Scientists have developed a pioneering technique for producing large-scale graphene current collectors. This breakthrough promises to significantly enhance the safety and performance of lithium-ion batteries.
The innovation comes from Swansea University, in collaboration with Wuhan University of Technology, Shenzhen University. This is in the form of a successful protocol for fabricating defect-free graphene foils on a commercial scale.
The foils offer improved thermal conductivity — up to 1,400.8 W m-1 K-1 – which is nearly ten times higher than traditional copper and aluminium current collectors used in lithium-ion batteries.
The method allows for the production of graphene current collectors at a scale and quality that can be readily integrated into commercial battery manufacturing.
This improves battery safety by efficiently managing heat. In addition it enhances energy density and longevity.
A concern in the development of high-energy lithium-ion batteries, especially those used in electric vehicles, is thermal runaway. This a dangerous scenario where excessive heat leads to battery failure, often resulting in fires or explosions.
The new graphene current collectors are designed to mitigate this risk by efficiently dissipating heat and preventing the exothermic reactions that lead to thermal runaway.
The aligned graphene structure provides a robust barrier against the formation of flammable gases and prevents oxygen from permeating the battery cells, which is necessary for avoiding catastrophic failures.
The newly developed process is not just a laboratory success but a scalable solution, capable of producing graphene foils in lengths ranging from meters to kilometres.
In a trial, the researchers produced a 200-meter-long graphene foil with a thickness of 17 micrometers. This foil retained high electrical conductivity even after being bent over 100,000 times, making it ideal for use in flexible electronics and other advanced applications.
This new approach also allows for the production of graphene foils with customizable thicknesses, which could lead to even more efficient and safer batteries.
The research appears in the science journal Nature, titled “Large-scale current collectors for regulating heat transfer and enhancing battery safety.”
