3D-Printed Batteries Could Be the Solution to Our Lithium Woes

What do Afghanistan and Bolivia have in common? Current geological estimates indicate that the two countries contain the most abundant lithium deposits on the planet. With booming demand, lithium's geopolitical importance is growing, and it doesn't take a conspiracy theorist to think that both Afghanistan and Bolivia's reserves are going to be targeted for exploitation. But, what if there was another way? Enter 3D-printed lithium-ion batteries.

A team of researchers from Harvard University and the University of Illinois at Urbana-Champaign recently printed lithium-ion microbatteries the size of a grain of sand. Less than the width of a single human hair, these microbatteries are printed as interlaced stacks of incredibly small electrodes.

“Not only did we demonstrate for the first time that we can 3D-print a battery; we demonstrated it in the most rigorous way,” said Jennifer A. Lewis, senior author of the study, and Hansjörg Wyss Professor of Biologically Inspired Engineering at the Harvard School of Engineering and Applied Sciences (SEAS). Lewis's former faculty position at the University of Illinois at Urbana-Champaign led to the scientific collaboration between the two schools' researchers. The study's co-author, Shen Dillon, is an assistant professor of materials science and engineering at the University of Illinois at Urbana-Champaign. The group's study was published online in Advanced Materials journal.

“The electrochemical performance is comparable to commercial batteries in terms of charge and discharge rate, cycle life and energy densities. We’re just able to achieve this on a much smaller scale,” Dillon said.

The demand for lithium-ion batteries, now powering everything from cars to smartphones, is creating a wildly-expanding market. For transportation alone, lithium ion batteries "will grow over 700%, from $2.0 billion annually in 2011 to greater than $14.6 billion by 2017," according to a Global Information, Inc. report.

Before this 3D-printed microbattery research took root, device manufacturers had to use other materials to build electrodes. This resulted in poor battery power and life. Lewis's team uses 3D-printers to build electrodes out of precisely-constructed layers of ink. According to a Harvard press release, the ink had to fulfill two tasks: exit out of fine nozzles, and then immediately harden into final form. They also had to operate as "electrochemically active materials to create working anodes and cathodes, and they had to harden into layers that are as narrow as those produced by thin-film manufacturing methods."

Researchers use one lithium metal oxide compound to create an ink for the anode, and use nanoparticles to create the cathode's ink. The 3D printer then deposits both inks onto two gold comb teeth. It is here that the stack of interlaced anodes and cathodes takes shape. Next, the researchers place the electrodes into a tiny container, filling it with an electrolyte solution, thus rendering it a microbattery. They then measure how much energy can be put into the batteries, the amount of power they can deliver, and length of charge.

“Jennifer’s innovative microbattery ink designs dramatically expand the practical uses of 3D printing, and simultaneously open up entirely new possibilities for miniaturization of all types of devices, both medical and non-medical," said Wyss Founding Director Donald Ingber, Professor of Bioengineering at Harvard SEAS. "It’s tremendously exciting."

What is also exciting about 3D-printed batteries—and I am speculating, of course—is that if this technology is refined, it could mean that countries with or without a great deal of lithium deposits will be able to domestically manufacture lithium-ion batteries. Imagine a new, competitive market opening up for those manufacturers who do it best. This technology could also reduce the potential for strained international relations over lithium trade.

Not to sound too cynical or conspiratorial, but it might even prevent the US from destabilizing countries and regions in the pursuit of lithium, as this government has done abroad with oil and other natural resources. 3D-printed batteries would also be a great alternative to Bolivia tearing apart Salar de Uyuni, the world's largest salt flat, which contains 50 to 70% of the world's lithium. (Don't suggest, with all of the tech devices now requiring lithium-ion batteries, that the US, China and other countries aren't enviously eyeing Bolivia's natural jackpot.)

Perhaps a 3D-printed lithium-ion battery process made available to all is just wishful thinking. The lithium industry isn't likely to let 3D-printed lithium-ion batteries come of age easily. Which is why this process, when ready, should be made available to the masses in an easy-to-follow way.