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.