Operando Mössbauer Spectroscopy Investigations of Li-Ion Batteries and Non-Precious Metal Electrocatalysts for PEM Fuel Cells

In the last decade, a growing number of Mössbauer spectroscopy papers dealing with Li-ion batteries and non-precious metal catalysts have been published.[1] As for other Material Science branches, this technique is first used in each of the steps leading to the synthesis of innovative materials. Moreover, Mössbauer spectroscopy is almost routinely used for ex situ and in situ investigations of the electrochemical behavior of electrode materials containing the common Mössbauer isotopes 121Sb[2] 119Sn[3] and more frequently 57Fe[4]. In this presentation, we will see how Mössbauer spectroscopy has became indispensable for optimizing the synthesis routes as well as the performances of functional materials. Through examples from our group and other published work, we will illustrate the importance of this technique for batteries study. Many iron and tin compounds will be presented (LiFe1-xMnxSO4F, LiFe1-xMnxPO4, TiSnSb etc). Among them, the newest cathode material LiFeSO4F can be given as a pedagogic example showing the role that can be played by Mössbauer spectroscopy in the preparation of this phase, its characterization, and the fabrication of polymeric electrode[5]. Finally, application of Mössbauer spectroscopy to heat-treated transition iron-NxCy electrocatalysts for O2 reduction in acid PEM Fuel cells will be presented [6]. References: [1] (a) J. C. Jumas and P. E. Lippens, Mössbauer Effect Reference and Data Journal 2010, 33., (b) 1. Jaouen, F.. In Non-Noble Metal Fuel Cell Catalysts, Wiley-VCH Verlag GmbH & Co. KGaA: 2014; pp 29-118. [2] C. Villevieille, C. M. Ionica-Bousquet, J. C. Jumas, and L. Monconduit, Hyperfine Interactions 2008, 187, 71. [3] F. Robert, P. E. Lippens, J. Olivier-Fourcade, J. C. Jumas, F. Gillot, M. Morcrette, and J. M. Tarascon, Journal of Solid State Chemistry 2010, 180, 339. [4] Ou Mao, R. A. Dunlap, I. A. Courtney, and J. R. Dahn, Journal of The Electrochemical Society 1998, 145, 4195. [5] M. Ati, Moulay T. Sougrati, N. Recham, P. Barpanda, J. B. Leriche, M. Courty, M. Armand, J. C. Jumas, and J. M. Tarascon, Journal of The Electrochemical Society 2010, 157, A1007. [6] A. Zitolo, V. Goellner, V Armel, M. T. Sougrati, T. Mineva, L. Stievano, E. Fonda, F. Jaouen. Nat Mater 2015, 14, 937.