About the technology of high - end diaphragm of lithium ion pool

It is understood that at present, China's power battery production enterprises have more than 200, is the world has the most power battery enterprises in the country. Data show that Chinese companies accounted for seven of the top 10 global power battery sales in 2017. China is expected to account for more than 70 percent of the global battery market by 2020, according to Forbes.

Although our country has formed a comparatively perfect power battery industry chain, the size is enough "big", but "strong" enough, still had some key core technology, there is the risk of zte type "stuck" neck.

Among them, lithium battery diaphragm technology is the current power battery industry in China a pain point. In lithium ion battery materials, positive and negative electrode materials and electrolytes are basically localized, and the diaphragm started late, domestic enterprises technology maturity is not high. Although the domestic production rate of lithium battery diaphragm in China has been increasing in recent years, it mainly occupies the market of low-end 3C battery diaphragm, and the domestic production rate of high-end 3C battery and diaphragm for power battery is still very low.

According to the energy conservation and new energy vehicle industry development plan (2011-2020) issued by the ministry of industry and information technology, China will have an annual production capacity of 2 million pure electric vehicles and plug-in hybrid electric vehicles by 2020. According to this estimate, China's annual need for high-quality automotive power battery diaphragm material demand will reach hundreds of millions of square meters.

As is known to all, the structure of lithium-ion batteries, the diaphragm is one of the lining of the key components, both to prevent the positive and negative contact, and to ensure that the electrolyte ions. So the quality of the diaphragm will directly influence on the performance of the battery capacity, cycle and safety features, such as excellent quality of diaphragm plays an important role to improve the comprehensive performance of the battery.

It is understood that the diaphragm is the lithium electricity material contains the highest technical barriers to a high value-added material, about 15% of the cost of lithium-ion battery, its technical difficulty lies in the pore of engineering technology, the base material, and manufacturing equipment.

Common problems in current domestic diaphragm is consistency is not high, mainly displays in irregular defect, porosity is not up to standard, thickness, porosity and pore size distribution is not equal. Uniaxial extension of domestic PP membrane on porosity and pore diameter distribution compared with foreign products close to; Two-way stretch in stages of the PE membrane compared with foreign products usually low porosity, pore size distribution is not ideal. These problems are the potential risk of industry "others", if the solution is not good may contain lithium electric industry health development in our country.

It is reported that the United States Celgard diaphragm co., LTD., PP membrane and Asahi PE membrane, respectively represents the highest level of the diaphragm industry products. Since Celgard Asahi acquisition in 2016, the best membrane products are from Asahi. Several other Japanese companies, such as UBE and Toray, also have the high level. In PP diaphragm and PE membrane technology in China and the United States, Japan and other state-owned large gap, in a passive position in the industry chain.

At present, lithium ion battery diaphragm preparation methods mainly wet process and dry process. Lithium ion battery diaphragm in the dry process in our country has made significant breakthrough, but in the field of wet diaphragm, diaphragm domestic enterprises are limited by many factors such as technology, technical, product level is still low, a large number of imported production equipment.

Like chips, high-end membrane technology has a very high threshold, not only to invest a huge sums of money, also need to have a strong r &d and production team, skilled technology and a high level of production line, and not a short time to breakthrough. A trade war with China, zte, huawei's events, however, has been to China's manufacturing industry is a wake-up call, for the whole power battery industry, the breakthrough lithium battery high-end diaphragm technology is urgent as soon as possible.

The good news is, the domestic existing zhongke science and technology, star source material, and other enterprises in high-end diaphragm have a major breakthrough in the technology. Believe that in the near future, in our country power lithium battery industry is bound to break the foreign technology monopoly, holding the initiative in their hands.

ChangYing in hand, can be tackled, black dragon. Especially in the manufacturing industry in our country in the international economy "upwind" of the moment, only to master the core technology, not only, to avoid "zte type" crisis, to become the real "market king"!

The page contains the contents of the machine translation.