3D Printing Prints Tiny Microbatteries the Size of a Grain of Sand (Video)
3D printing holds enormous potential--from creating food products for long space missions to actually forming "living" synthetic tissue. Now, scientists have found a new use for 3D printing. They've discovered a way to use the technique to print lithium-ion microbatteries the size of a grain of sand. The new microbatteries hold enormous potential for use in tiny devices in fields that range from medicine to communications.
Actually making these batteries wasn't easy, though. The scientists had to precisely print interlaced stacks of tiny battery electrodes, each less than the width of a human hair. In order to accomplish this feat, the researchers first created and tested several specialized inks. Unlike the ink in an office inkjet printer, the inks developed for this project had to fulfill two requirements; they had to exit fine nozzles like toothpaste from a tube and had to immediately harden into their final form. In addition, the "ink" had to function as electrochemically active materials to create working anodes and cathodes--the guts of a battery.
The scientists created two separate inks in the end--one for the anode and one for the cathode. The anode ink had nanoparticles of one lithium metal oxide compound while the cathode ink had nanoparticles of another. The printer then deposited these two inks into the teeth of two gold combs. This created a tightly interlaced stack of anodes and cathodes. The researchers then packaged the electrodes into a tiny container and filled it with an electrolyte solution in order to complete the battery.
"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 Lewis, senior author of the paper detailing the new finding, in a news release.
It turns out that the battery could pack a punch. Despite its tiny size and the method in which it was created, the battery's electrochemical performance is comparable to commercial batteries in terms of charge and discharge rate, cycle life and energy densities. Because of this, it could be used in practical applications, including many devices that have remained on lab benches for lack of a battery small enough to power them.
The findings are published in the journal Advanced Materials.
Want to see the printer in action? Check out the video below, courtesy of Vimeo and the Wyss Institute.