US team develops high-power 3D microbatteries

Thin-film lithium-ion batteries used in microdevices such as portable and medical electronics are often unable to provide enough power for many devices due to size limitations.

The new study from University of Illinois Urbana-Champaign outlines how researchers built a prototype with thick 3D electrodes using lithography and electrodeposition, that seals each unit in a gel electrolyte-filled package.

While most microbatteries have space-saving thin, flat anodes and cathodes, researchers said these are not sufficient for the wireless transmission required of today’s technologies. 

“The answer might seem to be to use thicker electrodes, which could hold more energy on a confined footprint, but that alone will only increase the pathway that ions and electrons must travel, cutting down on power,” project leader Pengcheng Sun said in a statement. 

“Using 3D porous electrodes filled with liquid electrolyte can shorten this pathway, but it is extremely challenging to package such microbatteries.”

According to the team, a previous study that used imprinting lithography to build a 3D microbattery achieved high peak power using a liquid electrolyte, but the performance of that example was measured from an unsealed battery under laboratory conditions.