Batteries have resisted the blazing progress of Moore’s Law, the observation that the number of transistors packed on computer chips—and thus the processing power—doubles every 18 months. The batteries that power all those super fast chips have only managed to perform about 5% to 8% better each year (except for the rare breakthroughs in new battery chemistries).
Scientists are split on whether such meager improvements in energy density should be the norm, or if transformational leaps of 10 to 100 times above today’s performance are possible.
A team at North Carolina State University is working on the latter. By fashioning infinitesimally small "nanoflowers" out of the semiconducting material germanium sulfide (GeS), the researchers have dramatically increased the surface area of lithium-ion (Li-ion) batteries to develop a "next-generation of energy storage devices and solar cells." Publishing their results in American Chemical Society Nano, the researches shows how the metal "nanoflowers," fabricated by vaporizing GeS powder in a furnace and then cooling it into sheets just 20 to 30 nanometers thick (less than a thousandth the width of a human hair) which resemble a flower, they could pack in several times more charge that conventional designs.
"Creating these GeS nanoflowers is exciting because it gives us a huge surface area in a small amount of space," said Linyou Cao, an assistant professor of materials science and engineering at NC State, and the study’s co-author, in a University release. "This could significantly increase the capacity of lithium-ion batteries, for instance, since the thinner structure with larger surface area can hold more lithium ions."
Although not the 100-times improvements coveted by vehicle and electronics manufacturers, it’s one of the many steps toward batteries that will drive a car 300 miles or power a phone for weeks without recharging.
This potential for nanotechnology to transform battery performance has already attracted Department of Energy (DOE) funding. A grant to VC-backed Amprius is testing nanomaterials with the potential to double Li-ion energy density from 225 to 460 watt hours per kilogram. A second DOE collaboration with A123 Systems will try to perfect scalable, mass production methods for nanocomposites extending the range of plug-in electric hybrids by 15%.
For batteries, at least, going big may mean being very, very small.