Depiction of microrobots in a hazardous environment (Image courtesy of Alex David Jerez Roman, Beckman institute, UIUC)
Researchers at the University of Illinois Urbana-Champaign say they created a high-voltage microbattery with high energy and power density.
According to the researchers, the energy and power density are “unparalleled” by any existing battery design. These batteries may power microdevices, microrobots and implantable medical devices.
Paul Braun, a material science and engineering professor, Sungbong Kim, an assistant at Korea Military Academy, and Arghya Patra, a grad student, published a paper detailing the development. The authors published the paper in Cell Reports Physical Science.
The team demonstrated hermetically sealed, durable, compact lithium batteries with low package mass fraction. These batteries came in single-, double- and triple-stacked configurations with unprecedented voltages and power and energy densities.
“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,” said Braun.
How the team developed its microbattery
According to the researchers, an issue arises when the batteries come smaller, allowing packaging to dominate battery volume and mass. Meanwhile, the electrode area becomes smaller. This results in drastic reductions in both energy and power for the battery.
To design the microbattery, the team developed novel packaging technology. This uses the positive and negative terminal current collectors as part of the packaging itself, rather htan a separate entity. The researchers said this allowed for the compact volume and low package mass fraction of the microbattery.
Additionally, the researchers vertically stacked the electrode cells in series, enabling high operating voltage. They used dense electrodes to offer energy density for the microbattery, too. Braun’s team fabricated the microbattery using the dense electroplated DirectPlate LiCoO2 electrodes manufactured by Xerion Advanced Battery Corporation. Xerion spun out of Braun’s research.
“Our work bridges the knowledge gap at the intersection of materials chemistry, unique materials manufacturing requirements for energy dense planar microbattery configurations, and applied nano-microelectronics that require a high-voltage, on-board type power source to drive microactuators and micromotors,” Kim noted.
