Newfound Lightweight Supercapacitor Materials Help Extend Battery Life for Mobile Electronic Devices

Two teams, one at the University of Houston and the second at the University of Michigan, have unveiled two new advanced material models for energy conversion and storage. Haleh Ardebili from the University of Houston led a team to develop a new electrode based on reduced graphene oxide and aramid nanofiber (rGO-ANF), which is lighter and more durable.

Meanwhile, the University of Michigan announced new research co-led by Edgar Meyhofer, professor of Mechanical Engineering, and Vladimir Shalaev, a professor of Electrical and Computer Engineering from Purdue, into the measurement of highly-energetic electrons called “hot charge carriers” induced in gold and silver nanostructures.

 

Artist's rendering of an electron trail on gold nanostructure and subsequent detection of "hot charge carriers" by using specialized gatekeeper molecules. Image credited to Enrique Shagun, Scixel

 

Supercapacitor Electrodes and Time of Flight

These advancements mean big changes are on the way for energy-hungry electronic systems. Supercapacitors possess high power density, which can be delivered to an electronic load much quicker than it can be drawn out of a lithium-ion battery.

This is critically important for applications involving motor systems, like drones and EVs, which need to be able to increase thrust at a moment’s notice. Storing energy in a fast charge/discharge capacitor during steady-state operation allows the flow of energy out of a battery to be more evenly regulated, improving overall ampere-hours (and flight-time).

The new rGO-AFN has an improved strength profile and researchers indicate that it is a possible replacement for steel. This durability improvement, coupled with enhanced power density will provide for a variety of applications for military use in electronic and high-energy ballistic warfare, and producing increasingly ruggedized personnel equipment.

 

Using Hot Charge Carriers for Storage Application Energy Conversion 

The research teams at the University of Michigan, and University of Purdue have reported the development of an electrode filter that can effectively detect “hot charge carriers” on the surfaces of thin nanomaterials of gold and silver produced by laser light to induce surface plasmons.

These highly energetic carriers possess the energy of a much hotter material – greater than 2000 degrees Fahrenheit. “For example, if you wanted to employ light to split water into hydrogen and oxygen, you can use hot charge carriers because electrons that are more energetic can more readily participate in the reaction and drive the reaction faster,” says Edgar Meyhofer, “That’s one possible use for hot carriers in energy conversion or storage applications”