Development of ionic liquid-based lithium battery prototypes

The lab-scale manufacturing of Li/LiFePO4 and Li4Ti5O12/LiFePO4 stacked battery prototypes and their performance characterization are described here. The prototypes were realized in the frame of an European Project devoted to the development of greener and safer lithium batteries, based on ionic liquid electrolytes, for integration with photovoltaic panels. N-Butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TESI) and N-butyl-N-methylpyrrolidinium bis(fluoromethanesulfonyl)imide (PYR14FSI), selected as the ionic liquids (ILs), were used to formulate the poly(ethylene oxide)-LiN(SO2CF3)(2)-PYR14TESI (PEO-LiTFSI-PYR14TFSI) polymer electrolyte and the LiTESI-PYR14FSI liquid electrolyte, which were employed to produce lithium metal and lithium-ion prototypes, respectively. The composite electrodes for the lithium metal and lithium-ion prototypes were prepared through, respectively, a solvent-free and a water-based procedure route. The performance of the lithium battery prototypes was evaluated in terms of specific capacity, energy, cycle life and coulombic efficiency at different current densities. The results have indicated high reproducibility and the feasibility of scaling-up solvent-free, lithium batteries based on ionic liquids for low and mid rate applications such as renewable energy storage. (C) 2011 Elsevier B.V. All rights reserved.