Scientist explores capabilities of nanotechnology for supercapacitors
Postdoctoral scientist Jay Gaillard investigates ways to improve energy storage and power delivery using supercapacitors as part of the Savannah River National Laboratory Postdoctoral Research Associate Program. Pictured above, he holds a pure double-walled carbon nanotube paper—called buckypaper—used as a flexible, high surface area material for storing charge in the supercapacitors.
Dr. Jay Gaillard knows that manipulating matter on a minute scale can provide wide-reaching solutions to large-scale problems like world hunger and energy dependence. With a doctorate degree in physics from Clemson University, Gaillard said he believes nanotechnology is the foundation for a better world; worldwide, other scientists agree.
“Due to their extremely small sizes, nanoparticles spark endless imagination and possibilities for discovery; we can create entirely new material properties by manipulating materials on the nano-level,” said Gaillard, who is currently a research fellow in the Savannah River National Laboratory Postdoctoral Research Associate Program, administered by the Oak Ridge Institute for Science and Education.
The program provides opportunities for doctorate-holding U.S. citizens to utilize the unique resources at SRNL to enhance their understanding of science, technology, environmental and math (STEM) fields.
“The SRNL research program has been a great opportunity to develop collaboration in the U.S. Department of Energy arena and to understand the interworking of a national laboratory,” Gaillard said.
He joined the SRNL program in July 2012 and will conduct his nanoparticle research until July 2013.
Nanoparticles are millions of times smaller than a grain of sand and exhibit properties significantly different from their larger counterparts, because as a material breaks down into smaller and smaller pieces, it gains a significant amount of surface area, much like a block of cheese broken into cubes has a greater surface area than a block of cheese straight out of the package. This surface area to volume ratio affects that material’s reactivity, solubility and stability among other characteristics.
Gaillard’s research focuses on carbon nanotubes, a member of a class of carbon-based nanoparticles. A carbon nanotube is a nano-sized, webbed cylinder of hexagonal carbon atoms. When the atoms are arranged in a certain way, carbon nanotubes have the potential to be hundreds of times stronger than steel but six times lighter.
At the Hydrogen Research Technology Laboratory at SRNL, Gaillard is determining how carbon nanotubes could be used to increase the performance of energy storage devices to save consumer costs.
“Since carbon nanotubes have a high surface area, high electrical conductivity and toughness, they are the perfect candidate for the active layer and electric current collector for the next generation supercapacitor,” he explained, adding that supercapacitors are the ideal energy storage technology above even today’s best chemical batteries because of the supercapacitor’s high power-density, high cycle-life and ability to rapidly harvest or supply energy.
A supercapacitor stores electric energy using two conducting plates, known as electrodes, soaked in an electrolyte solution. A thin insulating material is found between the plates. Static electric energy builds on the plates as the plates’ positive and negative charges are prevented from coming into contact with each other because of the insulation.
Traditional supercapacitors use activated carbon electrodes, and Gaillard wanted to try a different carbon variation: a double-walled carbon nanotube (DWNT). In the DWNT, Gaillard said the charge is stored as an electric double layer on the nanotube’s surface, which significantly increases the energy storage compared to traditional capacitors.
“We have produced a supercapacitor that uses millimeter-long DWNTs as the electrode material; these DWNTs were produced by a process known as chemical vapor deposition, using ethanol as the carbon source, then collected as a highly dense thin film directly after growth,” said Gaillard. “The film is freestanding and flexible and can be used as the active energy storage material and capacitor plate simultaneously, which significantly reduces weight and volume of the supercapacitors.”
Gaillard said his DWNT material allowed five times as much capacitance as other tried-and-tested single- and double-walled nanotubes, holding implications for clean, renewable energy that relies on capacitors for nighttime or intermittent energy storage.
Gaillard said future research will focus on using organic electrolytes and ionic liquids that can be used at higher voltages, which will improve specific energy. His ultimate goal is to develop the high-capacity energy storage technology to be market-transferable.
“I would like to secure grants to support research on energy storage for the next several years and develop a highly motivated and visible research foundation that primarily focuses on energy storage,” he said.
Aside from his research, Gaillard likes to spend time with his family and on the river, playing watersports, crabbing and fishing. Someday, he said he would like to catch a 500-pound Atlantic Blue Marlin. A strong, durable fishing rod—reinforced with nanotubes of course—might, just might, be the instrument in his hands when that day comes.