Energy density 450Whhand kg? Behind it is another new material that is on the rise!

With the in-depth development of the power battery industry, and the market pattern has initially taken shape, whether new enterprises want financing, or development, the best way is to use technology to "subvert" the existing mainstream route.

For little-known companies, this move is still very popular.

Recently, an Amprius company in California announced that it has produced a batch of lithium batteries with ultra-high energy density, with a single cell energy density of 450W / kg, 73% higher than that of Tesla Model 3. Some media use "hanging beating", "complete victory", and even "Tesla killer" to describe it.

Unexpectedly, Tesla is likely to be one of the investors in this company.

According to reports, Amprius claims to achieve the high energy density lithium battery of 450Wh/kg, mainly using silicon nanowire technology, so that a large number of silicon materials can be used in anode materials. Compared with the current mainstream graphite negative electrode, silicon itself has ultra-high gram capacity (the theoretical mass specific capacity of silicon is about 4200mAh mAh/g, while that of graphite is only 372mAh / g). Based on silicon nanowire technology, the proportion of silicon in anode materials is greatly increased, and the monomer energy density is higher than that of 400Wh/kg.

In fact, Amprius's silicon nanotechnology may have been used in cooperation with Tesla for a long time.

In August 2020, Tesla CEO Musk said on social media that Tesla would mass-produce batteries with a longer life and an energy density of 50% higher than that of the cell at that time, that is, more than 400Wh/kg, within 3-4 years.

In September of the same year, on the event preview page near Tesla's Battery Day, Tesla released a registration page for the Battery Day activity, with a background picture of the structure of a new battery material-silicon nanowires.

As a known technology, silicon nanowires can solve the pain points of easy expansion, fragmentation and circulation of silicon in battery applications.

However, on the "Battery Day" that year, Tesla did not announce anything about silicon nanotechnology, but only mentioned that the application proportion of silicon anode materials will gradually increase in the future battery anode materials, especially in 4680 batteries. To improve battery performance.

At that time, some people in the industry pointed out that the relationship between Amprius and Tesla was very mysterious. The location of Amprius office was near Tesla's battery manufacturing factory, and it was even reported that he had moved his office to Tesla's battery laboratory.

As mentioned earlier, silicon as a negative electrode material can greatly increase the energy density of the battery compared with graphite, and it has always been considered as one of the next generation mainstream anode material routes, but because the volume of silicon changes greatly in the process of charge and discharge, it is easy to break, so there are difficulties in application.

Researchers at Stanford University have found that using nanotechnology, lithium can be stored in tiny silicon nanowires, which are about 1/1000 of the thickness of a piece of paper. Silicon nanowires still expand after absorbing lithium, but nanotechnology can prevent silicon from rupturing and achieve the highest energy-to-power ratio on the market.

Cui Yi, founder of Amprius, a Chinese professor at Stanford University, has been working on the synthesis of nanomaterials and took the lead in combining nanotechnology with batteries.

To sum up, it can be seen that the 450Wh/kg lithium battery claimed by Amprius, from the perspective of material application, should rely on silicon nanotechnology on the negative electrode and use a large number of silicon negative electrode instead of graphite. However, the current performance of this battery in many aspects, such as cost, cycle, industrialization process and so on, remains to be seen, and there is no clear timetable for mass production. If it really has an unusual relationship with Tesla, then it is impossible to talk about the "Tesla killer". Even if it has nothing to do with Tesla, then "beating Tesla" may just be a publicity gimmick.

However, from here we can also see that silicon has great potential in lithium battery anode materials, both domestic and foreign enterprises are accelerating the application of this material. Especially in the Chinese market, the next few years are expected to be the stage of rapid increase in the permeability of silicon anode materials.

In 2021, car companies, including Ulai, GAC Ean and Zhiji Automobile, all applied power batteries using silicon anode materials on representative models, and Tesla also began to use silicon anode materials in 2170 and 4680 batteries.

For example, GAC Ean Aion LX has been selected by the Ministry of Industry and Information Technology of the Ministry of Industry and Information Technology for the 10th recommended list of new energy vehicles in 2021, using sponge silicon negative electrode battery technology, NEDC life up to 1008km.

On the battery side, Tesla announced that it had produced 1 million 4680 batteries at its pilot plant in California. This also proves that Tesla's self-made battery has been officially put into production, and the use of silicon negative electrode began to increase rapidly. Guoxuan Tech released the lithium iron phosphate cell with energy density of 210Wh/kg at the beginning of 2021, which is the first time to successfully apply silicon anode material in lithium iron phosphate battery. In addition, Guoxuan Tech uses silicon anode material for semi-solid ternary battery with energy density near 360Wh/kg, and Guoxuan Tech currently has a production capacity of 5000 tons of silicon carbon anode material. Zhiji automotive battery suppliers come from Ningde era, indicating that Ningde era has also introduced silicon negative electrode products on high-performance batteries.

In addition, a number of battery companies, including Funeng Technology, Yiwei Lithium Energy, Weilan New Energy, Lishen Battery, Xingheng Power supply, Bic Battery and so on, are also advancing rapidly in this regard.

Abroad, in addition to Tesla, Samsung SDI has previously said it will launch a second-generation battery with 7% silicon content in 2021 and a third-generation battery with 10% silicon content in 2024.

"the ducks with warm water in the river are the first to feel the smell of spring". As an upstream material company, it is based on market demand research and judgment, as well as the order of battery customers, plus the layout of silicon negative material production capacity.

On February 16, Bertre announced that the company plans to invest in a project with an annual production capacity of 40, 000 tons of silicon-based anode materials in Guangming District of Shenzhen City, with a total investment of 5 billion yuan. Among them, the first phase is planned to be completed and put into production with an annual production capacity of 15000 tons of silicon-based anode materials by the end of December 2023.

In November 2021, Sibao Technology announced that it would set up a wholly-owned subsidiary Sibao Technology (Meishan) New Energy Technology Co., Ltd. in Sichuan Pengshan Economic Development Zone to build 10,000 tons of silicon-carbon anode materials for lithium batteries.

In December last year, Shi Da Shenghua announced that it would invest 730 million yuan to build a 20, 000-ton silicon-based anode material project.

In addition, a number of material enterprises, including Putai Lai, BASF Shanshan, Zhongke Electric, Tianmu Pioneer, Yijin New Energy, Gelon New Materials, Zhengtuo New Energy, Xiang Fenghua, Xin'an Chemical and other materials enterprises have also laid out the production capacity of silicon anode materials. it is expected that the production capacity will be further expanded next.

Under the background of the rapid development of the new energy vehicle industry, consumers have put forward higher standards for the mileage of new energy vehicles, and the corresponding demand for silicon-based anode materials in battery applications will also increase rapidly. the silicon anode industry has also ushered in a period of rapid development. The improvement of battery performance driven by this is bound to promote the rapid penetration of high-end electric vehicles in the corresponding market.