Nanoflowers improve ultracapacitors

A novel design could boost energy storage.

09/22/2008



Imagine a cell-phone battery that recharges in a few seconds and that you would never have to replace. That's the promise of energy-storage devices known as ultracapacitors, but at present, they can store only about 5% as much energy as lithium-ion batteries, according to a story in MIT’s Technology Review . An advance by researchers at the Research Institute of Chemical Defense, in China, could boost ultracapacitors' ability to store energy.

A capacitor consists of two electrodes with opposite charges, often separated by an insulator that keeps electrons from jumping directly between them. The researchers have developed an electrode that can store twice as much charge as the activated-carbon electrodes used in current ultracapacitors. The new electrode contains flower-shaped manganese oxide nanoparticles deposited on vertically grown carbon nanotubes.

The electrodes deliver five times as much power as activated-carbon electrodes, says Hao Zhang, lead author of the Nano Letters paper describing the new work. The electrode's longevity also compares with that of activated-carbon electrodes, Zhang says: discharging and recharging the electrodes 20,000 times reduced the capacitor's energy-storage capacity by only 3%.

So far, ultracapacitors have been limited to niche applications that require high power and quick, repetitive recharging. For example, the devices provide quick bursts of power to buses, trucks, and light-rail trains over short stretches, and braking replenishes them. If they could store more energy, however, they could be a powerful, long-lasting replacement for batteries in hybrid-electric vehicles and portable electronics.





No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
Control Engineering Leaders Under 40 identifies and gives recognition to young engineers who...
Learn more about methods used to ensure that the integration between the safety system and the process control...
Adding industrial toughness and reliability to Ethernet eGuide
Technological advances like multiple-in-multiple-out (MIMO) transmitting and receiving
Virtualization advice: 4 ways splitting servers can help manufacturing; Efficient motion controls; Fill the brain drain; Learn from the HART Plant of the Year
Two sides to process safety: Combining human and technical factors in your program; Preparing HMI graphics for migrations; Mechatronics and safety; Engineers' Choice Awards
Detecting security breaches: Forensic invenstigations depend on knowing your networks inside and out; Wireless workers; Opening robotic control; Product exclusive: Robust encoders
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
News and comments from Control Engineering process industries editor, Peter Welander.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
Anthony Baker is a fictitious aggregation of experts from Callisto Integration, providing manufacturing consulting and systems integration.
Integrator Guide

Integrator Guide

Search the online Automation Integrator Guide
 

Create New Listing

Visit the System Integrators page to view past winners of Control Engineering's System Integrator of the Year Award and learn how to enter the competition. You will also find more information on system integrators and Control System Integrators Association.

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.