Analysis of the Electrocatalytic Activity of Nickelate Oxides As Cathode Electrocatalysts for Li-Air Batteries

Analysis of the Electrocatalytic Activity of Nickelate Oxides as Cathode Electrocatalysts for Li-Air batteries

 

Montserrat Diaz, Ayad Nacy, Samji Samira and Eranda Nikolla

Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI, 48202

Li-air batteries are among the most promising energy storage technologies due to their high theoretical energy density (11,680 Wh/kg), rivaling that of gasoline (13,000 Wh/kg).^{[1, 2]} One of the main challenges with Li-air batteries include the high overpotential losses due to the electrochemical reactions occurring on the cathode side [2Li + O₂ ↔ Li₂O₂], where precise reaction pathways remain undefined.  It has been shown that the kinetics of oxygen reduction and oxygen evolution reactions (ORR and OER) can be improved by incorporating active catalysts on the cathode surface.^[3]  Among these catalysts, noble metal nanoparticles (such as gold^[4], platinum^[4] and palladium^[5]) supported on porous carbon cathodes have shown superior performance. However, these metals are expensive and scarce.  Therefore, the development of cost effective cathode electrocatalysts for Li-air batteries remains a challenge.

In this contribution, we show our efforts in designing robust non-precious metal based heterogeneous catalysts for Li-air cathodes.  We find that the incorporation of layered nickelate oxide catalysts in Li-air cathodes significantly increases the decomposition rate of Li₂O₂ during the charging process due to their ability to lower the activation barrier for the oxygen evolution reaction.^[6]  We have also analyzed the effect of the chemical composition of nickelate oxides on the activity toward the electrochemical dissociation of Li₂O₂ with the aim of tuning their performance. The composition effects on the activity of nickelate oxides will be discussed.

[1]          Imanishi, N; Yamamoto O. Material Today 2014, 17, 1.

[2]          Luntz, A. C.; McCloskey, B. D. Chem Rev 2014, 114, 11721.

[3]          Girishkumar, G.; McCloskley, B.; Luntz, A.C; Sawson, S.; Wilcke, W   J. Phys. Chem. Lett. 2010, 1, 2193-2203

[4]          Lu, Y. C.; Xu, Z. C.; Gasteiger, H. A.; Chen, S.; Hamad-Schifferli, K.; Shao-Horn, Y. J Am Chem Soc 2010, 132, 12170.

[5]          Lei, Y.; Lu, J.; Luo, X. Y.; Wu, T. P.; Du, P.; Zhang, X. Y.; Ren, Y.; Wen, J. G.; Miller, D. J.; Miller, J. T.; Sun, Y. K.; Elam, J. W.; Amine, K. Nano Lett 2013, 13, 4182.

[6]          Nacy, A.; Ma, X. F.; Nikolla, E. Top Catal 2015, 58, 513.