  This chapter deals with the fundamental properties of polymer nanocomposites
(PNC) and their characteristics that play a significant role in deciding their
capability for the advanced energy storage device. The various synthesization
methods used for the preparation of the polymer electrolytes are described
followed by the characterization techniques used for the analysis. The
properties of the polymer host, salt, nanofiller, ionic liquid, plasticizer and
nanoclay/nanorod/nanowire are described. Various ion transport mechanism with
different nanoparticle dispersion in polymer electrolytes are highlighted. The
various important results are summarized and a pathway is built to fulfill the
dream of the future renewable source of energy that is economical and
environmental benign. Chapter motivation is focused on the investigation of the
role of polymer host, aspect ratio, surface area, nanoparticle shape and size
in terms of boosting the electrolytic/electrochemical properties of PNC. It
will certainly help in order to open new doors toward the development of the
advanced polymeric materials with overall balancing property for enhancement of
the fast solid state ionic conductor which would be revolutionized the energy
storage/conversion device technology.
