Cycling Performances of Lithium-Air Batteries Assembled with Ionic Liquid-Based Electrolytes

Li-air batteries have higher theoretical energy density than conventional rechargeable lithium batteries.[1,2]  However, recent studies of Li-air batteries with conventional organic solvent-based electrolytes demonstrate that most of these solvents may not have long-term chemical stability in the presence of the superoxide radical.[3]  Thus, improving the stability of electrolyte toward reduced oxygen species is the main key for developing the non-aqueous Li-air batteries with good capacity retention.  In this work, we tried to investigate ionic liquid-based electrolytes for the Li-air batteries.  They showed an oxidative stability higher than 5.3 V vs. Li/Li⁺, high ionic conductivity and good stability towards the superoxide radical.  As a result, the Li-air batteries employing these electrolytes exhibited good cycling stability exceeding 100 cycles at a current density of 0.1 mA/cm².  Good reversibility for oxygen reduction and evolution reaction was investigated by cycling voltammetry and ex-situ powder X-ray diffraction analysis.

References

[1] J. P. Zheng, R. Y. Liang, M. Hendricksonc, E. J. Plichta, J. Electrochem. Soc., 155(6), A432-A437(2008)

[2] Laoire, C. Ó., Mukerjee, S., Abraham, K. M., Plichta, E. J., Hendrickson, M. A. J. Phys. Chem. C, 114, 9178-9186(2010)

[3] F. Mizuno, S. Nakanishi, Y. Kotani, S. Yokoishi,. H.Iba, Electrochem, 78, 403- 405(2010)