Bruce-Vincent method

Table 2.1 Values of Li transference number obtained by the Bruce-Vincent method for polymer electrolytes consisting of 1M LiCI04 in PEO (5 x 10 g/mol) and 10% w/w of corresponding filler. Transport numbers measured by AC technique with Sprensen-Jackobsen formula lay within the range 0.28-0.41, with the same order. For noncomposite electrolyte it is 0.16. Data from the author s own work...

The behavior of the anion receptor TPEPB in a 1 M LiCl04 electrolyte in EC/DMC (1/2.5 v/v) was studied by Lee et al. [425]. The transference number of the lithium cation was enhanced by increasing the TPFPB content from 0.22 (0 M TPFPB) to 0.55 (0.1 M TPFPB), measured by the potentiostatic polarization method of Bruce and Vincent (see Section 17.4.6.4). The total ionic conductivity decreased due to the decreasing anionic conductivity, but the cationic conductivity increased. The interaction between TPFPB and Cl04, resulting in formation of a complex and advanced dissociation of LiCl04, was shown by FTIR analysis. 

The most common method of electrolytes examination is electrochemical impedance spectroscopy (EIS) with blocking (usually stainless steel) and/ or reversible electrodes (most often metallic lithium, or other metal, common with the salt used Saraswat et al. 1989). It allows determination of samples conductivity (Bauerle 1969), following the evolution of complete and half cells resistance upon storage (Sannier et al. 2007 Syzdek et al. 2007) sometimes it is used for transference number measurements (Ravn Sprensen and Jacobsen 1982), as well as a complementary technique in the studies on the crystallisation of solid electrolytes (Marzantowicz et al. 2006a,b,c, 2008), where detailed equivalent circuit considerations are applied. Another very important way of studying these systems is a set of DC techniques, i.e. voltammetry (Armand et al. 1980) and DC polarisation (chronoamperometry and chronopotentiometry). They allowed studies of the electrode reactions and examination of transport properties of electrolytes, especially transference number by Bruce and Vincent and co-workers (Bruce and Vincent 1987,1990 Bruce et al. 1987 Christie et al. 1999 Evans et al. 1987 MacCaUum et aL 1986) and/or Newman method (Doyle and Newman 1995 Hafezi and Newman 2000). 

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