Pomegranate Inspires Battery Design

Researchers at Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory has invented an electrode designed like a pomegranate with silicon nanoparticles clustered like seeds in a tough carbon rind, that they say overcomes several obstacles to using silicon for a new generation of lithium-ion batteries.

Experiments showed our pomegranate-inspired anode operates at 97 percent capacity even after 1,000 cycles of charging and discharging, they explained.

Silicon anodes, where energy is stored when a battery charges, could store 10 times more charge than the graphite anodes in today’s rechargeable lithium-ion batteries, but they also have major drawbacks: silicon is brittle, swells, and falls apart during battery charging, and it reacts with the battery’s electrolyte to form a substance that coats the anode and degrades its performance.

Using a microemulsion technique, they gathered tiny pieces into clusters, and coated each cluster with a second, thicker layer of carbon. These carbon rinds hold the pomegranate clusters together and provide a sturdy highway for electrical currents. And since each pomegranate cluster has just one-tenth the surface area of the individual particles inside it, a much smaller area is exposed to the electrolyte, thereby reducing the amount of muck that forms to a manageable level.

Although the clusters are too small to see individually, together they form a fine black powder that can be used to coat a piece of foil and form an anode. Lab tests showed that pomegranate anodes worked well when made in the thickness required for commercial battery performance.




The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.