Silicon-based anode, low-key development of electric vehicle "α"

This article is based on publicly available materials and is for informational purposes only and does not constitute any investment advice.

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 "subvert" the existing mainstream route with technology.

For obscure companies, this trick is still very popular.

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

As everyone knows, Tesla is likely to be among the investors of this company.

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

In fact, Amprius' 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 50% higher than that of batteries at that time in 3-4 years, that is, more than 400Wh/kg batteries.

In September of the same year, on the preview page of the tesla battery day near the event, Tesla released the registration page for the battery day event, and the background picture of the page was a new battery material - a structural diagram of silicon nanowires.

Silicon nanowires are a known technology that addresses the pain points of silicon itself in terms of easy expansion, fragmentation, and circulation in battery applications.

However, at the "Battery Day" of that year, Tesla did not announce anything about silicon nanotechnology, but only mentioned that in the future battery anode materials, especially in the 4680 battery, the proportion of silicon anode materials will be gradually increased to improve battery performance.

At that time, some insiders pointed out that the relationship between Amprius and Tesla was very mysterious, and the amprius office site was near Tesla's battery manufacturing plant, and some news even said that it had moved its office to Tesla's battery laboratory.

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

Researchers at Stanford University found that using nanotechnology, lithium can be stored in tiny silicon nanowires, which are about one thousandth of a piece of paper, and silicon nanowires still expand after absorbing lithium, but nanotechnology prevents silicon from cracking, achieving the highest energy/power ratio on the market.

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

In summary, it can be seen that the 450Wh/kg lithium battery claimed by Amprius Company, from the perspective of material application, should currently rely on silicon nanotechnology on the negative electrode, and a large number of silicon anodes are used 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 when to mass produce. If the relationship with Tesla is really not ordinary, then the "Tesla killer" can not be talked about, even if it is not related to Tesla, then "hanging Tesla" may only be a publicity gimmick.

However, from here we can also see that silicon has great potential in lithium battery anode materials, whether it is domestic companies, or foreign companies, are accelerating the application of this material. Especially in the Chinese market, the next few years are expected to be a stage of rapid increase in the penetration rate of silicon anode materials.

In 2021, car companies including Weilai, GAC Aegean, and Zhiji Automobile have applied power batteries using silicon anode materials on representative models, and Tesla has also begun to use silicon-containing anode materials in 2170 and 4680 batteries.

For example, GAC Aion LX has been selected into the 10th batch of new energy vehicle recommendation catalogues of the Ministry of Industry and Information Technology of the People's Republic of China in 2021, using sponge silicon anode chip battery technology, NEDC endurance of up to 1008km.

On the battery side, on February 19, Tesla announced that it had produced 1 million 4680 batteries at a pilot plant in California. This also proves that Tesla's self-produced batteries have been officially put into production, and the use of silicon anodes has begun to start rapidly; Guoxuan Hi-Tech released a lithium iron phosphate battery with an energy density of 210Wh/kg in early 2021, which is the first time that it has successfully applied silicon anode material in lithium iron phosphate batteries, in addition, Guoxuan Hi-Tech uses a semi-solid ternary battery of silicon anode material, the energy density has been near 360Wh/kg, and Guoxuan Hi-Tech currently has a production capacity of 5000 tons of silicon carbon anode material; Zhiji automotive battery suppliers come from the NINGDE era, indicating that the NINGDE era has also introduced silicon anode products on high-performance batteries.

In addition, many battery companies, including Fu Neng Technology, Ewell Lithium Energy, Weilan New Energy, Lishen Battery, Xingheng Power Supply, BAK Battery and so on, are also advancing rapidly in this regard.

On the foreign side, in addition to Tesla, Samsung SDI previously said that it will launch a second-generation battery with a silicon content of 7% in 2021 and a third-generation battery with a silicon content of 10% in 2024.

"Spring River Plumbing Duck Prophet", as an upstream materials enterprise, is based on market demand research and judgment, as well as orders from battery customers, to increase the layout of silicon anode material production capacity.

On February 16, Bertrui announced that the company intends to invest in the construction of a project with an annual output of 40,000 tons of silicon-based anode materials in the Guangming District of Shenzhen, with an estimated total investment of 5 billion yuan. Among them, the first phase is planned to be completed and put into operation by the end of December 2023 with an annual output of 15,000 tons of silicon-based anode material production capacity.

In November 2021, Silicon Treasure Technology announced that it will set up a wholly-owned subsidiary in Sichuan Pengshan Economic Development Zone To build a silicon carbon anode material for 10,000 tons /year for lithium batteries.

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

In addition, many material companies, including Putailai, BASF Shanshan, Zhongke Electric, Tianmu Pilot, Yijin New Energy, Gelong New Materials, Zhengtuo New Energy, Xiangfenghua, Xinan Chemical and other materials companies have also laid out the production capacity of silicon anode materials, and it is expected to further expand production capacity in the future.

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

Source of this article: Battery China