Jaswinder Sharma makes battery coin cells with a lightweight current collector made of thin layers of aligned carbon fibers in a polymer with carbon nanotubes. Credit: Genevieve Martin/ORNL, U.S. Dept. of Energy
Carbon fiber, nanotubes make lighter EV batteries
Electric vehicles can drive longer distances if their lithium-ion batteries deliver more energy in a lighter package. A prime weight-loss candidate is the current collector, a component that often adds 10% to the weight of a battery cell without contributing energy.
Researchers at the Department of Energy’s Oak Ridge National Laboratory developed a lighter, metal-free current collector made of a polymer-based composite with carbon fibers. The aligned fibers work together with a thin film of carbon nanotubes to enhance directional and uniform current flow.
Lab tests conducted at medium-fast battery charging rates showed the novel current collector performed as well as or better than the standard copper foil. ORNL’s carbon polymer material is less prone to corrosion and can stretch more easily for roll-to-roll manufacturing of electrodes.
“We are reducing 80% to 90% of the weight of the current collector,” said ORNL’s Jaswinder Sharma. “This will help a lot in increasing the energy density of battery packs.”
