Polymer electrolyte membranes polymeric, fabrication

Several ofher cross-linking methods can be applied. For example, acrylonitrile, methyl methacrylate (MMA), and its EO derivatives can be copolymerized and then cross-linked with diisocyanate. A thin gel membrane can be prepared by soaking a polyolefin nonwoven fabric in a solution of reactant(s), which is fhen cross-linked by means of ultraviolet radiation. The thickness of fhis fhin gel membrane is 50-100 pm, and the ionic conductivity is 2-4 X 10 3 S/cm. Compared to the gel polymer electrolyte made from dry PAN, fhis process is much simpler, and the energy consumption is 10% lower. However, there are also disadvantages. For example, imreacted monomer and residual catalyst are difficult to remove from the gel polymer electrolyte, leading to reduced ionic conductivity and stability of the polymer. To overcome these disadvantages, the acrylonitrile monomer is first polymerized in nonaqueous electrolyte, and then the unreacted monomer is removed by vacuum. Finally, a multifunctional monomer is added, and the battery is filled with the mixed solution. It is solidified by heating to get the gel polymer electrolyte. 

Most of the lithium-ion battery and supercapacitor research and development projects are focused on the fabrication of prototypes using liquid electrolytes. An important step forward in this technology is the replacement of the liquid electrolyte with an ionic membrane and, eventually, of the common inorganic-type electrode materials with advanced electronically conducting polymers, in order to produce novel devices having a full polymeric configuration. This is an interesting concept since it provides the prospect of a favourable combination of... 

The discovery and the characterization of ionically conducting polymeric membranes (see Chapters 1 and 2) have provided the interesting possibility of developing new types of lithium batteries having a thin-layer, laminated structure. Various academic and industrial laboratories [1-5] are presently engaged in the development of this revolutionary type of battery, i.e. the so-called Lithium Polymer Battery (LPB). The key component of the LPB is the polymeric ionic membrane which acts both as electrolyte and separator furthermore, the membrane can be easily fabricated in the form of a thin film (typically 50 jum thickness) by a number of convenient casting techniques. 

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