Researchers 3D print microbatteries

Engineers have invented many miniaturized devices, but the batteries to power them are often larger than the devices themselves. Now, researchers at Harvard University and the University of Illinois at Urbana-Champaign have developed techniques and the corresponding build materials to 3D print precisely interlaced stacks of tiny battery electrodes, each less than the width of a human hair. The result is lithium-ion microbatteries the size of a grain of sand.

Traditionally, manufacturers have deposited thin films of solid materials to build such batteries but they commonly don’t pack sufficient energy. To get around this limitation, the researchers created stacks of interlaced, ultrathin electrodes using custom-built 3D printers.

To print the electrodes, the group extruded nanoparticles of one lithium metal oxide compound for the anode and nanoparticles of another for the cathode. The printer deposited the build material onto the teeth of two gold combs, creating a tightly interlaced stack of anodes and cathodes. Then the researchers packaged the electrodes into a tiny container and filled it with an electrolyte solution to complete the battery.

“The electrochemical performance is comparable to commercial batteries in terms of charge and discharge rate, cycle life and energy densities,” said Shen Dillon, an Assistant Professor of Materials Science and Engineering at the University of Illinois at Urbana-Champaign. “We were just able to achieve this on a much smaller scale.”

The work of Dillon and project lead, Dr. Jennifer Lewis – Hansjörg Wyss Professor of Biologically Inspired Engineering at the Harvard School of Engineering and Applied Sciences (SEAS) – was supported by the National Science Foundation and the DOE Energy Frontier Research Center on Light-Material Interactions in Energy Conversion.
http://wyss.harvard.edu/