Incredible bulk

Materials researchers at the Materials Research Institute at Penn State University have reported the highest known breakdown strength for a bulk glass ever measured.

Breakdown strength, along with dielectric constant, determines how much energy can be stored in an insulating material before it fails and begins to conduct electricity.

A bulk glass with high breakdown strength and high dielectric constant would make an ideal candidate for the next generation of high-energy density storage capacitors to power more efficient electric vehicles, as well as other portable and pulsed power applications.

The highest dielectric breakdown strengths for bulk glasses are typically in the 4-9MV/cm range. The breakdown strength for the Penn State samples were in the 12MV/cm range, which in conjunction with a relatively high permittivity, resulted in energy densities of 35J/cm3, as compared to a maximum energy density of 10J/cm3 for polypropylene, the most common dielectric for pulsed power applications.

'For a bulk glass, this is extraordinary,' said Nick Smith, a PhD candidate in materials science and engineering at Penn State who performed the testing.