THE SOL-GEL GROUP

Mathieu Bervas

"Study of the intercalation of polycations in sol-gel prepared vanadium oxide for application in electrochemical devices"

  Lithium ion is usually considered as the perfect cation for intercalation mechanisms in batteries electrodes because it is very small, very light and because it is the most reductive element of the periodic table. However if polycations are used instead of lithium ion the quantity of electrons transiting in the open circuit per mole of ion intercalated can be double or triple. Hence very high energy density could in principle be obtained.

   Due to their charge, the motion of polycations under an electric field  is very slow in solid state materials. Good diffusion rates can nevertheless be achieved in nanosize layered-structure vanadium oxide. Such material is readily prepared by sol-gel process.

   For the electrochemical characterization of this system a counter electrode made of activated carbon is used. Hence the polycations intercalate and desintercalate the vanadium oxide at the working electrode while a double layer mechanism, like in supercapacitors, is taking place at the counter electrode. This “hybrid” concept has been developed at Telcordia Technologies.

This page is maintained by Manuel A. Alvarez.
Last updated March 28, 2002.
For any comments or questions please send e-mail to: solgel@rci.rutgers.edu