Some experts point out that copper foil, which has the advantages of both safety, high energy density and low cost, can partially replace traditional batterycopper foil and is expected to achieve mass production in the second half of 2023, with a penetration rate of 10% in 2025. Most companies are also currently accumulating R&D, and some manufacturers have completed preparations for sample production and verification, which indicates that mass production of battery copper foil will soon begin.
Table of Contents
What is a lithium battery negative collector?
To get a clear understanding of battery copper foil, we need to first figure out what a collector is. Collector, as the name implies, is the structure or part that brings together the current, mainly refers to the metal foil on lithium-ion batteries, which can also include the pole lug. Its function is mainly to form a larger current output to the outside, and the internal resistance should be as small as possible for the best.
The function is to reduce the internal resistance of the battery and improve the Coulomb efficiency, cycle stability and multiplicity of the battery. In addition, the traditional collector, negative electrode using copper foil, positive electrode using carbon coated aluminum foil, because aluminum and copper conductivity, good ductility, relatively cheap.
The process is still undefined and controversial
The battery copper foil industry is still in its early stages and there are no real mass-production companies yet. The mainstream battery copper foil production process has not yet been defined and is still controversial.
The current battery copper foil production process mainly includes one-step, two-step and three-step processes. In addition, the current battery copper foil base film mainly includes PET and PP, of which PP has more stable chemical properties than PET, but its requirements for equipment are higher and the process is more difficult to control.
As the industrialization process advances, the process with the advantage in cost and yield is more likely to be recognized by the market, and the coexistence of several process routes cannot be ruled out in the future.
Advantages of copper foil
With battery copper foil, the polymer layer in the middle of the composite collector will melt and break the circuit when the internal short circuit occurs, which can suppress the short circuit current and control the thermal runaway of the battery, thus fundamentally solving the problem of exploding and fire of the battery cell.
In addition, the battery copper foil has the advantage of low cost. The weight of the composite collector is more than 50% lower than the pure metal collector, while the battery energy density can be increased by 5%-10%, with obvious advantages.
(一) High safety
Cells with copper foil can pass the needling test: thermal runaway does not occur when the cells with composite collectors are needled, mainly because.
(1) When the needle is pierced inside the cell and short-circuit occurs and heats up, the polymer layer in the middle of the composite fluid will melt and break the circuit, which can inhibit the short-circuit current and control the thermal runaway of the battery, and fundamentally solve the problem of explosion and fire of the cell.
(2) The burr size generated when the composite fluid collector is punctured by needles is smaller, and the chance of internal short circuit is lower.
(二) Low cost
Copper foil has a greater potential for cost reduction. For pure copper foil, raw material costs are relatively high. At a copper price of 60,000 RMB/ton, the unit cost of battery copper foil is 3.7 RMB/ping (excluding tax), of which the cost of copper is 2.85 RMB/ping, accounting for nearly 77%. The PET copper foil can reduce the amount of copper by 2/3, and the raw material cost drops significantly. According to the estimation, with 80% yield, the cost of PET copper foil after mass production is about 2.85 RMB/m2, which is 0.85 RMB/m2 lower than that of battery copper foil (3.7 RMB/m2), and the cost will continue to decrease with the continuous improvement of yield.
(三) High energy density
Copper foil has a significant role in the improvement of battery energy density. On the one hand, the density of organic materials is lower than that of metal materials, which can reduce the overall mass of the collector; on the other hand, the proportion of battery copper foil becomes less and the thickness becomes thinner, which further reduces the mass of the collector.
It is measured that the mass of 6um PET composite battery copper foil with the same area is reduced by about 56.33% compared to 6um electrolytic battery copper foil due to the lighter PET material compared to copper. According to the formula for calculating the energy density of lithium battery: mass energy density = battery capacity / battery mass, reducing the mass can improve the energy density with the same battery capacity. It is shown that MA/MC is lighter in weight, 77% lower in density than battery copper foil, and 5%-10% higher in energy density.
Industry progress of copper foil
In terms of progress, upstream, midstream and downstream enterprises in the industry chain are actively laying out PET copper foil-related fields, and each has generally completed the accumulation of research and development, and some manufacturers have completed the preparation of sample production and validation, and the battery copper foil is expected to achieve batch shipment in 2023.
Among the upstream equipment enterprises, relevant enterprises have matured the production technology of second-generation magnetron sputtering equipment. Among midstream PET copper foil manufacturers, Jinmei plans 350 million ping of PET copper/aluminum foil, which has already achieved stable production and is planning mass production.
Among the downstream battery manufacturers, CATL and EVE, one of the two wheeler lithium battery manufacturers, have applied for patents related to composite collectors, providing complete downstream technical support for PET copper foil application in lithium batteries.
Market expectation-13.7 billion by 2025
It is widely believed in the industry that battery copper foil will start industrialization in 2023, with rapid increase in penetration rate and explosive growth in the industry.
According to calculations, industry output is expected to reach 200 million ping in 2023, corresponding to 17gwh battery demand, and is expected to reach about 800 million ping in 2024, with global demand expected to reach 2.9 billion ping in 2025, a space of 13.7 billion and a penetration rate of 10%; PET copper foil equipment will have a global space of 14.4 billion in 2025.
In the long term, the penetration rate of composite battery copper foil is expected to rise to 22% in 2030, with demand reaching 19.2 billion ping, market space reaching 77.1 billion RMB, and equipment space reaching 18.8 billion RMB.
However, although copper foil has advantages in safety, cost and energy density, the thickness of the metal layer on both sides of the copper foil is generally only 1 micron, resulting in a high copper foil resistance and limited overcurrent capability. This in turn affects the overall charging and discharging efficiency of the battery.
Therefore, we believe that battery copper foil can meet the 2C charging and discharging requirements, but may challenge it in the future in areas with fast charging needs. Based on the current technical progress, in addition to the pure electric 4C application scenario, copper foil is expected to be more competitive in the markets of energy storage, battery swap, low-end and mid-range vehicles.
Dear readers, My professional journey began with a master's degree in Electronic Engineering, after which I directed my focus towards in lithium battery swap systems. As a engineer at a renowned battery company, I've not only wholeheartedly contributed to several successful battery swapping station projects, but have also gained a wealth of experience. Through my writing, I aspire to share insights and knowledge about motorcycle battery swapping for you.
Battery materials-battery copper foil presentation
Some experts point out that copper foil, which has the advantages of both safety, high energy density and low cost, can partially replace traditional battery copper foil and is expected to achieve mass production in the second half of 2023, with a penetration rate of 10% in 2025. Most companies are also currently accumulating R&D, and some manufacturers have completed preparations for sample production and verification, which indicates that mass production of battery copper foil will soon begin.
What is a lithium battery negative collector?
To get a clear understanding of battery copper foil, we need to first figure out what a collector is. Collector, as the name implies, is the structure or part that brings together the current, mainly refers to the metal foil on lithium-ion batteries, which can also include the pole lug. Its function is mainly to form a larger current output to the outside, and the internal resistance should be as small as possible for the best.
The function is to reduce the internal resistance of the battery and improve the Coulomb efficiency, cycle stability and multiplicity of the battery. In addition, the traditional collector, negative electrode using copper foil, positive electrode using carbon coated aluminum foil, because aluminum and copper conductivity, good ductility, relatively cheap.
The process is still undefined and controversial
The battery copper foil industry is still in its early stages and there are no real mass-production companies yet. The mainstream battery copper foil production process has not yet been defined and is still controversial.
The current battery copper foil production process mainly includes one-step, two-step and three-step processes. In addition, the current battery copper foil base film mainly includes PET and PP, of which PP has more stable chemical properties than PET, but its requirements for equipment are higher and the process is more difficult to control.
As the industrialization process advances, the process with the advantage in cost and yield is more likely to be recognized by the market, and the coexistence of several process routes cannot be ruled out in the future.
Advantages of copper foil
With battery copper foil, the polymer layer in the middle of the composite collector will melt and break the circuit when the internal short circuit occurs, which can suppress the short circuit current and control the thermal runaway of the battery, thus fundamentally solving the problem of exploding and fire of the battery cell.
In addition, the battery copper foil has the advantage of low cost. The weight of the composite collector is more than 50% lower than the pure metal collector, while the battery energy density can be increased by 5%-10%, with obvious advantages.
(一) High safety
Cells with copper foil can pass the needling test: thermal runaway does not occur when the cells with composite collectors are needled, mainly because.
(1) When the needle is pierced inside the cell and short-circuit occurs and heats up, the polymer layer in the middle of the composite fluid will melt and break the circuit, which can inhibit the short-circuit current and control the thermal runaway of the battery, and fundamentally solve the problem of explosion and fire of the cell.
(2) The burr size generated when the composite fluid collector is punctured by needles is smaller, and the chance of internal short circuit is lower.
(二) Low cost
Copper foil has a greater potential for cost reduction. For pure copper foil, raw material costs are relatively high. At a copper price of 60,000 RMB/ton, the unit cost of battery copper foil is 3.7 RMB/ping (excluding tax), of which the cost of copper is 2.85 RMB/ping, accounting for nearly 77%. The PET copper foil can reduce the amount of copper by 2/3, and the raw material cost drops significantly. According to the estimation, with 80% yield, the cost of PET copper foil after mass production is about 2.85 RMB/m2, which is 0.85 RMB/m2 lower than that of battery copper foil (3.7 RMB/m2), and the cost will continue to decrease with the continuous improvement of yield.
(三) High energy density
Copper foil has a significant role in the improvement of battery energy density. On the one hand, the density of organic materials is lower than that of metal materials, which can reduce the overall mass of the collector; on the other hand, the proportion of battery copper foil becomes less and the thickness becomes thinner, which further reduces the mass of the collector.
It is measured that the mass of 6um PET composite battery copper foil with the same area is reduced by about 56.33% compared to 6um electrolytic battery copper foil due to the lighter PET material compared to copper. According to the formula for calculating the energy density of lithium battery: mass energy density = battery capacity / battery mass, reducing the mass can improve the energy density with the same battery capacity. It is shown that MA/MC is lighter in weight, 77% lower in density than battery copper foil, and 5%-10% higher in energy density.
Industry progress of copper foil
In terms of progress, upstream, midstream and downstream enterprises in the industry chain are actively laying out PET copper foil-related fields, and each has generally completed the accumulation of research and development, and some manufacturers have completed the preparation of sample production and validation, and the battery copper foil is expected to achieve batch shipment in 2023.
Among the upstream equipment enterprises, relevant enterprises have matured the production technology of second-generation magnetron sputtering equipment. Among midstream PET copper foil manufacturers, Jinmei plans 350 million ping of PET copper/aluminum foil, which has already achieved stable production and is planning mass production.
Among the downstream battery manufacturers, CATL and EVE, one of the two wheeler lithium battery manufacturers, have applied for patents related to composite collectors, providing complete downstream technical support for PET copper foil application in lithium batteries.
Market expectation-13.7 billion by 2025
It is widely believed in the industry that battery copper foil will start industrialization in 2023, with rapid increase in penetration rate and explosive growth in the industry.
According to calculations, industry output is expected to reach 200 million ping in 2023, corresponding to 17gwh battery demand, and is expected to reach about 800 million ping in 2024, with global demand expected to reach 2.9 billion ping in 2025, a space of 13.7 billion and a penetration rate of 10%; PET copper foil equipment will have a global space of 14.4 billion in 2025.
In the long term, the penetration rate of composite battery copper foil is expected to rise to 22% in 2030, with demand reaching 19.2 billion ping, market space reaching 77.1 billion RMB, and equipment space reaching 18.8 billion RMB.
However, although copper foil has advantages in safety, cost and energy density, the thickness of the metal layer on both sides of the copper foil is generally only 1 micron, resulting in a high copper foil resistance and limited overcurrent capability. This in turn affects the overall charging and discharging efficiency of the battery.
Therefore, we believe that battery copper foil can meet the 2C charging and discharging requirements, but may challenge it in the future in areas with fast charging needs. Based on the current technical progress, in addition to the pure electric 4C application scenario, copper foil is expected to be more competitive in the markets of energy storage, battery swap, low-end and mid-range vehicles.
For more articles about lithium-ion materials, please refer to top 10 lithium battery cathode material manufacturers in China, top 10 lithium manganate material manufacturer, lithium carbonate.