Effect of lithium ions on oxygen reduction in ionic liquid-based electrolytes

• Published in: Electrochemistry communications 2011-10, Vol.13 (10), p.1090-1093
• Main Authors: De Giorgio, Francesca, Soavi, Francesca, Mastragostino, Marina
• Format: Article
• Language: English
• Subjects: Applied sciences; Borane additive; Chemistry; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrochemistry; Exact sciences and technology; General and physical chemistry; Ionic liquid electrolyte; Kinetics and mechanism of reactions; Lewis acid and base; Lithium-air battery; Oxygen redox reaction
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2011.07.004

The effect of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) on the oxygen redox reaction (ORR) in several pyrrolidinium-based ionic liquids (ILs) is investigated by cyclic voltammetry. The results are compared to those found with LiTFSI-tetraglyme and LiTFSI-1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidone solutions. The effect of the addition of tris(pentafluorophenyl) borane (TPFPB) to IL-LiTFSI solutions is also investigated. The results demonstrate that the presence of 0.1 M Li + renders the ORR similar in the investigated ILs, lowers the reduction voltammetric currents and makes ORR electrochemically irreversible. The addition of TPFPB to IL-TFSI solutions favours the solubility of oxygen-based products of Li + and should positively affect the performance of IL-based lithium-air batteries. ► Ionic liquid-based electrolytes for lithium-air batteries ► Oxygen reduction in ionic liquids with and without lithium salt ► Effect of TPFPB borane additive on oxygen reduction in ionic liquid solutions