Energy density and mileage are always the focus of battery manufacturers. In addition to lithium, high nickel, sodium and other cathode materials, the negative electrode has also been paid more and more attention by the industry. As the mainstream anode material of man-made / natural graphite is gradually approaching the theoretical specific capacity limit, manufacturers begin to pay more attention to technological innovation.
Samsung SDI is vigorously promoting the research and development of silicon-based negative electrodes, TheElec reported today. This year, the company will launch a second generation of silicon-based negative electrodes with 7% silicon content; the third generation is expected to be released in 2024, with 10% silicon content. Previously, the company released the first generation of negative material SiO (silicon oxide) with 2% silicon content, which was first used in batteries in 2018.
In addition, according to sources, Samsung SDI's silicon anode materials have been supplied exclusively by Beitri, but now the former is considering increasing its suppliers and purchasing SiC (silicon carbide) from two South Korean companies.
The future trend of the negative electrode industry is clear and the absolute leader has not yet been decided.
Since the beginning of this year, the number of silicon-based negative electrode players has increased significantly, and the pace of technological development has also accelerated significantly. Weilai, Guangzhou Automobile and Guoxuan Hi-Tech have joined in one after another.
350Wh/kg energy density, 1000km mileage and other eye-catching words appear densely, what on earth is a silicon-based negative electrode?
At present, the mainstream anode material in the market is still graphite, but the upper limit of its theoretical capacity is 372mAhpG.At present, the high-end products have reached 360-365mAhCPG, which is close to the upper limit, so there is an urgent need for new materials with higher energy density to meet the requirements of technological progress. Therefore, the silicon with theoretical capacity 4200mAh/g has become the next generation anode material recognized by the market.
However, due to its poor electrical conductivity and serious volume expansion, it is generally used in combination with carbon materials in industrialization. according to the different sources of silicon, the silicon-based negative electrode route is mainly divided into silicon carbon (Si/C) and silicon oxygen (SiO/C). From the perspective of downstream applications, the latter is ahead of silicon carbon in commercialization and has applications in the fields of consumption and power.
Silicon-based negative electrode is still in the early stage of development, and the domestic permeability is low. Tianfeng Securities reported on July 25 that in 2020, domestic negative electrode shipments were 365000 tons, of which 9000 tons were shipped from silicon-based negative electrodes, with a permeability of only 2%. There is plenty of room for development.
In terms of market share, the above research report of Tianfeng Securities pointed out that the battery negative electrode pattern is relatively scattered, with 38% of global CR3 and 56% of domestic CR3, which is significantly lower than that of diaphragm (74%) and slightly lower than that of electrolyte (62%). In addition, the negative link did not come out of the absolute leader, TOP3 enterprises (Beitri, Pu Tailai, Chinese fir) did not open the absolute gap.
Looking to the future, the absolute leader of the industry needs to have omni-directional advantages: the high-end market pays more attention to technological competition, the negative electrode factory needs to maintain the leading technological iterative ability; the middle and low-end market pays more attention to cost competition, which depends on integration + process know-how reduction.
In terms of technology iteration, the trend towards silicon-based negative electrode is becoming more and more clear. Among the domestic industrial chain companies:
Beitre layout is the earliest (2006), the products have been supplied to Samsung and Panasonic in bulk, with a production capacity of 3000 tons, and cooperate with Huawei to develop projects related to silicon-based anode materials and apply for patent protection of related technologies. In addition, China's Baoan is the largest shareholder in Beitre, with a stake of 68.36%.
Pu Tai Lai began its layout in 2014 and cooperated with the Institute of Physics of the Chinese Academy of Sciences, which is the most advanced in silicon and carbon technology in China, and now has a pilot line.
The prospectus of Funeng Technology shows that it has high-capacity silicon-carbon anode technology and composite silicon anode material binder technology reserve.
Zhongke Electric has R & D investment in silicon-carbon anode products, with technology and product reserve;
Sibao Technology has built a pilot production line of silicon-carbon anode materials with a capacity of 50 tons per year, and a number of battery manufacturers have sent samples, which will be produced according to the cooperation progress with the manufacturers.
Shi Dashenghua plans to build a 1000 t / a silicon-carbon anode material project, including production equipment and supporting storage and transportation facilities.
