Researchers at Stanford University’s Precourt Institute for Energy have unveiled a new aluminum-ion battery that could one day replace the lithium-ion (Li-ion) batteries we use to power pretty much everything, from our watches to our tablets and our electric vehicles. The aluminum battery can be produced more cheaply than current alternatives, is not quite so bad for the environment as alkaline batteries, and unlike Li-ion batteries, it won’t explode—”even if you drill through it.”
The concept of creating an aluminum battery is nothing new; researchers have been toying with the idea for decades. It’s an attractive concept due to its safety, low cost, and high durability—and what Stanford has developed may be the closest thing we’ve seen to a commercially viable product. It utilizes a negatively charged anode, made from aluminum, and a positively charged cathode made from graphite along with an ionic liquid electrolyte, all of which is contained within a flexible polymer-coated pouch. Bending cell phones anyone?
The prototype can charge in just one minute—which stands in pretty staggering contrast to the time many of us spend sitting around waiting for our cellphone to charge—and can be recharged at least 7,500 times. The Stanford team says they have unpublished data to show it can hold up for even more charge cycles than that. And that holds a fascinating potential for efficient grid scale storage of renewable energy, where batteries need to be able to rapidly store and release energy many times over.
For now, the much smaller scale prototype produces around two volts, notably less than the 3.6 that is standard for li-ion batteries. Additionally, Engadget notes, the aluminum battery doesn’t quite perform as well as lithium batteries in terms of power density: “aluminum cells only carry 40 watts of electricity per kilogram compared to lithium’s 100 to 206 W/kg power density.”
As Stanford professor Hongjie Dai noted in a press release, “Otherwise, our battery has everything else you’d dream that a battery should have: inexpensive electrodes, good safety, high-speed charging, flexibility and long cycle life. I see this as a new battery in its early days. It’s quite exciting.”