In the last decade, a growing number of Mössbauer papers dealing with Li-ion batteries 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] 119}Sn^[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 compounds will be presented (LiFe_1-xMn_xSO₄F, LiFe_1-xMn_xPO₄, FeOF 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] (figure 1).

Tin containing phases for negative electrode have been intensively studied by Mössbauer spectroscopy. We will browse briefly the published work and finish with the detailed example of TiSnSb (figure 2).

The complementarity of Mössbauer spectroscopy and X-ray diffraction will be illustrated via the examples of the layered oxide Li₄FeSbO₆^[6] and the mixed valence borophosphate (NH4)_0.75Fe(H₂O)2 [BP₂O₈]•0.25H₂O^[7].

Finally, the 1^st examples of the use of synchrotron radiation (SMS, NFS) for batteries investigation will be presented.

References:

[1]           J. C. Jumas and P. E. Lippens, Mössbauer Effect Reference and Data Journal  2010, 33.

[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]       E. McCalla, A. Abakumov, G. Rousse, M. Reynaud, M. T. Sougrati, B. Budic, A. Mahmoud, R. Dominko, G. Van Tendeloo and R. P. Hermann, Chemistry of Materials 2015, JUST ACCEPTED.
[7]       L. Tao, G. Rousse, M. T. Sougrati, J.-N. Chotard and C. Masquelier, The Journal of Physical Chemistry C 2015, 119, 4540–