Summary of Sol-gel Capacitor Dielectric Offers Record-high Energy Storage
Researchers combined a hybrid silica sol-gel thin film bearing polar groups with a nanoscale self-assembled monolayer of octylphosphonic acid to create a capacitor dielectric that achieves battery-rivaling energy density and high power density. The bilayer blocks electron injection, yielding low leakage, high breakdown strength, and efficient energy extraction. If scalable, devices could outperform electrolytic capacitors in electromagnetic propulsion, electric vehicles, and defibrillators. Reported July 14 in Advanced Energy Materials, the work was funded by the Office of Naval Research and the Air Force Office of Scientific Research.
Parts used in the Sol-gel Capacitor Dielectric:
- Hybrid silica sol-gel thin film with polar groups linked to silicon atoms
- Octylphosphonic acid self-assembled monolayer (nanoscale)
- Bilayer dielectric structure combining sol-gel film and phosphonic acid monolayer
Using a hybrid silica sol-gel material and self-assembled monolayers of a common fatty acid, researchers have developed a new capacitor dielectric material that provides an electrical energy storage capacity rivaling certain batteries, with both a high energy density and high power density.
If the material can be scaled up from laboratory samples, devices made from it could surpass traditional electrolytic capacitors for applications in electromagnetic propulsion, electric vehicles and defibrillators. Capacitors often complement batteries in these applications because they can provide large amounts of current quickly.
The new material is composed of a silica sol-gel thin film containing polar groups linked to the silicon atoms and a nanoscale self-assembled monolayer of an octylphosphonic acid, which provides insulating properties. The bilayer structure blocks the injection of electrons into the sol-gel material, providing low leakage current, high breakdown strength and high energy extraction efficiency.
“Sol-gels with organic groups are well known and fatty acids such as phosphonic acids are well known,” noted a professor in the at the Georgia Institute of Technology. “But to the best of our knowledge, this is the first time these two types of materials have been combined into high-density energy storage devices.”
The research, supported by the Office of Naval Research and the Air Force Office of Scientific Research, was reported July 14 in the journal Advanced Energy Materials.
The need for efficient, high-performance materials for electrical energy storage has been growing along with the ever-increasing demand for electrical energy in mobile applicationsdefense
For more detail:
- What is the new capacitor dielectric made of?
It is made of a hybrid silica sol-gel thin film with polar groups linked to silicon and a nanoscale self-assembled monolayer of octylphosphonic acid. - How does the bilayer structure improve performance?
The bilayer blocks electron injection into the sol-gel, providing low leakage current, high breakdown strength, and high energy extraction efficiency. - Can this material rival batteries in energy storage?
According to the report, it provides an electrical energy storage capacity rivaling certain batteries, with high energy density and high power density. - What applications could benefit if the material is scaled up?
Possible applications include electromagnetic propulsion, electric vehicles, and defibrillators, where capacitors complement batteries by delivering large currents quickly. - Have sol-gels and fatty phosphonic acids been used together before?
Sol-gels with organic groups and fatty acids such as phosphonic acids are well known, but this combination into high-density energy storage devices is reported as a first by the researchers. - Who supported the research?
The research was supported by the Office of Naval Research and the Air Force Office of Scientific Research. - Where was the research published and when?
The research was reported July 14 in the journal Advanced Energy Materials.
