The industry is concerned about the new development of lithium-ion battery foil, covering the thickness, status, use and battery foil and electrical foils
Release time:2021-10-25Click:990
In the 20 years from 2016 to 2035, the compound growth rate of aluminum foil for automotive lithium-ion battery in China and the world can reach 15% or even higher, since the industrialization of aluminum production in 1888, never has a product grown at such a high rate for such a long time. In this paper, the basic concept of electronic/battery aluminum foil is introduced, and the general situation of electronic/battery foil enterprises which have been built or are being built in China in recent years is also introduced in detail. According to the data reviewed by the author, as of 2021, there are more than 200 large scale production enterprises in China, with a total production capacity of about 1.5 million tons per year. The production of battery foil in our country can completely meet the demand of aluminum foil for the development of automobile battery. The authors suggest that research and development of new batteries should be intensified in order to improve the performance of the lithium-ion battery, particularly its safety performance. Aluminum foil refers to the thickness ≤0.2 mm of aluminum and aluminum alloy thin strip, in some other countries have different provisions (table 1) . Aluminium foils are generally classified according to their thickness, condition and use. Divided by thickness: where the thickness of aluminum foil greater than 0.012 mm known as a single sheet foil, less than 0.012 mm said double sheet foil; there is also the thickness with a zero known as a single zero foil, after the decimal point with two zero known as double zero foil, such as 0.005 mm foil can be called Double Zero 5 foil. According to the status can be divided into hard foil, soft status foil, semi-hard foil, 3/4 hard foil, 1/4 hard foil. All-hard foil refers to foil that has not been annealed after rolling (completely annealed and cold-rolled by more than 75%) , such as container foil, decorative foil, medicated foil, etc. , such as food, cigarettes and other composite packaging materials and electrical foil, where the tensile strength of aluminum foil between the hard foil and soft foil, such as air-conditioning foil, cap foil, etc. Where the tensile strength between the full hard foil and semi-hard foil for 3/4 hard foil, such as air-conditioning foil, Foil for aluminum-plastic Pipe; Aluminum Foil tensile strength between the soft foil and semi-hard foil is called 1/4 hard foil. According to the surface state can be divided into single-sided light foil and double-sided light foil. Aluminum Foil Rolling Sheet Rolling and Double Rolling, sheet rolling, both sides of the foil and roll contact, both sides have a bright metal luster, known as double-sided foil. In double-rolling, only one side of each foil comes into contact with the roll, the side that comes into contact with the roll is bright, and the two sides that come into contact with each other are dark. The minimum thickness of double-sided smooth aluminum foil mainly depends on the diameter of work roll, usually not less than 0.01 mm, the thickness of single-sided smooth foil is usually not more than 0.03 mm, the current minimum thickness can reach 0.004 mm. Aluminum foil can be divided into packaging foil, medicine foil, daily necessities foil, battery foil, electrical foil, construction foil, etc. . The use of aluminium foil is shown in Table 2. Battery foil and electrical foil, the battery foil is used to make all kinds of battery work pieces of aluminum foil, and electrical foil is used to make other kinds of electrical work pieces of aluminum foil, they can also be collectively referred to as electronic foil. Battery foil is a kind of high-tech products, in the next few years, its annual compound growth rate can reach more than 15% . The Mechanical Properties of cable foils and battery foils are shown in tables 3 and 4. The period from 2019 to 2022 is a period of great development for Chinese battery foil enterprises. There are about 200 enterprises in production and under construction, with a total production capacity of about 1.5 million tons. Electrolytic capacitor aluminum foil is actually a deep processing products. It is a kind of corrosion material which works under polar condition. There are three kinds of aluminum foils: 0.015-0.06 mm thick cathode foils, 0.065-0.1 mm thick high voltage anode foils, 0.06-0.1 mm thick low voltage anode foils. The aluminum used for anode foil is industrial high purity aluminum, the mass fraction should be greater than or equal to 99.93% , and the purity of aluminum used for high voltage anode should be greater than or equal to 4N. The main impurities of industrial high purity aluminum are Fe, SI, Cu, and Mg, Zn, MN, Ni, Ti as micronutrient. The content of FE, SI and Cu is only regulated in Chinese standard, but not in other elements. The impurity content of aluminum foils for batteries abroad is obviously lower than that at home. According to GB/T8005.1, the aluminum foil with thickness not less than 0.001 mm and less than 0.01 mm is called double zero foil. The commonly used alloys are 1145,1235,1350, etc. . Thickness not less than 0.01 mm and less than 0.10 mm. The aluminum foil is called single zero foil, and the capacitor is usually 1235-H18(0.020-0.050 mm thick) ; the cell phone battery is 1145-H18,8011-H18,0.013-0.018 mm thick; and the cable foil is 1235-O, 0.010-0.070 mm thick. The thickness of 0.10-0.20 mm foil is called no zero foil, the main varieties are decorative foil, air conditioning foil, cable foil, bottle cap foil, shutter foil. Overview of China’s aluminum foil industry in 2020, according to the joint statistics of the Non-ferrous metal and Beijing Antaike Information Co. , Ltd. , China’s aluminum production in 2020 amounted to 42.1 million tons, 720,000 tons of aluminum foil strip billet, 4.15 million tons of aluminum foil production, the rate of finished products is 88% , which is among the highest in the world. The output of strip is 3.7% higher than that of the previous year. The output of aluminum foil by product type is shown in Table 5. The output of aluminum foil is shown in Table 5. Except for the drop of air-condition foil, all the other products have increased, especially the battery foil, which has the largest increase of 16.7% , mainly driven by the rise of automobile battery. China imported 72,000 tons of aluminum foil in 2020, up 4.8 percent from 2019, and exported 1.233 million tons of aluminum foil in 2020, down 4.8 percent from the same period last year. In 2020, China’s aluminum foil industry applied for 1,660 patents, of which 500 were for invention, 1,121 for utility model and 39 for design. According to statistics, in 2020 more than 500 foil strip rolling lines, production capacity of more than 5.5 million tons per year. As of 2020, China has imported 60-70 sets of German Ashenbach Foil Mill. Aluminum Foil in China to industrial applications in the first place, accounting for more than 60% , and industrial developed countries in packaging and household applications accounted for more than 60% . The per capita consumption of aluminum foil packaging in China is 0.72 kg in 2020, which is much lower than that in Europe, North America and Japan, which is 1.2 kg and 0.9 kg respectively. The state banned plastic in 2020, setting the 2023 as a time point. In addition to the concept of green fees, aluminum foil packaging will have great potential.
Source: Non-ferrous metal, by Wang Zhutang