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In recent years, emerging industries such as new energy vehicles and energy storage have experienced high prosperity, and the output of lithium batteries has shown explosive growth. Lithium battery companies in the world put forward more stringent requirements for high energy density, high safety, and quality and efficiency improvement of lithium battery materials. The composite current collector has become one of the best solutions to increase the energy density of batteries due to its advantages in energy density, cycle life, safety and battery cost. Among them, the new technology composite copper foil is a typical representative.
1. What is composite copper foil?
Lithium battery copper foil is the key basic material of lithium battery anode. In lithium ion battery, it is not only the carrier of anode active material, but also the collector and conductor of anode electrons. The thickness of the traditional copper foil used in the anode is usually 6um-12um, which accounts for about 9% of the battery mass and 8%-10% of the cost. In addition to reducing the thickness of copper foil, composite copper foil is another alternative to traditional copper foil.
The composite copper foil has a "copper-polymer material-copper" sandwich structure, with polymer insulating resin PET/PP/PI and other materials as the "sandwich" layer, and metal aluminum or metal copper is deposited on the upper and lower sides. The common thickness specification is 4.5 μm, and copper layers are respectively plated on both sides of the base film, and the common specification is 1 μm.
Due to its good electrical conductivity, flexibility, machinability, mature processing technology, and low processing cost, copper foil is the first choice for the anode material carrier and current collector of lithium batteries. It plays the role of conducting and collecting the lithium battery current to generate the maximum output current.
2. Advantages of composite copper foil over traditional copper foil
In the production of lithium batteries, the anode active material is uniformly mixed with about 90% anode active material carbon material, 4%-5% acetylene black conductive agent, and 6% - 7% binder. Then it is coated on the surface of copper foil current collector, and after drying, rolling, slitting and other processes, the anode can be obtained. Therefore, in addition to the anode active material, the performance of the copper foil also has a great influence on the performance of the lithium battery. It can be said that composite copper foil, as a new type of anode current collector material for lithium batteries, has the advantages of high safety, high specific energy, long life, low cost, and strong compatibility.
It is expected to replace traditional copper foil and become the mainstream technology route. Compared with traditional copper foil, composite copper foil has the advantages of good safety, light weight, which helps to increase energy density, and low expected cost of mass production. Composite copper foil can be used in lithium iron phosphate batteries, ternary lithium batteries, and sodium-ion batteries, effectively improving safety and energy density. The direction and purpose of the research and development of lithium battery copper foil is light and thin, low cost, and composite copper foil is one of the important research and development directions.
As a battery anode collector, it has the advantages of high safety, low cost, and improved battery quality and energy density. It will gradually replace traditional copper foil in the future. According to estimates, the demand for composite copper foil is expected to reach 3.93 billion m2 in 2025, totaling 19.6 billion RMB, and the composite copper foil equipment is about 14.3 billion RMB. It can be said that composite copper foil is about to open a tens of billions of blue ocean market with huge development potential.
3. China's lithium battery copper foil potential continues to grow
From the perspective of the increase in lithium battery copper foil production capacity, the main increase from 2022 to 2023 will mainly come from mainland China and some other Asian countries. In general, the increase in lithium battery copper foil production capacity in 2022 will be 183,400 tons, of which mainland China will account for 88%. In 2023, the capacity increase of lithium battery copper foil will be 197,500 tons, all of which will come from mainland China. The huge demand has driven China's composite copper foil to form a complete industrial chain.
The upstream is raw material and equipment manufacturers, the midstream is copper foil manufacturers, and the downstream includes power, consumption, and energy storage battery factories. Among them, the upstream equipment and base film have great potential for home substitution in China. Specifically, the composite copper foil base film mainly adopts PET base film, and the permeability of PP base film will be improved after the introduction of water electroplating process. The core production equipment of composite copper foil includes magnetron sputtering equipment, water electroplating equipment and ultrasonic seam welding equipment.
4. Composite copper foil industrialization is accelerating
From the trend point of view, China's composite copper foil industry has increased its layout in recent years, and its industrialization has accelerated. For example, in 2021, China's lithium battery copper foil production capacity will reach 316,000 tons, a year-on-year increase of 37.99%, accounting for 43.8% from 30% in 2017. Many copper companies are gradually laying out composite copper foil, CATL, EVE, BYD and other power/energy storage battery manufacturers continue to increase their investment, actively develop and apply for patents related to composite current collectors, and promote the verification of composite current collectors.
In the global data, as of the end of 2021, the lithium battery copper foil production capacity of WASON, NUODE, DEFU, and JIAYUAN in lithium battery copper foil companies ranks among the top in the world. According to estimates, the demand for composite copper foil is expected to reach 3.93 billion m2 in 2025, totaling 19.6 billion RMB. Composite copper foil equipment is about 14.3 billion RMB, including 6.9 billion yuan magnetron sputtering equipment and 7.4 billion RMB water electroplating equipment.
Under this trend, assuming that the penetration rate of composite copper foil increases to 20% in 2025, the scale of composite copper foil in China will increase from 20 million square meters in 2021 to 3.92 billion square meters in 2025, and at the same time increase from 90 million RMB to 19.61 billion RMB. With technological progress and cost reduction, the unit price of composite copper foil has dropped slightly year by year, from 6 RMB per square meter in 2021 to 5 RMB per square meter in 2025. The reduction in cost and price means that China's composite copper foil is about to open a tens of billions of blue ocean market, with huge development potential.
Related articles: lithium battery copper foil, lithium ion battery anode material companies, battery materials