How a pomegranate inspired a new lithium ion battery design

The lithium ion battery could get a boost from the humble pomegranate. According to researchers at Stanford, including Amprius founder Yi Cui, and the SLAC National Accelerator Laboratory, clustering tiny silicon particles in a hard carbon rind — like seeds in a pomegranate — could be a helpful design breakthrough for using silicon in the next generation of lithium ion batteries.
A lithium-ion battery — the standard being used in gadgets today — is made up of three pieces: an anode, a cathode and an electrolyte that shuttles lithium-ions between the cathode and anode. That shuttling process is what happens when you charge and discharge a battery.
pomegranate battery
Scientists have long wanted to use silicon in the anode of a lithium ion battery because it can hold more energy per given volume than the traditional graphite that is commonly used — so a silicon anode battery could be smaller and lighter but also more energy dense.
But silicon can degrade and break over time throughout the charging and discharging process. Cui has spearheaded a lot of the work on nano-structured silicon battery anodes that can hold up under the charging process, and Amprius is using that technology for its longer-lasting battery.
pomegranate battery
This new pomegranate design further works on that research and could be commercialized in batteries for cell phones, tablets and even electric cars. In experiments the team says that the structure holds up with 97 percent capacity after 1,000 cycles. The carbon rind around the silicon pomegranate seeds enables electrical current but protects the silicon from reacting with the electrolyte.
The scientists published their findings in Nature Nanotechnology this week. More incremental battery innovations will be needed to provide long-enough lasting batteries to power our always-on gadgets and the coming way of electric cars.