Graphene, a two-dimensional hexagonal lattice of carbon atoms, has great potential in a number of EV-related applications, including anodes, lithium-sulfur batteries and ultracapacitors. With current technology, however, itâ€™s impractical to use on a large scale, and researchers have been limited to using small flakes of the material.
Now a team of researchers at the DOEâ€™s Oak Ridge National Laboratory (ORNL) have fabricated polymer composites containing 2-inch square sheets of graphene, using chemical vapor deposition. The resulting composite structures have the potential to outperform current materials in both mechanical properties and electrical conductivity.
The teamâ€™s findings, reported in the journal ACS Applied Materials & Interfaces, could enable large-scale fabrication of graphene composites. â€œBefore our work, superb mechanical properties of graphene were shown at a micro scale,â€ said ORNL team leader Ivan Vlassiouk. â€œWe have extended this to a larger scale, which considerably extends the potential applications and market for graphene.â€
Most approaches for polymer nanocomposition construction use tiny flakes of graphene that are difficult to disperse in the polymer. Using larger sheets of graphene enabled Vlassioukâ€™s team to eliminate the flake dispersion and agglomeration problems, allowing the material to better conduct electricity with less actual graphene in the polymer.
â€œWe were able to use chemical vapor deposition to make a nanocomposite laminate that is electrically conductive with graphene loading that is 50 times less compared to current state-of-the-art samples,â€ said Vlassiouk.