Researcher Han Lin holds his wafer-thin 3D printed battery. Credit: Swinburne University

Swinburne University of Technology researchers have developed a method for 3D printing a powerful battery that charges in seconds, can be recharged millions of times – and would barely be noticeable, laced inside your watchband.

The magic ingredient is called graphene — a one-atom-thick sheet of carbon with an extremely large surface area that allows a huge amount of charge to attach to its surface. Under a current, charged particles zip between graphene sheets much faster than in the sluggish chemical reactions at the electrodes in normal batteries.

But, to be useful as a battery, in this case called a ‘supercapacitor’, graphene needs to be stacked as thousands of overlapping sheets, something that until recently was impossible to create with current laboratory methods.

Swinburne University’s Han Lin found a way. First he sprayed flexible plastic with a layer of graphene oxide, a water-soluble graphene precursor. Then, he shone the laser beam from a 3D printer through this thin layer, which broke oxygen molecules from the graphene oxide and fused the precursor film into layers of thousands of graphene sheets in one shot.  

Tests revealed Lin’s graphene supercapacitor charges thousands of times faster than the lithium-ion batteries that currently power devices. “It’s much faster because it doesn’t involve any chemical reaction, so you can put a high current on it,” Lin explained.

The 3D printed graphene battery is still expensive to produce. But because there are no chemical reactions during charging and discharging, graphene doesn’t suffer the wear-and-tear of normal batteries. “The lifetime is a thousand times longer – so the cost per unit energy is much lower,” Lin pointed out.

Lin recently teamed up with a commercial partner to negotiate a large-scale production line, and is hoping to replace batteries which are harmful to the environment, such as the lead acid battery. Graphene batteries require no special disposal and, Lin calculated, have double the energy capacity per kilogram of a lead acid battery.

Thanks to Lin’s work, futuristic energy storage is now within reach. Flexible, thin-film batteries in your clothes and trains and buses that flash-charge their super-batteries when they reach a station are all conceivable with this technology.

Lin is optimistic: “The possibilities are waiting for exploration.”

Read more about Swinburne University of Technology’s world-changing research in Swinburne Research Impact