poly(vinylidene fluoride–hexafluoropropylene) (PVdF–HFP) as electrolytes. The
cycling behavior of LiMn 2 O 4 –polymer electrolyte (PE)–Li cells is also described
(Stephan 2006). Another review by Zhang et al. covered the separators used in liquid
electrolyte Li–ion batteries. The classification of separators was done on the basis of
the structure and composition of the membranes followed by a discussion on the
manufacture, characteristics, performance, and modifications of the separators
(Zhang 2007a). Stephan et al. discussed the composite polymer electrolytes
(CPEs) with the main focus on electrochemical and physical properties for the
applications in lithium batteries. The polymer hosts discussed were poly(ethylene
oxide) (PEO), poly(acrylonitrile) (PAN), poly(methyl methacrylate) (PMMA), and
poly(vinylidene fluoride) (PVdF) (Stephan and Nahm 2006). The above reviews
mostly covered the gel and liquid polymer electrolytes with the main focus on the
properties of the polymer electrolytes. To the best of our knowledge, no review
articles with the main focus on the shape of the nanofiller in polymer electrolyte have
been systematically concluded till now. Polymer nanocomposites are basically the
solid polymer electrolytes which are a two-phase system; the first phase acts as host
matrix in which different nanoparticles are dispersed (Suthanthiraraj and Johnsi
2017). The polymer nanocomposite enables us to develop polymer electrolyte with
improved mechanical, thermal properties, voltage stability window, and electrochemical properties.
In this chapter, a brief summary of polymer nanocomposites (PNCs) with
nanoparticles of various shapes is given in detail. First, the status of the LIB
technology in the current practical applications is described and followed by the
working principle of the battery. Then we discussed the characteristics of the
polymer electrolytes and the properties of the constituents used, i.e., polymer host,
salt, ionic liquid, plasticizer, nanoclay, nanofiller, nanorod, and nanowire. Then the
preparation methods and the common characterization techniques used to identify
the suitability of the polymer nanocomposites are discussed followed by the factors
influenced by the addition of different nanoparticles. Finally, we have summarized
the recent key developments done till now in the field of the solid polymer
electrolytes.
8.2 Polymer Electrolytes
In energy storage devices, polymer electrolyte plays the dual role of both electrolytes
and separator and is sandwiched between the electrodes. So, the polymer host which
is to be used has some special characteristics that make its candidature stronger as
compared to the other. The polymer electrolytes are classified into three types, (i) gel
polymer electrolytes, an organic solvent is added in the polymer matrix; (ii) solid
polymer electrolyte, polymer matrix acts as host matrix and provides coordinating
sites for cation migration and no organic solvent required; and (iii) composite
polymer electrolyte, here nanoparticle is dispersed in the polymer–salt matrix, also
known as polymer nanocomposites. Figure 8.4 depicts the properties that are
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A. Arya and A. L. Sharma
cycling behavior of LiMn 2 O 4 –polymer electrolyte (PE)–Li cells is also described
(Stephan 2006). Another review by Zhang et al. covered the separators used in liquid
electrolyte Li–ion batteries. The classification of separators was done on the basis of
the structure and composition of the membranes followed by a discussion on the
manufacture, characteristics, performance, and modifications of the separators
(Zhang 2007a). Stephan et al. discussed the composite polymer electrolytes
(CPEs) with the main focus on electrochemical and physical properties for the
applications in lithium batteries. The polymer hosts discussed were poly(ethylene
oxide) (PEO), poly(acrylonitrile) (PAN), poly(methyl methacrylate) (PMMA), and
poly(vinylidene fluoride) (PVdF) (Stephan and Nahm 2006). The above reviews
mostly covered the gel and liquid polymer electrolytes with the main focus on the
properties of the polymer electrolytes. To the best of our knowledge, no review
articles with the main focus on the shape of the nanofiller in polymer electrolyte have
been systematically concluded till now. Polymer nanocomposites are basically the
solid polymer electrolytes which are a two-phase system; the first phase acts as host
matrix in which different nanoparticles are dispersed (Suthanthiraraj and Johnsi
2017). The polymer nanocomposite enables us to develop polymer electrolyte with
improved mechanical, thermal properties, voltage stability window, and electrochemical properties.
In this chapter, a brief summary of polymer nanocomposites (PNCs) with
nanoparticles of various shapes is given in detail. First, the status of the LIB
technology in the current practical applications is described and followed by the
working principle of the battery. Then we discussed the characteristics of the
polymer electrolytes and the properties of the constituents used, i.e., polymer host,
salt, ionic liquid, plasticizer, nanoclay, nanofiller, nanorod, and nanowire. Then the
preparation methods and the common characterization techniques used to identify
the suitability of the polymer nanocomposites are discussed followed by the factors
influenced by the addition of different nanoparticles. Finally, we have summarized
the recent key developments done till now in the field of the solid polymer
electrolytes.
8.2 Polymer Electrolytes
In energy storage devices, polymer electrolyte plays the dual role of both electrolytes
and separator and is sandwiched between the electrodes. So, the polymer host which
is to be used has some special characteristics that make its candidature stronger as
compared to the other. The polymer electrolytes are classified into three types, (i) gel
polymer electrolytes, an organic solvent is added in the polymer matrix; (ii) solid
polymer electrolyte, polymer matrix acts as host matrix and provides coordinating
sites for cation migration and no organic solvent required; and (iii) composite
polymer electrolyte, here nanoparticle is dispersed in the polymer–salt matrix, also
known as polymer nanocomposites. Figure 8.4 depicts the properties that are
270
A. Arya and A. L. Sharma