Colorado State University start-up Prieto Battery says it has successfully produced a 3D foam-filled battery that could one day power grid-scale electric systems and electric vehicles.
The solid-state battery uses foam as the raw material for the batteries onto which the anode, which is made of copper antimonide, is electroplated.
The foam is so porous that it is actually mostly air, but a small fragment can contain an enormous surface area, which means the distance the ions have to travel is reduced, increasing the power and energy density.
Once coated with the anode, the foam is layered with a polymer electrolyte that provides a physical barrier across which ions can move.
Finally, the cathode is applied in the form of a dark, inky slurry and the final product is a couple of inches across and with the thickness of a sheet of paper.
The use of porous materials as battery components is not new, but the notion of an entire battery made with a porous internal architecture arose from the work of Debra Rolison, a research chemist at the United States Naval Research Laboratory (NRL), who began her research into new catalyst materials for fuel cells in the 1990s.
When she presented her idea to compose a battery of carbon aerogels to create a 3D battery, ‘99% of people thought I was wacked out of my brain’, she says.
Prieto Battery’s first product was a drop-in replacement copper foam anode that could replace graphite anodes in conventional batteries.
Prieto’s first replacement anodes could be on the market by late 2016, says Prieto founder Amy Prieto, and a complete battery could follow by 2018.
3-D battery technology like Prieto’s, says Max Hamedi, a Harvard researcher who is working on elastic foam batteries made from wood pulp, “has the potential to surpass any battery that you can build in 2-D systems. This work is just exploding right now.”