Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Liberating devices from their power cords: New structural “supercaps” take a lickin’, keep on workin’

20.05.2014

Imagine a future in which our electrical gadgets are no longer limited by plugs and external power sources.

This intriguing prospect is one of the reasons for the current interest in building the capacity to store electrical energy directly into a wide range of products, such as a laptop whose casing serves as its battery, or an electric car powered by energy stored in its chassis, or a home where the dry wall and siding store the electricity that runs the lights and appliances.

It also makes the small, dull grey wafers that graduate student Andrew Westover and Assistant Professor of Mechanical Engineering Cary Pint have made in Vanderbilt’s Nanomaterials and Energy Devices Laboratory far more important than their nondescript appearance suggests.

“These devices demonstrate – for the first time as far as we can tell – that it is possible to create materials that can store and discharge significant amounts of electricity while they are subject to realistic static loads and dynamic forces, such as vibrations or impacts,” said Pint. “Andrew has managed to make our dream of structural energy storage materials into a reality.”

That is important because structural energy storage will change the way in which a wide variety of technologies are developed in the future. “When you can integrate energy into the components used to build systems, it opens the door to a whole new world of technological possibilities. All of a sudden, the ability to design technologies at the basis of health, entertainment, travel and social communication will not be limited by plugs and external power sources,” Pint said.

The new device that Pint and Westover has developed is a supercapacitor that stores electricity by assembling electrically charged ions on the surface of a porous material, instead of storing it in chemical reactions the way batteries do. As a result, supercaps can charge and discharge in minutes, instead of hours, and operate for millions of cycles, instead of thousands of cycles like batteries.

In a paper appearing online May 19 in the journal Nano Letters, Pint and Westover report that their new structural supercapacitor operates flawlessly in storing and releasing electrical charge while subject to stresses or pressures up to 44 psi and vibrational accelerations over 80 g (significantly greater than those acting on turbine blades in a jet engine).

Furthermore, the mechanical robustness of the device doesn’t compromise its energy storage capability. “In an unpackaged, structurally integrated state our supercapacitor can store more energy and operate at higher voltages than a packaged, off-the-shelf commercial supercapacitor, even under intense dynamic and static forces,” Pint said.

One area where supercapacitors lag behind batteries is in electrical energy storage capability: Supercaps must be larger and heavier to store the same amount of energy as lithium-ion batteries. However, the difference is not as important when considering multifunctional energy storage systems.

“Battery performance metrics change when you’re putting energy storage into heavy materials that are already needed for structural integrity,” said Pint. “Supercapacitors store ten times less energy than current lithium-ion batteries, but they can last a thousand times longer. That means they are better suited for structural applications. It doesn’t make sense to develop materials to build a home, car chassis, or aerospace vehicle if you have to replace them every few years because they go dead.”

Westover’s wafers consist of electrodes made from silicon that have been chemically treated so they have nanoscale pores on their inner surfaces and then coated with a protective ultrathin graphene-like layer of carbon. Sandwiched between the two electrodes is a polymer film that acts as a reservoir of charged ions, similar to the role of electrolyte paste in a battery. When the electrodes are pressed together, the polymer oozes into the tiny pores in much the same way that melted cheese soaks into the nooks and crannies of artisan bread in a Panini. When the polymer cools and solidifies, it forms an extremely strong mechanical bond.

“The biggest problem with designing load-bearing supercaps is preventing them from delaminating,” said Westover. “Combining nanoporous material with the polymer electrolyte bonds the layers together tighter than superglue.”

The use of silicon in structural supercapacitors is best suited for consumer electronics and solar cells, but Pint and Westover are confident that the rules that govern the load-bearing character of their design will carry over to other materials, such as carbon nanotubes and lightweight porous metals like aluminum.

The intensity of interest in “multifunctional” devices of this sort is reflected by the fact that the U.S. Department of Energy’s Advanced Research Project Agency for Energy is investing $8.7 million in research projects that focus specifically on incorporating energy storage into structural materials. There have also been recent press reports of several major efforts to develop multifunctional materials or structural batteries for use in electric vehicles and for military applications. However, Pint pointed out that there have not been any reports in the technical literature of tests performed on structural energy storage materials that show how they function under realistic mechanical loads.

Amrutur Anilkumar, professor of the practice in mechanical engineering, postdoctoral associate Shahana Chatterjee, graduate student Landon Oakes, undergraduate mechanical engineering majors John Tian, Shivaprem Bernath and Farhan Nur Shabab and high school student Rob Edwards collaborated in the project.

The research was supported by National Science Foundation grants CMMI 1334269 and EPS 104083. Materials fabrication was conducted in part at the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory that is supported by the Office of Basic Energy Sciences of the U.S. Department of Energy.

Visit Research News @ Vanderbilt for more research news from Vanderbilt. [Media Note: Vanderbilt has a 24/7 TV and radio studio with a dedicated fiber optic line and ISDN line. Use of the TV studio with Vanderbilt experts is free, except for reserving fiber time.]

David F. Salisbury | Vanderbilt University
Further information:
http://www.vanderbilt.deu

Further reports about: Vanderbilt batteries battery cycles develop electricity electrodes technologies

More articles from Power and Electrical Engineering:

nachricht New welding process joins dissimilar sheets better
28.09.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen GmbH

nachricht Cooling buildings with solar heat
26.09.2016 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

 
Latest News

A perfect sun-storm

28.09.2016 | Earth Sciences

New welding process joins dissimilar sheets better

28.09.2016 | Power and Electrical Engineering

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>