China achieves breakthrough in developing high-performance super thin copper foil material

A group of Chinese researchers have succeeded in developing a super thin copper foil material simultaneously featuring the properties of ultrahigh strength, high conductivity and high thermal stability, paving the way for manufacturing next-generation batteries and integrated circuits.

The findings were published in the journal Science on Friday.

Copper foil serves both as a channel for electric current and as a conductor of heat. For decades, the material has faced a long-standing challenge: improving strength typically comes at the expense of conductivity, while better conductivity often weakens thermal stability.

In other words, gains in one property have long tended to come at the expense of the others.

According to the researchers, the material is a 10-micrometer-thick copper foil featuring nanoscale grains and periodically distributed gradient super-nano domains of approximately 3 nanometers in size throughout its thickness, and can be produced through an industrially scalable electrodeposition process.

In terms of strength, conventional industrial copper foil typically has a tensile strength of around 300 to 600 megapascals, while the newly developed material reaches about 900 megapascals, roughly twice that of standard products.

Despite the sharp increase in strength, the material retains electrical conductivity equivalent to 90 percent of high-purity copper. Compared with traditional copper alloys of similar strength, its conductivity is roughly twice as high.

It also demonstrates strong thermal stability. While many high-strength materials tend to see performance degradation within days, the new copper foil material shows no decline after six months of storage under normal conditions, making it well suited for electronic devices and batteries that require long-term stability.

According to the researchers, these properties stem from a dual stabilization-strengthening mechanism, in which periodically distributed super-nano domains simultaneously enhance strength and stabilize grain boundaries.

With its demonstrated industrial scalability, the material is expected to support next-generation upgrades in smartphones, artificially intelligence (AI) chips and electric vehicles.