Chinese Scientists Develop Copper Foil Combining 900 MPa Strength With High Conductivity

A Thin Copper Foil With Three Powerful Properties

Chinese scientists led by Lu Lei at the Institute of Metal Research (IMR), Chinese Academy of Sciences, have developed a copper foil just 10 micrometers thick that combines tensile strength of up to 900 megapascals with about 90 percent of the electrical conductivity of pure copper. The material also showed no performance degradation after six months of storage under normal conditions.

The achievement, published in Science, addresses a persistent problem in metal design: making a material stronger usually comes at the expense of its ability to conduct electricity or maintain a stable internal structure. Bringing strength, conductivity and thermal stability together is the challenge described as the "impossible triangle" of materials science.

Lu's team tackled that problem by changing the arrangement of tiny structures inside copper. Its design, called a gradient nano-domain architecture, contains densely packed domains approximately three nanometers in size. These structures help hold the metal's internal arrangement in place while preserving the high copper purity needed for efficient electrical conduction.

The breakthrough offers a new route to high performance copper foil for integrated circuits and lithium-ion batteries. Potential uses include more precise smartphone chips, artificial intelligence computing equipment and thinner battery designs for electric vehicles. The material could also help reduce overheating and energy losses in demanding applications.

Manufacturing is central to the development. The researchers used electrodeposition, a technique already widely employed to produce commercial copper foil, rather than a process limited to unusual laboratory equipment. Their approach allows continuous production under standard industrial conditions, creating a practical route toward large scale manufacturing.

Why Copper Has Been Difficult to Strengthen

Pure copper conducts electricity very well, but it lacks the mechanical strength needed for some demanding applications. Engineers therefore face a difficult choice when selecting materials for small electronic components or battery parts: preserve copper's electrical performance, or strengthen it and accept other compromises.

Copper alloys address the strength problem by adding other elements. An alloy is a metal mixed with other elements to change its properties. In the conventional materials described in the research, that increased strength comes with a substantial reduction in electrical conductivity and thermal stability.

High strength nanostructured materials face another difficulty. Their useful properties depend on an internal arrangement of extremely small structures, and that arrangement can become unstable. When the structure changes, performance can decline rapidly. Thermal stability describes the material's ability to keep its internal structure and useful properties when exposed to heat.

The new foil brings the three priorities together through structural design. Instead of relying on substantial additions of other elements to strengthen copper, the researchers created tiny domains within the metal. This approach allows the copper to remain highly pure while its internal architecture supplies the strengthening effect.

How Structures Three Nanometers Across Hold Copper Together

The team's gradient nano-domain architecture places a high density of extremely small domains throughout the foil. Each domain measures approximately three nanometers, and the domains are periodically distributed in a gradient pattern. A nanometer is one thousandth of a micrometer, showing how much smaller these internal features are than the foil itself.

The finished sheet is 10 micrometers thick, approximately one seventh of the thickness of a human hair. Within that thin sheet, the domains act like tiny fastening points that resist movement in the surrounding copper structure.

Lu Lei's research team at the Institute of Metal Research described the mechanism using the familiar image of rivets holding a material in place:

These tiny copper domains act like rivets embedded inside the copper. They hinder the movement of copper grains, thereby increasing strength and thermal stability while maintaining high copper purity.

Copper grains are the small crystal regions that make up the metal. Restricting their movement helps the foil resist mechanical stress and keeps its structure more stable. The domains therefore serve two connected purposes: strengthening the material and stabilizing it.

High copper purity preserves electrical conductivity. The result is a material whose strength comes from the way its internal structures are arranged, while its ability to carry electricity remains close to that of pure copper.

What the Performance Figures Show

Conventional copper foil typically has a tensile strength of 300 to 600 megapascals (MPa). Tensile strength measures how much pulling stress a material can withstand before breaking. The new foil reaches up to 900 MPa, placing it above that conventional range and above conventional copper alloys.

The comparison depends on which part of the commercial range is used. Against foil rated at 300 MPa, the new material's maximum strength is three times as high. Against foil rated at 600 MPa, it is 1.5 times as high. The breakthrough was described as offering roughly double the strength of standard commercial products.

Electrical conductivity remains equivalent to approximately 90 percent of high purity copper. Against traditional copper alloys with similar strength, the new foil conducts electricity about two to three times as well. Its value lies in combining that electrical performance with much greater mechanical strength.

The material also showed no degradation after six months of storage under normal conditions. Maintaining performance over time matters for electronic devices and energy storage systems that need to operate reliably over extended periods. This stability addresses a weakness of many strong nanostructured materials, whose internal structures can change and cause their properties to deteriorate.

Strength, conductivity and stability are therefore connected parts of the achievement. A stronger foil is more useful when it can still carry electricity efficiently and retain the structure responsible for its performance.

What It Could Mean for Chips and AI Equipment

Copper foil is a critical material in integrated circuits and chip interconnects, the connections that carry electrical signals between parts of a chip. In advanced electronics, the foil's mechanical properties and electrical performance both affect what manufacturers can build.

The new material's greater strength and thermal stability could support the production of more precise smartphone chips. Its high conductivity also offers a route to reducing overheating during prolonged use, a persistent concern in mobile devices and artificial intelligence computing equipment.

AI computing equipment places demanding requirements on the materials used in its electronic components. Copper that combines strength with efficient electrical conduction offers manufacturers another way to address those requirements while preserving the stability needed for sustained operation.

The breakthrough provides a new technological pathway for advanced manufacturing. No date was given for its introduction into finished smartphones, AI equipment or batteries. Its immediate industrial promise rests on the foil's measured properties and on the use of a manufacturing method already familiar to producers.

Why Battery Makers Could Benefit

Lithium-ion batteries use copper foil as a current collector. This component carries electrical current between the battery's active material and the rest of the circuit. Its job makes electrical conductivity essential, while sufficient strength helps the thin foil withstand manufacturing and use.

The new copper foil could allow thinner and safer battery designs while reducing energy loss during charging at high current. That combination is relevant to electric vehicles, where manufacturers seek batteries that deliver power efficiently and maintain reliable performance.

Grid scale energy storage systems could also benefit. These systems use batteries to store electricity for later use, and they depend on materials that can maintain useful properties over extended operational lifespans. The foil's combination of conductivity, strength and stability offers a promising option for that sector.

The battery application connects directly to the original materials problem. Making a current collector stronger is useful only if it can continue carrying electricity efficiently. By preserving about 90 percent of pure copper's conductivity, the new architecture offers a way to improve mechanical performance without accepting the large electrical losses associated with similarly strong traditional alloys.

A Manufacturing Method Industry Already Uses

Electrodeposition is the foundation of the production process. The technique uses electricity to deposit metal from a solution onto a surface, building up a layer that becomes foil. Commercial copper foil manufacturers already use this method widely.

The researchers added trace amounts of organic additives during electrodeposition to create the gradient arrangement of super-nano domains. Those small additions help form the internal structures responsible for the material's combination of properties.

Production can run continuously under standard industrial conditions. This gives the technology immediate industrial viability and suggests that the transition from laboratory demonstration to mass manufacturing can proceed rapidly. Existing manufacturing infrastructure provides a starting point, without requiring entirely new production facilities.

The foil's thickness also supports that transition. At 10 micrometers, it aligns with current industry specifications for electronics and battery applications, removing the need for additional processing or adaptation to reach that thickness.

Marc S. Lavine, an editor of the research publication, noted the substantial promise for manufacturing foils used in lithium-ion batteries and integrated circuits. Continuous production under industrial conditions is a major practical advantage because it can reduce the time and investment usually needed to turn a research discovery into a market ready product.

China's Position in Electronics and Energy Supply Chains

Copper foil is a fundamental raw material for advanced microelectronics and electric vehicle batteries, two industries central to current technology supply chains. The development arrives as countries prioritize domestic manufacturing capabilities in semiconductors and clean energy.

For China, the technology supports greater self reliance and control in electronic information and new energy industries. Producing internationally leading copper foil domestically could reduce dependence on imported high performance materials and strengthen supply chain security.

The research also supports China's objectives for advanced manufacturing. Solving a materials problem that has constrained product development gives domestic industry a potential competitive advantage in artificial intelligence hardware and new energy systems, both sectors experiencing rapid global growth.

Lu's team presented the work as both a new design approach for copper foil and an example of the broader potential of engineering metal structures at the nanoscale. The same methodology could potentially be applied to other metals facing similar conflicts between strength and useful functional properties.

The central advance remains concrete: a foil only 10 micrometers thick combines strength of up to 900 MPa, conductivity near that of pure copper and structural stability, using a production technique already established in industry. That combination connects a materials science achievement with practical manufacturing needs.

What to Know

• Lu Lei's team at the Institute of Metal Research, Chinese Academy of Sciences, developed the copper foil, with the achievement published in Science.
• The foil is 10 micrometers thick and contains domains approximately three nanometers across, arranged in a gradient pattern.
• Tensile strength reaches up to 900 MPa, compared with a typical range of 300 to 600 MPa for conventional copper foil.
• Conductivity is about 90 percent of high purity copper and two to three times that of traditional alloys with similar strength.
• The material showed no performance degradation after six months of storage under normal conditions.
• Electrodeposition with trace organic additives supports continuous production using established industrial methods.
• Potential applications include integrated circuits, smartphone chips, AI equipment, electric vehicle batteries and grid scale energy storage.