Wu Hui: in 2020, the proportion of localization of lithium diaphragm in China reached 93%. Wet diaphragm shipments accounted for more than 70%.

On April 26, Super High strength + online diaphragm new products conference and industry seminar of Shanxi Lanketu New Materials Technology Co., Ltd. were held. More than 100 guests from politics, business, industry, learning and research, as well as media representatives gathered in Yongji City, Shanxi Province. jointly witnessed the release of Shanxi Lanketu new products.

At the press conference, Wu Hui, general manager of the Research Department of Yiwei Economic Research Institute and president of China Battery Industry Research Institute, delivered a keynote speech entitled "Research on the Development status and trend of Lithium Battery diaphragm Industry in China". The development status of the diaphragm industry, the competition pattern of the diaphragm industry chain, and the analysis of the development trend of the diaphragm industry are shared. Some of its wonderful viewpoints are selected by the battery network for readers:

The proportion of domestic lithium diaphragm in China reached 93% in 2020.

According to Wu Hui, global shipments of lithium-ion battery diaphragms in 2020 were 6.28 billion square meters, an increase of 21.5% over the same period last year. Among them, shipments of lithium-ion battery diaphragms in China were 3.87 billion square meters, an increase of 29.9% over the same period last year, which is higher than the global growth rate.

It is worth noting that the proportion of domestic lithium diaphragms in China rose rapidly from 40 per cent to 93 per cent from 2013 to 2020. "in the future, all types of barriers will further enhance the degree of localization." Wu Hui expects.

Judging from the proportion of shipments of different types of diaphragms in China, in 2020, wet diaphragm shipments reached 2.72 billion square meters, accounting for 70.28% of shipments, up from 29.27% in 2014; dry diaphragm shipments of 1.15 billion square meters, down from 70.73% in 2014 to 29.72%.

From the perspective of the scale of different types of diaphragm market in China, the market scale of diaphragm in China reached 4.57 billion yuan in 2020, showing a positive growth over the same period last year.

For the development characteristics of the diaphragm industry, Wu Hui analyzed that it is mainly reflected in the following points: first, overseas enterprises have increased their efforts to open up the domestic market, and domestic diaphragm enterprises have expanded and built factories overseas from simple product exports. Including Xingyuan material and Shanghai Enjie have all begun to build diaphragm factories in Europe to meet the localization requirements of overseas power battery enterprises in the future. Second, the application of wet process + coating in ternary power battery has gradually become the mainstream, but with the large-scale application of lithium iron phosphate battery in the fields of automobile, energy storage and small power, the shipment of dry diaphragm has increased obviously. Third, new diaphragm technologies emerge one after another, for example, new substrates, functional coating materials, blue coating ultra-high strength diaphragm and other new materials; Lanke coating, Enjie shares and other new online coating technology application. Fourth, the integration and reorganization between enterprises is becoming more and more obvious. Enjie acquires Jieli, Numi, Tonrui, and a joint venture with Polypore; Sinopec Science and Technology acquires Lithium; Jinli acquires Xinheng; celgard and Asahi merge; Toray and East Combustion joint venture to build a plant. At the same time, the scale of production capacity has become an important barrier for enterprises, such as Lanketu, Jiangsu Housheng, Pu Tailai, Enjie shares, Wuhan Huiqiang and other enterprises are expanding production. Fifth, the development of solid-state batteries has accelerated, and some diaphragm enterprises have begun to launch a forward-looking layout for semi-solid and solid-state products.

The coating process has become one of the important barriers to lithium diaphragm.

At the seminar, Wu Hui also said that the coating link has become one of the important barriers to lithium diaphragm.

Specifically, in 2020, domestic shipments of alumina ceramic materials for diaphragm coating are about 9000 tons, with prices ranging from 18000 yuan / ton to 24000 yuan / ton. the main domestic companies that supply high-purity alumina ceramic materials for lithium battery diaphragms include Zhejiang Polar Shield, Shanghai Huaming Gaona, Lianlian Chemical, National porcelain Materials, Qinghai Sheng Nuo, Tianma New Materials, etc., with the improvement of domestic alumina production capacity, net imports gradually decline.

The demand for boehmite in China is about 8700 tons in 2020 and is expected to maintain a compound growth rate of more than 30 per cent in the future. The global producers of boehmite mainly include Nabaltec AG of Germany, Sasol Ltd. of South Africa, Yishitong, Hehe Lime of Japan, Daming Chemical of Japan, Zhengzhou Research Institute of Chinalco and so on.

In 2020, the total domestic demand for PVDF for lithium-ion batteries reached 9700 tons, of which the market demand for PVDF for cathode materials for lithium-ion batteries was 7800 tons, and the demand for PVDF for diaphragm coating materials for lithium-ion batteries was 1900 tons. In terms of price, domestic 9-120000 / ton, import 13-200000 / ton. In PVDF positive material binder products, domestic production enterprises mainly include Shandong Dongyue, Zhejiang Funolin, Shanghai Sanai Fu, East Sunshine, etc., but in PVDF diaphragm coating products, because domestic enterprises have not yet reached the corresponding technical level, the market is still monopolized by foreign companies such as France Acoma, American Su Wei and Japan Wu Yu.

In addition, aramid coating has been widely used in the NCA battery supplied by Panasonic to Tesla. The composite coating is dispersed into inorganic particles in the polymer coating slurry, mixed evenly and coated on the diaphragm substrate. At present, it is mainly laboratory research, but it has not been applied on a large scale. Such as ceramic and PVDF mixed coating and organic-inorganic composite coating.

Wu Hui said that at present, the domestic lithium battery diaphragm coating plant can be divided into three modes: battery factory coating, base membrane factory coating and third-party coating. Including Ningde era, BYD, Guoxuan, ATL, etc., have their own coating plants, basement membrane plants including Enjie, Xingyuan material, Cangzhou Pearl, Hebei Jinli and other diaphragm enterprises have their own coating production lines, third-party coating factory from the external procurement of base membrane coating and then sold to the battery factory, on behalf of enterprises including Dongguan Zhuogao, Shanghai Dinghao, Yangzhou Lithium, Jiangsu Hillhouse, Xuran Electronics and so on.