Significant research has occurred over the past several years on super capacitors that employ graphene to increase the surface area of the electrode material and thus the capacitance. Super capacitors are thereby reaching a theoretical limit. In contrast, there has been only marginal advances over the same period in finding materials with superior dielectric constants for the traditional and most widely used electrostatic (dielectric) capacitors.
Navy researchers have developed a new class of dielectrics—super dielectric materials—with dielectric constants near 0 Hz, greater than 10^5. The specific dielectric employed is a high surface area alumina impregnated, to the consistency of paste, with an aqueous solution of weak boric acid. This material repeatedly shows dielectric constants greater than 4 × 10^8. The high dielectric constants measured may support development of a classic electrostatic capacitor as an alternative to super capacitors for electrical energy storage and power delivery. Data from the Navy suggests that with optimization these novel capacitors, made of remarkably inexpensive material, could surpass super capacitors and rival batteries in terms of volumetric energy density.
- The measured dielectric constant of one example, high surface area alumina incorporating a solution of boric acid, is orders of magnitude higher (~10^9) than any form of barium titanate (~10^3)
- Cyclic charging and discharging show that these capacitors behave as near ideal capacitors over a limited, repeatable voltage range
- Materials are markedly cheaper than those used in super capacitors
- US patent 9,530,574 available for license
- Potential for collaboration with Navy researchers