A Harvard University materials scientist has devised a way to make lithium-ion batteries using a 3D printer. The technology is still in development stage. The concept is to make inks that are used to print anodes for lithium-ion batteries, the inks use suspended nanoparticles of the desired materials, such as compounds of lithium for batteries and silver for wires.
Jennifer Lewis, the scientist behind the development, added nanoparticles of lithium titanium oxide to a vial of deionised water and ethylene glycol. Ceramic balls are then added to the mixture to act as grinders that will prevent particles clumping.
The mixture is spun for 24 hours, after which the balls and larger particles are removed using filters and a centrifuge.
The resulting ink, placed in a custom-made syringe, is now ready for use in a standard 3-D printer. The syringe is inserted into a high–pressure dispenser added to a conventional 3-D printer. Although the ink is solid when still, it flows under high pressure. It returns to a solid state once it leaves the syringe.
Next, white anode ink is extruded on a glass substrate. In practice, it would be printed atop a gold current collector patterned on the glass. Following digital instructions, a fine nozzle extrudes ink layer by layer to form the battery’s cathode.
The printed batteries are only 1mm square, but perform as well as standard batteries because of the micro-scale architectures that Lewis constructed with 100-nanometer accuracy.
