Polymer electrolytes as solid solvents and their applications

Polymer electrolytes as solid solvents and their applications 

Abstract This chapter details the preparation and mechanism of polymer electrolytes and their applications in electrochemical fields, such as lithium ion batteries, fuel cells, alkahne batteries, supercapacitors, solar cells, electrochromic devices and the like. Polymer electrolytes used in lithium ion batteries are divided into three categories solid, gel and composites. Recent progress made in these three categories is highlighted. Moreover, in addition to the lithium ion battery, appUcations of polymer electrolytes in other electrochemical fields and their ion conducting performance are also briefly described. 

Key words polymer electrolyte, hthium ion battery, ion conductivity, safe performance, oxetane-derived polyether. 

A polymer electrolyte is also referred to as a solid solvent that possesses ion transport properties similar to that of the common liquid ionic solution. It usually comprises a polymer matrix and electrolyte, wherein the electrolyte such as a lithium salt dissolves in a polymer matrix. The research and development of polymer electrolytes have drawn great attention in the last three decades as they are applied in many electrochemical devices such as hthium batteries, nickel - metal hydride (Ni/MH) batteries, fuel cells/direct methanol fuel cells, supercapadtors, electrochromic devices and the like (Gray, 1991 Stephan, 2006). 

In recent years, information technology (FT) has pervaded every field of society throughout the world. During this process, electrochemical devices such as advanced batteries and fuel cells are expected to play a vital role, since they are the most convenient and highly efficient mobile power sources (Takamura, 2006). Additionally, an important issue in the twenty-first century is to reduce the consumption of fossil fuels, otherwise, the warming of our global atmosphere will drastically change the climate of the ecosystem which is critical for our continued survival. The utilization of cells 

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Irradiated PVDF and poly(VDF-co-TrFE) copolymer possess ferroelectric properties that allow the use of such fluorinated polymer in the domain of captors, sensors, and detectors [47,194]. Another interesting property of crosslinked poly(VDF-co-HFP) copolymer is their insolubihty in organic solvent [195]. Cured fluorinated polymers can be processed as membranes for many electrochemical applications such as fuel cell and batteries [196]. For example, a poly(VDF-co-HFP) copolymer has been crossUnked with various systems such as polyols [197], by irradiation with electron beam or y-rays [197] or with aliphatic amines [198] in order to elaborate a solid polymer electrolyte for non aqueous lithium battery [197,198]. This electrolyte is particularly interesting for its ionic conductivity, its adhesion with an electro-conductive substrate and also remarkably enhanced heat resistance. 

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