern home computers is basically calculated in units of billions.

On his side, even if it is upgraded once, the computing power of a single chip may not reach [-] million.

Even if he uses multiple chips, the computing power cannot be compared with modern chips.

However, if it is only used to write and set some fixed programs to control the operation of the aircraft engine, it is enough.

After all, he doesn't need to perform various tasks and control various instruments like an airplane in human society.

For this aircraft, the only thing that needs to use the control program is the electric propulsion engine.

He does not need other control programs such as air replacement system, automatic landing system, angle of attack and sideslip angle boundary control system, aiming control system, etc. in the aircraft.

Because this aircraft takes off and lands vertically, he only needs to control the output power of the electric propulsion engine.

And the speed required to complete the task is only [-] kilometers per hour.

To be honest, this speed is only the speed per hour for takeoff and landing on an ordinary civil aviation aircraft.

Not to mention airplanes, even cars can reach this speed at certain times.

For example, the linear speed of a famous F1 racing car has already exceeded [-] kilometers per hour.

If it wasn't for the mission requirement to manufacture 'aircraft', South Korea would have the idea of ​​manufacturing cars and building roads to complete the mission.

After all, the system does not require the manufactured aircraft to maintain a speed of [-] kilometers per hour, it only needs to exceed the limit flight speed of [-] kilometers per hour.

Compared with manufacturing an aircraft, manufacturing a car with a speed exceeding [-] per hour is much simpler.

And the security aspect is also much higher.

Shaking his head, Han Yuan threw out the thoughts in his mind, pushed open the door of the storage room, and buried himself in looking for materials for making high-energy lithium batteries.

The high-energy storage lithium battery he took out this time is not a 'lithium-air battery', but a type of 'lithium-sulfur battery'.

Although the lithium-sulfur battery sounds a grade worse than the lithium-air battery, the force is also lowered a lot.

But in fact, lithium-sulfur batteries are also a kind of battery that humans are still in the stage of scientific research and experimentation, and they are also a type of battery that humans are currently focusing on.

Because lithium-sulfur batteries are more likely to be realized within ten years than lithium-air batteries.

As for lithium-air batteries, not to mention ten years, even 20 or 30 years, human beings may not necessarily find the right path.

Regarding this aspect, Han Yuan feels that at least on earth, no one has more right to speak than him.

This b, he thinks he can afford it.

Lithium-air batteries, more accurately called lithium-oxygen batteries (Li-O2).

It is a battery that converts electrical energy based on the chemical energy of metal and air.

It is a battery that uses lithium as the negative electrode and oxygen in the air as the positive electrode reactant.

After obtaining the knowledge information of intermediate electric energy applications and finding the knowledge information about lithium-air batteries, Han Yuan also made a special trip back to the earth and arranged for the laboratory to collect a wave of relevant information.

At present, the difficulty in the research and development of lithium-air batteries in human society is that lithium oxide, which is produced during solid reaction, will accumulate on the positive electrode, blocking the contact between the electrolyte and air, resulting in discharge failure.

This is one of the biggest difficulties, which belongs to the problem of inhibiting the growth of lithium dendrites of metallic lithium, and is called the "lithium analysis problem".

Secondly, there are Li+ solid-state electrolyte problems with high ionic conductivity; the isolation problem of water and air in the air electrode and the metal lithium negative electrode; the interference problem of carbon dioxide in the air (because carbon dioxide will react with lithium to form lithium carbonate, and lithium carbonate cannot be regenerated. recycled) and so on.

Let's put it this way: "Fuel cells have some problems, they have some problems with lithium batteries, and they have problems that lithium batteries and fuel cells don't have."

To sum up, the current human research on lithium-air batteries has only found a lot of unsolvable problems.

So lithium-air batteries are really just an elusive dream at present.

But these are from the perspective of human scientific research.

For Won, he has already seen the manufacturing information related to lithium-air batteries, and he knows how to solve these problems.

The reason why it was said that human beings may not find the right path in 20 or 30 years is because the fundamental problems of lithium-air batteries are not those.

The fundamental problem of lithium-air batteries is that no country or laboratory has really found a suitable system, and can determine the electrolyte, electrolyte, cathode and anode materials.

Because this is a brand new system.

It is a completely different system from "lithium-ion batteries", and the principles involved are also quite different.

So to solve the lithium-air battery, besides his shot, the biggest possibility is another super genius like 'Alessandro Volt'.

And this kind of epoch-making super genius is rare in a hundred years.

In fact, the concept of "lithium-air battery" was proposed very early, as early as the [-]th century.

Its core principle is to allow lithium to react with oxygen in the air and convert the generated energy directly into electricity.

This is like burning wood or coal. As the most common way for human beings to obtain energy, the direct reaction of raw materials with oxygen brings about extremely high energy release.

This seemingly simple combination of lithium and air raises the physical ceiling of battery technology by an entire order of magnitude!

Moreover, the oxygen it uses comes from the air, which is a nearly unlimited raw material.

However, the idea is beautiful, but the result is cruel.

Scientists have been working tirelessly on lithium-air batteries since they came up with the idea.

But after 50 years, at the beginning of the 21st century, several top lithium-air experts from the United States and the European Union got together and wrote an article introducing the development status of lithium-air batteries for the "Nature" journal "Energy".

It begins with the sentence: "At a fundamental level, we know very little about the reaction processes in lithium-air batteries."

Then, followed by: "No one knows whether lithium-air batteries will become a technology, but for the sake of social development and the future of mankind, we should do our best to explore the possibility (of lithium-air batteries)."

What these two sentences mean is that after more than 50 years of development, the most outstanding scholars in this field can only sigh in a low voice when facing the world:

"We know next to nothing."

This shows the difficulty of research and development of lithium-air batteries.

At present, lithium-air batteries are still a chaotic article, and all prospects are hidden in the dark, looking forward to a bright light to illuminate it at a certain moment.

However, this is not the case for Korean won,

He has already memorized the knowledge and information related to lithium-air batteries.

Just like the fruit hanging on a tall fruit tree, you only need a ladder and you are within reach.

It's just that what he lacks most now is the time to make ladders.

Because the lithium-air battery is a brand new system, it would take too long to get it out.

And there are only less than [-] days left in this mission, and it is impossible for the Korean won to spend too much time on the battery.

Therefore, lithium-sulfur batteries, which are inferior to lithium-air batteries, have become a substitute for this mission goal.

"Lithium-sulfur battery" is a lithium battery that uses sulfur as the positive electrode of the battery and metal lithium as the negative electrode. It has an ultra-high theoretical specific energy of the battery.

Of course, the problems encountered in the research and development of lithium-sulfur batteries are also not small.

The first major problem is also the formation of beautiful but deadly 'lithium dendrites'.

This problem has been difficult for human beings for at least half a century, but there is still no good solution.

The second main problem is that the lithium polysulfide compound is dissolved in the electrolyte, and sulfur is used as a non-conductive substance, so the conductivity is very poor, which is not conducive to the high rate performance of the battery.

Besides that, there are some other problems.

For example, during the charging and discharging process of sulfur, the volume expands and shrinks very much, which may cause battery damage and the like.

However, compared with lithium-air batteries, lithium-sulfur batteries are still possible, not a big cake.

At present, although the research and development of lithium-sulfur batteries is still in the laboratory stage, most of the problems have found solutions or alternatives.

Except for the problem of "lithium dendrite" growth.

The word 'lithium dendrite' should be heard by even those who don't pay much attention to the scientific community and the battery industry.

He is the dendritic metal lithium formed when lithium ions are reduced during charging of the lithium battery. Of course, when lithium appears on the negative electrode side, the form of lithium is not necessarily lithium dendrites.

However, no matter which one it is, it is collectively called "lithium analysis".

The growth of lithium dendrites is one of the fundamental problems affecting the safety and stability of lithium-ion batteries, and it is also the most difficult problem to solve.

The formation of lithium dendrites will lead to the instability of the electrode-electrolyte interface during the cycle of lithium-ion batteries, and destroy the formed solid electrolyte interface film.

To put it simply, after the lithium dendrites are formed, they will damage the protective film and cause problems with the lithium battery, such as combustion, explosion, explosion, and explosion.

In addition, the lithium dendrites will continuously consume the electrolyte during the growth process and lead to the irreversible deposition of metallic lithium, forming dead lithium and resulting in low coulombic efficiency.

To put it bluntly, in fact, the lithium in the battery is consumed, and the storage capacity is reduced or even gone.

This is the difficult problem of lithium dendrite formation.

And this is what the Korean won has to solve.

With a bunch of materials and equipment, Han Yuan came to the dust-free studio.

At the same time, people from the battery industry, industry, chemistry, materials and even the press who received the news poured into the live broadcast room.

Everyone is waiting for Won to start the experiment and the final results.

(End of this chapter)