Graphene ink to print energy storage devices

Consumers are constantly demanding ever greater storage capacity from the batteries in smart phones, tablets and other devices. And if solar, wind, and wave power are ever to contribute a substantial proportion of our electricity mix, industry will need to find a more effective way to store the energy they produce.

To this end, researchers at the Manchester Metropolitan University are developing techniques to allow for the rapid 3D printing of energy storage devices using conductive graphene ink.

This would allow researchers to design novel 3D structures for supercapacitors and batteries, which they could then immediately build and test in the laboratory, according to Prof Craig Banks, who is leading a £500,000 EPSRC-funded project to investigate additive manufacturing of next generation energy storage devices.

“Graphene is more conductive than metals, so it’s a fantastic material, but the biggest problem is trying to get it into a structure that everybody can use,” said Banks. “What we’re trying to do is put it into a conductive ink, so we can take the properties of graphene and put it into a form that can be printed and manipulated into a structure that is beneficial for batteries and supercapacitors.”

The ability to print unique 3D structures incorporating graphene ink should increase the charge storage of batteries and supercapacitors, Banks said.

Researchers have so far developed so-called semi-graphene inks. These contain graphene but also carbon blacks and graphite, which are undesirable as they reduce the conductive performance of the material.

But printing 3D structures from true graphene ink is extremely difficult, as each layer must be cured for an hour in an oven before another layer can be added on top, said Banks.

“At the moment it takes ages to make anything above the micron level, so we want to shine a UV light onto the ink as it is printed, to cure it in situ and ensure it holds its structural integrity,” he said.

Ultimately, we could all print our own batteries from a 3D printer in our office or home, he said. “You could imagine just clicking in a cartridge containing graphene conductive ink, and manipulating it into a unique structure,” he said.