High-end diaphragm technology for lithium batteries needs to be broken

At present, the US-sponsored sword refers to the "Made in China 2025" trade war continues to ferment, "ZTE event" caused a strong shock in the industry. Recently, the United States seems to be pointing its finger at Huawei, the global communications equipment giant, once again touching the pain point of China's manufacturing industry lacking core technology. In the raging trade war, the United States is pressing harder and firing on multiple lines. China's power lithium battery industry should also guard against similar risks.

According to Battery China.com, there are more than 200 power battery manufacturers in China, and it is the country with the largest number of power battery companies in the world. According to the data, Chinese companies accounted for 7 of the top 10 global power battery sales in 2017. According to Forbes News, China's share of the global battery market is expected to exceed 70% by 2020.

Although China has formed a relatively complete power battery industry chain, the scale is already "big", but not enough "strong". Some key core technologies are still subject to people, and there is a risk of ZTE's "being necked".

Among them, lithium battery separator technology is a pain point in China's power battery industry. In the lithium ion battery materials, the positive and negative materials and the electrolyte are basically localized, and the diaphragm starts late, and the technical maturity of domestic enterprises is not high. Although the localization rate of lithium battery separators in China has been increasing in recent years, it is mainly dominated by the low-end 3C battery separator market. The localization rate of high-end diaphragms is still very low. The high-end 3C batteries and diaphragms for power batteries still rely heavily on imports. .

According to the "Energy Conservation and New Energy Vehicle Industry Development Plan (2011-2020)" issued by the Ministry of Industry and Information Technology, by 2020, the production capacity of China's pure electric vehicles and plug-in hybrid vehicles will reach 2 million vehicles per year. Based on this estimation, the demand for high-quality automotive power battery separator materials required by China in the future will reach hundreds of millions of square meters.

It is well known that in the structure of a lithium battery, the separator is one of the key inner layer components, both to prevent contact between the positive and negative electrodes and to ensure the passage of electrolyte ions. Therefore, the quality of the diaphragm will directly affect the capacity, cycle and safety performance of the battery. The separator with excellent quality plays an important role in improving the overall performance of the battery.

It is reported that the diaphragm is the highest value-added material with the highest technical barriers in lithium-ion materials, accounting for about 15% of the cost of lithium batteries. The technical difficulty lies in the engineering technology, matrix materials and manufacturing equipment for pore-forming.

The current common problem in domestic diaphragms is that the consistency is not high, mainly in the irregular defects, the porosity is not up to standard, the thickness pore, distribution and pore size distribution are not uniform, the uniaxially stretched domestic PP separator is similar to foreign products in terms of porosity and pore size distribution; the porosity of the bi-directional step-stretched PE membrane is generally lower than that of foreign products, and the pore size distribution is not ideal. These problems are the potential risks of the industry being “subject to people”. If it is not solved well, it may curb the healthy development of China's lithium battery industry.

According to Battery China.com, the PP diaphragm of Celgard Diaphragm Co., Ltd. and the PE diaphragm of Asahi represent the highest level of products in the diaphragm industry. Since the acquisition of Celgard by Asahi in 2016, the best diaphragm products have come from Asahi. Several other Japanese companies, such as UBE and Toray, also have higher levels. China has a huge gap between PP diaphragm and PE diaphragm technology and the United States, Japan and other countries, and is in a passive position in the industrial chain.

At present, the preparation method of the lithium ion battery separator is mainly divided into a wet method and a dry method. China's lithium-ion battery separators have made major breakthroughs in the dry process. However, in the field of wet-membrane, domestic diaphragm companies are limited by many factors such as process and technology, and the product level is still low. The production equipment relies heavily on imports.

Like chips, high-end diaphragm technology has a very high threshold, not only to invest huge amounts of money, but also to have a strong R & D and production team, skilled process technology and high-level production lines, and can be broken in a short time. However, the Sino-US trade war and the ZTE Huawei incident have already sounded the alarm for China's manufacturing industry. For the entire power battery industry, it is imperative to break through the high-end diaphragm technology of lithium batteries as soon as possible.

Fortunately, domestic companies such as Zhongke Technology and Xingyuan Materials have made major breakthroughs in high-end diaphragm technology. It is believed that in the near future, China's power lithium battery industry will be able to break the monopoly of foreign technology and take the initiative in its own hands.

Long shackles are in hand to be able to shackle the dragon. Especially when China's manufacturing industry encounters the "backwind" of the international economy, only by mastering the core technology will it not be subject to people, and it will be able to avoid the "Zhongxing" crisis and become a true "market king"!

The page contains the contents of the machine translation.