Ricerc@Sapienza

Two ionic liquids (ILs), which are functionalized with bis(oxalato)borate (BOB) and difluoro(oxalato)borate (DFOB) as the anion, have been synthesized and applied as additives for the battery grade electrolyte 1 M LiPF6 in an equivolume mixture of EC-DEC-DMC (LP71). When 0.3 M IL was added to LP71,peaks attributed to the formation of solid electrolyte interface (SEI) were observed during cyclic voltammetry for both cathodic and anodic sides. The presence of peaks during anodic scans suggests thatthe ILs possess the ability to form SEI on cathode surfaces.

A novel electrochemical method is proposed to synthesize nanostructured cobalt electrodes for lithium-ion batteries (LIBs). An array of cobalt nanowires (CoNWs) supported by a nanostructured copper current collector was obtained by the sequential electrodeposition of cobalt and copper into the nanopores of alumina templates and selective etching of alumina. The illustrated method can be implemented with one-side open alumina templates generated by one-step aluminium anodization, thus excluding the application alumina membranes and their coating by sputter metal deposition.

We demonstrate that the addition of 1-butyl-1-methylpyrrolidinium hexafluorophosphate ([Py14]PF6)to1.0 M LiPF6in ethylene carbonate-dimethyl carbonate (LP30) widens the temperature range, in which theelectrolyte mixtures are ion conductive and safe. Specifically, at the concentrations of [Py14]PF6above50 wt%, the electrolyte mixtures exhibit aflash point higher than room temperature and fulfill the re-quirements of liquids having controlledflammability.