3D-printed ‘veggie battery’ could power devices more sustainably

23 Mar 2021

A 3D printer in action. Image: © pressmaster/Stock.adobe.com

A University of Glasgow-led project has produced a 3D-printed battery that could be more environmentally friendly than current lithium-ion equivalents.

A team of engineers led by the University of Glasgow has developed a new type of 3D-printed battery that uses electrodes made from vegetable starch. The researchers claim that it could provide mobile devices with a more environmentally friendly and higher-capacity power source than current lithium-ion equivalents.

Lithium-ion batteries are used in a wide range of devices, including smartphones, laptops and electric vehicles, and can endure multiple charging and discharging cycles. A positive electrode, typically made from lithium cobalt or lithium iron phosphate, passes lithium ions through an electrolyte to the negative electrode, which is made from lithium metal.

‘Lithium-ion batteries have their own sustainability issues, so it’s important that we look to find new ways to make them better and more environmentally friendly’

The lithium ions are stored in the negative electrode when the battery is charged. When the battery is being used, the ions flow in the opposite direction and generate energy to power devices through an electrochemical reaction.

Lithium-ion batteries currently on the market have thick electrodes that limit how much energy they can store and release. They restrict diffusion of the lithium ions across the electrode and are also more prone to cracking, which means the battery can no longer be used.

With the aim of overcoming these restrictions, the team of engineers introduced tiny nanoscale and microscale holes into the electrodes of their battery design. This increased the surface area of the electrodes without changing the battery’s external dimensions.

The pores were added through 3D printing, which allowed the team to tightly control their size and placement. The researchers used a material they developed combining polylactic acid, lithium-iron phosphate and carbon nanotubes. The polylactic acid is a biodegradable material processed from the starch of corn, sugar cane and sugar beet, making the battery recyclable and more sustainable.

‘A new metamaterial’

Dr Shanmugam Kumar from the University of Glasgow’s James Watt School of Engineering led the research with colleagues from Khalifa University of Science and Technology in Abu Dhabi and Texas A&M University and Arizona State University in the US.

“Lithium-ion batteries are increasingly common in everyday life and are likely to continue to increase in ubiquity as we move towards more electrification of transport and a more sustainable world,” Kumar said. “However, lithium-ion batteries have their own sustainability issues, so it’s important that we look to find new ways to make them better and more environmentally friendly.

“The 3D-printing process we’ve used in this research gives us a remarkable amount of control over the electrodes’ porosity, allowing us to engineer very precisely a new metamaterial capable of addressing some of the shortcomings of the current generation of lithium-ion batteries.

“These are promising initial results, and we’re keen to continue to explore the possibilities that these kinds of micro-architected materials offer to create better, more recyclable batteries for future consumers.”

The research paper has been published in the Journal of Power Sources.

Lisa Ardill was careers editor at Silicon Republic until June 2021