For some years now, Lithium-ion cells have been the power supply for all of our more technically advanced gadgets. But for the next significant jump in capacity, we’re going to need a new material. Scientists at Stanford University believe that the key ingredient is aluminum, and they have created an impressive prototype to prove it. The new battery can recharge in under a minute, while also being bendable and relatively safe in the event of damage.
Researchers have long been interested in using aluminum for power storage, not least because it is very light. But previous attempts have always resulted in negligible success. While this prototype is unable to produce the kind of voltage required by a phone or tablet, it is showing early signs of promise. The breakthrough is the combination of materials used for the electrodes — the entrance and exit points for electricity in the battery. One is aluminum, while the other is made from graphite foam, and they are submersed in an electrolyte (a liquid salt solution).
The performance of this setup is pretty remarkable. Along with the rapid charging, the pack has a lifespan of 7,500 recharge cycles, which is way beyond what lithium is capable of. Unlike the highly flammable electrodes inside a lithium-ion battery, the aluminum prototype is largely harmless when punctured, as the only thing which pours out is a type of salt that is liquid at room temperature. What’s more, the voltage output of this early version is already half that of current lithium options, making it more giving than alkaline batteries, and using aluminum and graphite makes it cheap to produce.
Before we all get too excited about instant charging and flexible devices, there are a few bumps to overcome on the road to mass production. For instance, it is possible that a higher capacity version might cause the graphite foam to expand and contract. Equally, charging might slow with scale.
The work produced thus far, however, is impressing the scientific community, and the physical prototype proves the potential. With a bit more work, aluminum might just bring instant charging closer than we thought.