Rebirth 99 to become a car giant

BMW's inspection trip to Nanshan Battery was more grand than Cao Yang imagined.

Phillips, President of Asia Pacific Region, General Manager of China Branch and General Manager of BMW Huacheng, Executive Deputy General Manager, Deputy General Manager, Director of R\u0026D Center, Director of Technology Department, Director of Purchasing Department of BMW Huacheng...

A group of more than a dozen people came to Nanshan Battery in a mighty manner.

This level of emphasis definitely goes without saying.

However, the more BMW pays attention to it, the more it shows that it is serious this time.

Otherwise, if everyone has so many meetings every day, how would they have the time to fly over and visit your factory?

"Mr. Cao, I've heard about his name for a long time, and finally met him today."

Phillips speaks Chinese very authentically. If it weren't for his appearance that could be seen at a glance, you wouldn't know he was a foreigner.

"Everyone is welcome to visit Nanshan Battery. We are very much looking forward to having more in-depth cooperation with BMW."

"In recent years, with the development of China's economy, there have been more and more wealthy people, and the sales growth rate of luxury cars has been significantly higher than that of other cars."

"I believe that BMW's sales in China will also increase year by year and eventually become the number one market for BMW in the world."

Cao Yang exchanged business cards with Phillips and others in the large conference room. After a brief greeting, Lin Cheng went on stage to personally introduce the situation of Nanshan Battery to everyone.

If you want to visit, you must listen to the introduction of the factory before visiting. Only by going to the site in a targeted manner will you gain more.

Otherwise, the effect will be greatly reduced.

"Mr. Cao, I would like to ask, the industry is generally optimistic about lithium iron phosphate batteries. Why is your company vigorously developing ternary lithium batteries while developing lithium iron phosphate batteries, and promoting ternary lithium batteries to passenger cars? How about using it in the car?”

After listening to the introduction of the Nanshan battery manufacturer, Phillips first raised a question that many people are concerned about.

"Cobalt in ternary materials is a relatively rare metal, and the reserves on the earth are limited. This causes the price of batteries containing this element to remain low."

"As for lithium iron manganese phosphate, these elements are very abundant on the earth and will never be depleted. So from an economic perspective, everyone thinks we should choose the lithium iron phosphate battery route, right?"

Cao Yang did not answer this question directly, but followed Phillips's intention and asked a question.

"From the analysis of market demand and national policy trends, since the energy of a single ternary material can reach 180Wh/kg and the ultimate density can reach 250-260Wh/kg, ternary materials will be the development trend of power lithium batteries in the future."

"Currently, the cobalt element used in ternary lithium batteries has very few reserves in China, and most of it needs to be imported from overseas, which limits the price. However, the reserves of related elements in lithium iron phosphate batteries are very abundant in China, which is beneficial to reducing costs."

"So we at Nanshan Battery adhere to two routes together and promote lithium iron phosphate battery technology in commercial vehicles."

"Promote ternary lithium battery technology in passenger cars."

"Compared with our peers, whether it is lithium iron phosphate batteries or ternary lithium batteries, we can achieve higher compaction density, lower internal resistance, and stronger output power."

"The most important thing is that while meeting these requirements, the uniformity of each cell of our battery is very good."

“I can even say with great pride that in China and even the world, no one’s car batteries have better cell uniformity than our Nanshan batteries.”

"When you visit the site later, you will find that our battery production line is highly automated."

“We use equipment to handle any process that can be solved through automation.”

"Whether it is in terms of material formulation or processing technology, our Nanshan battery has many unique advantages."

Cao Yang is still very confident in Nanshan battery technology.

To put it bluntly, it will take at least five years for other domestic battery manufacturers to catch up with Nanshan Battery.

This is enough for Nanshan Battery to completely secure its position as the industry leader.

The most critical thing is the battery industry. The greater your production volume, the cheaper the cost will be.

Nanshan Battery, which takes the lead, is not only technologically advanced, but also lower in cost than other manufacturers.

Under such circumstances, it would not be difficult for others to surpass Nanshan Battery.

"Compared with ternary lithium batteries, in addition to cost, lithium iron phosphate batteries have other unique advantages, such as stronger thermal stability and less prone to spontaneous combustion or collision and deflagration of ternary lithium batteries."

"And the cycle life is longer. Lithium iron phosphate batteries will start to decay after the number of charge and discharge cycles is greater than 3,500 times, but the number of charge and discharge cycles of ternary lithium batteries is only 2,000 times."

"How does Nanshan Battery consider this impact?"

Which battery technology route is more suitable? This question still has no answer within BMW.

Taking this opportunity, Phillips naturally wanted to see what Nanshan Battery's point of view was.

"The synthesis process of traditional electrodes will lead to the formation of an impurity called lithium substrate. Although this situation can be reduced by reducing the lithium content in the battery, it will also make its electrochemical performance worse."

"According to our current tests, ternary lithium batteries can fully meet the issues of safety and number of charging cycles."

"Our company uses a special electrode synthesis method that can adjust the ratio of lithium and other metals, thereby reducing impurities formed during the production and heating process of battery materials, thereby improving the battery's charge and discharge cycle life."

"According to the current experimental results, this technology can enable ternary lithium batteries to support 3,000 charge and discharge cycles and extend its life to 1 million kilometers."

"Of course, while we attach great importance to the development of ternary lithium batteries, we have also made a big technological revolution in lithium iron phosphate batteries."

"Even with lithium iron phosphate batteries, we can achieve the battery life level of other manufacturers' ternary lithium batteries. This is because Nanshan batteries have a unique patented design."

“In the design of this patent, the cathode material effectively inhibits the dissolution of sulfur and polysulfides by forming a metal sulfide shell in situ. The capacity of the battery assembled from the cathode material coated with the metal sulfide shell can be further improved. At the same time, the cycle performance of the battery has also been significantly improved!”

"This is also an important reason why our lithium iron phosphate buses can have a driving range of 300 kilometers and the ternary lithium battery passenger cars can have a driving range of 400 kilometers."

Since it wants to attract the attention of BMW, let the other party regard Nanshan Battery as the most promising battery supplier.

Naturally, we need to throw out some useful information.

Among the people who came with us for inspection, there were also technical experts.

After Cao Yang answered Phillips, someone immediately asked: "Does your company's ternary lithium battery support fast charging?"

Obviously, BMW is most interested in Nanshan Battery’s ternary lithium batteries.

This is also the best battery for use in passenger cars.

However, they may think that Nanshan Battery's ternary lithium battery can achieve a range of 400 kilometers because it has made some special arrangements in charging and discharging.

Regarding this question, Cao Yang simply said: "Ternary lithium batteries will face the problem of battery capacity attenuation under frequent fast charging."

"This is mainly due to the large DC power of fast charging. During the charging process, a large number of electrons continue to accelerate from the positive electrode to the negative electrode of the battery."

"The high heat generated during this process will rupture the semipermeable membrane on the surface of the battery's negative electrode and cause a reaction, generating foreign matter on the electrode and decomposing the electrolyte."

"Over time, the battery's maximum capacity will slowly decrease."

“This can be completely solved or mitigated through technical means.”

"To give just a few examples, Nanshan Battery's ternary lithium battery uses fully nanosized nickel-cobalt-manganese cathode materials to build a super-electronic network that extends in all directions, reducing the resistance to the escape of lithium ions during the charging process, thus accelerating the movement of lithium ions."

"In terms of anode material innovation, we use fast ion ring technology to modify the graphite surface, increase the lithium ion insertion channels and shorten the insertion distance, and build a highway for current conduction."

"In terms of electrolyte conduction, we have developed a new ultra-high conductive electrolyte formula, which can effectively reduce the viscosity of the electrolyte and significantly increase the conductivity."

"In addition, Nanshan Battery also optimizes the ultra-thin separator to further reduce conduction resistance."

"At the same time, we also improved the isolation membrane's high porosity and low tortuosity pores, thereby improving the lithium ion liquid phase transport rate."

“In this way, fast charging can be achieved without affecting the durability of the battery, thereby ensuring the true reliability and durability of the cruising range.”

Although what Cao Yang said was relatively professional, Phillips, Aimoha and others did not particularly understand it.

However, when they saw the technical experts in their company nodding frequently, they knew that what Cao Yang was talking about was probably not simple.

The two parties communicated in the conference room for more than an hour before moving to the production site.

"The battery cell is the smallest unit of a battery system."

"Multiple cells form a module, and multiple modules form a battery pack. This is the basic structure of a vehicle power battery."

"A battery is like a container that stores electrical energy. The capacity it can store is determined by the amount of active material covered by the positive and negative electrodes."

"The design of the positive and negative electrode pieces needs to be tailored according to different models."

"The gram capacity of positive and negative electrode materials, the ratio of active materials, the thickness of the electrode piece, the compaction density, etc. are also crucial to the capacity."

After entering the scene, the job of explaining was handed over to Lin Cheng.

The group of people came to the first process of the battery factory.

"So the pulping of active materials, that is, the mixing process, is very important, and it can also reflect the technical secrets of different battery manufacturers."

“Blending is the process of mixing active materials through a vacuum mixer into a slurry.”

"This is the first process of battery production. The quality control of this process will directly affect the quality of the battery and the finished product qualification rate."

"Furthermore, the process flow of this process is complex and has high requirements on raw material ratio, mixing steps, mixing time, etc."

"During the mixing process, dust needs to be strictly controlled to prevent dust from affecting the consistency of the battery. The level of dust control in Nanshan Battery's production workshop is equivalent to pharmaceutical level."

Lin Cheng took a microphone and began to introduce directly in English.

Although both Phillips and Aimoha understand Chinese, some of the visiting personnel obviously do not have a high level of Chinese proficiency.

If it was transmitted through a translator, Lin Cheng was worried that the information in the middle would be transmitted incorrectly, so he directly turned on the English introduction mode.

This actually made Phillips and others feel Lin Cheng's professionalism even more.

"After the stirring process, the stirred slurry needs to be applied to the copper foil. This is the second process in battery cell production - the coating process."

"This process is to evenly apply the slurry that has been stirred after the previous process to the top and bottom of the 4,000-meter-long copper foil at a speed of 80 meters per minute."

"The copper foil before coating is only 6 microns thick, which can be described as 'as thin as a silkworm's wing'."

"Coating is very important, and the thickness and weight of the pole pieces need to be consistent, otherwise it will affect the consistency of the battery."

"The coating must also ensure that no particles, debris, dust, etc. are mixed into the pole piece."

"Otherwise, the battery will discharge too quickly and may even cause safety hazards."

Following Lin Cheng's introduction, Phillips and others also stared at each piece of equipment attentively, trying to figure out something.

Before coming to Nanshan for battery inspection, it was not like they had never visited other battery manufacturers.

But once you enter the site, you can feel the difference between other manufacturers and Nanshan batteries.

In particular, the uniformly automated production lines and the extremely clean and tidy site are obviously different from the situation of other battery factories in this era.

According to Phillips' understanding, the Panasonic batteries he once visited at the Hamamatsu factory in Japan are of this level.

This made Phillips and the BMW team take it more seriously.

While Lin Cheng introduced the process, technical experts from BMW who came to inspect also frequently asked some questions.

As long as some core secrets were not involved, Lin Cheng and Cao Yang both gave each other satisfactory answers.

In a short period of time, Cao Yang learned that BMW had no idea of ​​producing its own batteries.

So there is no need to worry that they ask so many questions because they want to steal Nanshan battery technology.

"After the coating process is completed, the negative electrode material on the copper foil needs to be pressed tightly and then cut. This is our third process - cold pressing and pre-slitting."

“In the rolling workshop, the pole pieces attached with positive and negative electrode materials are rolled by rollers. On the one hand, the coated materials are made more compact, the energy density is increased, and the thickness is ensured. On the other hand, it will be further controlled. Dust and humidity.”

"What we are seeing now is the cold pressing of negative electrode materials, and the process for positive electrodes is similar."

After Lin Cheng said this, a BMW expert couldn't help but ask: "In this process of yours, how do you confirm that the burrs of the products after slitting meet the requirements?"

"The burrs on the electrodes need to be fully cleaned, and because the burrs are so small, they need to be seen clearly under a microscope. In order to prevent the burrs from piercing the separator and causing serious safety hazards, our Nanshan Battery has adopted some unique control methods."

Lin Cheng stopped talking halfway.

The other party figured it out quickly. This is probably one of the core secrets of Nanshan Battery.

“The next process is the tab die cutting and striping.”

"We know that a battery has positive and negative poles, and the tabs are the metal conductors that lead out the positive and negative poles from the battery core. In layman's terms, the tabs on the positive and negative poles of the battery are the contact points during charging and discharging."

"To put it simply, the pole die cutting is to make small ears with positive and negative poles, and then proceed to the next step of winding process."

“Here, the positive electrode sheet, negative electrode sheet, and separator film of the battery are combined into a bare cell in a rolled manner.”

"The advanced photographic inspection equipment independently developed by Nanshan Equipment for our factory can realize automatic detection and automatic correction to ensure that the battery pole pieces are not in position."

"then……"

Lin Cheng had to stop near the equipment of each process to give Phillips and others a good introduction.

In addition to not being able to take photos, some confidential content will not be explained in detail, and other things are basically known.

Such an on-site visit will naturally allow Phillips and others to fully appreciate the technological advancement of Nanshan Battery.

If they just talked in the conference room, Phillips and others just thought that the introduction materials of Nanshan Battery were good, but they still had questions about the technology.

Well now after visiting the factory, most of the doubts have disappeared.

"Mr. Lin, what kind of tests will your batteries do before they come off the assembly line?"

For products like batteries, production is important, but it is also important to ensure that the parts produced meet the drawing requirements.

And these need to be achieved through testing.

"Before our batteries come off the production line, we will check the full performance of the module, including module voltage and resistance, battery cell voltage, withstand voltage test, and insulation resistance test."

"Each battery pack contains several battery cells, integrated with connectors, controllers and cooling systems, and packaged in an aluminum shell."

"It is automatically tightened by bolts and connected by electrical connectors. Even if a failure occurs, only a single module needs to be replaced instead of the entire battery pack. The maintenance workload and risk are greatly reduced. Replacing the module only requires replacing the cooling system. Disassembly does not involve other components.”

"In addition, we will also conduct a series of tests such as vibration testing, extrusion testing, and collision testing to ensure that the battery pack meets the usage requirements."

"Of course, the test items in this area can also be adjusted and added based on customer needs."

Lin Cheng is very confident in the Nanshan battery factory.

Along the way, he also watched the reactions of Phillips and others.

Obviously, the other party is also very satisfied with Nanshan batteries.

"Mr. Lin, can you explain in detail how the extrusion test is done?"

Phillips recalled that when BMW MINI E was undergoing road testing in Europe, there was a car accident and the battery caught fire after being squeezed, which affected the launch work.

Now I heard that Lin Cheng said that the test project included a squeeze test, and I was immediately full of interest.

"The squeeze test is used to simulate the situation when the battery is squeezed in a traffic accident. As the deformation of the battery increases, the positive and negative current collectors will be torn first."

"A very large current is generated at the short-circuit point, and the heat is concentrated and released, causing the temperature of the short-circuit point to rise sharply. Therefore, it is easy to cause thermal runaway and then cause a fire or explosion."

"During the extrusion test, pressure will be applied until the battery pack shell is significantly deformed, the internal structure is damaged, the battery core is punctured by internal components, and a high-voltage short circuit occurs, causing thermal runaway."

"The passing criteria for the extrusion test are generally no fire or explosion."

"Nanshan Battery's products can even continue to work normally to a certain extent despite being extruded and deformed."

"Phillips, look, this is our extrusion test bench. The force exerted by this equipment on the battery pack is ten tons."

"The weight of a 12-meter bus is 7 tons, and the weight of passengers and luggage is close to 10 tons. This means that this can at least simulate the crushing of a 12-meter bus during an impact."

“As for the crush test simulation of passenger cars, that’s even more problematic.”

After hearing what Lin Cheng said, Phillips breathed a sigh of relief.

It seems that Nanshan Battery has a good solution for this problem that I am worried about.

Then the cooperation between the two parties is really promising.

When the group visited the production site and returned to the conference room to communicate, the atmosphere became noticeably more relaxed and harmonious.

BMW people proactively stated that they would send BMW's various requirements for battery packs and cells to Nanshan Battery, so that Nanshan Battery could confirm whether it could meet all the above requirements.

As long as it is determined that Nanshan Battery can meet these requirements, BMW will issue a formal RFQ (request for quotation), and the two parties will officially enter a new stage of fixed-point cooperation.

Once Nanshan's battery quotation meets BMW's expectations, it can directly sign a strategic cooperation agreement and discuss how to supply batteries for BMW's new models.

In this regard, Nanshan Battery naturally has no problems.

Even in the next few days, Lin Cheng arranged for a group of people to interpret and confirm the technical requirements of BMW cars overnight.

There are hundreds of pages of content, and it takes a lot of time to confirm page by page.

However, the technical level of Nanshan batteries is very high, and most of the requirements for BMW cars are relatively basic.

Therefore, although there are many terms, it is not very difficult to correspond to them.

Occasionally, if there are one or two requirements that are not well understood, they can be quickly resolved by communicating directly with the other party.

Therefore, less than a week after Phillips and others visited, Nanshan Battery gave its own reply to the technical requirements of BMW cars.

All can be satisfied!

Many indicators even exceed technical requirements!

In this regard, the people at BMW are naturally very happy.

Not only did an RFQ be issued immediately, but it was also decided that the R\u0026D personnel from the German headquarters would come over for further communication.

At this time, rumors began to spread that Nanshan Battery would cooperate with BMW.

Some people are anxious.