Nanocomposite electrolytes

Stathatos E., Lianos R., Zakeeruddin S. M., Liska P. and Gratzel M. (2003), A qnasi-solid-state dye-sensitized solar cell based on a sol-gel nanocomposite electrolyte containing ionic hqnid , Chem. of Materials 15, 1825-1829. 

Pradhan, D.K., R. Choudhary, and B. Samantaray, Studies of structural, thermal and electrical behavior of polymer nanocomposite electrolytes. Express Polymer Letters, 2008. 2 630-638. 

Hwang, I Liu, H., 2002. Influence of organophilic clay on the morphology, plasticizer-maintaining ability, dimensional stability, and electrochemical properties of gel polyacrylonitrile (PAN) nanocomposite electrolytes. Macromolecules 35,7314-7319. 

Tkng, C., Hackenberg, K., Fu, Q., AJayan, P.M., Ardebili, H., 2012. High ion conducting polymer nanocomposite electrolytes using hybrid nanoflllers. Nano lett. 12,1152-1156. 

Li conducting pathways at the ceramic surface [44-46]. Therefore, according to this model, the structural modifications at microscopic levels promote consistent enhancement in the transport properties of the electrolyte. In addition, the all-solid configuration (no addition of liquids) gives to these nanocomposite electrolytes a high compatibility with the lithium metal electrode [47-50], all these properties making them suitable for use as safe and efficient separators in rechargeable lithium batteries [51]. 

Best A, Adebahr J, Jacobsson P, MacEarlane D, Forsyth M (2001) Microscopic interactions in nanocomposite electrolytes. Macromolecules 34(13) 4549-4555... 

The PVDF-HFP (Aldrich, USA) and lithium perchlorate, LiClO (Merck, Germany) were dried under vacuum for 2 days at 50 and 100°C, respectively. The Caj(PO )j was also dried under vacuum at 50°C for 5 days before use. Nanocomposite electrolytes were prepared by dispersing appropriate amounts of Caj(PO )j in PVDF-HFP for different concentrations of LiClO (as depicted in Table 1) and the powder was hot-pressed into films, as described elsewhere (Appetecchi et al., 2003 Manuel etal., 2009). The nanocomposite electrolyte films had an average thickness of 30-50 pm. This procedure yielded a homogenous and mechanically strong membrane, which were dried under vacuum at 50°C for 24 hr for further characterization. 

Mohapatra SR, Thakur AK, Choudhary RNP (2009) Effect of nanoscopic confinement on improvement in ion conduction and stability properties of an intercalated polymer nanocomposite electrolyte for energy storage applications. J Power Sources 191 601-613 Napolitano S, Cangialosi D (2013) Interfacial free volume and vitrification rednctiai in Tg in proximity of an adsorbing interface explained by the free volume holes diffusitm model. Macromolecules 46 8051-8053... 

Native and surface-trimethylsilylated CNC were employed as the particulate phase in nanocomposites with a cellulose acetate butyrate matrix to improve the mechanical properties of polymers and to enhance adhesion between the particulate and matrix phase in composites [187]. Poly(oxyethylene)-based polymer electrolytes should be used above their melting temperature to display appropriate conductivity. Unfortunately, at this temperature the mechanical properties were very poor. In this regard, Azizi Samir et al. [188] evaluated the effect of CNC extracted from timicate to improve the mechanical properties of poly(oxyethylene) (PEO)-based nanocomposite electrolytes above its melting temperature. The SEM fracture surface of CNC-PEO... 

By addition ofwater to the nanocomposite electrolyte (1 wt%) the long-term switching behavior could be improved up to 50,000 switching cycles with only small changes on the EC behavior Fig. 35-10(b), Sun, 2002, 2003,2004). The switching kinetics was also improved and the switching in behavior of the EC-devices shortened. The memory effect of the devices made with a wet composite electrolyte was slightly reduced because they return faster to their bleached state than those made with a dry electrolyte. The behavior is nevertheless still adequate for windows as only a 40% relative variation is observed after about 17 h (Sun, 2003, 2004). 

Walls, H. J., M. W. Riley, R. R., Singhal, R. J. Spontak, P. S. Fedwik, and S. A. Khan, 2003. Nanocomposite electrolytes with fumed silica and hectorite clay networks Passive versus active filters. Adv Func Mater 13 710-17. 

Figure 1.8 Schematic model of the surface interactions of the ceramic particle with the polymer chain and with the salt anion in PE0-LiC104 nanocomposite electrolytes...

Finally, the model has been confirmed by spectroscopic analysis. Raman results reported by Best et al. have demonstrated the specific interaction between nanometric Ti02 powders and the salt. In addition, NMR data have shown that the diffusion of Li ions, and thus the related T+ value, in the nanocomposite electrolytes, is considerably higher than that of the parent ceramic-free electrolytes. 

Nakajima, T., Tamaki, T., Ohashi, H., Yamagnchi, T., Introduction of size-controlled Nafion/Zr02 nanocomposite electrolyte into primary pores for high Pt utihzation in PEFCs, J. Electrochem. Soc., 2013, 160, E129-E134. 

KIM, s., HWANG, E., JUNG, Y., HAN, M. and PARK, s., 2008. lonic conductivity of polymeric nanocomposite electrolytes based on poly(ethylene oxide) and organo-clay materials. Colloids and Surfaces A Physicochemical and Engineering Aspects,... 

Single-ion conductors can be obtained by the intercalation of PEO on clay due to the presence of cation charge at the silicate surface. The conductivity values of electrolytes based on POEM with the addition of 2 and 5 wt% clay were found to be around 4 x 10 S/cm at 70 °CF The conductivity obtained can be anisotropic. Molecular dynamic simulation has shown that the Li" ions are solvated preferentially by the silicate oxygen atom rather than PEO. The conductivity is too low for practical applications, even with a cationic transference number equal to one. In order to increase conductivity, but with a cationic transference number different from one, lithium salts were added to PEO/clay nanocomposites. At room temperature, the nanocomposite electrolyte exhibited higher ionic conductivity than unfilled polymer due to the larger content of the PEO amorphous phase. The improvement in conductivity depends on the nature of the clay. Fan et al. have shown that 250-Li-MMT, i.e. Li-MMT heated to 250°C, was more effective in enhancing the conductivity of (PE0)i6LiC104 than Org-MMT, dodecylamine modified Li-MMT, and Li-MMT, since 250-Li-MMT forms an exfoliated structure in the PEO matrix. 

A.2 Conductivity of PE02oLiCp3S0310 wt% AI2O3 nanocomposite electrolytes with different AI2O3 surface groups, extracted from Croce ef a/. ... 

The nanocomposite electrolyte PE0-LiC104-Zn0 exhibits the same conductivity as the unfilled electrolyte at high temperatures, whereas at room temperature, nanocomposite electrolytes have a much higher conductivity (Fig. 4.4). The nature and amount of fillers were found to have no effect on conductivity at high temperature in PEO-LiSOsCFs electrolytes obtained by hot-pressing with the addition of both Si02 and AI2O3 fillers. ... 

Lin and co-workers ° prepared a nanocomposite of poly(n-isopropylacryl-amide) with MMT clay and applied it to a liquid electrolyte system as gel-lator. The DSSC assembled with the polymer nanocomposite electrolyte presented J c = 12.6 mA cm , Voc = 0.73 V, FF = 0.59 and rj = 5.4% while the DSSC prepared with the electrolyte gelled with the pure polymer... 

WALLS, H.J., RILEY, M.W., siNGHAL, R.R., et ol., Nanocomposite electrolytes with fumed siUca and hectorite clay networks passive versus active fillers, Adv. Funct. Mater., 2003,13,710. 

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