Researchers at Penn State University are working on a new
type of thin glass capable of storing energy, a material that could help make
electric and plug-in hybrid vehicles more affordable and reliable.
Thin and flexible glass has already been widely
commercialized for computer and electronic displays. An even thinner version –
about one-tenth the thickness of typical displays – can be manipulated to store
energy at high temperatures and for high-power applications, such as electric
vehicles, wind turbines and grid-tied solar photovoltaics, according to Penn
State’s Materials Research Institute.
The researchers came to this conclusion after testing a
variety of alkali-free glass compositions and thicknesses, and comparing their
energy density with the commercial polymer capacitors used today in electric
vehicles to send energy from the battery to the electric motor.
Because those capacitors require a separate cooling
system, they are large and bulky. But the 10-micron-thick glass tested by Penn
State (and made by Nippon Electric Glass) retains a very high charge-discharge
efficiency at temperatures up 356 degrees Fahrenheit, without requiring that
extra cooling component.
The researchers worked in collaboration with Strategic
Polymer Sciences to produce the glass in thin sheets, using the same
roll-to-roll process used by leading glass manufacturers — which means the
material should be relatively straightforward to manufacture.
Photo: Penn State Postdoctoral researcher Mohan Manoharan unspools a
ribbon of 10-micron-thick, flexible glass for energy storage.
The glass was then coated with polymers that increased
the energy density by 2.25 times and made them less subject to sudden failures,
says Penn State post-doctoral researcher Mohan Manoharan, who lead the study.
“These flexible glass capacitors will reduce weight and
cost if replacing polypropylene capacitors,” says Manoharan. “They could be
used in any high energy density capacitor application — not only in electric
vehicles, but in heart defibrillators or weapons systems such as the electric
railgun the Navy is developing.”
For more about the Penn State research: