For the gift, start research and development of graphene batteries

Chapter 76 The battery fire is about to become history

Of course, the idea is good, but it is extremely difficult to realize.

After all, the most basic lithography machine is currently controlled by Xia Guo.

It is even more difficult to break through on this basis.

But Jiang Ming kept this matter in mind, and if he had the chance, he still had to try it, maybe it would work.

The team that sent away the electrolyte, and the rest continued to discuss the improvement of the diaphragm.

"You see, our common diaphragm is a five-layer composite structure. According to my idea, another layer is added to it for temperature determination."

Jiang Ming pulled up the structural diagram of the diaphragm and then said to everyone.

Everyone is an expert in this industry, so they can understand what Jiang Ming said.

There is no problem with adding another layer, but how to use this layer to judge the temperature is a problem.

You should know that although general materials have certain temperature ductility, how to say, the change range is very small, generally less than 5%.

This is done to ensure that no matter how long the diaphragm is used or at what temperature, its basic mechanism will not change greatly.

Now it's the other way around, and everyone is looking for a material that changes significantly according to the temperature.

And this kind of change is not a random change, but a change within the controllable range.

It is difficult to find such materials.

For a moment, the scene fell into silence.

Jiang Ming didn't speak either, he was thinking about this question.It's hard for a clever woman to cook without rice. Without this kind of material, Jiang Ming has nothing to do.

It doesn't mean that Jiang Ming has a technology tree system that can solve all problems.

The biggest change that the technology tree system has brought to Jiang Ming is the confidence in the future technology of the industry.

Take a classic example.

The atomic bomb technology is difficult. The research on the atomic bomb, from theory to formation, took decades, and 10,000+ people participated in the research, and finally came out.

But Xia Guo, it only took two years to succeed.

Can you say that Xia Kingdom's technology is more advanced than Deng~ Country's? Not necessarily.

Technology, in many cases, is just a layer of window paper. If you pierce it, the research and development will be successful. If you pierce it, it will always be difficult for you.

The research and development of technology does not depend on the number of people, but on whether there is a clear direction.

Why does R&D burn money? That’s because R&D is to explore unknown things, and you don’t even know if this road will work.

In many cases, after investing huge sums of money in research and development to a certain extent, it was discovered that the original direction was wrong.

When this happens, the previous investment will be in vain. Do you think the price is heavy?

The same is true for various high-end technologies.Once the first research is done, the second is not far away.

Gein was the first to know that this matter would definitely succeed.If you can't succeed, it's because you didn't study deeply enough.

If the direction is right, it will save a lot of worry.

Everyone stared wide-eyed, and for a moment, the scene fell into an embarrassing situation.

"Temperature judgment, temperature judgment."

Jiang Ming was sucking at these few words, if he had semiconductor technology, it would be easy.

However, the current semiconductor technology cannot meet the process requirements of 0.1nm, so this solution will not work.

"what!"

Suddenly, Yao Lei from Yunjie Technology let out a light sigh, as if he had discovered something.

Seeing Yao Lei's actions, Wang Mingyang quickly asked:
"Boss Yao, what can I do?"

Wang Mingyang couldn't help but be excited, because Yunjie Technology is researching battery separators. Its technology is one of the best in the industry, and it has a deeper technical background than anyone else present.

"There's no way. I just have some doubts."

Yao Lei also didn't dare to take it too seriously, and said modestly.

"Come and talk, we brainstorm."

Wang Mingyang continued.

"Just think of it as a brainstorm, it doesn't matter how bold you are, just say it."

Wang Mingyang continued.

"It's like this. Our Yunjie Technology has a material with a relatively large deformation."

Yao Lei said.

"it is good!"

Hearing Yao Lei's words, Wang Mingyang called out.

"Old Wang, don't be in a hurry, wait for me to finish speaking."

"This kind of material was unintentionally researched by us. The material is relatively deformed by the change of temperature, so it can be regarded as a waste product."

This point, everyone can understand.

Generally, diaphragm manufacturers have very strict requirements on materials, and the deformation must be controlled to a certain extent.

This kind of change is too big and seems useless.

"After deformation, what is the rate of change of the pores?"

Jiang Ming was always interrupted when he saw Yao Lei's words, and he asked without saying anything for a long time.

"At normal temperature, the porosity is almost 55%, but when the temperature reaches 80°C, due to the influence of deformation, the porosity is only 25%."

Hearing Jiang Ming's words, Yao Lei hurriedly spoke.

"25% is still a bit high."

Jiang Ming thought for a moment, then said with a frown.

The pores of the diaphragm are channels for ion conduction, and the porosity is too low to allow chemical reactions to proceed.

A normal separator has a porosity of 40% or more. Jiang Ming took a look at the carbon-based battery this time and found that the separator has a porosity of 70%.

This level of technology is leading in the industry.

If this 55% porosity diaphragm is added, the porosity of the entire diaphragm will inevitably be lowered.

For ordinary batteries, the value of 55% is enough, but for graphene batteries, it is a bit less.

In addition, the porosity after high temperature, 25% is also a bit high.

Although in general lithium battery design, the porosity of the separator exceeds 40%, it can be used, but lower than this value does not mean that the chemical reaction is terminated.

Instead, if this kind of diaphragm is used, the internal resistance of the battery is relatively large, and the temperature rise of the battery will be relatively high under the condition of high current use.

With a porosity of 25%, the internal resistance of the battery will be much higher, but the corresponding chemical reaction will still continue.

It's been going on, albeit at a much slower pace.

When the heat of the battery accumulates to a certain level, what should catch fire will still catch fire, and the safety issue of the battery is still not resolved.

At room temperature, there is still a solution to the porosity of the battery. If you want to further increase the 55%, it is still possible to think of a way.

However, the porosity in this high-temperature environment still needs to be carefully considered.

"The porosity at high temperature is still a bit high, is there a way to reduce it?"

Jiang Ming asked Yao Lei.

"Mr. Jiang, how should I put it? It's very difficult. We have also experimented before. Although there is still room for reduction in the porosity of 25%, to be honest, the range will not be very large."

This is a little trickier.

According to Yao Lei, no matter how hard he tried, it would drop to about 20%. To be honest, this level is not enough.

According to Jiang Ming's vision, it is best to reduce it to below 10%.

Only in this case, the short circuit in the battery will be terminated and the battery will be truly safe.

Could it be that we are going to develop new materials again, but the time is a bit too late?
Since Yunjie Technology can find this kind of material, Jiang Ming believes that there will definitely be more efficient materials, as long as he is willing to spend time, there will be a way.

But what is lacking now is time, and everyone can't wait.

Wang Mingyang was also scratching his head and scratching his head, a little anxious.

During the intermission, everyone should drink water, and it should be convenient.

Looking at the exhaust fan in the bathroom, Jiang Ming felt emotional for a while.

You said that if the diaphragm can be added with a controllable exhaust fan, which is turned on when in use and turned off when not in use, then the problem will be solved.

It's just that the diaphragm is not a window, and it can't be added if you want.

Hey, there is a situation!
Jiang Ming looked at the fan, thought of its purpose of ventilation, and then glanced at the louver fan next to it, and had an idea in his mind.

If one film is less than 10%, can an additional film be added?No one said that only one layer of film can be added.

Even, can the two layers of film be targeted to open holes in this direction of the blinds.

In this way, to a certain extent, the porosity at high temperature can be further reduced.

As long as it is reduced to a certain level, and then combined with the electrolyte and other methods, the problem of thermal runaway will be properly solved?

Thinking of this, Jiang Ming quickly packed up and came to the conference room, fearing that he would miss the idea.

Sometimes, a flash of inspiration is just a matter of one moment, if you miss it, it will be gone.

Jiang Ming came to the meeting room and had an in-depth communication with Yao Lei. Not to mention, it is theoretically feasible.

Because according to the information given by Yao Lei, the interlayer of the diaphragm can change the direction of the pores to a certain extent.

In this case, when two diaphragm interlayers with opposite directions are used, the thermal runaway will be abruptly terminated.

In this way, the structure of the diaphragm was changed to seven layers.Among them, five layers are traditional diaphragm composite structure, and the other two layers are temperature control layers.

These two temperature control layers are located at the upper and lower ends of the diaphragm respectively, which are regarded as the portal of the diaphragm.

Under normal circumstances, these two temperature control layers are completely connected, and the role of the micropores is fully exerted.

When a partial short circuit occurs in the battery, the temperature inside the battery will rise sharply.

When the diaphragm is affected, the temperature layer will be deformed, causing the porosity of the diaphragm to change.

The pores of the upper and lower layers are at a certain angle.

In the first layer, due to the large decrease in porosity, the passage of ions will also drop precipitously.

The ions that can pass through by luck will further reduce the passability when they hit the structure of the bottom layer.

According to calculations, after two temperature control layers, the porosity is less than 10%. In this case, the micropores of the membrane are basically closed.

The channels between ions are considered to be separated, and internal short circuits are also suppressed.

Suppressing the excitement in his heart, he finalized the final plan with Yao Lei.

Yao Lei hurriedly contacted the factory, made a batch of samples as quickly as possible, and then sent them to the testing agency in Kyoto to prepare for assembling new batteries.

After several days of busy work, the final sample cell was successfully produced.

Because new materials were used, the previous test data was no longer useful. We had to start over and arrange tests for all projects.

Because only the diaphragm was changed, Jiang Ming was still optimistic about the passability of the previous test items.

In fact, the general electrical performance of the new batteries passed the test without any surprises, and the difference from the previous data is not very big.

Because the diaphragm has increased by two layers, it will indeed increase the internal resistance of the battery.

However, the increase is not very large, and compared with the realization of thermal runaway control, it is very cost-effective.

In a blink of an eye, it was time for the last and most important item of the test: the acupuncture test.

The previous battery cell failed in this project. Jiang Ming didn't want the previous failure to repeat itself.

The thick steel needle was slowly inserted into the battery at a constant frequency.

"Pfft!"

There was a faint sound when the steel needle collided with the battery core.

If it weren't for the fact that the whole laboratory was so quiet, I wouldn't be able to hear it at all.

This is obviously different from the loud sound when the steel needle was inserted before.

The steel needle was firmly inserted into the battery core, forming a micro short circuit inside the battery core.

Under this kind of micro short circuit, the heat of the battery will rise sharply.

From sparks, to smoke, and finally to fire.

This was the case with previous batteries, but I don’t know if there will be any changes with the new carbon-based batteries.

"There it is, the batteries are starting to smoke."

After a short period of time, a faint light can be seen inside the pierced battery cell, which is a phenomenon of internal short circuit.

The smoke and dust of the battery also proves that the inside of the battery cell is accumulating energy.

According to previous experience, next, there should be thick smoke everywhere, and the temperature of the battery core will rise sharply.

Whether it can burn up in the end depends on whether the heat can be dissipated.

But the situation at the scene shocked everyone.

The part of the battery cell that was short-circuited produced thick smoke.However, the expected short-circuit spread and caused a chain reaction did not appear.

Except for the burnt part of the battery cell, the other parts are intact.

At the same time, the white smoke from the short-circuited cells did not intend to continue to expand as time went on, but gradually shrank.Depending on the situation, it is a small part of the short circuit. After the short circuit is completed, there will be no further information.

"This, this effect is too good!"

Some technicians said so.

Good guy, I know that the thermal runaway control method proposed by everyone is effective, but I didn't expect that the effect is so outstanding.

According to the phenomenon just now, it is estimated that the thermal runaway of the battery was perfectly controlled at the short-circuit point and did not spread.

This means that each area inside the battery is independent.It will not affect the entire battery system because of a problem in one of them.

Of course, this kind of conclusion can only be reached after dissecting the battery as a whole.

But in any case, this solution to control thermal runaway is feasible.

In other words, regardless of whether it is a carbon-based battery or not, this solution can solve the problem of battery fire.

This kind of meaning is really too great.

If this technology can be used well, the fire problem in the battery field can be reduced by at least 100%, not to mention 80%.

This effect is really amazing!

(End of this chapter)