Structural dielectrics for multifunctional capacitors

Abstract

As U.S. Army systems and vehicles become more dependent on electronic devices and subsystems, there is an increasing need for improving the mass-and volume-efficiency of energy storage components. The conventional approach for saving mass and volume is to increase component energy density. Alternatively, overall system weight can be reduced by replacing purely structural components, such as armor or frame members, with structures that also store energy. Specifically, we are developing capacitors that can also carry structural loads by intercalating glass fiber reinforced polymer dielectric layers with metallized polymer film electrodes.In previous work, we developed a metric, the multifunctional efficiency (MFE), for comparing various structural capacitor preparations and guiding multifunctional design. Modeling and characterization of fiber composite-based structural capacitors has shown that the MFE is sensitive to fiber shape, orientation, volume fraction, and dielectric constant. In this work, various dielectric materials are studied against this MFE metric and the effect of fiber properties and volume fraction on MFE is explored experimentally.

Effects of phase constitution and microstructure on energy storage properties of barium strontium titanate ceramics

“…This is essential for pulsed power applications and regenerative braking system [3,4]. In order to meet the increasing need for improving the mass-and volume-efficiency of energy storage components, the energy density of capacitors must be increased [5]. At least two approaches are utilized to address this issue.…”

Design and performance of multifunctional structural composite capacitors

“…Elastic modulus, mechanical strength, capacitance, dielectric strength, and energy density are reported for a series of structural composite capacitors. The study builds on our previous work on structural capacitors, 39–41 presenting a systematic exploration of the effect of fiber volume fraction on multifunctional performance. Because the work presented here was motivated by the need for pulsed power energy storage on mobile platforms, mass-normalized energy density is the primary metric for capacitive performance.…”

Cyanate ester-nanoparticle composites as multifunctional structural capacitors

“…In addition to characterizing the distribution of constituents, the micrographs showed no evidence of voids that would result in a decrease in the PMC's measured dielectric constant. Specimen Dispersed BaTiO 3 (%) 0% E-glass/10% BaTiO 3 1.9 15% E-glass/10% BaTiO 3 2.0 30% E-glass/10% BaTiO 3 6.4…”

“…However, as an ensemble the synergy achieved by the combination of each constituent's characteristics allows for system-level benefits that cannot be achieved through the optimization of the separate subsystems. Thus in addressing the previously mentioned goals, overall design efficiency increases by producing multifunctional components using materials that deliver improvements of both dielectric and thermo-mechanical properties, over existing materials of separate components [1][2][3].…”

“…Continuous GF embedded within fully cured BECy.Implications and future directionsThe multifunctional systems developed throughout these experiments do not yet exhibit the energy density values desired for the next generation of structural capacitors, U > 2 J/cm3 . Nevertheless, the evidence gathered throughout the investigations demonstrated that the constituents explored have the potential to be used in production of such devices.…”