Chinese researchers create ultra-thin copper foil with exceptional strength

Chinese researchers have created an ultra-thin copper foil with exceptional strength, conductivity, and thermal stability, opening new possibilities for advanced batteries and integrated circuits.

Copper foil functions as both an electric current pathway and a heat conductor. Historically, enhancing strength often compromised conductivity, and improving conductivity typically reduced thermal stability.

Now, Chinese researchers claim they have overcome this trade-off. The new 10-micrometer-thick copper foil features nanoscale grains and periodically arranged gradient super-nano domains about 3 nanometers in size throughout its thickness.

It can be manufactured via an industrially scalable electrodeposition process. Conventional copper foil typically has a tensile strength of 300-600 MPa, whereas this new material reaches about 900 MPa, nearly twice as strong.

By decoupling strength from conductivity, it maintains electrical conductivity at approximately 90% of that of high-purity copper. Compared to similar-strength traditional copper alloys, its conductivity is approximately twice as high. It also shows strong thermal stability.

While many high-strength materials tend to degrade within days, the new copper foil shows no decline after six months of storage under normal conditions. It will make it well-suited for electronic devices and batteries that require long-term stability.

The researchers attribute these impressive properties to a dual stabilization-strengthening mechanism, in which the periodically distributed super-nano domains enhance strength while stabilizing grain boundaries.

With its proven industrial scalability, this material is expected to support next-generation advancements in smartphones, artificial intelligence (AI) chips, and electric vehicles.