Heading towards 400Wh/kg! New changes in lithium battery materials

In the new energy passenger car market, although the growth rate of plug-in hybrid (including extended-range) models far exceeds that of pure electric models at this stage, a considerable number of people in the industry believe that although hybrid models are currently showing a rapid rise, they will ultimately rely on pure electric models. Because pure electric vehicles are the ultimate weapon to replace fuel vehicles and realize the electrification of passenger cars.

In order to truly lead this disruptive innovation of "replacing fuel vehicles", pure electric vehicles still need to improve in terms of high safety, long range, low cost, and fast energy replenishment. Taking the increase in vehicle range as an example, with the launch and delivery of new models such as the new NIO ET7, Zhiji L6, and Zeekr 001, China's pure electric passenger vehicles have entered the "1,000-kilometer range era" ahead of the world.

It is worth mentioning that behind the driving range of more than 1,000 kilometers, the research and development and application of battery cells with an energy density exceeding 360Wh/kg has become the focus of the layout of leading battery companies for the "next generation" battery cells.

In fact, China's mainstream battery companies including CATL, BYD (Fudi Battery), EVE Energy, Zhengli New Energy, Guoxuan High-tech, Farasis Energy, Xinwoda, Ruipu Lanjun, Lishen Battery, Honeycomb Energy, Tailan New Energy, and Qingtao Energy are all focusing on the research and development of high-energy-density battery cells.

It is worth noting that the application of new materials is a key factor in the development of the "next generation" high-energy-density battery cells. How to ensure the high safety of batteries while improving the energy density of battery cells? How to upgrade the material production process to improve the battery cell yield and production efficiency? How to reduce material costs to enhance the market competitiveness of pure electric vehicles equipped with high-energy-density batteries? These issues have not only attracted great attention from leading battery companies, but also spawned application opportunities for new materials.

Industry insiders said that among the new battery materials that can be mass-produced at present, composite current collectors (including composite aluminum foil and composite copper foil) are regarded by the industry as one of the new materials that can comprehensively improve the performance of battery cells. Its application will help battery companies further increase the energy density of battery cells, improve battery safety and production efficiency, and reduce material costs.

According to market news, GAC Aion's Bullet Battery 2.0 and CATL's Kirin Battery, which will be launched in 2023, both use composite current collector technology, and relevant installation news has been revealed. As a result, the composite current collector has begun to enter the "market introduction" stage.

The agency predicts that by 2027, the global market demand for composite copper foil will reach 874,000 tons, or 13.99 billion square meters, with a five-year compound growth rate of 105.8%; the market demand for composite aluminum foil will reach 21,000 tons, or 620 million square meters, with a five-year compound growth rate of 68%. In the future, the market size of composite current collectors will exceed 100 billion.

△The picture shows Li Yongwei, Chairman of Anmate Technology (Beijing) Co., Ltd., giving a speech

"Composite current collectors are new materials that have emerged in response to the development trend of battery technology. They have a 'sandwich' structure, which is different from traditional copper foil and aluminum foil." Recently, at the "5th International Exchange Conference on New Energy Vehicles and Power Batteries (CIBF2024 Chongqing)", Li Yongwei, Chairman of Anmat Technology (Beijing) Co., Ltd., shared the cutting-edge technology of composite current collectors and Anmat's research and development results with the delegates.

01

Composite current collector has obvious advantages

Industry insiders believe that the energy density of power battery cells that can be mass-produced currently exceeds 360Wh/kg and is heading towards 400Wh/kg. In this process, it is becoming increasingly difficult to ensure and improve the high safety of batteries.

At the same time, in application scenarios such as new energy vehicles and energy storage, the problems caused by battery thermal runaway are still relatively prominent, among which internal battery short circuit is one of the main reasons.

The composite current collector technology developed by Anmate Technology is expected to fundamentally solve the above-mentioned industry pain points and seize the high ground in the new lithium battery material market.

It is reported that based on the five innovative technologies of metal polymer interface modification technology, deposition layer crystal structure control technology, high-efficiency vacuum evaporation deposition technology, large-scale manufacturing adaptation technology, and product structure design for application scenarios, Anmat Technology's composite current collector products have the following advantages over traditional current collectors:

First, high security

According to Li Yongwei, "The composite current collector adopts a 'sandwich' structure, which is a new type of lithium battery current collector material made of polymer materials as the middle substrate and two layers of deposited metal. Therefore, the composite current collector has an active safety mechanism. When it is cracked by needle puncture or other circumstances, the extremely thin conductive layer is melted by high current and the middle layer polymer substrate structure fails, which can quickly block the positive and negative short circuits in a very short time, thereby fundamentally solving the problem of fire and explosion caused by thermal runaway."

Second, reduce the amount of metal used

Traditional current collectors are generally 6μm metal copper/aluminum foil, while Anmetal Technology's composite current collector is 1μm metal copper/aluminum foil + 4~8μm polymer substrate + 1μm metal copper/aluminum foil, which significantly reduces the use of metal materials. For the composite copper foil market, Anmetal Technology expects to reduce the use of about one million tons of metal copper by 2030.

Third, improve the energy density of the battery cell

Through material innovation, the current collector can be made lightweight. For example, the density of the PET substrate of PET composite copper foil is less than 1/6 of the density of copper, which can increase the energy density of the battery cell by 5%-6%.

Fourth, reduce costs

According to reports, taking PET composite copper foil as an example, its metal usage is reduced by 2/3, and the unit volume cost of PET substrate is 2% of copper. The cost reduction effect of using PET composite copper foil to replace traditional copper foil is significant. At the same time, when the yield rate of composite current collector reaches 95%, its production cost is estimated to be reduced by about 70%.

Fifth, it has good adaptability to battery functions

Adopting the composite current collector technology of Anmat Technology, the pole piece is burr-free and has high process adaptability.

There is a saying in the new energy vehicle market that "safety is the highest level of luxury for passenger cars". In the view of Battery China, while leading battery companies are moving towards 400Wh/kg, firstly, composite current collectors can greatly improve the safety of high-energy-density batteries through their active safety mechanisms. This is one of the core values ​​of composite current collectors replacing traditional current collectors; secondly, as power cells enter the "0.3 yuan/Wh era", composite current collectors provide battery companies with a path to significantly reduce material costs; thirdly, the "all-dry one-time vacuum evaporation film forming technology" adopted by Anmate Technology can deposit a functional layer of up to more than 2000 nanometers on the base film at one time, which also meets the requirements of lithium electrode manufacturing and has broad application potential.

02

Fully dry one-step vacuum evaporation film forming technology

Extreme manufacturing in the TWh era for the lithium battery industry requires new materials to give battery cells higher performance and faster manufacturing efficiency.

According to Li Yongwei, Anmat Technology is the first in the industry to develop the "all-dry one-time vacuum evaporation film-forming technology". Compared with the "multiple plating" technology currently used by most of the industry, Anmat Technology can vacuum evaporate and deposit a 1000-nanometer metal layer in one time.

Taking composite aluminum foil as an example, the calendering process of traditional aluminum foil requires 8-9 steps, and the workshop is dusty and foreign matter is difficult to control; while using the full dry one-time vacuum evaporation film-forming technology, the composite aluminum foil manufacturing process only requires 2-3 steps, and the vacuum cavity constitutes a closed environment, making the product cleaner.

From the perspective of material properties, this composite aluminum foil has outstanding advantages in key indicators such as conductivity, ductility, tensile strength, bonding strength, tensile strength, surface tension, etc. It can improve the performance of the electrode and help improve the core indicators of lithium batteries such as energy density, charge and discharge rate, and cycle life.

In terms of composite copper foil, Anmat Technology uses "magnetron sputtering + vacuum evaporation" to form a metal coating on the surface of the substrate. In terms of material performance, it has obvious advantages in mechanical strength, resistivity, bonding strength, production capacity, etc.