194: Chapter 194 Battery Experiments

Zhao Yang did not rush to leave. After the data processing was completed, he remained in the laboratory, watching the researchers busy at their various equipment.

Professor Wu Kai also noticed that Zhao Yang was interested in the specific experimental processes. For this mathematical genius who had solved their core problem, Professor Wu Kai showed great patience.

"Dr. Zhao, looking at data models isn't intuitive enough. Would you like to try the experimental operations yourself?"

Professor Wu Kai asked Zhao Yang with a smile, "Understand how these data turn from materials into batteries."

Zhao Yang nodded: "Sure."

Professor Wu Kai personally took Zhao Yang to the material preparation workshop and battery assembly room at the end of the corridor.

He began to introduce the complete process from materials to batteries to Zhao Yang.

"This is a homogenizer."

Professor Wu Kai pointed to a piece of equipment running at high speed.

"We mix the synthesized ternary cathode powder with conductive agent Super P and binder PVDF in a 90:5:5 ratio. Then add N-Methyl-2-pyrrolidone as a solvent, stirring it into a slurry with specific viscosity."

"What is the controlled viscosity?" Zhao Yang asked, looking at the black slurry.

"Generally, it will be between 3000 and 5000 mPa·s. If the viscosity is too low, it will flow during coating; if the viscosity is too high, the electrode surface will crack."

Professor Wu Kai explained while handing Zhao Yang a set of white anti-static clothing and gloves, "Come, try coating."

Zhao Yang dressed neatly and walked to a small laboratory-grade coating machine.

The researcher poured the stirred slurry onto aluminum foil. Professor Wu Kai guided Zhao Yang to adjust the scraper gap.

"Set the gap to 120 micrometers to ensure consistent surface density after drying. Pull at a constant speed."

Zhao Yang placed his hands on the operating lever. His physique of 18 points made his hands very steady; he did not have hand tremors or uneven force like a novice.

Accompanied by the steady mechanical sliding sound, the scraper pushed across the aluminum foil, leaving a black coating with extremely uniform thickness and a surface as smooth as a mirror.

The researcher in charge of coating nearby took a look, a flash of surprise in his eyes. This level of flatness could usually only be achieved by a skilled worker.

Professor Wu Kai next to him also looked at Zhao Yang in surprise.

"I didn't expect Dr. Zhao to have such talent in experimental operations! You did this so well; usually, it takes a skilled worker more than half a year to achieve this!"

Zhao Yang shook his head with a smile.

"My hands are just naturally steady."

"Haha, who said Dr. Zhao was arrogant? This is very humble!"

Professor Wu Kai looked at Zhao Yang with a smile, and Zhao Yang also smiled and shook his head.

The electrode pieces next to it were dried in a vacuum drying oven, compacted by a roller press, and finally punched into small round pieces with a diameter of 14 mm.

"Let's go, let's go to the next place."

Saying this, Professor Wu Kai took Zhao Yang into the glove box operation room filled with high-purity argon.

"Lithium metal is extremely sensitive to moisture and oxygen, so assembly must be performed inside a glove box. The water and oxygen content is strictly controlled below 0.1 ppm."

Zhao Yang put his hands into the thick rubber gloves of the glove box.

Following Professor Wu Kai's instructions, he picked up tweezers and sequentially placed the cathode sheet, polypropylene separator, and lithium metal anode sheet into the bottom casing of the CR2032 coin cell, added an appropriate amount of electrolyte, covered it with spacers and springs, and finally pressed it tight with a sealing machine.

For the series of actions, Zhao Yang only watched the demonstration once, and when he operated it, there were no unnecessary wasted movements. His Super Vision could clearly judge the degree of infiltration of every drop of electrolyte, ensuring there were no dead corners.

Professor Wu Kai looked at the dozen perfect coin cells Zhao Yang assembled, his eyes full of amazement.

"Really amazing! Dr. Zhao!"

"Just a small matter."

Zhao Yang smiled and shook his head.

"Alright, Dr. Zhao, verifying the data you mentioned will take some time. You can just do as you please in the lab; I still have work to do."

Professor Wu Kai said to Zhao Yang.

"Hmm."

Zhao Yang nodded.

Three days later.

The first batch of high-nickel ternary coin cells, doped with a quantitative amount of aluminum in the co-precipitation stage according to Zhao Yang's model parameters, officially came off the line.

This batch of batteries was connected in batches to a row of battery test cabinets against the wall in the lab.

In order to speed up the verification, the lab did not use the conventional 0.1C slow charge and slow discharge, but directly adopted a 1C high-rate charge and discharge protocol for accelerated aging testing.

The voltage upper limit was set to 4.3 V, and the lower limit was set to 2.8 V.

The test channel started, and green indicator lights lit up densely on the test cabinet.

Data began to be continuously transmitted back to the main control computer in the analysis room through the local area network.

As time passed, charge and discharge cycles accumulated.

The result was even better than everyone expected.

The undoped baseline control group batteries, after experiencing 100 cycles of 1C high-rate charge and discharge, had their capacity retention rate drop to 84% due to the continuous micro-cracking and phase transition of the lattice structure, and the decay curve showed an obvious parabolic accelerated downward trend.

While the experimental group optimized with aluminum doping according to Zhao Yang's mathematical model, the capacity retention rate remained steadily at 96.2%.

Researchers sent several cycled batteries into the glove box for destructive disassembly, took out the positive electrode sheets, washed away the residual electrolyte on the surface with DMC (dimethyl carbonate), and sent them into an X-ray diffractometer (XRD).

Half an hour later, the XRD diffraction pattern was printed out.

On the pattern, the (003) crystal plane diffraction peak representing the layered structure was still sharp and had extremely high intensity, while the characteristic peak representing rock-salt phase impurities was almost unobservable.

The peak intensity ratio of (003) to (104) was much greater than 1.2, which is ironclad proof in crystallography that the layered structure remained intact, proving that the material did not undergo an irreversible transformation to a non-active rock-salt phase.

The physical and chemical data confirmed the mathematical manifold mapping results that Zhao Yang derived on the computer.

Professor Wu Kai held the test report in his hand, his eyes showing strong excitement.

The core material lifespan problem that had plagued their entire core R&D team for three whole months had been completely conquered by this eighteen-year-old young man in just a few short days.

"Dr. Zhao! Thank you so much!"

Professor Wu Kai turned around, his eyes full of excitement.

Zhao Yang smiled and shook his head.

"I am compensated for my work, so this is only natural."

After all, Zhao Yang didn't come here to do charity.

CATL offered Zhao Yang the highest-level special expert contract. The terms of the contract were extremely strict and generous.

First was a strict non-disclosure agreement; all raw data and formula parameters in the lab must not be leaked to any third-party commercial organization.

As a reciprocal condition, CATL paid a fixed base salary of 50,000 RMB into Zhao Yang's personal account every month. In 2009, for a technical consultant who didn't need to punch a clock, this was definitely an astronomical price in the industry.

In addition, the contract also stipulated extremely detailed performance bonus clauses.