Ligand influence in Li-ion battery hybrid active materials: Ni methylenediphosphonate vs. Ni dimethylamino methylenediphosphonate.

The influence of a ligand on the structural, morphological and electrochemical properties of organic-inorganic hybrid nickel diphosphonates was assessed using Ni methylenediphosphonate (NiMeDP) and Ni dimethylamino methylenediphosphonate (NiDMAMDP) as model electrode materials.

Modified electrodes prepared from ferrocene functionalized silicate xerogels: analysis of the electrochemical response in isotropic and fractal structural systems.

New xerogels functionalized by ferrocenes as redox probes have been prepared using various types of catalysis. The analysis of the electrochemical response in the case of modified electrodes allows us to get an insight into the gel nanostructure which has been found to be isotropic in the case of acidic catalysis, and fractal in the case of fluoride catalysis, provided that the amount of functionalized silanes is not too high. Indeed the results of electrochemical measurement prove that the fractality of functionalized hybrid silica is general in the case of basic catalysis, except in the case of very high functional moieties loading, where the electrode become essentially organic and isotropic. On the other hand, in the case of acidic catalysis, whatever the amount of organic material, the hybrid gel remains isotropic, and a classical electron pseudo-diffusive behaviour is observed. The diffusion coefficient values extracted from the current-time slopes do not vary monotonically with the amount of redox probe in the case of fractal xerogel structures, which is indicative that not all the functional moieties are electroactive in that case.

Electrochemical analysis of the sol-gel synthesis of phosphonate-modified titania through the diffusion of a functionalised ferrocene.

Titanium oxide/phenylphosphonate hybrids were prepared by a two-step sol-gel processing, in the presence of ferrocenylphosphonic acid as an electrochemical probe. We showed that as expected the diffusion of the redox species was related to the kinetics of the sol-gel polymerization. The probable passage through cluster Ti(4)O(O(i)Pr)(8)(PhPO(3))(3) has been confirmed by the electrochemical response under partial hydrolysis conditions.