Berkeley Lab researchers have created a graphene and tin nanoscale composite material for high-capacity energy storage in renewable lithium ion batteries.
By encapsulating tin between sheets of graphene, the researchers constructed a new, lightweight “sandwich” structure that should bolster battery performance.
“For an electric vehicle, you need a lightweight battery that can be charged quickly and holds its charge capacity after repeated cycling,” said Yuegang Zhang, a staff scientist with Berkeley Lab’s Molecular Foundry, in the Inorganic Nanostructures Facility, who led this research.
“Here, we’ve shown the rational design of a nanoscale architecture, which doesn’t need an additive or binder to operate, to improve battery performance,” he stated.
Graphene is a single-atom-thick, “chicken-wire” lattice of carbon atoms with stellar electronic and mechanical properties, far beyond silicon and other traditional semiconductor materials.
The change in height between the graphene layers in these new nanocomposites helps during electrochemical cycling of the battery, as the volume change of tin improves the electrode’s performance.
In addition, this accommodating behaviour means the battery can be charged quickly and repeatedly without degrading — crucial for rechargeable batteries in electric vehicles.
The study appeared in the journal Energy and Environmental Science.