115 Fenske Laboratory
Pennsylvania State University
University Park, 16802
Major - Chemical Engineering
BTech, Indian Institute of Technology Madras, India (2001-2006)
MTech, Indian Institute of Technology Madras, India (2001-2006)
Hobbies and interests:
Photography, fiction writing and blogging, action and adventure sports,
cartooning and sketching, listening to music
Duration in group: 2006 - 2011
I. Effect of nanoparticle dispersion on
conductivity of PEO
Liquid electrolytes used in today's lithium ion batteries pose problems
with mechanical flexibility and toxicity issues at end-of-life
disposal. Therefore, scientists are turning to the use of solid
polymer electrolytes such as polyethylene oxide (PEO). However, PEO
has poor conductivity at room temperature. Recent studies have shown
that the addition of about 10 wt% nanoparticles increase the
conductivity by a few orders of magnitude, and shows great promise
for use in practical applications.
My research objective is to study the effect of nanoparticle
dispersion and spacing on the conductivity of PEO, because this
issue has not been addressed so far. I want to investigate the
effect of two extreme levels of dispersion - evenly distributed
nanoparticles, and aggregated nanoparticles.
It is widely accepted that high polymer host mobility helps in
lithium ion transport, and hence, the conductivity. I want to find
out how nanoparticle dispersion affects the mobility of the bulk
polymer, and in turn how the conductivity is affected. Measurement
of polymer mobility is carried out using neutron scattering, which
is discussed in more detail in the
research techniques page.
The biggest challenge is to synthesize polymer nanocomposites where
we can control the spacing between the nanoparticles. This is
because the interaction energies between the particles play a
significant role at lengths of the order of 10 nm. Therefore, we are
using a method inspired by miniemulsion polymerization so as to
achieve uniform dispersion of nanoparticles (alumina).
II. Conductivity and mobility of
single-ion conductors (ionomers)
Ionic conductivity in PEO is contributed both by anions and lithium
cation. To evaluate the contribution of lithium ion alone and to
understand the effect of polymer on just the lithium ion, the anion
is chemically bonded to the polymer backbone, rendering it immobile.
Our objective is to study the mechanism of cation transport as a
function of the polymer chain length, cation used (lithium or
sodium) and the extent of ionization of the polymer chain.