Figure: Periodic gradient ordering of ~3-nm-size nanodomains along the thickness direction has been achieved within a copper foil.

Supported by the National Natural Science Foundation of China (Grants Nos. 92463302 and U24A2027，etc.), the research team led by Professor Lu Lei at the Institute of Metal Research, Chinese Academy of Sciences, together with collaborators, has made significant progress in the field of unit-ordered metals. This research, titled “Super-nano domains enable strength-conductivity synergy in copper foils”, was published in Science on April 17, 2026 (https://www.science.org/doi/10.1126/science.aed7758).

As a critical current collector in lithium-ion batteries and a primary conductive substrate in integrated circuits, copper foil must withstand complex mechanical loads while meeting stringent requirements for high electrical conductivity, high thermal conductivity, and long-term thermal stability. With the increasing demands of AI computing, communications, and next-generation energy systems, overcoming the long-standing trade-off of strength vs. ductility, conductivity, and thermal stability in copper foils has become a critical bottleneck for future applications.

The research team designed a novel “gradient super-nano domains (GSD)” microstructure. By incorporating trace amounts of organic additives, they achieved, within a 10‑μm‑thick copper foil (99.91% purity), a nanoscale gradient ordering of super‑nano domains with an average size of only 3 nm. These domains are periodically distributed along the thickness direction, alternating between “lean” and “rich” regions (Figure). Experimental results show that the GSD Cu foil exhibits a tensile strength as high as 900 MPa, surpassing the strength limit of conventional copper foils. Simultaneously, the foil maintains an electrical conductivity of 90% IACS,which is approximately twice that of copper alloys with comparable strength, and shows no performance degradation after nearly six months of room‑temperature storage. This breakthrough successfully resolves the “impossible triangle” of simultaneously achieving high strength, high conductivity, and excellent thermal stability.

This research opens a new design paradigm for high-performance Cu foils, demonstrating the great potential of the “gradient ordering” strategy for developing next-generation structural–functional integrated materials. The GSD Cu foil is already capable of continuous production under industrial conditions, offering significant strategic importance for the development of the electronic industry and the new energy sector.