The rechargeable battery, which so often lets us down at the worst moments, has been due for an overhaul for some time now. Indeed, scientists have been slaving away for years on a lithium-ion battery with a longer lifespan. But who would’ve thought that the inspiration for the most promising new design would come from inside a pomegranate?
Developed over the course of eight years by a team at Stanford and the Department of Energy’s SLAC National Accelerator lab, this new battery houses silicon nanoparticles clustered inside like pomegranate seeds within a rind of carbon.
Similar to the way pomegranate fruits pack more antioxidant punch than blueberries, silicon anodes (a battery’s negative electrodes) can store 10 times more charge than the graphite anodes currently used in lithium-ion batteries. But historically, silicon has proved difficult to use in batteries, because it gets brittle and breaks easily. Additionally, silicon reacts with other chemicals in batteries, creating a gunk that eventually kills the whole system. The designers at Stanford solved this problem by encasing the silicon nanoparticles in a cozy membrane of carbon—much like the way pomegranate seeds are housed within a squishy pulp. During charging, the silicon seeds can swell within the membrane, lessening breakage and reducing gunky interactions between silicon and other battery chemicals.
"Experiments showed our pomegranate-inspired anode operates at 97% capacity even after 1,000 cycles of charging and discharging, which puts it well within the desired range for commercial operation," said Yi Cui, associate professor at Stanford and lead researcher, in a press release. "While a couple of challenges remain, this design brings us closer to using silicon anodes in smaller, lighter and more powerful batteries for products like cell phones, tablets and electric cars."
It might be a few years before you’re charging your very own pomegranate battery—the designers are still perfecting the design and are sourcing cheaper silicon particles to make it affordable for the consumer market. But however long it takes, it's an exciting step in battery design. It appears this hyped superfood is good news not just for the health world, but for the tech world, too.