Electric cars cost high due to lithium ion batteries four difficulties to break through

ଲେଖକ: ଆଇଫ୍ଲୋପାୱାର - პორტატული ელექტროსადგურის მიმწოდებელი

At present, due to the high manufacturing costs, the country is carrying high subsidies for electric vehicles. The cost of electric vehicles is costly. The most important reason is that the cost of lithium-ion batteries is too high, and the cost has exceeded one-third of the vehicle.

The reason for the cost of lithium ion battery is closely related to chemical materials involved. The positive electrode material of the positive electrode material lithium ion battery is important with lithium cobaltate, lithium manganese acid, nickel manganese cobalt, and lithium iron phosphate. Among them, lithium iron phosphate is regarded as an ideal positive material material due to the potential advantages of the circulatory life, safety and material costs of several materials.

At present, the problem is that important raw electron grade carbonate (lithium carbonate content is 99.5%) from imported, and the second is that lithium iron phosphate production technology is also from abroad. It is understood that lithium electrode carbonate can be extracted from lithium ore or saline and then purified.

my country's lithium resource is second, but due to technical issues, domestic ore extracting lithium carbonate is low in production of lithium carbonate. Salt Lake extracts electron-grade carbonate, there is no product advent. So can only import electronic grade carbonate from abroad.

Because of the large import volume, domestic companies have basically no pricing power, completely said by foreign manufacturers. Technically, my country's phosphate development is originally synchronized with the international basics, but the country has not yet been born in the real leader, the industry lacks original innovation technology. At present, there are three companies in the leading position in the lithium iron phosphate and ion battery industry, namely the US Gaobo (A123) company and Valence and Canada's Phostech Company.

Lithium iron phosphate technology is obligated abroad, the United States, Canada and other governments, do not hesitate to participate in technical barriers in the country. In the field of lithium iron phosphate materials, there are two core technical patents, one of which is a carbon technology and the other is a carbon thermal reduction technology. The former has exclusive use rights by Fosteke, Canada, and has applied for patents in my country.

The latter's patent is owned by the US Gaoobo. It has not yet applied for patents in my country, but the company has set up two companies in Suzhou, which is responsible for the production of lithium iron phosphate materials and battery manufacturing. The core patents of lithium iron phosphate ion batteries have been mastered by several foreign companies.

Foreign company patents transfer to my country will face high patent licensing fees, which make up huge potential threats to the industry. To get rid of the low-end and passive status in the industrial chain, we must work hard from three aspects: First, through technology research and development, thereby accelerating domestic phosphate patent application. The second is to lay out around the core patents of foreign companies.

The third is to strengthen battery structural design, battery combination control. The electrolyte electrolyte is used in the lithium ion battery, and the negative electrode is used to conduct electrons, and it is a guarantee for the advantages of high voltage, high ratio energy. The electrolyte is generally raw material such as high purity organic solvent, electrolyte lithium salt, and necessary additives, and under certain conditions, it is formulated.

The electrolytes of the important use of lithium-ion batteries have lithium perchlorate, lithium hexafluorophosphate, etc. However, the low temperature effect made of lithium ochlorite is not good, there is a danger of explosion, Japan and the United States have banned. The battery-made cell performance is good, no explosion hazards, strong applicability, in addition to lithium lithium phosphate, in addition to the above advantages, the processing of waste batteries is relatively simple, and is friendly ecological environment, so The market outlook of this type of electrolyte is very wide.

At present, the electrolyte supporting has basically realized localization, but the soft rib is a lithium electrolyte hexafluorophosphate that is about half of the cost of electrolyte. It is basically no company to produce. At present, the lithium hexafluorophosphate market is monopolized by several Japanese companies such as Kantong Electrochemistry, Sutrakemifa, Senfa Chemistry.

Global hexafluoro phosphate production is 4,000 tons / year or so. Japan's three manufacturers have a production of 3430 tons / year, accounting for about 85% of global production. my country Tianjin Jinniu Power Supply Co.

ТАА is currently only 250 tons / year, and is not available for sale. Lithine lithium phosphate used in domestic electrolyte manufacturers imported from Japan and Germany.

An important reason for this situation is that the technical threshold of lithium hexafluorophosphate is quite high. Lithium hexafluorophosphate requires high purity, low moisture, but because the product itself is extremely easy to absorbed, the production is very difficult, and the material and equipment are demanding, a typical high-tech, high-risk production environment, high difficult '' three high "technical products. Three important raw materials for lithium hexafluorophosphate are pentachloride, no hydrofluoric acid and lithium fluoride, which is the largest in the production process, and domestic companies have made breakthroughs in production process.

The diaphragm diaphragm is used to prevent positive and negative short circuits in a lithium ion battery, and a lithium ion transport passage is supplied during charging and discharging of lithium ion batteries. In short, the diaphragm is a layer of porous plastic film. But it directly affects the capacity, cycle performance, and safety performance of the battery.

In the component of the lithium-ion battery, it is the highest technical content, accounting for 20% to 30% of the cost of lithium ion battery. At present, 80% of my country's lithium-ion battery diaphragm rely on imports. The reason for the high film technology content is that its hole is difficult.

At present, the mainstream products of the internationally diaphragm are single-layer polypropylene (PP) nano microplate, single-layer polyethylene (PE) nanoporous membrane, PP / PE / PP, three-layer composite nano Hole film and other types. Production of PE, PP diaphragm, a multi-step, complex and precise processing process, including blow molding, cast film, continuous precision stretching, etc. The domestic diaphragm has a big gap between the uniformity of the thickness and the uniformity of the hole.

At present, the international and domestic markets are basically controlled by several powerful foreign manufacturers, such as Celgard, Entek, Japan's Astronomical, east-burn, etc. Many domestic companies have tried to break through foreign technical barriers, develop lithium-ion battery diaphragms, but the difficulty is large. The difficulty is important in the following three aspects: First, the relevant patents of traditional preparation diaphragm processes are basically monopolized by minorities in the United States and Japan.

my country lacks independent intellectual property rights in production technology; the second is the key technologies of domestic companies in the production of diaphragms. Especially in industrialization technology, many companies often come out better samples at the small test, but the consistency of products during large-scale production is poor; the third is the research and international research in my country in new processes, new methods. Synchronization, but new processes often have high requirements for equipment and process, and my country's precision processing equipment is weak, limiting industrialization.

Although the difficulty is large, the domestic septum has begun to start. Some companies have achieved some technical breakthroughs in China, such as Shenzhen Xingyuan Material Technology Co., Ltd.

, Foshan Jinhui Gaojiao Photoelectric Material Co., Ltd., Henan Xinxiang Geen New Energy Materials Co.

, Ltd., etc., these companies It has produced a lithium-ion battery diaphragm with independent intellectual property, but most of the supply, low-end markets, and further maturity of film technology.

With the gradual promotion of new energy vehicles, by 2012, it is expected that new energy vehicles will turn the demand for lithium-ion battery diaphragm to turn 10 times. The problem of domesticization of the diaphragm is solved, not only for the lithium-ion battery industry, the development of the entire electric vehicle industry will be revolutionary. The negative electrode negative electrode material content is relatively low, generally using graphite to do a negative electrode, and is the only material that achieves industrialized in the four major key components of the domestic lithium ion battery.

Domestic companies have a lot of achievements in the field of technical content. Shenzhen Beitry New Energy Materials Co., Ltd.

, Shanghai Shanxi Technology Co., Ltd., etc.

have been among the expert-level companies. Among them, Shenzhen Bertry Market Posage has ranked second in the world. Clients include more than 130 manufacturers such as Panasonic, Samsung, Hitachi, BYD.

However, although the graphite negative electrode material is successful, it can always be replaced by non-carbon materials due to the weakness of the carbon as a negative electrode. Because graphite forms a passivation film in the electrolyte, although the film can transmit lithium ions, it can cause loss of energy. Moreover, when the battery is overcharged, the graphite negative surface will precipitate metal lithium to cause battery short circuit.

As the temperature increases, the graphite negative of the lithium state will first exist with the electrolyte, and it is possible to generate a flammable gas, combustion. So the graphite is not the most ideal negative electrode material, looking for a more good non-carbon negative material is an important topic of lithium-ion battery research. Although there are currently a wide study of various non-carbon negative electrode materials, in particular, non-carbon negative electrode materials such as nanostructure in recent years, the composite oxide, titanium oxide, and titanate, etc.

, are received by many lithium-electric workers. However, there are still many problems of these materials that have not been solved, still unable to apply a lot, and the continuous improvement of routes and processes.