Surprising effect of nanoparticle inclusion on ion conductivity in a lithium doped organic ionic plastic crystal
Data(s) |
01/01/2009
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Resumo |
Doping lithium bis(trifluoromethanesulfonyl)amide (Li[NTf<sub>2</sub>]) into the <i>N</i>-ethyl,<i>N′</i>-methylpyrrolidinium bis(trifluoromethanesulfonyl)amide ([C<sub>2</sub>mpyr][NTf<sub>2</sub>]) plastic crystal material has previously indicated order of magnitude enhancements in ion transport and conductivity over pure [C<sub>2</sub>mpyr][NTf<sub>2</sub>]. Recently, conductivity enhancements in this ionic plastic crystal induced by SiO<sub>2</sub> nanoparticles have also been reported. In this work the inclusion of SiO<sub>2</sub> nanoparticles in Li ion doped [C<sub>2</sub>mpyr][NTf<sub>2</sub>] has been investigated over a wide temperature range by differential scanning calorimetry (DSC), impedance spectroscopy, positron annihilation lifetime spectroscopy (PALS), Raman spectroscopy, NMR spectroscopy and scanning electron microscopy (SEM). Solid state <sup>1</sup>H NMR indicates that the addition of the nanoparticles increases the mobility of the [C<sub>2</sub>mpyr] cation and positron lifetime spectroscopy (PALS) measurements indicate an increase in mean defect size and defect concentration as a result of nanoparticle inclusion, especially with 10 wt% SiO<sub>2</sub>. Thus, the substantial drop in ion conductivity observed for this doped nanocomposite material was surprising. This decrease is most likely due to the decrease in mobility of the [NTf<sub>2</sub>] anion, possibly by its adsorption at the SiO<sub>2</sub>/grain boundary interface and concomitant decrease in mobility of the Li ion. <br /> |
Identificador | |
Idioma(s) |
eng |
Publicador |
Royal Society of Chemistry |
Relação |
http://dro.deakin.edu.au/eserv/DU:30030254/forsyth-surprisingeffect-2009.pdf http://dx.doi.org/10.1039/B814175D |
Direitos |
2009, Royal Society of Chemistry |
Tipo |
Journal Article |