There are still nearly two months before New Year's Day. Wu Tong feels that there is still plenty of time, so he can slow down and take things slowly, and do research and development as if he were on vacation!
Her research team had been preparing for this project for over a year. While not all their efforts were devoted to it, at least half were.
Therefore, this time Wu Tong changed her style and prepared to work with the team. She would provide inspiring guidance, while the team would do the actual operations, which would also further enhance their scientific research capabilities.
Team growth and development is also a crucial issue. She could take on all R&D tasks, but that would make her team meaningless. The team is full of talented individuals, and Wu Tong certainly wouldn't waste them! With this group of people growing up, the future is very promising!
Therefore, Wu Tong wants to use the project to give team members enough opportunities to gain experience and learn!
The news that Wu Tong wanted to bring his research team to work on this project naturally delighted the team. After so many years working on new energy batteries, it would be a lie to say they didn't want to personally achieve a breakthrough. However, compared to Boss Wu, their progress lagged behind, and for a moment, they were too embarrassed to mention it.
However, now, President Wu is willing to take them to do it together, which is equivalent to them asking for personal guidance from a top mentor. If they cannot seize and make good use of this opportunity, it would be a real waste!
Wu Tong held an initial project seminar, and several core team members seized the opportunity to speak freely.
"...Lithium is the most ideal negative electrode material, but it also poses a fatal threat. When charging, the lithium ions that return to the negative electrode will never be as obedient as people wish and turn back into a lithium metal layer. Instead, they will form a beautiful but deadly branch like a flower." Thinking of the obstacles encountered in this year's experiment, Tao Ran couldn't help but feel a toothache.
The dendritic metallic lithium formed when lithium ions are reduced during the charging process of this lithium battery is called lithium dendrites by scientific researchers, but the form of lithium when it appears on the negative electrode side is not necessarily lithium dendrites, which is collectively referred to as lithium plating.
Lithium dendrite growth is one of the fundamental issues affecting the safety and stability of lithium-ion batteries. The growth of lithium dendrites can lead to instability in the electrode-electrolyte interface during the cycling of lithium-ion batteries, destroying the formed solid electrolyte interface (SEI) film. During their growth, lithium dendrites continuously consume electrolyte and lead to irreversible deposition of metallic lithium, forming dead lithium and causing low coulombic efficiency.
Once this thing is formed, it will continue to grow uncontrollably with continuous charging, and will eventually pierce the diaphragm like a sharp fork and contact the positive electrode. In this state, it is no different from a wire together with the positive and negative poles of the battery. A direct short circuit is a minor problem.
Organic electrolytes are flammable. The formation of lithium dendrites can pierce the separator, causing a short circuit within the lithium-ion battery, leading to thermal runaway and potentially combustion and explosion. Ruan Chengxu cooperated well and carefully analyzed the issue.
"A classic example of lithium dendrites is the Moli company. Their product almost made history, but because they used lithium as the negative electrode, a major safety incident occurred. This led to the recall of NTT mobile phones, which once led to the decline of Moli. Later, they declared bankruptcy and were acquired. This was also closely related to this incident!"
For this reason, lithium metal was abandoned by the industry as anode material. Short circuits caused by dendrite growth turned the battery into a firebomb, bringing down a publicly traded company with a market capitalization of tens of billions. A single fatal flaw led to the downfall of a major company—truly brutal!
In contrast, Sony was very clever. They used graphite as the negative electrode and launched lithium-ion batteries, which quickly captured the market and led to the rise of Sony! However, substitutes are substitutes after all, and there is a limit to their potential.
"Current lithium-ion batteries mainly use graphite as the negative electrode. We calculated through the product LiC6 that the theoretical specific capacity of graphite is 372mAh/g. If we don't consider the cost, we can increase this number to 747mAh/g in the laboratory through graphene technology.
However, compared to lithium's capacity of 3860mAh/g, the tenfold difference is clear from the numbers. If we can make a breakthrough in this field, the future prospects will be very broad!"
This gap is what has attracted countless scientific researchers and material research laboratories to rush into the field of lithium batteries, investing heavily in experiments. The reason is that it represents a huge temptation of hundreds of billions of market prospects.
Internationally, both private companies and international sectors have not stopped researching and developing negative electrode materials for lithium metal.
"Our initial experiments were similarly arranged. We started with 95.7% graphite as the negative electrode material, sodium carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) as the binder, and copper foil as the current collector.
The graphite layer gradually tends to be preferred at different thicknesses. At 90 microns, the positive electrode active material uses LiFePO4 and the current collector is aluminum foil.
As for the diaphragm, we use a three-layer Celgard 2325 diaphragm, and the thickness is also the optimal 25 microns tested in experiments. This is also the current mainstream!
"So, we still have to find a way out in the negative electrode material coating film!" Their research over the past year has not been in vain. "We have also made many attempts here..."
Since it was a brainstorming session, no one was afraid of making a fool of themselves. Various ideas were reported one by one and everyone spoke freely. The young people's active thinking and various unique perspectives made Wu Tong and Mr. Cheng, who was also participating in the meeting, smile.
Scientific research requires this kind of brainstorming and active thinking. To use your brain scientifically, you must learn to think scientifically. This not only achieves twice the result with half the effort, but also fosters creativity. Scientific research is inherently an extremely arduous and complex creative intellectual endeavor.
Of course, on the other hand, we also require scientific researchers to work diligently and conscientiously, without any hypocrisy. Scientific research cannot tolerate falsification or reckless behavior! Because reckless behavior will cost you dearly!
"Lithium-ion batteries are sensitive to water and oxygen, and the commonly used technical methods for characterizing SEI are very limited!"
"What about conventional transmission electron microscopy?" someone raised their hand and tried to ask, "Let me throw some ideas in the air!"
Wu Tong nodded slightly. She remembered this student recommended by senior brother Zhang Shaoming. Although he was still a little green, according to the observation reports of Tao Ran and junior brother, his learning attitude was serious and he had talent. He was worth cultivating. Not long ago, he was absorbed into the core team.
Continue read on readnovelmtl.com
