Stacked 3D supercapacitors (energy-storage devices important for portable, flexible electronics) have been produced and tested by Rice University scientists in recent development of laser-induced graphene (LIG).
The Rice lab of chemist James Tour discovered last year that firing a laser at an inexpensive polymer burned off other elements and left a film of porous graphene, the much-studied atom-thick lattice of carbon.
The researchers viewed the porous, conductive material as a perfect electrode for supercapacitors or electronic circuits.
To prove it, members of the Tour group have since extended their work to make vertically aligned supercapacitors with laser-induced graphene on both sides of a polymer sheet. The sections are then stacked with solid electrolytes in between for a multilayer sandwich with multiple microsupercapacitors.
Combining energy and power density
The flexible stacks show excellent energy-storage capacity and power potential and can be scaled up for commercial applications. LIG can be made in air at ambient temperature, perhaps in industrial quantities through roll-to-roll processes, Tour said.
The research was reported in Applied Materials and Interfaces.
A schematic shows the process developed by Rice University scientists to make vertical microsupercapacitors with laser-induced graphene. The flexible devices show potential for use in wearable and next-generation electronics. (Credit: Tour Group/Rice University)
Capacitors use an electrostatic charge to store energy they can release quickly, to a camera’s flash, for example. Unlike chemical-based rechargeable batteries, capacitors charge fast and release all their energy at once when triggered.
But chemical batteries hold far more energy. Supercapacitors combine useful qualities of both — the fast charge/discharge of capacitors (power density) and high-energy capacity of batteries (energy density) — into one package.
Tour said that while thin-film lithium ion batteries are able to store more energy, LIG supercapacitors of the same size offer three times the performance in power (the speed at which energy flows). And the LIG devices can easily scale up for increased capacity.
“We’ve demonstrated that these are going to be excellent components of the flexible electronics that will soon be embedded in clothing and consumer goods,” he said.
Read the full article from Kurzweil AI: http://www.kurzweilai.net/