Bifunctional catalysts for Lithium-Air Batteries in aqueous alkaline electrolytes

Abstract

Bifunctional catalysts for Lithium-Air Batteries in aqueous alkaline electrolytes D. Wittmaier, Timo Danner, N. Wagner, K. A. Friedrich German Aerospace Center Institute of Technical Thermodynamics Pfaffenwaldring 38-40 70569 Stuttgart, Germany [email protected] Lithium-Air Batteries (LAB) are one of the most promising upcoming energy storage devices. With a theoretical energy density of 11680 Wh/kg [1] and a practical energy density around 1700Wh/kg [1] a LAB has similar energy densities to gasoline. Furthermore a practical energy density of 1700 Wh/kg would mean a 5-10 [2] fold increase over todays Li-Ion Batteries (LIB) with 100-200 Wh/kg [1]. One of the major limiting factors on performance and round-trip efficiency is the catalyst used. Today´s LAB still suffer from high charge- and discharge overpotentials caused by insufficient catalysts. The major goal is to reduce overpotentials by using bifunctional catalysts catalyzing both the oxygen reduction reaction (ORR) as well as the oxygen evolution reaction (OER). Noble metal catalysts show good performance on both reactions [3] but with increasing prices of noble metals metal oxides [4] have drawn attention recently. This poster will show promising metal oxides like perovskite type oxides as well as spinel type oxides and various other types of catalysts used as bifunctional catalysts for a LAB with an aqueous alkaline electrolyte. For comparison some results using standard noble metal combinations will be also shown. [1] Girishkumar G., McCloskey B., Luntz A.C., Swanson S., Wilcke W, The Journal of Physical Chemistry Letters 1 (2010) 2193. [2] Padbury R., Zhang X., Journal of Power Sources 196 (2011) 4436. [3] Lu Y.C., Xu Z., Gasteiger H. A., Chen S., Hamad-Schifferli K., Shao-Horn Y., Journal of the American Chemical Society 132 (2010) 12170. [4] Jörissen L., Journal of Power Sources 155 (2006) 23