Nanodielectric Materials fabrication for energy storage solutions

The NNL is conducting R&D on artificial polymer based nanodielectrics for energy storage solutions. There is a tremendous need to develop electronic circuits on flexible substrates to meet the growing demand for low-cost, large-area, flexible and lightweight devices. The highest capacitive density achieved with commercial polymer composite technology is in the order of 10 nF/cm².  Achieving permittivity values K greater than 100 is difficult even with the mature ceramic-filled polymer technology. Experimentally, relative K values of 70 are considered excellent for polymer/ferroelectric composites. The concept of putting metal nanoparticles instead of ceramic comes up because metals can, in principle, be thought of as the limiting case of high permittivity particles.

Initial investigation revealed that polymers with nanosize metal fillers exhibit percolative behavior, which enhances the dielectric constant of the composite by many folds. Large-scale multiphysics coupling 3D simulation using percolation theory shows such an increase in capacitance with a minimum energy loss is mainly due to uniformly distributed nanoparticles in the host polymer without compromising the inter-particle spacing. The envisioned technology will lead to fabrication of embedded supercapacitors that will have use in many cutting edge, plastics related, electronic devices where size, weight, and cost are a premium.

Although the nanostructured materials technology can be used for small scale integration as embedded capacitors in polymers electronics, it also can be scaled up for load bearing capacitor banks that offer energy storage capabilities with structural properties, and which can be, for instance, integrated as part of buildings and vehicles design.