APPLICATION

In recent days, international crude oil prices have continued to fall, and New York light crude oil has fallen below the level of $80 per barrel; Moreover, the upside may be limited in the next year or two. A recent Reuters survey showed that more than one-third of respondents believe that North Sea Brent crude will be below $100 in 2013 (currently around $91 per barrel), and nearly half believe that the average price of North Sea Brent crude oil in 2014 will be below $100.

If analysts' forecasts are accurate, oil prices will remain low for some time to come. This will undoubtedly add difficulties to the development of electric vehicles, because the economics of electric vehicles relative to fuel vehicles will be discounted. As the most optimistic source of explosive growth of lithium batteries in the future, the development prospects of electric vehicles will undoubtedly affect the development of lithium batteries and upstream materials industries.

Of course, the main body of the lithium battery industry is still consumer products. This article makes some brief analysis of the recent development of China's lithium battery upstream material industry. As we all know, cathode materials, negative electrode materials, electrolytes and separators are the four most important raw materials for lithium batteries, and they have been playing an important role in the development of the lithium battery industry.

These four materials are not only the focus of lithium battery technology innovation and performance improvement, but also the field of fierce competition for domestic and foreign manufacturers. Ternary materials gradually become stars Among the four main lithium battery cathode materials of lithium cobalt oxide, lithium manganate, ternary materials and lithium iron phosphate, ternary materials (nickel cobalt lithium manganate accounted for the absolute majority) in the first half of this year are undoubtedly the biggest stars.

Previous research by the Gaogong Lithium Battery Research Institute showed that in the past few years, the proportion of lithium cobalt oxide, which once occupied the absolute majority, in cathode materials has decreased year by year, while the proportion of other cathode materials, including ternary materials, has gradually increased, as shown in Figure 1.

According to survey statistics, the output of ternary materials in China in the first half of 2012 reached 5300 tons, an increase of 20% over the same period last year.

In the nickel-cobalt-lithium manganate ternary material, most of the Chinese manufacturers chose the ratio of 5:2:3 (that is, nickel: cobalt: manganese = 5:2:3). In addition to replacing some lithium cobalt oxide for consumer electronics due to the cost advantage, lithium batteries made of ternary materials are also widely used in electric bicycles.

It is expected that from 2014, ternary materials will replace lithium cobalt oxide as the largest proportion of cathode materials, as shown in Table 1. On the other hand, the manufacturers of lithium iron phosphate, the star material in previous years, have had a difficult operation in the past two years, due to the small overall demand for lithium iron phosphate and many manufacturers, many manufacturers have almost no sales in the near future.

Compared with lithium iron phosphate, the main advantages of ternary materials are their high gram capacity and good production consistency. New anode materials came into being The traditional lithium battery anode materials mainly include natural graphite and artificial graphite, which together account for more than 95% of the total output of anode materials in China.

China's two giants of anode materials - Shenzhen Betray and Shanghai Shanshan each have advantages in the field of natural graphite and artificial graphite, the two companies last year the output of anode materials were 7100 tons and 5100 tons, accounting for about 66% of the domestic anode material market. Since the gram capacity of the carbon anode material produced now has reached 360mAh/g, close to the theoretical gram capacity of 372mAh/g, there is little room for improvement. In this context, silicon-based anode materials with a gram capacity of about 4000mAH/g (silicon doped in graphite) came into being.

At present, Shanghai Shanshan is in the pilot stage of 100 kg. At the same time, Nanjing Amprius (headquartered in California) has successfully developed silicon nanowire anode materials, and the energy density of the whole single battery test reaches 640Wh/L, the cycle life is greater than 550 times, and the energy density is expected to reach 800Wh/L in 2014. Compared with silicon-carbon anode materials, silicon anodes are more expensive. However, Amprise claims that the cost of silicon anodes for battery manufacturers will be comparable to high-grade graphite anodes. On the other hand, lithium titanate also becomes an ideal anode material due to its "zero strain", that is, the lattice constant and volume change of lithium titanate crystals are small when they are embedded or removed from lithium ions, less than 1%.

In the charge-discharge cycle, this "zero strain" can avoid structural damage caused by the expansion and contraction of the electrode material, thereby improving the cycle performance and service life of the electrode, reducing the specific capacity attenuation caused by the cycle, and has very good overcharge and overdischarge resistance.

The lithium titanate material developed by Zhejiang Changxing Weihong Power System is said to be able to reach the level of 20,000 cycles at 6C magnification. However, the high cost of lithium titanate has become the main constraint, compared with the price of natural graphite 6-100,000 yuan / ton and artificial graphite 8-100,000 yuan / ton, the price of lithium titanate is more than 200,000 yuan / ton. With the continuous improvement of people's requirements for the performance of lithium battery materials, various new anode materials will be paid more and more attention, and will be continuously developed and marketed. Lithium hexafluorophosphate is always the focus

The main manufacturers of electrolytes in China include Jiangsu Guotai Huarong, Tianjin Jinniu, Dongguan Shanshan, Xinzhubang and Guangzhou Tianci. Among them, Cathay Huarong, which ranked first in terms of output, produced more than 4,300 tons in 2011, and about 50% of its electrolyte was exported. At present, the electrolyte industry has fierce competition at home and abroad, and there are many new manufacturers.

At the same time, many manufacturers have large-scale expansion plans, such as polyfluoride plans to reach a production capacity of 20,000 tons of electrolyte by the end of 2013, and Xinzhoubang plans to reach 12,000 tons in 2012. As the core raw material for the configuration of electrolyte, lithium hexafluorophosphate has always been the focus of attention of electrolyte companies, and has also become a field that major enterprises are vying to enter.

Among the main producers of electrolytes, Guotai Huarong, Dongguan Shanshan and Xinzhubang have not yet mass-produced lithium hexafluorophosphate. Major domestic producers of lithium salt (lithium hexafluorophosphate) include Tianjin Jinniu (about 300 tons in 2011), Henan Polyfluoride (195 tons in 2011) and Guangzhou Tianci (92 tons in 2011).

At the same time, lithium salt producers at home and abroad have different degrees of expansion plans. For example, Japan's Morita Chemical, one of the world's three giants of lithium hexafluorophosphate, has planned a production capacity of 2,500 tons in Zhangjiagang; Foosung, which claims to be South Korea's only lithium hexafluorophosphate producer, is expanding its production capacity from 2,000 tons to 3,000 tons, and its Nantong plant will start operations in January 2013. Formosa Plastics Taiwan plans to expand its production capacity from 200 tons to 1,000 tons; Polyfluoride is planned to be expanded to 2,000 tons; Jiujiu is planned to be 1600 tons. With the successive production of new production capacity, the profit margin of up to 60% of lithium hexafluorophosphate will be difficult to maintain. In addition to lithium hexafluorophosphate, high-voltage electrolytes have also become a hot spot in recent research and development. For example, a high voltage of 4.65V can be achieved in ternary materials simply by adding appropriate additives without changing the existing electrolyte system.

The rise of diaphragm domestic brands As the most technically difficult and the latest localized lithium battery material among the four major materials, the separator has become a hot spot for investment due to its high profits (for example, Foshan Jinhui's gross profit margin in 2010 was as high as 65.8% and net profit margin was 48.5%). The raw materials used in the diaphragm are mainly polyethylene (PE) and polypropylene (PP), which have low cost, so the main source of diaphragm production cost is depreciation of production equipment and low yield. Diaphragm production has the characteristics of large investment scale, high technical difficulty and long time accumulation.

The equipment for the production of lithium battery separators is not ready-made, and the manufacturer needs to participate in the design, thus becoming a technical threshold. At present, an important development trend of the diaphragm industry is the rise of domestic brands, compared with foreign diaphragm giants such as Celgard, although there is still a gap between domestic diaphragms, but in recent years there has been great progress, and the gap with foreign countries continues to narrow.

Foreign manufacturers also admit that from the perspective of the quality of domestic diaphragms (referring to the diaphragms of first-class manufacturers), their technical level is close to the international advanced level. The shortcomings of domestic diaphragm manufacturers are mainly reflected in the poor product consistency, continuous production capacity and batch stability; Process management needs to be improved.

In 2011, China's diaphragm production was mainly concentrated in Xinxiang Greon, Shenzhen Xingyuan Material and Foshan Jinhui 3 companies, as shown in Figure 2. According to the survey, according to the development of new entrants in the market and the expansion plan of the old factory, the first half of 2013 will be the concentrated release period of domestic diaphragm production capacity, and the annual production capacity is expected to reach 1 billion square meters.

In 2012, the output of domestic diaphragm is expected to be about 250 million square meters, of which Xinxiang Grid and Shenzhen Xingyuan materials are about 60 million square meters, Foshan Jinhui is about 50 million square meters, and the three giants still occupy the main share of the market.