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NANOPOWER: By Carl Picconatto SUMMARY: As the increased capabilities and decreased sizes of electronic devices demand more and more from their strained power systems, new technologies must be found to increase their power and energy capacities. Nanotechnology promises the manufacturing techniques and materials capable of providing such a boost. Power Drain Our days—at home, at play, at the office—are spent tethered to electronic devices that, while their batteries last, improve our quality of life and increase our productivity. You may have noticed, however, that those devices don't last as long between battery charges as they used to. In the good old days, laptops ran for eight hours on a single charge, cell phones would still function after being left in your purse for weeks, and portable video games and music players would last the entire twelve-hour drive to grandma's house. But the rise in the capabilities of electronic devices, paired with the shrinking size of those devices, is pushing the limits of the power and energy (P&E) systems that supply their juice. Electronic devices demand more and more power but provide less and less space to store that power. Consumer electronics aren't the only systems facing P&E issues. Electronic devices designed for national defense and intelligence also are increasing in capability while shrinking in size. In extreme cases, the P&E systems for these devices are larger than the devices themselves, severely limiting their utility. As a matter of national security, new P&E solutions are needed. Nanotechnology Is Leading the Way Forward While there is room for improving the efficiency of power systems, there are fundamental limits to how much energy can be provided. Outside of nuclear or radiation sources, power comes from chemical processes. All chemical reactions have a thermodynamic limit—an upper bound for the maximum amount of energy that can be obtained. Improving the mechanics of a power system can help us approach that limit, but to move beyond it requires fundamentally new approaches and/or new chemistries. P&E systems based on nanotechnology are a likely way forward. Such systems have the potential to improve conventional energy processes to realize more of their existing thermodynamic potential. Further, nanotechnology may enable alternative approaches with superior thermodynamic characteristics.
How nanotechnology improves the performance of P&E systems depends on the individual technologies involved. Nevertheless, there are a few general principles:
Likely Near-term Impacts Developing nano-enabled P&E systems is not just about making tiny new power sources; it's also about drastically improving the energy and power density of conventional systems. For example, perhaps the most important near-term application of P&E nanotechnology will be improving the efficiency of current batteries. Nanofabrication techniques are being used to reconfigure the electrodes, which permits a larger battery capacity as well as faster charging and discharging, resulting in higher power. Another technique incorporates nanomaterials, such as carbon nanotubes or nanofiber vanadium oxide, into the electrodes, which allows a greater percentage of the battery capacity to be used at high discharge currents. It also improves the battery performance at low temperatures.
Other researchers are developing entirely new nano-enabled approaches to change the thermodynamics altogether. For example, work at Rutgers University has focused on the use of metal fluorides, which generally make poor battery electrodes on the bulk scale due to their insulating properties. However, nanostructured metal fluorides conduct strongly, even better than traditional battery materials. This has led to a prototype battery with an improvement in specific capacity of almost 100 percent. Beyond these substantial improvements to conventionally sized batteries, nanotechnology also is having a dramatic impact on the development of P&E systems for revolutionary new applications. Nanofabrication techniques, especially self-assembly, have allowed the development of novel ultra-small battery systems. These ultrasmall batteries have shown extremely high nominal energy and power densities compared to conventional systems and could be used to power ultra-miniaturized systems for sensing or communications. Nano-enabled systems are being targeted as solutions for national energy issues as well. Nanotechnology is enabling greater efficiency in renewable energy sources, providing new methods for the storage and transport of energy, and developing safer and more efficient delivery mechanisms. Fuel cells also stand to be vastly improved by nano-engineered catalysts. All of these areas represent fertile ground for R&D efforts and are being actively pursued. MITRE's Role MITRE is working closely with academic and industrial collaborators not only on researching and developing new nanoenabled P&E technologies, but also on employing MITRE's systems engineering expertise to integrate existing nano-enabled P&E technologies into new applications. Current MITRE projects include developing improved battery systems for communications and sensor technologies, increasing the efficiency of portable power sources for dismounted soldiers and small autonomous vehicles, and investigating power transmission and "smart grid" applications. Meeting our future power needs will require not only new fundamental discoveries, but also concerted systems engineering efforts to integrate the state of the art into new applications. Nanotechnology will play a critical role in the development of both the evolutionary and revolutionary improvements in capability that are necessary, and MITRE will continue to take an active role in pioneering this emerging technological effort. Related Information Articles and News Technical Papers and Presentations Websites |
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For more information, please contact Carl Picconatto using the employee directory. Page last updated: April 15, 2009 | Top of page |
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