A team of scientists from the University of Illinois Urbana-Champaign, University of Pennsylvania, Korea University, Sogang University, the Korea Military Academy, and Xerion Advanced Battery Corporation have announced a big breakthrough in tiny batteries — coming up with a novel design to boost the storage capacity of high-voltage microbatteries.
"We need powerful tiny batteries to unlock the full potential of microscale devices, by improving the electrode architectures and coming up with innovative battery designs," explains Paul Braun, co-author and a material science and engineering professor at the University of Illinois Urbana-Champaign, of the team's focus.
That's easier said than done, however: as the battery becomes smaller, the packaging begins to take up more of the room — limiting the electrode area and thus battery performance.
Rather than looking at the battery chemistry, then, the team set about coming up with a new packaging technology — turning the positive and negative terminal current collectors into packaging, to save space. Combined with vertical stacking and grown "fully-dense" electrodes which don't require polymers and carbon additives, the result is a microbattery that can easily outperform the competition in voltage and capacity.
"To date, electrode architectures and cell designs at the micro-nano scale have been limited to power dense designs that came at the cost of porosity and volumetric energy density," explains co-first author Arghya Patra. "Our work has been successful to create a microscale energy source that exhibits both high power density and volumetric energy density."
"The high voltage is important for reducing the electronic payload that a microrobot needs to carry," co-author James Pikul, assistant professor at the University of Pennsylvania, explains of the team's voltage-boosting series design.
"9V can directly power motors and reduce the energy loss associated with boosting the voltage to the hundreds or thousands of volts needed from some actuators. This means that these batteries enable system level improvements beyond their energy density enhancement so that the small robots can travel farther or send more critical information to human operators."
The team's work has been published in Cell Reports Physical Science under open-access terms.