Polymer electrolytes nanocomposite

Polymer electrolytes are a class of materials which play a key role in modern energy technology. In particular, they are presently widely studied for the development of high energy density batteries, with special interest in lithium metal and lithium ion batteries. 

As a result of the above limitations, various approaches to raising the conductivity have been considered, such as the addition of plasticisers, e.g. organic liquids, propylene carbonate or ethylene carbonate or low molecular weight ethylene glycols. However, the gain in conductivity is adversely associated with a loss of the mechanical properties and by a loss of the compatibility with the lithium electrode, both effects resulting in serious problems since they affect the battery cycle life and increase the safety hazard. 

A promising approach to circumvent the issue of the temperature dependence of the conductivity, which still ensures efficient cyclability of the lithium anode and a high safety level, is the use of solid plasticisers solid additives which promote amorphicity at ambient temperature without affecting the mechanical and the interfacial properties of the electrolyte. Examples of such additives are ceramic powders, e.g. TiOi, AI2O3 and Si02, composed of nanoscale particles. 

The general concept of adding ceramic powders to PEO-LiX polymer electrolytes dates back to the early 1980s when this procedure was successfully employed to improve their mechanical properties, their interface with the lithium electrode and their ionic conductiv-ity [66,67] it is only recently that the role of the dispersed 

When ceramic nanoparticles are added, the conductivity is almost one order of magnitude higher over the entire temperature range the break is 

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A polymer electrolyte with acceptable conductivity, mechanical properties and electrochemical stability has yet to be developed and commercialized on a large scale. The main issues which are still to be resolved for a completely successful operation of these materials are the reactivity of their interface with the lithium metal electrode and the decay of their conductivity at temperatures below 70 °C. Croce et al. found an effective approach for reaching both of these goals by dispersing low particle size ceramic powders in the polymer electrolyte bulk. They claimed that this new nanocomposite polymer electrolytes had a very stable lithium electrode interface and an enhanced ionic conductivity at low temperature. combined with good mechanical properties. Fan et al. has also developed a new type of composite electrolyte by dispersing fumed silica into low to moderate molecular weight PEO. 

F. Croce, G. B. Appetecchi, L. Persi, and B. Scrosati. Nanocomposite polymer electrolytes for hthium batteries. Nature, 394 456-458, 1998... 

Croce, E, Curini, R., MartineUi, A., Persi, L., Rond, E, Scrosati, B., Caminiti, R., 1999. Physical and chemical properties of nanocomposite polymer electrolytes. J. Phys. Chem. B 103,10632-10638. 

Samir, M.A.S., Alloin, F., Sanchez, J.-Y., Dufresne, A. Cross-linked nanocomposite polymer electrolytes reinforced with cellulose whiskers. Macromolecules 37, 4839-4844 (2004)... 

V. Aravindan, P. Vickraman, K. Krishnaraj, Polym. Int. 2008, 57, 932-938. Lithium difluoro(oxalate)borate-based novel nanocomposite polymer electrolytes for lithium ion batteries. 

Azizi Samir MAS, Alloin F, Sanchez J-Y et al (2004d) Cross-linked nanocomposite polymer electrolytes reinforced with cellulose whiskers. Macromolecules 37 4839 844 Azizi Samir MAS, Alloin F, Sanchez J-Y et al (2004e) Preparation of cellulose whiskers reinforced nanocomposites from an organic medium suspension. Macromolecules 37 1386-1393 Azizi Samir MAS, Mateos AM, Alloin F et al (2004f) Plasticized nanocomposite polymer electrolytes based on poly(oxyethylene) and cellulose whiskers. Electrochim Acta 49 4667-4677 Azizi Samir MAS, Alloin F, Dufi-esne A (2005a) Review of recent research into cellulosic whiskers, their properties and their application in nanocomposite field. Biomacromolecules 6 612-626 Azizi Samir MAS, Chazeau L, Alloin F et al (2005b) POE-based nanocomposite polymer electrolytes reinforced with cellulose whiskers. Electrochim Acta 50 3897-3903 Azizi Samir MAS, Alloin F, Dufresne A (2006) High performance nanocomposite polymer electrolytes. Compos Interfaces 13 545-559... 

Borodin O, Smith GD, Bandyopadhyaya R, Redfem P, Curtiss LA (2004) Molecular dynamics study of nanocomposite polymer electrolyte based on poly(ethylene oxide)/LlBF4. Model Sim Mater Sci Eng 12 S73... 

Croce F, Appetecchi G, Persi L, Scrosati B (1998) Nanocomposite polymer electrolytes for lithium batteries. Nature 394 456-458... 

Wang Y-J, Kim D (2007) Crystallinity, morphology, mechanical properties and conductivity study of in situ formed PVdF/LiC104/Ti02 nanocomposite polymer electrolytes. Electrochim Acta 52(9) 3181-3189... 

I. Nicotera, A. Enotiadis, K. Angjeh, L. Coppola, D. Goumis, Evaluation of smectite clays as nanofiUers for the synthesis of nanocomposite polymer electrolytes for fuel ceU applications, Int. J. Hydrogen Energy 37 (2012) 6236-6245. 

Poly (ethylene oxide) (PEO) - LiX complexes appear to be the most suitable electrolytes for lithium polymer batteries, however, the local relaxation and segmental motion of the polymer chains remain a problem area (Armand et al., 1997). Therefore, the PEO-based electrolytes show an appreciable ionic conductivity only above 100°C (Gorecki et al., 1986). This is, of course, a drawback for applications in the consumer electronic market. On the other hand, the gel polymer electrolytes although offer high ionic conductivity and appreciable lithiiun transport properties it suffers from poor mechanical strength and interfacial properties (Croce et al., 1998 Gray et al., 1986 Kelly et al., 1985 Weston et al., 1982). Recent studies reveal that the nanocomposite polymer electrolytes alone can offer safe and reliable lithium batteries (Appetecchi... 

Figure 1. TEM image of the calcium phosphate nanoparticles (PEO CaCI, (a) 2 1, (b) 4 1, (c) 5 1). Preparation of Nanocomposite Polymer Electrolytes...

When the content of CajfPO ) in the NCPE is increased to 20% the ionic conductivity of the NCPE decreases. This decrease in the ionic conductivity can also be attributed to the change in the crystallinity of PEO in the nanocomposite polymer electrolytes (Capuglia et al., 1999). According to Scrosati and co-workers (Scrosati et al., 2001), the Lewis acid groups of the added inert filler may compete with the Lewis acid lithium cations for the formation of complexes with the PEO chains as well as the anions of the added lithium salt. In the present study, the filler nano CajfPO lj, which has a basic center can react with the Lewis acid centers of the polymer chain and these interactions lead to the reduction in the crystallinity of the polymer host. Nevertheless, the result provides LL conducting pathways at the filler surface and enhances ioiuc transport. 

The PVDF-HFP based NCPE electrolytes were prepared for various concentrations of nano CajCPO ) and LiClO. The nanocomposite polymer electrolytes with a com-... 

Samir My Ahmed Said Azizi, Alloin Fannie, and Dufresne Alain. High performance nanocomposite polymer electrolytes. Compos. Interf. 13 no. 406 (2006) 545-559. 

The dispersion of selected nanosized ceramics leads to the development of true solid-state PEO-liX nanocomposite polymer electrolytes that, in the 30-80 °C range, possess excellent... 

Tripathi, B.P. and Shahi, V.K. (2011) Organic-inorganic nanocomposite polymer electrolyte membranes for fuel cell applications. Prog. Polym. Set,... 

Liu, Y., Lee, J.Y., and Hong, L. (2003) Morphology, crystallinity, and electrochemical properties of in situ formed poly(ethylene oxide)/Ti02 nanocomposite polymer electrolytes. 

Chen-Yang, Y.W., Wang, Y, Chen, Y, Li, Y, Chen, H., and Chiu, H. (2008) Influence of silica aerogel on the properties of polyethylene oxide-based nanocomposite polymer electrolytes for lithium battery, J. Power Sourc., 182, 340-348. 

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