Representation of microrobots in a dangerous environment. Credit: Alex David Jerez Roman, Beckman Institute, UIUC
A relentless technological difficulty has been the trouble in reducing the electrochemical performance of large-format batteries to smaller sized, microscale power sources, hindering their capability to power microdevices, microrobots, and implantable medical gadgets. Nevertheless, researchers at the University of Illinois Urbana-Champaign have overcome this challenge by developing a high-voltage microbattery (> > 9 V) with remarkable energy and power density, exceptional by any existing battery style.
Material Science and Engineering Professor Paul Braun (Grainger Distinguished Chair in Engineering, Materials Research Laboratory Director), Dr. Sungbong Kim (Postdoc, MatSE, existing assistant professor at Korea Military Academy, co-first author), and Arghya Patra (Graduate Student, MatSE, MRL, co-first author) just recently published a paper detailing their findings in Cell Reports Physical Science.
The group showed hermetically sealed (firmly near to prevent direct exposure to ambient air), resilient, compact, lithium batteries with remarkably low bundle mass portion in single-, double-, and triple-stacked configurations with extraordinary operating voltages, high power densities, and energy densities.
Braun describes, “We need powerful small batteries to unlock the complete potential of microscale gadgets, by improving the electrode architectures and coming up with ingenious battery designs.” The problem is that as batteries end up being smaller sized, the packaging controls the battery volume and mass while the electrode location lessens. This results in extreme reductions in energy and power of the battery.
In their unique design of powerful microbatteries, the team developed novel product packaging innovation that utilized the favorable and unfavorable terminal existing collectors as part of the packaging itself (instead of a separate entity). This permitted for the compact volume (≤ 0.165 cm3) and low plan mass portion (10.2%) of the batteries. In addition, they vertically stacked the electrode cells in series (so the voltage of each cell includes), which enabled the high operating voltage of the battery.
Another method these microbatteries are enhanced is by using very dense electrodes which offers energy density. The microbatteries in this research study were fabricated using the thick electroplated DirectPlateTM LiCoO2 electrodes manufactured by Xerion Advanced Battery Corporation (XABC, Dayton, Ohio), a company that spun out of Brauns research study.
Patra discusses, “To date, electrode architectures and cell styles at the micro-nano scale have actually been limited to power-dense styles that came at the expense of porosity and volumetric energy density. Our work has actually been successful to develop a microscale energy source that displays both high power density and volumetric energy density.”
An essential application area of these microbatteries consists of powering insect-size microrobots to get valuable details throughout natural catastrophes, search and rescue missions, and in hazardous environments where direct human gain access to is difficult. Co-author James Pikul (Assistant Professor, Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania) explains that “the high voltage is necessary for lowering the electronic payload that a microrobot requires to carry. 9 V can directly power motors and decrease the energy loss connected with enhancing the voltage to the hundreds or thousands of volts needed from some actuators. This means that these batteries make it possible for system-level enhancements beyond their energy density improvement so that the small robots can take a trip farther or send out more crucial information to human operators.”
Kim adds, “Our work bridges the understanding space at the intersection of products chemistry, unique materials producing requirements for energy-dense planar microbattery setups, and applied nano-microelectronics that require a high-voltage, on-board type power source to drive micromotors and microactuators.”
Braun, a pioneer in the field of battery miniaturization, concludes, “our existing microbattery design is well-suited for high-energy, high-power, high-voltage, single-discharge applications. The next step is to equate the design to all solid-state microbattery platforms, batteries which would inherently be much safer and more energy thick than liquid-cell counterparts.”
Referral: “Serially integrated high-voltage and high power mini batteries” by Sungbong Kim, Arghya Patra, Ryan R. Kohlmeyer, Seongbin Jo, Xiujun Yue, Alissa Johnson, Chadd T. Kiggins, Beniamin Zahiri, Keunhong Jeong, Jahyun Koo, Taewook Kang, Pengcheng Sun, John B. Cook, James H. Pikul and Paul V. Braun, 22 December 2022, Cell Reports Physical Science.DOI: 10.1016/ j.xcrp.2022.101205.
The problem is that as batteries become smaller sized, the packaging dominates the battery volume and mass while the electrode area ends up being smaller sized. This results in extreme reductions in energy and power of the battery.
In addition, they vertically stacked the electrode cells in series (so the voltage of each cell adds), which made it possible for the high operating voltage of the battery.
The microbatteries in this research were produced utilizing the thick electroplated DirectPlateTM LiCoO2 electrodes produced by Xerion Advanced Battery Corporation (XABC, Dayton, Ohio), a business that spun out of Brauns research.
This suggests that these batteries allow system-level improvements beyond their energy density improvement so that the little robots can travel further or send out more vital details to human operators.”