Nav: Home

Delivering a power punch

December 05, 2016

Energy storage units that can be integrated into wearable and flexible electronic systems are becoming increasingly important in today's world. A research team from KAUST has now developed a microsupercapacitor that exploits three-dimensional porous electrodes. These micropower units are expected to enable a new generation of "smart"products, such as self-powered sensors for wearables, security, structural health monitoring and "internet of things" applications.

However, for these units to be tiny yet still efficient, the highest energy density must go into the smallest area.

One approach to carrying this out is to construct microbatteries using films with a thickness of just a few micrometers or less and to replace traditional electrolytes with solid-state ones. Thin film batteries have demonstrated relatively high energy density, which is the amount of energy they can store in a given area. However, they are afflicted by limited cycle life and poor power density, meaning they are slow to charge and discharge.

Microsupercapacitors are a faster alternative, and these may prove suitable for applications requiring power pulsing and very long cycle life.

"Also, while batteries must be charged at a constant voltage, a supercapacitor charges most efficiently by drawing the maximum current that the source can supply, irrespective of voltage," said KAUST Professor of Material Science and Engineering Husam Alshareef from the University's Functional Nanomaterials & Devices group.

This makes supercapacitors more appealing for self-powered system applications where the power source may be intermittent.

Alshareef's team has now developed integrated microsupercapacitors with vertically-scaled three-dimensional porous current collectors made from nickel foams to improve microsupercapacitor performance. The pores in the foam work to increase the surface area.

"This three-dimensional porous architecture allows excellent electrolyte permeability, good conductivity and faster ion transportation with maximum mass-loading of active material, which increase energy and power density in a given area," Alshareef said.

The microsupercapacitors were also asymmetric, using two different electrode materials for the cathode (nickel cobalt sulfide) and anode (carbon nanofiber), which nearly doubled the operating voltage. As a result, while delivering high power density (four milliwatts per square centimeter), the microsupercapacitors had an energy density of 200 microwatt-hours per square centimeter.

This is superior to state-of-the-art microsupercapacitors, which achieve between one and forty microwatt-hours per square centimeter, and is comparable to various types of thin film batteries. These high capacities were maintained even after 10,000 operating cycles.

"The high energy and power density achieve in these devices may meet the demand of on-chip storage for various types of integrated microsystems," noted KAUST Ph.D. student Qiu Jiang, the lead author of the study.
-end-


King Abdullah University of Science & Technology (KAUST)

Related Batteries Articles:

A seaweed derivative could be just what lithium-sulfur batteries need
Lithium-sulfur batteries have great potential as a low-cost, high-energy, energy source for both vehicle and grid applications.
Batteries from scrap metal
Chinese scientists have made good use of waste while finding an innovative solution to a technical problem by transforming rusty stainless steel mesh into electrodes with outstanding electrochemical properties that make them ideal for potassium-ion batteries.
Better cathode materials for lithium-sulphur-batteries
A team at the Helmholtz-Zentrum Berlin (HZB) has for the first time fabricated a nanomaterial made from nanoparticles of a titanium oxide compound (Ti4O7) that is characterized by an extremely large surface area, and tested it as a cathode material in lithium-sulphur batteries.
Bright future for self-charging batteries
Who hasn't lived through the frustrating experience of being without a phone after forgetting to recharge it?
Making batteries from waste glass bottles
Researchers at the University of California, Riverside's Bourns College of Engineering have used waste glass bottles and a low-cost chemical process to create nanosilicon anodes for high-performance lithium-ion batteries.
Batteries -- quick coatings
Scientists at Oak Ridge National Laboratory are using the precision of an electron beam to instantly adhere cathode coatings for lithium-ion batteries -- a leap in efficiency that saves energy, reduces production and capital costs, and eliminates the use of toxic solvents.
Lighter, more efficient, safer lithium-ion batteries
Researchers from Universidad Carlos III de Madrid and the Council for Scientific Research (initialed CSIC in Spanish) have patented a method for making new ceramic electrodes for lithium-ion batteries that are more efficient, cheaper, more resistant and safer than conventional batteries.
Clarifying how lithium ions ferry around in rechargeable batteries
IBS scientists observe the real-time ultrafast bonding of lithium ions with the solvents, in the same process that happens during charging and discharging of lithium batteries, and conclude that a new theory is needed.
A new approach to improving lithium-sulfur batteries
Researchers from the University of Delaware and China's Northwestern Polytechnical University, Shenzhen University and Hong Kong Polytechnic University have demonstrated a new polysulfide entrapping strategy that greatly improves the cycle stability of Li-S batteries.
Looking for the next leap in rechargeable batteries
USC researchers may have just found a solution for one of the biggest stumbling blocks to the next wave of rechargeable batteries -- small enough for cellphones and powerful enough for cars.

Related Batteries Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...