Topic of Lecture:M?ssbauer spectroscopy for electrochemical energy storage and conversion materials

Lecturer:Dr. Moulay-Tahar Sougrati

Time of Lecture:Friday, Nov. 03, 2017 2:30 - 4:30 p.m.

Location of Lecture:Mingde Building A204

Introduction to the Lecturer:

Dr.Moulay-Tahar Sougratiworks in the National Center for Scientific Research of France and Institute Charles Gerhardt of Montpellier. He is a M?ssbauer spectroscopy and synchrotron expert of EUSA and electrochemical energy storage network platform. He has published more than 100 papers on M?ssbauer effect and its applications on top-ranking SCI journals (includingNatureandScience).

Description of Lecture:

In the last decade, there is reportedly a marked growth in the number of M?ssbauer spectroscopy studies covering electrochemical energy storage and conversionapplications.^[1]As in other Material Science branches, this technique has been very useful in the optimization of the synthesis of innovative materials containing common M?ssbauer isotopes such as¹²¹Sb^[1],¹¹⁹Sn^[2]and more frequently⁵⁷Fe^[3-5]. Nowadays, operando M?ssbauer spectroscopy is routinely used for the investigations of the electrochemical mechanisms of electrode materials. In this presentation, we will see how M?ssbauer spectroscopy has become indispensable for optimizing the synthesis routes as well as the performance of functional materials. Through examples from our group and other published works, the role and the importance of this technique in battery studies will be highlighted.The topical cases of several iron and tin electrode materials, such as LiFe_1-xMn_xSO₄F, LiFe_1-xMn_xPO₄and TiSnSb, will be highlighted. Among them, one of the newest cathode materials LiFeSO₄F is a pedagogic example showing the role that can be played by M?ssbauer spectroscopy in the synthesis, the characterization, and the fabrication of polymer electrodes^[6].In their quest for affordable alternatives to platinum group metals, chemists have recently focused their efforts on new materials based on common transition metals such as iron and cobalt as catalysts for the conversion of chemical energy to electrical energy. Hence many iron based systems have been proposed as serious candidates to make next generation fuel cell electrodes. After a general review of iron based fuel cell catalytic materials, a more detailed overview of the Fe-N-C system considered as one of the most promising ones will be given^[7-9].

Highlighted Publications:

1. McCalla, E.; Abakumov, A.; Rousse, G.; Reynaud, M.; Sougrati, M. T.,et al.Chemistry of Materials2015,27.

2. Chamas, M.; Sougrati, M.-T.; Reibel, C.; Lippens, P.-E.Chem. Mater.2013,25.

3. Sougrati, M. T.; Darwiche, A.; Liu, X.; Mahmoud, A.; Hermann, R. P.,et al.Angew. Chem., Int. Ed.2016,55.

4. Sathiya, M.; Rousse, G.; Ramesha, K.; Laisa, C. P.; Vezin, H.,et al.Nat Mater2013,12.

5. Barpanda, P.; Ati, M.; Melot, B. C.; Rousse, G.; Chotard, J. N.,et al.Nat. Mater.2011,10.

6. Ati, M.; Sougrati, M. T.; Recham, N.; Barpanda, P.; Leriche, J. B.,et al.J. Electrochem. Soc.2010,157.

7. Sougrati, M. T.; Goellner, V.; Schuppert, A. K.; Stievano, L.; Jaouen, F.Catalysis Today2016,262.

8. Tian, J.; Morozan, A.; Sougrati, M. T.; Lefevre, M.; Chenitz, R.,et al.Angew. Chem., Int. Ed.2013,52.

9. Zitolo, A.; Goellner, V.; Armel, V.; Sougrati, M.-T.; Mineva, T.,et al.Nat Mater2015,14.

Host Organizations: School of Chemistry and Chemical Engineering, The State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, SWPU Science and Technology Department