Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Liberating devices from their power cords

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.


Close-up of structural supercapacitor. (Joe Howell / Vanderbilt)

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.”

When you can integrate energy into the components used to build systems, it opens the door to a whole new world of technological possibilities.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.

Supercapacitors store ten times less energy than current lithium-ion batteries, but they can last a thousand times longer.“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 the 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.

Contact:
David Salisbury, (615) 322-NEWS
david.salisbury@vanderbilt.edu

David Salisbury | Vanderbilt University
Further information:
http://www.vanderbilt.deu
http://news.vanderbilt.edu/2014/05/liberating-devices/

Further reports about: Energy Vanderbilt batteries battery cycles electricity electrodes ions materials pores structural

More articles from Power and Electrical Engineering:

nachricht One Step Closer to a Single-Molecule Device
28.05.2015 | Columbia University School of Engineering and Applied Science

nachricht Researchers develop intelligent handheld robots
27.05.2015 | University of Bristol

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: Lasers are the key to mastering challenges in lightweight construction

Many joining and cutting processes are possible only with lasers. New technologies make it possible to manufacture metal components with hollow structures that are significantly lighter and yet just as stable as solid components. In addition, lasers can be used to combine various lightweight construction materials and steels with each other. The Fraunhofer Institute for Laser Technology ILT in Aachen is presenting a range of such solutions at the LASER World of Photonics trade fair from June 22 to 25, 2015 in Munich, Germany, (Hall A3, Stand 121).

Lightweight construction materials are popular: aluminum is used in the bodywork of cars, for example, and aircraft fuselages already consist in large part of...

Im Focus: Solid-state photonics goes extreme ultraviolet

Using ultrashort laser pulses, scientists in Max Planck Institute of Quantum Optics have demonstrated the emission of extreme ultraviolet radiation from thin dielectric films and have investigated the underlying mechanisms.

In 1961, only shortly after the invention of the first laser, scientists exposed silicon dioxide crystals (also known as quartz) to an intense ruby laser to...

Im Focus: Advance in regenerative medicine

The only professorship in Germany to date, one master's programme, one laboratory with worldwide unique equipment and the corresponding research results: The University of Würzburg is leading in the field of biofabrication.

Paul Dalton is presently the only professor of biofabrication in Germany. About a year ago, the Australian researcher relocated to the Würzburg department for...

Im Focus: Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents

Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.

Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...

Im Focus: IoT-based Advanced Automobile Parking Navigation System

Development and implementation of an advanced automobile parking navigation platform for parking services

To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International symposium: trends in spatial analysis and modelling for a more sustainable land use

20.05.2015 | Event News

15th conference of the International Association of Colloid and Interface Scientists

18.05.2015 | Event News

EHFG 2015: Securing health in Europe. Balancing priorities, sharing responsibilities

12.05.2015 | Event News

 
Latest News

Quasi-sexual gene transfer drives genetic diversity of hot spring bacteria

29.05.2015 | Life Sciences

First Eastern Pacific tropical depression runs ahead of dawn

29.05.2015 | Earth Sciences

Donuts, math, and superdense teleportation of quantum information

29.05.2015 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>