What is the difference between the water system and the oil system of the lithium ion battery?

Regardless of the pulping process, the ultimate goal is to closely combine the positive and negative powders and the conductive material with the current collector.

Water system - DI water (solvent), CMC (thickener), SBR (binder)

Oil system - NMP (solvent), PVDF (binder)

The positive electrode material is mostly oil-based, although the internal resistance will be too large, but the pulping effect is good, and the pole piece is dense, and at the same time, the introduction of moisture can be avoided to produce the battery flatulence and the like.

The water system and the oil system are distinguished for the negative electrode.

The water system uses deionized water as a solvent to improve battery safety and stability. The disadvantage is low adhesion.

The oil solvent is NMP, the bonding force is high, and the process is troublesome.

Refers to the binder used in the preparation of the slurry. The water system is generally LA132, which is better controlled during the preparation of the slurry; the oil system is an organic system only, NMP is a solvent binder, which is in the preparation process. Need to be closed and toxic.

Water-based ion batteries are also known as saline batteries. The biggest difference is to change the flammable and explosive electrolyte from organic to salt. The forefront of this energy density and power density through this salt water battery, simply sacrificed these two characteristics, you have to do all of these features in a battery is very challenging. That is to say, a special application based on energy storage means that you don’t have to carry this battery to run around. I will first use this energy density and power density if it is used for solar energy. It should be said that this power density is also It's not very important. If you sacrifice these two things for a while, I am more eager to pursue safety, recycling, cost and sustainability. It is called recycling, and chooses very low cost in the choice of materials. It is also in a relatively open environment and can be produced at low cost. Finally, we hope that these materials have their recycling value, that is, they can be used for recovery. It is valuable, not to say that it costs a lot of money and costs to recycle. That is to say, it is very easy to recycle in the early design. This water-based ion battery is not a thing that emerges from the air, but also has a long history of research and development, dating back to 1994. This research and development has continued since that time, and until recently, the development of this water-based ion battery has been carried out, but the process of industrialization has lagged behind. If you look up the patent for a lithium-ion battery , it is estimated that you can find 100,000 pieces, but it is not much to check the patent of this water-based ion battery. It was originally due to the fact that this famous Canadian lithium-ion battery scientist applied for the first patent in this area. In 1995, this patent had passed 20 years and had expired. Later in 2005, two professors from Fudan University issued a patent, which is also relatively early. Next up is CMU in the United States. The university's professors also issued patents and applied for patents in China and the United States. The university's professors got the famous venture capital investment from Bill Gates and KPCB, and industrialized the water battery in the United States. Enli Energy is working with Prof. Xia and Professor Yonggang Wang from Fudan University. We are now a cooperative relationship and obtained exclusive patents from Fudan University in 2005, and then started the road of R&D and industrialization.

One of the biggest challenges in stabilizing the battery in the water system is water. Those of you who have an electrochemical background know that beyond 1.23v, this is going to break down, it's not going to be 3.7v or higher like a lithium-ion battery, it's going to be curved and you're going to have to choose the right materials. At present, all the lead-acid and nickel-metal hydride, nickel-iron and other batteries in the market are also called water battery in a broad sense. Anyway, they are either acid or alkali. There is no battery in neutral water in the market. At least there is no industrialization. The difficulty is that you have to find the reactor in this neutral water, which is stuck in this window of water decomposition, and can be recycled, which I think is a challenge. With the development of material technology, this is possible. So not only do you have to find this material, which is very cheap, but you also have to solve the problem of corrosion. And now this anode material is critical, you have to find something that's stable enough to cycle in a neutral water system, and a certain specific volume. Similarly, the new battery faces the same challenge, which means that your production equipment and process cannot be bought off the shelf, and it needs to be done together with the development of process and equipment. After nearly five years of technological breakthroughs, enli energy should now say that we think we have solved this series of problems, and we will enter the mass production stage in 2017.

I mentioned this recycling just now. I think that the generalized water battery such as lead-acid battery and nickel-hydrogen battery can realize the recycling and reuse of materials, and the recycling itself is valuable. Just now, lithium-ion batteries have to be put into cost to be recycled or disposed of. Basically, this recycled raw material has value. The most important material in our system is worth recycling. This shell looks like a lead acid, which can be crushed and reused. The other is the current collector, which is a metal that has been treated with anti-corrosion treatment. After the metal has been used for a long time, the anti-corrosion layer is lowered. The rust is removed and then protected. The other is the electrode material. We are an oxide in itself. Simply put, it is broken, divided into one minute and then burned. It can be reused. I think the design of this battery, the morning of the lithium ion battery also talked about who is in charge of this old battery or the main body. We think that if we sell this battery, we would like to take this battery back. If the battery can't be used after 10 years, or how many years later the battery can't be used, I'm willing to take it back because it has value in it. This is a single cell of ours. The charge-discharge curve is such an image. The battery that ran for nearly 2 years has now ran 3,000 times and is also attenuating. This is the level two years ago, it is a 3000 cycle. After two years of hard work, our current battery will be greatly improved.

This is the technical performance of our battery and there is such a peer in the United States, they are a pioneer in this industry, starting this industrialization three or five years earlier than us. We and their battery specifications from energy density to rate and cycle life, it can be said that in all aspects of the current level at the battery level exceeds it. Our battery design is modular, and we can continue to serialize a 48V module from the series of two single cells. This is like a building block, a flexible stack. There are families living in these villas abroad, such as Germany, Japan, the United States, and many of their roofs have been put on photovoltaics. In the early days, they relied on state subsidies and then sold electricity. Buy electricity from the grid while selling electricity. In this way, Germany stopped in 2020, and this subsidy stopped, and Japan will follow it. In addition, they will subsidize energy storage, you can use it yourself. For example, in the United States, there is a basement in this place, and there is also room for the battery. Because the short board of our battery is relatively large, if you have a place to put it down, it is safer and more environmentally friendly. This home application is a scenario. There is also a commercial application, and the bigger thing to do next is the microgrid application.

That is to say, the water-based ion battery that we have made can be drilled with an electric drill to release the water inside, and it will continue to work without safety problems. Not only can it be long-lived, low-cost, but the most important thing is that we can recycle it. Enli Energy applied for the reproduction of the battery. When the battery has a problem, we can let it live again. If it is an open system, the water battery can have a chance to let it live again, even if it is dead, it can be recycled, we have patent protection. Enli energy is an entrepreneurial start-up. Recently, Tsinghua  University has strategically invested in Enli energy. Now Enli energy and a series of national teams, including the institute of physics, Fudan university and USTC, have jointly undertaken the smart grid technology and sodium-based energy storage battery project of national key research and development plan in the 13th five-year plan. In addition, Enli and Tsinghua  University together form this energy storage technology industry research institute. In this research institute, it is to do energy storage. Therefore, it does not exclude any batteries. There are lithium-ion batteries in this, and there are lead-acid batteries and our water systems batteries. Welcome everyone to join us. Thank you all.

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