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Subject of the postdoc

Correlating morphological and structural modification of sulfide-based solid electrolyte by advanced operando techniques

Financed post-doctoral position.
Published on 27 October 2021
Joint Postdoc position at SyMMES (CEA-IRIG) and ILL (18 months + 18 months) (Grenoble, France).

Context/Project
All-solid-state batteries have been presented as the ideal solution to address i) the safety limitations of conventional Li-ion batteries by suppressing the flammable organic electrolytes and ii) the problem of insufficient energy densities. To date, two types of solid Li-ion electrolytes have been mainly studied, namely, sulfur-based and ceramic-based materials. As they are easy to process and they offer a high lithium-ion conductivity in the range of 1-12 mS/cm [1,2], sulfide-based electrolytes such as e.g. thio-LISICONs and argyrodites are therefore regarded as suitable candidates to be used in lithium all-solid-state batteries.
Despite the progress in the development of superionic conductor, many aspects regarding their chemical and mechanical issues remain unsolved especially during electrochemical activities where the electrolyte is heavily decomposed [3]. If the electrode engineering i.e. composite electrode (mixture of electroactive material, conductive agent and solid electrolyte) is under intense investigation, the role of the solid electrolyte pellet (i.e. separator) is so far poorly studied. As an example, if the sintering (even cold sintering) is not properly performed, the Li-ion conduction will not be optimal that could create kinetics problem, as well as if voids appear in the solid electrolyte pellet, it will lower the ionic conductivity and the voids could then evolve and propagate into cracks during electrochemical cycling. 
In a joint ANR project between LEPMI, CEA-IRIG and ILL in Grenoble, CEA and ILL are looking for a joint postdoctoral researcher to work on the advanced characterisations of solid-state batteries using thiosulfates solid electrolyte to correlate structural and morphological information. We are proposing an in depth (operando and postmortem) multiscale investigation of the parameter controlling the “shaping” of commercial based solid electrolytes and its consequence on the electrochemical activity. Information from bulk to surface analysis using electrochemical (EIS, CV, etc.) X-rays (XRD, XAS, micro and nano-XRT, FIB-SEM, etc.) and neutron-based techniques (NPD, etc.) will be used to reveal the relationship between shaping and electrochemical performance. The results obtained here should serve as a preliminary basis to develop better solid-state batteries using sulfide-based electrolyte.

Applicant profile
The applicant should hold a PhD degree in Material Science, Chemistry, Physics or related field. Knowledge in electrochemistry and batteries is required. The postdoctoral researcher will work in close collaboration with a PhD student also hired for this project. 

Application
To apply to this position please send your CV and cover letter to Dr. Sandrine Lyonnard (CEA-IRIG-SyMMES), Dr. Emmanuelle Suard (ILL), Dr. Claire Villevieille (LEPMI).

References
[1]  Q. Zhang, D. Cao, Y. Ma, A. Natan, P. Aurora, H. Zhu, Sulfide-Based Solid-State Electrolytes: Synthesis, Stability, and Potential for All-Solid-State Batteries, Adv. Mater. 31 (2019) 1-42

[2]  N. Kamaya, K. Homma, Y. Yamakawa, M. Hirayama, R. Kanno, M. Yonemura, T. Kamiyama, Y. Kato, S. Hama, K. Kawamoto, A. Mitsui, A lithium superionic conductor, Nat. Mater. 10 (2011) 682-686

[3]  L.R. Mangani, C. Villevieille, Mechanical vs. chemical stability of sulfide-based solid-state-batteries. Which one is the biggest challenge to tackle? Overview of solid state batteries and hybrid solid state batteries, J. Mater. Chem. A. (2020)